WorldWideScience

Sample records for wild fish populations

  1. First genealogy for a wild marine fish population reveals multigenerational philopatry

    KAUST Repository

    Salles, Océane C.

    2016-11-01

    Natal philopatry, the return of individuals to their natal area for reproduction, has advantages and disadvantages for animal populations. Natal philopatry may generate local genetic adaptation, but it may also increase the probability of inbreeding that can compromise persistence. Although natal philopatry is well documented in anadromous fishes, marine fish may also return to their birth site to spawn. How philopatry shapes wild fish populations is, however, unclear because it requires constructing multigenerational pedigrees that are currently lacking for marine fishes. Here we present the first multigenerational pedigree for a marine fish population by repeatedly genotyping all individuals in a population of the orange clownfish (Amphiprion percula) at Kimbe Island (Papua New Guinea) during a 10-y period. Based on 2927 individuals, our pedigree analysis revealed that longitudinal philopatry was recurrent over five generations. Progeny tended to settle close to their parents, with related individuals often sharing the same colony. However, successful inbreeding was rare, and genetic diversity remained high, suggesting occasional inbreeding does not impair local population persistence. Local reproductive success was dependent on the habitat larvae settled into, rather than the habitat they came from. Our study suggests that longitudinal philopatry can influence both population replenishment and local adaptation of marine fishes. Resolving multigenerational pedigrees during a relatively short period, as we present here, provides a framework for assessing the ability of marine populations to persist and adapt to accelerating climate change.

  2. Morphological plasticity and phylogeny in a monogenean parasite transferring between wild and reared fish populations.

    Directory of Open Access Journals (Sweden)

    Ivona Mladineo

    Full Text Available It is widely accepted that disease interactions between cultured and wild fish occur repeatedly, although reported cases have mainly relied just on the observation of similar symptoms in affected populations. Whether there is an explicit pathogen transfer between fish stocks, or each develops its own pathogen population, has been insufficiently studied and rarely supported by molecular tools. In this study, we used population dynamics and genetic structure of the monogenean Furnestinia echeneis in reared and neighbouring wild sea bream to indicate pathogen transfer, characterized by the phenotypic plasticity of the parasite attachment apparatus and the lack of phylogenetic differentiation. The observed pattern of genetic variation inferred by nuclear DNA Internal Transcribed Spacer 1 (ITS1 and mtDNA cytochrome C oxidase 1 (COI, between parasite populations is most likely caused by a recent shared demographic history like a reduced species area in the last glacial period. In spite of such recent expansion that populations underwent, F. echeneis shows differentiation in haptor morphometry as an adaptive trait in closely related populations at the aquaculture site. This suggests that differentiation in morphology may occur relatively rapidly in this species and that adaptive forces, not the speciation process, drives this monogenean parasitation. On the other hand, the observed phylogenetic inertia suggests a low to moderate gene flow (based on F ST between parasites in cultured and wild fish, evidencing for the first time the transfer of pathogens at the aquaculture site inferred by a molecular tool.

  3. A review of the effects of azole compounds in fish and their possible involvement in masculinization of wild fish populations.

    Science.gov (United States)

    Matthiessen, Peter; Weltje, Lennart

    2015-05-01

    Endocrine-mediated effects in fish populations have been widely documented. Most attention has been focused on feminization caused by estrogenic substances, but this paper reviews evidence for the effects of a group of fungicides and pharmaceuticals, the azoles, which have been reported to cause masculinization in fish. The paper considers information from laboratory studies on the effects of azole compounds on fish endocrinology, and on the potential existence of such effects in wild fish. The occurrence of some azoles in effluents and surface waters has also been briefly reviewed. Under laboratory conditions, many azoles are able to cause masculinization or defeminization in fish by inhibition of the P450 enzyme aromatase (CYP19). However, in no case where such effects have been observed in the field has a link been established with this group of substances. In most instances, other more convincing explanations have been proposed. Peak concentrations of some azoles in surface waters can approach those which, under continuous long-term exposure in the laboratory, might lead to some aromatase inhibition. However, available data on exposure and effects provide reassurance that the concentrations of azoles found in surface waters are too low to cause adverse effects in fish by interference with their endocrine system. Compared to the widespread observations of feminization and estrogenic effects in (male) fish, there are relatively few papers describing masculinization or defeminization in (female) wild fish populations, suggesting that this is quite a rare phenomenon. The significance of this result is emphasized by the fact that fish are among the best studied organisms in the environment.

  4. Proxy measures of fitness suggest coastal fish farms can act as population sources and not ecological traps for wild gadoid fish.

    Science.gov (United States)

    Dempster, Tim; Sanchez-Jerez, Pablo; Fernandez-Jover, Damian; Bayle-Sempere, Just; Nilsen, Rune; Bjørn, Pal-Arne; Uglem, Ingebrigt

    2011-01-17

    Ecological traps form when artificial structures are added to natural habitats and induce mismatches between habitat preferences and fitness consequences. Their existence in terrestrial systems has been documented, yet little evidence suggests they occur in marine environments. Coastal fish farms are widespread artificial structures in coastal ecosystems and are highly attractive to wild fish. To investigate if coastal salmon farms act as ecological traps for wild Atlantic cod (Gadus morhua) and saithe (Pollachius virens), we compared proxy measures of fitness between farm-associated fish and control fish caught distant from farms in nine locations throughout coastal Norway, the largest coastal fish farming industry in the world. Farms modified wild fish diets in both quality and quantity, thereby providing farm-associated wild fish with a strong trophic subsidy. This translated to greater somatic (saithe: 1.06-1.12 times; cod: 1.06-1.11 times) and liver condition indices (saithe: 1.4-1.8 times; cod: 2.0-2.8 times) than control fish caught distant from farms. Parasite loads of farm-associated wild fish were modified from control fish, with increased external and decreased internal parasites, however the strong effect of the trophic subsidy overrode any effects of altered loads upon condition. Proxy measures of fitness provided no evidence that salmon farms function as ecological traps for wild fish. We suggest fish farms may act as population sources for wild fish, provided they are protected from fishing while resident at farms to allow their increased condition to manifest as greater reproductive output.

  5. Proxy measures of fitness suggest coastal fish farms can act as population sources and not ecological traps for wild gadoid fish.

    Directory of Open Access Journals (Sweden)

    Tim Dempster

    Full Text Available BACKGROUND: Ecological traps form when artificial structures are added to natural habitats and induce mismatches between habitat preferences and fitness consequences. Their existence in terrestrial systems has been documented, yet little evidence suggests they occur in marine environments. Coastal fish farms are widespread artificial structures in coastal ecosystems and are highly attractive to wild fish. METHODOLOGY/PRINCIPAL FINDINGS: To investigate if coastal salmon farms act as ecological traps for wild Atlantic cod (Gadus morhua and saithe (Pollachius virens, we compared proxy measures of fitness between farm-associated fish and control fish caught distant from farms in nine locations throughout coastal Norway, the largest coastal fish farming industry in the world. Farms modified wild fish diets in both quality and quantity, thereby providing farm-associated wild fish with a strong trophic subsidy. This translated to greater somatic (saithe: 1.06-1.12 times; cod: 1.06-1.11 times and liver condition indices (saithe: 1.4-1.8 times; cod: 2.0-2.8 times than control fish caught distant from farms. Parasite loads of farm-associated wild fish were modified from control fish, with increased external and decreased internal parasites, however the strong effect of the trophic subsidy overrode any effects of altered loads upon condition. CONCLUSIONS AND SIGNIFICANCE: Proxy measures of fitness provided no evidence that salmon farms function as ecological traps for wild fish. We suggest fish farms may act as population sources for wild fish, provided they are protected from fishing while resident at farms to allow their increased condition to manifest as greater reproductive output.

  6. Salmon Life Cycle Models Illuminate Population Consequences of Disparate Survival and Behavior Between Hatchery- and Wild-Origin Fish

    Science.gov (United States)

    Beakes, M.; Satterthwaite, W.; Petrik, C.; Hendrix, N.; Danner, E.; Lindley, S. T.

    2016-02-01

    In past decades there has been a heavy reliance on the production of hatchery-reared fish to supplement declining population numbers of Pacific salmon. In some cases, the benefits of hatchery supplementation have been negligible despite concerted long-term stocking efforts. The management and conservation of depressed salmon populations, via hatchery practices or otherwise, can be improved by expanding our understanding of the dissimilarities between hatchery and wild salmon and how each interacts with the environment. In this study we use a stage-structured salmon life-cycle model to explore the population consequences of disparate survival and behavior between hatchery and wild-origin fall-run Chinook Salmon (Oncorhynchus tshawytscha) in the California Central Valley. We couple empirically-based statistical functions with deterministic theoretical models to identify how environmental conditions (e.g., water temperature, flow) and habitat drive the survival and abundance of both hatchery and wild salmon as they integrate across riverscapes and cross marine and freshwater ecosystem boundaries during their life cycle. Results from this study suggest that hatchery practices can lead to dissimilar interactions between hatchery and wild salmon and the environmental conditions they experience. As such, the population dynamics of fall-run Chinook Salmon in the California Central Valley are partly dependent on the composition of individuals that make up their populations. In total, this study improves out ability to conserve imperiled salmonids by identifying mechanistic linkages between the natal origin of salmon, survival and behavior, and the environment at spatiotemporal scales relevant to salmon populations and fisheries management.

  7. A fish of many scales: extrapolating sublethal pesticide exposures to the productivity of wild salmon populations.

    Science.gov (United States)

    Baldwin, David H; Spromberg, Julann A; Collier, Tracy K; Scholz, Nathaniel L

    2009-12-01

    For more than a decade, numerous pesticides have been detected in river systems of the western United States that support anadromous species of Pacific salmon and steelhead. Over the same interval, several declining wild salmon populations have been listed as either threatened or endangered under the U.S. Endangered Species Act (ESA). Because pesticides occur in surface waters that provide critical habitat for ESA-listed stocks, they are an ongoing concern for salmon conservation and recovery throughout California and the Pacific Northwest. Because pesticide exposures are typically sublethal, a key question is whether toxicological effects at (or below) the scale of the individual animal ultimately reduce the productivity and recovery potential of wild populations. In this study we evaluate how the sublethal impacts of pesticides on physiology and behavior can reduce the somatic growth of juvenile chinook salmon (Oncorhynchus tshawytscha) and, by extension, subsequent size-dependent survival when animals migrate to the ocean and overwinter in their first year. Our analyses focused on the organophosphate and carbamate classes of insecticides. These neurotoxic chemicals have been widely detected in aquatic environments. They inhibit acetylcholinesterase, an enzyme in the salmon nervous system that regulates neurotransmitter-mediated signaling at synapses. Based on empirical data, we developed a model that explicitly links sublethal reductions in acetylcholinesterase activity to reductions in feeding behavior, food ration, growth, and size at migration. Individual size was then used to estimate size-dependent survival during migration and transition to the sea. Individual survival estimates were then integrated into a life-history population projection matrix and used to calculate population productivity and growth rate. Our results indicate that short-term (i.e., four-day) exposures that are representative of seasonal pesticide use may be sufficient to reduce the

  8. Genetic effects of hatchery fish on wild populations in red sea bream Pagrus major (Perciformes, Sparidae) inferred from a partial sequence of mitochondrial DNA.

    Science.gov (United States)

    Hamasaki, K; Toriya, S; Shishidou, H; Sugaya, T; Kitada, S

    2010-12-01

    Variation in the mitochondrial DNA transcriptional control region sequence was investigated in wild and hatchery-released red sea bream Pagrus major from Kagoshima Bay, where an extensive hatchery-release programme has been conducted for >30 years. The programme has successfully augmented commercial catches in the bay (released juveniles have been produced from the captive broodstock, repeatedly used over multiple generations). Samples were also obtained from outside the bay, where limited stocking has occurred. Genetic diversity indices measured as number of haplotypes, haplotype richness, haplotype diversity and nucleotide diversity were lower in hatchery-released fish than in wild fish. Genetic differences in wild fish from the bay, especially in the inner bay, compared with fish from outside the bay were detected in terms of decreased genetic diversity indices and changed haplotype frequencies. Unbiased population pair-wise F(ST) estimates based on an empirical Bayesian method, however, revealed low genetic differentiation between samples from the bay and its vicinity. Mixed stock identification analyses estimated the proportion of hatchery-released fish in wild populations in the inner and central bays at 39·0 and 8·7%, respectively, although the precision of the estimates was very low because of the small genetic differentiation between populations and relatively small sample sizes. Hence, the long-term extensive hatchery release programme has affected the genetic diversity of wild populations in the bay; however, the genetic effects were low and appeared to remain within the bay. © 2010 The Authors. Journal of Fish Biology © 2010 The Fisheries Society of the British Isles.

  9. Surveillance of viruses in wild fish populations in areas around the Gulf of Cadiz (South Atlantic Iberian Peninsula).

    Science.gov (United States)

    Moreno, Patricia; Olveira, José G; Labella, Alejandro; Cutrín, Juan Manuel; Baro, Jorge C; Borrego, Juan Jose; Dopazo, Carlos P

    2014-10-01

    This report describes a viral epidemiological study of wild fish around the Gulf of Cadiz (southwestern Iberian Peninsula) and is focused on infectious pancreatic necrosis virus (IPNV), viral hemorrhagic septicemia virus (VHSV), and viral nervous necrosis virus (VNNV). One fish species (Chelon labrosus) was sampled inside the gulf, at the mouth of the San Pedro River. Another 29 were sampled, in three oceanographic campaigns, at sites around the Bay of Cadiz. The fish were processed individually and subjected to isolation in cell culture and molecular diagnosis. VHSV was not isolated from any species. Thirteen IPNV-type isolates were obtained from barracuda (Sphyraena sphyraena), axillary seabream (Pagellus acarne), common two-banded seabream (Diplodus vulgaris), common pandora (P. erythrinus), Senegal seabream (D. bellottii), and surmullet (Mullus surmuletus). Six VNNV isolates were obtained from axillary seabream, common pandora, black seabream (Spondyliosoma cantharus), red mullet (Mullet barbatus), Lusitanian toadfish (Halobatrachus didactylus), and tub gurnard (Chelidonichtys lucerna). In the river mouth, viruses were detected only after reamplification, obtaining prevalence percentages of IPNV and VNNV (44.4 and 63.0%, respectively) much higher than those observed in the oceanographic campaigns (25.7 and 19.6%, respectively). The opposite results were obtained in the case of VHSV after reamplification: 11.1% in the river mouth and 43.6% in the oceanic locations. Analyzing the results with respect to the proximity of the sampling sites to the coast, an anthropogenic influence on wild fish is suggested and discussed. The type of viruses and the presence of natural reassortants are also discussed. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  10. Consumer beliefs regarding farmed versus wild fish.

    Science.gov (United States)

    Claret, Anna; Guerrero, Luis; Ginés, Rafael; Grau, Amàlia; Hernández, M Dolores; Aguirre, Enaitz; Peleteiro, José Benito; Fernández-Pato, Carlos; Rodríguez-Rodríguez, Carmen

    2014-08-01

    Aquaculture is a food-producing activity, alternative to traditional extractive fishing, which still acts as a reference for most consumers. The main objective of the present paper was to study which consumer beliefs, regarding farmed versus wild fish, hinder the potential development of the aquaculture sector. To achieve this purpose the study was organized into two complementary steps: a qualitative approach (focus groups) aimed at assessing consumer perception about wild and farmed fish and to identify the salient beliefs that differentiate them; and a quantitative approach (survey by means of a questionnaire) to validate the results obtained in the focus group discussions over a representative sample of participants (n = 919). Results showed that participants perceive clear differences between farmed and wild fish. Although no significant differences between both kinds of fish were detected on safety, in general farmed fish was perceived to be less affected by marine pollution, heavy metals and parasites. In the contrary, wild fish was considered to have healthier feeding, to contain fewer antibiotics and to be fresher, healthier, less handled and more natural. Beliefs related to quality were in favour of wild fish, while those related to availability and price were in favour of farmed fish. Significant differences were observed in the perception of both kinds of fish depending on the consumers' objective knowledge about fish, on the level of education, age and gender and on the three segments of consumers identified: "Traditional/Conservative", "Connoisseur", "Open to aquaculture". The results provided could play an important role when planning and designing efficient marketing strategies for promoting farmed fish by adapting the information provided to the perception of each segment of consumers identified by the present study. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Fish population dynamics

    National Research Council Canada - National Science Library

    Gulland, J. A

    1977-01-01

    This book describes how the dynamics of fish populations can be analysed in terms of the factors affecting their rates of growth, mortality and reproduction, with particular emphasis on the effects of fishing...

  12. Wild populations of the invasive Australian red claw crayfish Cherax quadricarinatus (Crustacea, Decapoda near the northern coast of Jalisco, Mexico: a new fishing and profitable resource

    Directory of Open Access Journals (Sweden)

    Fernando Vega-Villasante

    2015-09-01

    Full Text Available The red claw crayfish Cherax quadricarinatus is native to freshwater habitats of northern Australia and Papua New Guinea. Its high reproductive and adaptive capacity in different environments allows it to be cultivated, where escaped individuals have established wild populations in countries far from their natural range. In the late 90's and beginning of the 21st century, this crayfish was introduced illegally along the coast of southern Jalisco. Mismanagement led to escape and dispersion. Currently there are wild crayfish in the Cajón de Peñas Reservoir and surrounding streams in northern Jalisco, Mexico. The aim of this study was to evaluate the presence of C. quadricarinatus in fisheries in this area of Jalisco and analyze its importance in generating economic benefits for fishermen, comparing these results with those of the fishery for M. americanum, whose fishery is traditional. To catch specimens, traps were set for 24 h in the La Sanja Stream and the Cajón de Peñas Reservoir. The results of the survey showed that C. quadrica rinatus is an important part of the crustacean catch in this area: 32% of the total catch in the stream corresponded to C. quadricarinatus and the rest to M. americanum. While 85% of the catch in the dam corresponded to C. quadricarinatus, only 15% referred to M. americanum. Crayfish fishing in the reservoir is now an important part of the productive activity of local families dependent on fishing. The ecological consequences of wild crayfish proliferation remain to be studied.

  13. Fishing amplifies forage fish population collapses.

    Science.gov (United States)

    Essington, Timothy E; Moriarty, Pamela E; Froehlich, Halley E; Hodgson, Emma E; Koehn, Laura E; Oken, Kiva L; Siple, Margaret C; Stawitz, Christine C

    2015-05-26

    Forage fish support the largest fisheries in the world but also play key roles in marine food webs by transferring energy from plankton to upper trophic-level predators, such as large fish, seabirds, and marine mammals. Fishing can, thereby, have far reaching consequences on marine food webs unless safeguards are in place to avoid depleting forage fish to dangerously low levels, where dependent predators are most vulnerable. However, disentangling the contributions of fishing vs. natural processes on population dynamics has been difficult because of the sensitivity of these stocks to environmental conditions. Here, we overcome this difficulty by collating population time series for forage fish populations that account for nearly two-thirds of global catch of forage fish to identify the fingerprint of fisheries on their population dynamics. Forage fish population collapses shared a set of common and unique characteristics: high fishing pressure for several years before collapse, a sharp drop in natural population productivity, and a lagged response to reduce fishing pressure. Lagged response to natural productivity declines can sharply amplify the magnitude of naturally occurring population fluctuations. Finally, we show that the magnitude and frequency of collapses are greater than expected from natural productivity characteristics and therefore, likely attributed to fishing. The durations of collapses, however, were not different from those expected based on natural productivity shifts. A risk-based management scheme that reduces fishing when populations become scarce would protect forage fish and their predators from collapse with little effect on long-term average catches.

  14. Vibrio diseases of marine fish populations

    Science.gov (United States)

    Colwell, R. R.; Grimes, D. J.

    1984-03-01

    Several Vibrio spp. cause disease in marine fish populations, both wild and cultured. The most common disease, vibriosis, is caused by V. anguillarum. However, increase in the intensity of mariculture, combined with continuing improvements in bacterial systematics, expands the list of Vibrio spp. that cause fish disease. The bacterial pathogens, species of fish affected, virulence mechanisms, and disease treatment and prevention are included as topics of emphasis in this review.

  15. On the reproductive success of early-generation hatchery fish in the wild.

    Science.gov (United States)

    Christie, Mark R; Ford, Michael J; Blouin, Michael S

    2014-09-01

    Large numbers of hatchery salmon spawn in wild populations each year. Hatchery fish with multiple generations of hatchery ancestry often have heritably lower reproductive success than wild fish and may reduce the fitness of an entire population. Whether this reduced fitness also occurs for hatchery fish created with local- and predominantly wild-origin parents remains controversial. Here, we review recent studies on the reproductive success of such 'early-generation' hatchery fish that spawn in the wild. Combining 51 estimates from six studies on four salmon species, we found that (i) early-generation hatchery fish averaged only half the reproductive success of their wild-origin counterparts when spawning in the wild, (ii) the reduction in reproductive success was more severe for males than for females, and (iii) all species showed reduced fitness due to hatchery rearing. We review commonalities among studies that point to possible mechanisms (e.g., environmental versus genetic effects). Furthermore, we illustrate that sample sizes typical of these studies result in low statistical power to detect fitness differences unless the differences are substantial. This review demonstrates that reduced fitness of early-generation hatchery fish may be a general phenomenon. Future research should focus on determining the causes of those fitness reductions and whether they lead to long-term reductions in the fitness of wild populations.

  16. Consumer perception versus scientific evidence of farmed and wild fish

    DEFF Research Database (Denmark)

    Verbeke, Wim; Sioen, Isabelle; Brunsø, Karen

    2007-01-01

    The increasing number of marketable fish being supplied from aquaculture is a response to the increasing demand for healthy food and is filling the gap left by depleting natural fish stocks. Little is known about the awareness and perception of the consumer in terms of farmed fish versus fish from...... capture fisheries. The consumer's subjective point of view is of overriding importance for the production system and product acceptance as well as for future market success. In this paper consumer perception in Belgium is explored and compared against scientific evidence of farmed versus wild fish....... Primary data were collected through a consumer survey (April 2003) and focus group discussions (May 2004) with Belgian consumers. The majority of the consumer sample reported no perceived differences between farmed versus wild fish. However, mean perception scores were slightly in favour of wild fish...

  17. Ecological role of bluefin tuna (Thunnus thynnus) fish farms for associated wild fish assemblages in the Mediterranean Sea.

    Science.gov (United States)

    Stagličić, Nika; Šegvić-Bubić, Tanja; Ugarković, Pero; Talijančić, Igor; Žužul, Iva; Tičina, Vjekoslav; Grubišić, Leon

    2017-12-01

    The ecological effects of tuna fish farms are largely undocumented. This study confirmed their high capacity to attract surrounding wild fish. The aggregation effect persisted year round, without detectable seasonal differences. Farm impact was restricted to close proximity of the sea cages, and was more prominent over the bottom than in the water column strata. Tuna fish farms proved to be high energy trophic resources, as indicated by the enhanced fitness status of two focal species, bogue and seabream. Under abundant food supply, seabream appear to allocate the majority of energy reserves to gonad development. Farm associated bogue had greater parasite loads, with no detrimental effect on fitness status. Overall, tuna fish farms can be regarded as population sources for aggregated wild fish, and under the no fishing conditions within the leasehold areas, can serve as functional marine protected areas. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. A model describing the effect of sex-reversed YY fish in an established wild population: The use of a Trojan Y chromosome to cause extinction of an introduced exotic species.

    Science.gov (United States)

    Gutierrez, Juan B; Teem, John L

    2006-07-21

    A novel means of inducing extinction of an exotic fish population is proposed using a genetic approach to shift the ratio of male to females within a population. In the proposed strategy, sex-reversed fish containing two Y chromosomes are introduced into a normal fish population. These YY fish result in the production of a disproportionate number of male fish in subsequent generations. Mathematical modeling of the system following introduction of YY fish at a constant rate reveals that female fish decline in numbers over time, leading to eventual extinction of the population.

  19. Market tntegration between farmed and wild fish

    DEFF Research Database (Denmark)

    Bronnmann, Julia; Ankamah-Yeboah, Isaac; Nielsen, Max

    2016-01-01

    Following decade-long growth in worldwide farming of pangasius and tilapia, imports to Germany, a main European market, have been reduced since 2010. One reason for this might be supply growth of wild species at the total German whitefish market, if market integration exists between farmed and wild...

  20. A predation cost to bold fish in the wild

    DEFF Research Database (Denmark)

    Hulthén, Kaj; Chapman, Ben; Nilsson, Anders P.

    2017-01-01

    is challenging and there is currently little data from the wild. We assayed individual behaviour and electronically tagged hundreds of fish (roach, Rutilus rutilus) before releasing them into their lake of origin, thereby exposing them to predation risk from avian apex predators (cormorants, Phalacrocorax carbo......Studies of predator-mediated selection on behaviour are critical for our understanding of the evolution and maintenance of behavioural diversity in natural populations. Consistent individual differences in prey behaviour, especially in the propensity to take risks ("boldness"), are widespread...... in the animal kingdom. Theory predicts that individual behavioural types differ in a cost-benefit trade-off where bolder individuals benefit from greater access to resources while paying higher predation-risk costs. However, explicitly linking predation events to individual behaviour under natural conditions...

  1. The dual myths of the healthy wild fish and the unhealthy farmed fish

    OpenAIRE

    Bergh, Øivind

    2007-01-01

    Although diseases, suffering and death have always been recognized as intrinsic parts of life as far as humans are concerned, it seems that many people tend to disregard these factors when it comes to animals. In particular, wild fish are generally assumed to be ‘healthy’, although the public concept of that term is unclear. In contrast, farmed fish are often popularly viewed as ‘unhealthy’. Present knowledge of the importance of epizootics among wild fish is clearly limited, especially re...

  2. Methods for assessing fish populations

    Science.gov (United States)

    Kevin L. Pope; Steve E. Lochmann; Michael K. Young

    2010-01-01

    Fisheries managers are likely to assess fish populations at some point during the fisheries management process. Managers that follow the fisheries management process (see Chapter 5) might find their knowledge base insufficient during the steps of problem identification or management action and must assess a population before appropriate actions can be taken. Managers...

  3. Species-specific patterns of aggregation of wild fish around fish farms

    Science.gov (United States)

    Dempster, T.; Sanchez-Jerez, P.; Uglem, I.; Bjørn, P.-A.

    2010-01-01

    Fish-farming structures are widespread in coastal waters and are highly attractive to wild fish. Several studies have estimated that tons to tens of tons of wild fish aggregate around fish farms. These estimates assumed that the majority of wild fish are concentrated immediately beneath farms, although this assumption has never been explicitly tested. We tested the hypothesis that abundances of wild fish would be greatest immediately beneath farms and progressively diminish with distance at 4 full-scale coastal salmon ( Salmo salar) farms in Norway. At each farm, fish were counted with a video-camera system at 5 different distances from the cages (farm = 0 m, 25, 50, 100 and 200 m) throughout the water column on three separate days. Combined across all locations and times, the total abundance of wild fish was 20 times greater at the farm than at the 200 m sampling distance. Saithe ( Pollachius virens) dominated assemblages at all 4 farms and were consistently significantly more abundant at the farm than at the 25-200 m distances. This 'tight aggregation' around farms corresponds to the reliance of saithe on waste feed when they school near farms. In contrast, patterns of distribution of both cod ( Gadus morhua) and poor cod ( Trisopterus minutus) varied among farms, with either highest abundances at the farm or a more even distribution of abundance across all 5 distances sampled. No specific pattern of aggregation was evident for the bottom-dwelling haddock ( Melanogrammus aeglefinus). Our results suggest that the present 100 m no-fishing zone around salmon farms protects the greatest proportion of farm-aggregated saithe and cod from fishing during the daytime. However, whether this reduces their overall susceptibility to fishing requires further research regarding nighttime distribution and movements.

  4. Survey of viral haemorrhagic septicaemia virus in wild fishes in the southeastern Black Sea.

    Science.gov (United States)

    Ogut, H; Altuntas, C

    2014-05-13

    Species diversity in the Black Sea ecosystem has been declining rapidly over the last 2 decades. To assess the occurrence and distribution of viral haemorrhagic septicaemia virus (VHSV) in various wild fish species, a wild marine fish survey was carried out in 2009, 2010, and 2011. The pooled or individual samples of kidney, liver, and spleen of 5025 specimens, belonging to 17 fish species, were examined virologically using cell culture. The cells showing cytopathic effects (CPE) were subjected to ELISA and multiplex reverse transcriptase polymerase chain reaction (RT-mPCR), for VHSV and infectious pancreatic necrosis virus (IPNV), after blind passaging to determine the virus species causing CPE. The virus species and possibility of co-infection with IPNV were verified by the RT-mPCR developed in this study. Twelve species of fish (pontic shad Alosa immaculata, red mullet Mullus barbatus, three-bearded rockling Gaidropsarus vulgaris, black scorpionfish Scorpaena porcus, Mediterranean horse mackerel Trachurus mediterraneus, whiting Merlangius merlangus euxinus, stargazer Uranoscopus scaber, pilchard Sardina pilchardus, garfish Belone belone, round goby Neogobius melanostomus, thornback ray Raja clavata, and anchovy Engraulis encrasicolus) tested positive for VHSV Genotype Ie (VHSV-Ie). Except whiting, pilchard, and round goby, the rest are new host records for VHSV. The extent and spread of VHSV-Ie was significantly higher among bottom fish than among pelagic fish. Sensitivity and specificity of the RT-mPCR developed was sufficiently high, suggesting that this assay may be used for both diagnostic and surveillance testing. According to the RT-mPCR results, IPNV was not present in wild fish. These results support the hypothesis that the VHSV-Ie genotype, highly prevalent among fish species in the Black Sea, may have a serious impact on the population dynamics of wild fish stocks.

  5. Effective size of a wild salmonid population is greatly reduced by hatchery supplementation.

    Science.gov (United States)

    Christie, M R; Marine, M L; French, R A; Waples, R S; Blouin, M S

    2012-10-01

    Many declining and commercially important populations are supplemented with captive-born individuals that are intentionally released into the wild. These supplementation programs often create large numbers of offspring from relatively few breeding adults, which can have substantial population-level effects. We examined the genetic effects of supplementation on a wild population of steelhead (Oncorhynchus mykiss) from the Hood River, Oregon, by matching 12 run-years of hatchery steelhead back to their broodstock parents. We show that the effective number of breeders producing the hatchery fish (broodstock parents; N(b)) was quite small (harmonic mean N(b)=25 fish per brood-year vs 373 for wild fish), and was exacerbated by a high variance in broodstock reproductive success among individuals within years. The low N(b) caused hatchery fish to have decreased allelic richness, increased average relatedness, more loci in linkage disequilibrium and substantial levels of genetic drift in comparison with their wild-born counterparts. We also documented a substantial Ryman-Laikre effect whereby the additional hatchery fish doubled the total number of adult fish on the spawning grounds each year, but cut the effective population size of the total population (wild and hatchery fish combined) by nearly two-thirds. We further demonstrate that the Ryman-Laikre effect is most severe in this population when (1) >10% of fish allowed onto spawning grounds are from hatcheries and (2) the hatchery fish have high reproductive success in the wild. These results emphasize the trade-offs that arise when supplementation programs attempt to balance disparate goals (increasing production while maintaining genetic diversity and fitness).

  6. Fish populations in Plynlimon streams

    Directory of Open Access Journals (Sweden)

    D. T. Crisp

    1997-01-01

    Full Text Available In Plynlimon streams, brown trout (Salmo trutta L. are widespread in the upper Wye at population densities of 0.03 to 0.32 fish m-2 and show evidence of successful recruitment in most years. In the upper Severn, brown trout are found only in an area of c. 1670 -2 downstream of Blaenhafren Falls at densities of 0.03 to 0.24 fish -2 and the evidence suggests very variable year to year success in recruitment (Crisp & Beaumont, 1996. Analyses of the data show that temperature differences between afforested and unafforested streams may affect the rates of trout incubation and growth but are not likely to influence species survival. Simple analyses of stream discharge data suggest, but do not prove, that good years for recruitment in the Hafren population were years of low stream discharge. This may be linked to groundwater inputs detected in other studies in this stream. More research is needed to explain the survival of the apparently isolated trout population in the Hafren.

  7. [Book review] Fish Gene Pools: preservation of genetic resources in relation to wild fish stocks, edited by N. Ryman

    Science.gov (United States)

    Simon, R.C.

    1984-01-01

    Review of: Fish Gene Pools: Preservation of Genetic Resources in Relation to Wild Fish Stocks. Edited by N. Ryman. The Editorial Service/FRN, Box 6710, S-11385, Stockholm, Sweden. 1981. 111 pages. $16.00 (paper).

  8. Seafood research from fish to dish : quality, safety and processing of wild and farmed fish

    NARCIS (Netherlands)

    Luten, J.B.

    2006-01-01

    In this book, scientists from various disciplines address the advances in seafood research with respect to quality, safety, consumer’s demands and processing of wild and farmed fish. The nutritional properties of marine lipids and lipid oxidation from model systems to seafood are presented. Several

  9. 19 CFR 12.26 - Importations of wild animals, fish, amphibians, reptiles, mollusks, and crustaceans; prohibited...

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Importations of wild animals, fish, amphibians..., Birds, and Insects § 12.26 Importations of wild animals, fish, amphibians, reptiles, mollusks, and... crustacea), amphibians, reptiles, or the offspring or eggs of any of the foregoing which the Secretary of...

  10. Inherited XX sex reversal originating from wild medaka populations.

    Science.gov (United States)

    Shinomiya, A; Otake, H; Hamaguchi, S; Sakaizumi, M

    2010-11-01

    The teleost fish, medaka (Oryzias latipes), has an XX/XY sex-determining mechanism. A Y-linked DM domain gene, DMY, has been isolated by positional cloning as the sex-determining gene in this species. Previously, we conducted a field survey of genotypic sex and found that approximately 1% of wild medaka are sex-reversed (XX males and XY females). Here, we performed genetic analyses of nine spontaneous XX sex-reversed males to elucidate its genetic basis. In all cases, the F(1) progeny were all females, whereas XX males reappeared in the backcross (BC) progeny, suggesting that XX sex reversal is a recessive trait. Although the incidences of sex reversal in the BC progeny were mostly low, 40% were males derived from one XX male. We performed linkage analysis using 55 BC males and located a single major factor, sda-1 (sex-determining autosomal factor-1), controlling sex reversal in an autosomal linkage group. Thus, genes involved in the sex-determining pathway can be isolated from spontaneous mutants in wild populations.

  11. Characteristics Of Smoked Catfish (Hemibagrus Nemurus) Prepared Frompond Culture, Cage And Wild Fish

    OpenAIRE

    Maskilin, Jippo; Hasan, Bustari; Leksono, Tjipto

    2017-01-01

    This study was aimed to evaluate the sensory quality, proximate composition, amino acids and fatty acids profiles of smoked catfish prepared from pond, cage culture and wild fish. Catfish samples 300-350 grams in weight wastaken respectualy from wild (Kampar river), pond and cage culture in Sungai Paku, Kampar. The fish was smoked using hot smoking method, and the smoked fish was evaluated for smoking yield, sensory quality, proximate composition, amino acid and fatty acid profile.The smoking...

  12. Wild and hatchery populations of Korean starry flounder (Platichthys stellatus) compared using microsatellite DNA markers.

    Science.gov (United States)

    An, Hye Suck; Byun, Soon Gyu; Kim, Yi Cheong; Lee, Jang Wook; Myeong, Jeong-In

    2011-01-01

    Starry flounder (Platichthys stellatus) is an important sport and food fish found around the margins of the North Pacific. Aquaculture production of this species in Korea has increased because of its commercial value. Microsatellite DNA markers are a useful DNA-based tool for monitoring the genetic variation of starry flounder populations. In this study, 12 polymorphic microsatellite DNA markers were identified from a partial genomic starry flounder DNA library enriched in CA repeats, and used to compare allelic variation between wild and hatchery starry flounder populations in Korea. All loci were readily amplified and demonstrated high allelic diversity, with the number of alleles ranging from 6 to 18 in the wild population and from 2 to 12 in the farmed population. A total of 136 alleles were detected at the 12 microsatellite loci in the two populations. The mean observed and expected heterozygosities were 0.62 and 0.68, respectively, in the hatchery samples and 0.67 and 0.75, respectively, in the wild samples. These results indicate lower genetic variability in the hatchery population as compared to the wild population. Significant shifts in allelic frequencies were detected at eight loci, which resulted in a small but significant genetic differences between the wild and hatchery populations (F(ST) = 0.043, P hatchery populations. These microsatellite loci may be valuable for future population genetic studies, monitoring the genetic variation for successful aquaculture management and the preservation of aquatic biodiversity.

  13. Fish population density estimates - 1969 Fredericton District

    National Research Council Canada - National Science Library

    Hyatt, R.A

    1969-01-01

    Discussions with biologists concerning electroseining methods for fish population density estimates led to the conduct of a series of comparisons between the Peterson Index type of estimate (mark and recapture...

  14. A Genetic Study of Wild Populations and Evolution A Genetic Study of Wild Populations and Evolution

    Directory of Open Access Journals (Sweden)

    Hovanitz William

    1944-06-01

    Full Text Available The determination of the scientific basis of heredity within the last two decades and the verification of the principal conclusions in many different plants and animals has made possible the application of analytical methods in the study of variations in wild populations. As with the physical and chemical sciences, genetics has been enabled to make use of mathematics to compound (often theoretically out of simple units, the genes, the complexity known as an organism, much in the same way as a chemist compounds molecules with atoms and the physicist compounds atoms with protons and electrons. The determination of the scientific basis of heredity within the last two decades and the verification of the principal conclusions in many different plants and animals has made possible the application of analytical methods in the study of variations in wild populations. As with the physical and chemical sciences, genetics has been enabled to make use of mathematics to compound (often theoretically out of simple units, the genes, the complexity known as an organism, much in the same way as a chemist compounds molecules with atoms and the physicist compounds atoms with protons and electrons.

  15. Common fish diseases and parasites affecting wild and farmed

    African Journals Online (AJOL)

    ACSS

    leading to economic losses to commercial fish farms and associated natural aquatic ecosystems. This survey assessed health profiles of selected commercial fish farms and adjacent natural aquatic ecosystemsto identify fish diseases ... fish deficit (Dickson et al., 2012; Nunan,. 2014). Cases of aquatic diseases incidences.

  16. Better Redd than Dead: Optimizing Reservoir Operations for Wild Fish Survival During Drought

    Science.gov (United States)

    Adams, L. E.; Lund, J. R.; Quiñones, R.

    2014-12-01

    Extreme droughts are difficult to predict and may incur large economic and ecological costs. Dam operations in drought usually consider minimizing economic costs. However, dam operations also offer an opportunity to increase wild fish survival under difficult conditions. Here, we develop a probabilistic optimization approach to developing reservoir release schedules to maximize fish survival in regulated rivers. A case study applies the approach to wild Fall-run Chinook Salmon below Folsom Dam on California's American River. Our results indicate that releasing more water early in the drought will, on average, save more wild fish over the long term.

  17. Common fish diseases and parasites affecting wild and farmed ...

    African Journals Online (AJOL)

    Intensification of aquaculture production in Uganda is likely to result into disease out-breaks leading to economic losses to commercial fish farms and associated natural aquatic ecosystems. This survey assessed health profiles of selected commercial fish farms and adjacent natural aquatic ecosystemsto identify fish ...

  18. Estimate of herpetofauna depredation by a population of wild pigs

    Science.gov (United States)

    Jolley, D.B.; Ditchkoff, S.S.; Sparklin, B.D.; Hanson, L.B.; Mitchell, M.S.; Grand, J.B.

    2010-01-01

    Herpetofauna populations are decreasing worldwide, and the range of wild pigs (Sus scrofa) is expanding. Depredation of threatened reptile and amphibian populations by wild pigs could be substantial. By understanding depredation characteristics and rates, more resources can be directed toward controlling populations of wild pigs coincident with threatened or endangered herpetofauna populations. From April 2005 to March 2006 we used firearms to collect wild pigs (n = 68) and examined stomach content for reptiles and amphibians. We found 64 individual reptiles and amphibians, composed of 5 different species, that were consumed by wild pigs during an estimated 254 hours of foraging. Primarily arboreal species (e.g., Anolis carolinensis) became more vulnerable to depredation when temperatures were low and they sought thermal shelter. Other species (e.g., Scaphiopus holbrookii) that exhibit mass terrestrial migrations during the breeding season also faced increased vulnerability to depredation by wild pigs. Results suggest that wild pigs are opportunistic consumers that can exploit and potentially have a negative impact on species with particular life-history characteristics. ?? 2009 American Society of Mammalogists.

  19. Do hatchery-reared sea urchins pose a threat to genetic diversity in wild populations?

    Science.gov (United States)

    Segovia-Viadero, M; Serrão, E A; Canteras-Jordana, J C; Gonzalez-Wangüemert, M

    2016-04-01

    In salmonids, the release of hatchery-reared fish has been shown to cause irreversible genetic impacts on wild populations. However, although responsible practices for producing and releasing genetically diverse, hatchery-reared juveniles have been published widely, they are rarely implemented. Here, we investigated genetic differences between wild and early-generation hatchery-reared populations of the purple sea urchin Paracentrotus lividus (a commercially important species in Europe) to assess whether hatcheries were able to maintain natural levels of genetic diversity. To test the hypothesis that hatchery rearing would cause bottleneck effects (that is, a substantial reduction in genetic diversity and differentiation from wild populations), we compared the levels and patterns of genetic variation between two hatcheries and four nearby wild populations, using samples from both Spain and Ireland. We found that hatchery-reared populations were less diverse and had diverged significantly from the wild populations, with a very small effective population size and a high degree of relatedness between individuals. These results raise a number of concerns about the genetic impacts of their release into wild populations, particularly when such a degree of differentiation can occur in a single generation of hatchery rearing. Consequently, we suggest that caution should be taken when using hatchery-reared individuals to augment fisheries, even for marine species with high dispersal capacity, and we provide some recommendations to improve hatchery rearing and release practices. Our results further highlight the need to consider the genetic risks of releasing hatchery-reared juveniles into the wild during the establishment of restocking, stock enhancement and sea ranching programs.

  20. The Implications of Ranaviruses to European farmed and wild freshwater fish

    DEFF Research Database (Denmark)

    Jensen, Ann Britt Bang

    -living fish. The following specific objectives are addressed: Objective 1: To determine the susceptibility of selected European freshwater fish to a panel of ranaviruses Objective 2: To determine whether ornamental fish are susceptible to or can be carriers of ranaviruses Objective 3: To develop a model...... describing the risk of introduction and spread of exotic ranaviruses in European wild and farmed aquatic ecosystems Objectives 1 and 2 have been addressed by experimental trials involving bath challenges of both European farmed and wild fish species and ornamental fish species. The results showed that some...... and susceptibility trials in fish, and discussed in the context of taxonomy and legislation. Objective 3 was addressed by using the principles from the OIE risk assessment framework to develop a generic risk model for assessing the risk of introducing exotic ranaviruses into the EU via imports of infected ornamental...

  1. Introgression of Crop Alleles into Wild or Weedy Populations

    NARCIS (Netherlands)

    Ellstrand, N.C.; Meirmans, P.; Rong, J.; Bartsch, D.; Ghosh, A.; de Jong, T.J.; Haccou, P.; Lu, B-R.; Snow, A.A.; Stewart, C.N.; Strasburg, J.L.; van Tienderen, P.H.; Vrieling, K; Hooftman, D.A.P.

    2013-01-01

    The evolutionary significance of introgression has been discussed for decades. Questions about potential impacts of transgene flow into wild and weedy populations brought renewed attention to the introgression of crop alleles into those populations. In the past two decades, the field has advanced

  2. Hatcheries, Harvest and Wild Fish: An Integrated Program at Warm Springs National Fish Hatchery, Oregon

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Warm Springs National Fish Hatchery is operated by the U.S. Fish and Wildlife Service and is located on the Warm Springs River within the Warm Springs Indian...

  3. The Implications of Ranaviruses to European farmed and wild freshwater fish

    DEFF Research Database (Denmark)

    Jensen, Ann Britt Bang

    describing the risk of introduction and spread of exotic ranaviruses in European wild and farmed aquatic ecosystems Objectives 1 and 2 have been addressed by experimental trials involving bath challenges of both European farmed and wild fish species and ornamental fish species. The results showed that some...... and susceptibility trials in fish, and discussed in the context of taxonomy and legislation. Objective 3 was addressed by using the principles from the OIE risk assessment framework to develop a generic risk model for assessing the risk of introducing exotic ranaviruses into the EU via imports of infected ornamental...... in the introduction pathway. The pathway and the hazard identification were important outcomes of this model, together with the estimates of the risk of an exotic ranavirus being introduced into the EU by importation of ornamental fish from Asia. The risk for farmed fish is considered low, whereas the risk...

  4. Analysis of microsatellite DNA markers reveals no genetic differentiation between wild and hatchery populations of Pacific threadfin in Hawaii.

    Science.gov (United States)

    Pan, Gang; Yang, Jinzeng

    2010-12-15

    Pacific threadfin, Polydactylus sexfilis, is popular fish in recreational fishing, as well as aquaculture in Hawaii. Its natural population has been continuously declining in the past several decades. Microsatellite DNA markers are useful DNA-based tool for monitoring Pacific threadfin populations. In this study, fifteen Microsatellite (MS) DNA markers were identified from a partial genomic Pacific threadfin DNA library enriched in CA repeats, and six highly-polymorphic microsatellite loci were employed to analyze genetic similarity and differences between the wild population and hatchery population in Oahu Island. A total of 37 alleles were detected at the six MS loci in the two populations. Statistical analysis of fixation index (F(ST)) and analysis of molecular variance (AMOVA) showed no genetic differentiation between the wild and hatchery populations (F(ST) = 0.001, CI(95%) = -0.01-0.021). Both high genetic diversity (H(o) = 0.664-0.674 and H(e) = 0.710-0.715) and Hardy-Weinberg equilibrium were observed in the wild and hatchery populations. Results of genetic bottleneck analysis indicated that the hatchery was founded with sufficient numbers of brooders as inbreeding coefficient is very low (F(IS) = 0.052-0.072) in both wild and hatchery populations. Further studies are needed for comprehensive determinations of genetic varieties of primary founder broodstocks and successive offspring of the hatchery and wild populations with increased number of Pacific threadfin sample collections.

  5. Effects of Sound on the Behavior of Wild, Unrestrained Fish Schools.

    Science.gov (United States)

    Roberts, Louise; Cheesman, Samuel; Hawkins, Anthony D

    2016-01-01

    To assess and manage the impact of man-made sounds on fish, we need information on how behavior is affected. Here, wild unrestrained pelagic fish schools were observed under quiet conditions using sonar. Fish were exposed to synthetic piling sounds at different levels using custom-built sound projectors, and behavioral changes were examined. In some cases, the depth of schools changed after noise playback; full dispersal of schools was also evident. The methods we developed for examining the behavior of unrestrained fish to sound exposure have proved successful and may allow further testing of the relationship between responsiveness and sound level.

  6. PMCV and PRV occurrence in wild and farmed fish in Denmark

    DEFF Research Database (Denmark)

    Mikkelsen, Susie Sommer; Arnö, J.; Bruun, Morten Sichlau

    Muscle Inflammation (HSMI) and Cardiomyopathy Syndrome (CMS), respectively. In 2013, broodstock from four different rivers in Denmark were received for surveillance. These rivers are Ribe, Varde, Skjern and Store Å, which are all west-facing rivers. Of these fish 8 were Sea Trout and the rest Salmon. 184...... fish were tested by real-time RT-PCR for PRV and 30 fish from each river were tested by real-time RT-PCR for PMCV. This is the first time wild and farmed fish have been tested for either virus in Denmark....

  7. How sea lice from salmon farms may cause wild salmonid declines in Europe and North America and be a threat to fishes elsewhere.

    Science.gov (United States)

    Costello, Mark J

    2009-10-07

    Fishes farmed in sea pens may become infested by parasites from wild fishes and in turn become point sources for parasites. Sea lice, copepods of the family Caligidae, are the best-studied example of this risk. Sea lice are the most significant parasitic pathogen in salmon farming in Europe and the Americas, are estimated to cost the world industry euro300 million a year and may also be pathogenic to wild fishes under natural conditions. Epizootics, characteristically dominated by juvenile (copepodite and chalimus) stages, have repeatedly occurred on juvenile wild salmonids in areas where farms have sea lice infestations, but have not been recorded elsewhere. This paper synthesizes the literature, including modelling studies, to provide an understanding of how one species, the salmon louse, Lepeophtheirus salmonis, can infest wild salmonids from farm sources. Three-dimensional hydrographic models predicted the distribution of the planktonic salmon lice larvae best when they accounted for wind-driven surface currents and larval behaviour. Caligus species can also cause problems on farms and transfer from farms to wild fishes, and this genus is cosmopolitan. Sea lice thus threaten finfish farming worldwide, but with the possible exception of L. salmonis, their host relationships and transmission adaptations are unknown. The increasing evidence that lice from farms can be a significant cause of mortality on nearby wild fish populations provides an additional challenge to controlling lice on the farms and also raises conservation, economic and political issues about how to balance aquaculture and fisheries resource management.

  8. Population Viability Analysis of Riverine Fishes

    Energy Technology Data Exchange (ETDEWEB)

    Bates, P.; Chandler, J.; Jager, H.I.; Lepla, K.; Van Winkle, W.

    1999-04-12

    Many utilities face conflkts between two goals: cost-efficient hydropower generation and protecting riverine fishes. Research to develop ecological simulation tools that can evaluate alternative mitigation strategies in terms of their benefits to fish populations is vital to informed decision-making. In this paper, we describe our approach to population viability analysis of riverine fishes in general and Snake River white sturgeon in particular. We are finding that the individual-based modeling approach used in previous in-stream flow applications is well suited to addressing questions about the viability of species of concern for several reasons. Chief among these are: (1) the abiIity to represent the effects of individual variation in life history characteristics on predicted population viabili~, (2) the flexibili~ needed to quanti~ the ecological benefits of alternative flow management options by representing spatial and temporal variation in flow and temperaturty and (3) the flexibility needed to quantifi the ecological benefits of non-flow related manipulations (i.e., passage, screening and hatchery supplementation).

  9. Isolation of Birnavirus serogroup B in wild and aquacultured fish species

    DEFF Research Database (Denmark)

    Skall, Helle Frank; Mellergaard, Stig; Olesen, Niels Jørgen

    2000-01-01

    During cruises with Danish research vessels more than 17,000 wild marine fish belonging to 41 different species were sampled and examined virologically. Birnavirus serogroup B was isolated from 7 marine fish species: plaice (Pleuronectes platessa), dab (Limanda limanda), flounder (Platichthys...... and the Kattegat. Surveillance of aquacultured fish, mainly rainbow trout (Oncorhynchus mykiss), for VHS, IHN and IPN, in Denmark during the previous 30 years, have resulted in Birnavirus serogroup B isolations twice. These isolations were from healthy rainbow trout. Samples sent to the Danish Veterinary...... Laboratory for virological examination and characterisation have revealed the presence of Birnavirus serogroup B in haddock (ML Melanogrammus aeglefinus), plaice and dab from wild marine fish caught by Irish fishermen and from Icelandic farmed halibut (Hippoglossus hippoglossus)....

  10. Termite fishing by wild chimpanzees: new data from Ugalla, western Tanzania.

    Science.gov (United States)

    Stewart, Fiona A; Piel, Alex K

    2014-01-01

    Chimpanzees manufacture flexible fishing probes to fish for termites in Issa, Ugalla, western Tanzania. These termite-fishing tools are similar in size and material to those used by long-studied communities of chimpanzees in western Tanzania (Pan troglodytes schweinfurthii) and in West Africa (P. t. verus), but not central African populations (P. t. troglodytes). This report adds to the patchwork of evidence of termite-fishing tool use behaviour by chimpanzees across Africa.

  11. An evaluation of the effects of conservation and fishery enhancement hatcheries on wild populations of salmon

    Science.gov (United States)

    Naish, Kerry A.; Taylor, Joseph E.; Levin, Phillip S.; Quinn, Thomas P.; Winton, James R.; Huppert , Daniel; Hilborn , Ray

    2007-01-01

    The historical, political and scientific aspects of salmon hatchery programmes designed to enhance fishery production, or to recover endangered populations, are reviewed. We start by pointing out that the establishment of hatcheries has been a political response to societal demands for harvest and conservation; given this social context, we then critically examined the levels of activity, the biological risks, and the economic analysis associated with salmon hatchery programmes. A rigorous analysis of the impacts of hatchery programmes was hindered by the lack of standardized data on release sizes and survival rates at all ecological scales, and since hatchery programme objectives are rarely defined, it was also difficult to measure their effectiveness at meeting release objectives. Debates on the genetic effects of hatchery programmes on wild fish have been dominated by whether correct management practices can reduce negative outcomes, but we noted that there has been an absence of programmatic research approaches addressing this important issue. Competitive interactions between hatchery and wild fish were observed to be complex, but studies researching approaches to reduce these interactions at all ecological scales during the entire salmon life history have been rare, and thus are not typically considered in hatchery management. Harvesting of salmon released from fishery enhancement hatcheries likely impacts vulnerable wild populations; managers have responded to this problem by mass marking hatchery fish, so that fishing effort can be directed towards hatchery populations. However, we noted that the effectiveness of this approach is dependant on accurate marking and production of hatchery fish with high survival rates, and it is not yet clear whether selective fishing will prevent overharvest of wild populations. Finally, research demonstrating disease transmission from hatchery fish to wild populations was observed to be equivocal; evidence in this area has

  12. Population structure and adaptation in fishes

    DEFF Research Database (Denmark)

    Limborg, Morten

    Marine fishes represent a valuable resource for the global economy and food consumption. Accordingly, many species experience high levels of exploitation necessitating effective management plans. However, long term sustainability may be jeopardized from insufficient knowledge about intra-specific......Marine fishes represent a valuable resource for the global economy and food consumption. Accordingly, many species experience high levels of exploitation necessitating effective management plans. However, long term sustainability may be jeopardized from insufficient knowledge about intra...... genome-scan based investigation of local adaptation was conducted in the salmonid Oncorhynchus mykiss. Despite profound socio-economic importance many populations have experienced strong declines and future conservation can be improved from identification of key environmental parameters and genes...

  13. Quantifying realized inbreeding in wild and captive animal populations.

    Science.gov (United States)

    Knief, U; Hemmrich-Stanisak, G; Wittig, M; Franke, A; Griffith, S C; Kempenaers, B; Forstmeier, W

    2015-04-01

    Most molecular measures of inbreeding do not measure inbreeding at the scale that is most relevant for understanding inbreeding depression-namely the proportion of the genome that is identical-by-descent (IBD). The inbreeding coefficient FPed obtained from pedigrees is a valuable estimator of IBD, but pedigrees are not always available, and cannot capture inbreeding loops that reach back in time further than the pedigree. We here propose a molecular approach to quantify the realized proportion of the genome that is IBD (propIBD), and we apply this method to a wild and a captive population of zebra finches (Taeniopygia guttata). In each of 948 wild and 1057 captive individuals we analyzed available single-nucleotide polymorphism (SNP) data (260 SNPs) spread over four different genomic regions in each population. This allowed us to determine whether any of these four regions was completely homozygous within an individual, which indicates IBD with high confidence. In the highly nomadic wild population, we did not find a single case of IBD, implying that inbreeding must be extremely rare (propIBD=0-0.00094, 95% CI). In the captive population, a five-generation pedigree strongly underestimated the average amount of realized inbreeding (FPed=0.013inbreeding at the individual or population level, and we show analytically that it can capture inbreeding loops that reach back up to a few hundred generations.

  14. It is the economy, stupid! Projecting the fate of fish populations using ecological-economic modeling.

    Science.gov (United States)

    Quaas, Martin F; Reusch, Thorsten B H; Schmidt, Jörn O; Tahvonen, Olli; Voss, Rudi

    2016-01-01

    Four marine fish species are among the most important on the world market: cod, salmon, tuna, and sea bass. While the supply of North American and European markets for two of these species - Atlantic salmon and European sea bass - mainly comes from fish farming, Atlantic cod and tunas are mainly caught from wild stocks. We address the question what will be the status of these wild stocks in the midterm future, in the year 2048, to be specific. Whereas the effects of climate change and ecological driving forces on fish stocks have already gained much attention, our prime interest is in studying the effects of changing economic drivers, as well as the impact of variable management effectiveness. Using a process-based ecological-economic multispecies optimization model, we assess the future stock status under different scenarios of change. We simulate (i) technological progress in fishing, (ii) increasing demand for fish, and (iii) increasing supply of farmed fish, as well as the interplay of these driving forces under different scenarios of (limited) fishery management effectiveness. We find that economic change has a substantial effect on fish populations. Increasing aquaculture production can dampen the fishing pressure on wild stocks, but this effect is likely to be overwhelmed by increasing demand and technological progress, both increasing fishing pressure. The only solution to avoid collapse of the majority of stocks is institutional change to improve management effectiveness significantly above the current state. We conclude that full recognition of economic drivers of change will be needed to successfully develop an integrated ecosystem management and to sustain the wild fish stocks until 2048 and beyond. © 2015 John Wiley & Sons Ltd.

  15. Full life-cycle assessment of gene flow consistent with fitness differences in transgenic and wild-type Japanese medaka fish (Oryzias latipes).

    Science.gov (United States)

    Pennington, Kelly M; Kapuscinski, Anne R; Morton, Michael S; Cooper, Anne M; Miller, Loren M

    2010-01-01

    Transgenic fish in development for aquaculture could escape from farms and interbreed with wild relatives in the nearby environment. Predicting whether escapes would result in transgene introgression is a major challenge in assessing environmental risks of transgenic fish. Previous studies have simulated gene flow from transgenic fish using mathematical modeling of fitness traits to predict the relative selective value of transgenic genotypes. Here, we present the first study of gene flow over the full life cycle in openly-breeding populations of transgenic animals, along with measurement of fitness traits. We conducted two invasion experiments in which we released two lines of growth-enhanced transgenic fish (T67 and T400), Japanese medaka (Oryzias latipes), into populations of wild-type (W) medaka in structured mesocosms. After several generations, the frequency of transgenic fish varied across replicates in the first invasion experiment (6 months), but the frequency of transgenic fish decreased in the second experiment (19 months). We also measured selected fitness traits in transgenic and wild-type medaka because these traits could be used to predict the relative selective value of a genotype. We found that: T400 males were more fertile than W males; offspring of W females lived longer than those with transgenic mothers; and W and T67 females reached sexual maturity sooner than T400 females. In contrast with other research that reported larger transgenic males had a mating advantage, we found that W males obtained more matings with females than T males; genetic background effects may account for our differing results as we compared W and T fish derived from different strains. The decreasing frequency of transgenic fish in the second invasion experiment suggests that transgenic fish had a selective disadvantage in the experimental environment. Our finding of transgenic advantage of some fitness traits and wild-type advantage in others is consistent with our

  16. The importance of wild fish in the epidemiology of Clonorchis sinensis in Vietnam.

    Science.gov (United States)

    Bui, Thanh Ngoc; Pham, Thanh Thi; Nguyen, Nguyen Thi; Nguyen, Ha Van; Murrell, Darwin; Phan, Van Thi

    2016-09-01

    Preliminary findings of a high prevalence of Clonorchis sinensis in wild-caught fish in a North Vietnam reservoir (Thac Ba reservoir, Yen Bai Province) prompted a longitudinal epidemiological study of fish infections. Monthly collections of fish from September 2014 to August 2015 were processed for recovery of metacercariae; 1219 fish, representing 22 species, were examined. Seven species were infected with C. sinensis metacercariae. Four species, Toxabramis houdemeri, Hemiculter leucisculus, Cultrichthys erythropterus, and Culter recurvirostris, had high prevalence (31.1 to 76.7 %); metacercarial intensities ranged from 3.9 to 65.7 metacercariae/fish. A seasonal variation of C. sinensis prevalence was observed in T. houdemeri. Variation in intensity of infection occurred in C. erythropterus and H. leucisculus. Intensity and prevalence of C. sinensis in the most highly infected species, T. houdemeri, varied by fish size; prevalence was higher in fish weighing more than 3 g, and intensity was higher in fish weighing more than 5 g. The distribution of metacercariae in the body region of T. houdemeri was significantly higher in the caudal fin (14.7 metacercariae/g), compared to the body and head regions (0.7 and 1.4 metacercariae/g, respectively). Further epidemiological investigations on C. sinensis in this reservoir region should include assessing the relative risk of the different fish species for humans based on the latter's food preferences, and the prevalence of C. sinensis in the community. The snail intermediate host(s) in the reservoir should also be identified along with the ecological factors influencing its exposure to C. sinensis eggs and its subsequent transmission of cercariae to fish. Also needed are investigations on the relative importance of wild and domestic reservoir hosts as sources of egg contamination of the reservoir.

  17. Heavy metal concentrations in wild fishes captured from the South China Sea and associated health risks.

    Science.gov (United States)

    Gu, Yang-Guang; Lin, Qin; Wang, Xue-Hui; Du, Fei-Yan; Yu, Zi-Ling; Huang, Hong-Hui

    2015-07-15

    Heavy metal concentrations were measured in 29 marine wild fish species from the South China Sea. Concentrations (wet weight) were 0.51-115.81 ng/g (Cd), 0.54-27.31 ng/g (Pb), 0.02-1.26 μg/g (Cr), 8.32-57.48 ng/g (Ni), 0.12-1.13 μg/g (Cu), 2.34-6.88 μg/g (Zn), 2.51-22.99 μg/g (Fe), and 0.04-0.81 μg/g (Mn), respectively. Iron concentrations in all and Mn in some fish species were higher than the acceptable daily upper limit, suggesting human consumption of these wild fish species may pose a health risk. Human health risk assessment, however, indicated no significant adverse health effects with consumption. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Population genetics of foxtail millet and its wild ancestor

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    Wang Yongfang

    2010-10-01

    Full Text Available Abstract Background Foxtail millet (Setaria italica (L. P. Beauv., one of the most ancient domesticated crops, is becoming a model system for studying biofuel crops and comparative genomics in the grasses. However, knowledge on the level of genetic diversity and linkage disequilibrium (LD is very limited in this crop and its wild ancestor, green foxtail (Setaria viridis (L. P. Beauv.. Such information would help us to understand the domestication process of cultivated species and will allow further research in these species, including association mapping and identification of agricultural significant genes involved in domestication. Results In this study, we surveyed DNA sequence for nine loci across 50 accessions of cultivated foxtail millet and 34 of its wild progenitor. We found a low level of genetic diversity in wild green foxtail (θ = 0.0059, θ means Watterson's estimator of θ. Despite of a 55% loss of its wild diversity, foxtail millet still harbored a considerable level of diversity (θ = 0.0027 when compared to rice and sorghum (θ = 0.0024 and 0.0034, respectively. The level of LD in the domesticated foxtail millet extends to 1 kb, while it decayed rapidly to a negligible level within 150 bp in wild green foxtail. Using coalescent simulation, we estimated the bottleneck severity at k = 0.6095 when ρ/θ = 1. These results indicated that the domestication bottleneck of foxtail millet was more severe than that of maize but slightly less pronounced than that of rice. Conclusions The results in this study establish a general framework for the domestication history of foxtail millet. The low level of genetic diversity and the increased level of LD in foxtail millet are mainly caused by a population bottleneck, although gene flow from foxtail millet to green foxtail is another factor that may have shaped the pattern of genetic diversity of these two related gene pools. The knowledge provided in this study will benefit future population

  19. Severe inbreeding depression in a wild wolf (Canis lupus) population.

    Science.gov (United States)

    Liberg, Olof; Andrén, Henrik; Pedersen, Hans-Christian; Sand, Håkan; Sejberg, Douglas; Wabakken, Petter; Kesson, Mikael; Bensch, Staffan

    2005-03-22

    The difficulty of obtaining pedigrees for wild populations has hampered the possibility of demonstrating inbreeding depression in nature. In a small, naturally restored, wild population of grey wolves in Scandinavia, founded in 1983, we constructed a pedigree for 24 of the 28 breeding pairs established in the period 1983-2002. Ancestry for the breeding animals was determined through a combination of field data (snow tracking and radio telemetry) and DNA microsatellite analysis. The population was founded by only three individuals. The inbreeding coefficient F varied between 0.00 and 0.41 for wolves born during the study period. The number of surviving pups per litter during their first winter after birth was strongly correlated with inbreeding coefficients of pups (R2=0.39, p<0.001). This inbreeding depression was recalculated to match standard estimates of lethal equivalents (2B), corresponding to 6.04 (2.58-9.48, 95% CI) litter-size-reducing equivalents in this wolf population.

  20. Genetic variability of wild and captivity populations of Colossoma macropomum (Cuvier, 1818 - doi: 10.4025/actascibiolsci.v34i2.7149

    Directory of Open Access Journals (Sweden)

    Vera Maria Fonseca de Almeida-Val

    2012-03-01

    Full Text Available Tambaqui (Colossoma macropomum is among the most important fish species of the Amazon and one of the most cultivated in Brazil. In the present work we have evaluated the genetic variability of wild and captivity populations of C. macropomum. Enzymatic markers were used to estimate the genetic variability of 41 specimens from a wild group; and 30, 33 and 45 from three captivity groups, which came from Pentecostes (Ceará State, Jaboticabal (São Paulo State and Itacoatiara (Amazonas State, respectively. Nine isoenzymic systems were used to evaluate the genetic variability of these populations. Using zimogram data we obtained the polymorphism level, allele number, allelic frequency, observed and expected heterozigosity, Wright F statistics (FIS, FST, genetic distance, level of similarity and group analysis. The isoenzymic data showed that, from the nine systems, six presented polymorphic loci (Fbp-2, G6pdh-2, G6pdh-3, Pgi-1, Pgi-2 and Pgm-1. The populations from Pentecostes and Jaboticabal presented loss of genetic variability and low heterozigosity, compared to the wild population and to the artificial population acquired at Itacoatiara fish farm. Based on these results and on fish farmer information we could consider the population from Itacoatiara as recently derived from a wild population. Concluding, we suggest that the artificial populations of tambaqui, which contain animals originated from this funding population at Pentecostes, should be renewed with the introduction of a new group of individuals with genetic variability equivalent to the wild population.

  1. Concentrations of heavy metals in marine wild fishes captured from the southern sea of Korea and associated health risk assessments

    Science.gov (United States)

    Hwang, Dong-Woon; Kim, Seong-Soo; Kim, Seong-Gil; Kim, Dong-Sun; Kim, Tae-Hoon

    2017-07-01

    Concentrations of heavy metals (As, Cd, Cr, Cu, Hg, Pb, and Zn) were determined in edible parts (muscle) of 34 marine wild fish caught from the southern sea of Korea in 2007 and 2008 in order to understand the accumulation pattern of heavy metals in wild fish and to assess the potential health risk posed by fish consumption. The highest concentrations in the muscle of 17 pelagic and 17 demersal fishes were Zn and As, respectively, while the lowest concentration in both fishes was Cd. The mean concentrations of all metals except As in wild fish were much lower than the regulatory limits for fish and fishery products applied in a number of countries. Unlike other metals, As concentration in wild fish of this study region was relatively higher than that found in other country. Estimated daily intake (EDI) of the metals was in the range of 0.05% to 22.5% of the provisional maximum tolerable daily intakes (PMTDI). Similarly, the target hazard quotient (THQ) was below 1.0 for each metal. These results imply that the consumption of the investigated wild fish do not cause significant adverse health effects.

  2. Concentrations of heavy metals in marine wild fishes captured from the southern sea of Korea and associated health risk assessments

    Science.gov (United States)

    Hwang, Dong-Woon; Kim, Seong-Soo; Kim, Seong-Gil; Kim, Dong-Sun; Kim, Tae-Hoon

    2017-12-01

    Concentrations of heavy metals (As, Cd, Cr, Cu, Hg, Pb, and Zn) were determined in edible parts (muscle) of 34 marine wild fish caught from the southern sea of Korea in 2007 and 2008 in order to understand the accumulation pattern of heavy metals in wild fish and to assess the potential health risk posed by fish consumption. The highest concentrations in the muscle of 17 pelagic and 17 demersal fishes were Zn and As, respectively, while the lowest concentration in both fishes was Cd. The mean concentrations of all metals except As in wild fish were much lower than the regulatory limits for fish and fishery products applied in a number of countries. Unlike other metals, As concentration in wild fish of this study region was relatively higher than that found in other country. Estimated daily intake (EDI) of the metals was in the range of 0.05% to 22.5% of the provisional maximum tolerable daily intakes (PMTDI). Similarly, the target hazard quotient (THQ) was below 1.0 for each metal. These results imply that the consumption of the investigated wild fish do not cause significant adverse health effects.

  3. Phylogenetic Diversity of Koala Retrovirus within a Wild Koala Population.

    Science.gov (United States)

    Chappell, K J; Brealey, J C; Amarilla, A A; Watterson, D; Hulse, L; Palmieri, C; Johnston, S D; Holmes, E C; Meers, J; Young, P R

    2017-02-01

    Koala populations are in serious decline across many areas of mainland Australia, with infectious disease a contributing factor. Koala retrovirus (KoRV) is a gammaretrovirus present in most wild koala populations and captive colonies. Five subtypes of KoRV (A to E) have been identified based on amino acid sequence divergence in a hypervariable region of the receptor binding domain of the envelope protein. However, analysis of viral genetic diversity has been conducted primarily on KoRV in captive koalas housed in zoos in Japan, the United States, and Germany. Wild koalas within Australia have not been comparably assessed. Here we report a detailed analysis of KoRV genetic diversity in samples collected from 18 wild koalas from southeast Queensland. By employing deep sequencing we identified 108 novel KoRV envelope sequences and determined their phylogenetic diversity. Genetic diversity in KoRV was abundant and fell into three major groups; two comprised the previously identified subtypes A and B, while the third contained the remaining hypervariable region subtypes (C, D, and E) as well as four hypervariable region subtypes that we newly define here (F, G, H, and I). In addition to the ubiquitous presence of KoRV-A, which may represent an exclusively endogenous variant, subtypes B, D, and F were found to be at high prevalence, while subtypes G, H, and I were present in a smaller number of animals. Koala retrovirus (KoRV) is thought to be a significant contributor to koala disease and population decline across mainland Australia. This study is the first to determine KoRV subtype prevalence among a wild koala population, and it significantly expands the total number of KoRV sequences available, providing a more precise picture of genetic diversity. This understanding of KoRV subtype prevalence and genetic diversity will be important for conservation efforts attempting to limit the spread of KoRV. Furthermore, KoRV is one of the only retroviruses shown to exist in

  4. Farmed and wild fish in the prevention of cardiovascular diseases: assessing possible differences in lipid nutritional values.

    Science.gov (United States)

    Cahu, C; Salen, P; de Lorgeril, M

    2004-02-01

    The consumption of fish and fish-derived products is recommended as a means of preventing cardiovascular and other diseases, and has considerably increased over recent decades. However, as the world's wild fish stocks are limited, consumers are now being proposed farmed fish as an alternative. The aim of this study was to compare the fat composition of farmed and wild fish in order to estimate whether the expected health effects of the former (especially in relation to cardiovascular diseases) are potentially the same as those of the latter. The data presented in this paper were collected from the recently published literature. The lipid composition of farmed fish is more constant and less affected by seasonal variations than that of wild fish because, as it is largely dependent on the fatty acid composition of their feed, it can be customised by adjusting dietary intakes. Vegetable food is increasingly replacing fishmeal in fish feeds, and may induce a relative decrease in n-3 polyunsaturated fatty acids (PUFAs), expressed as a percentage of total fatty acids. However, as farmed fish generally have higher total lipid levels than wild fish, 100 g of farmed fish fillet can provide a higher amount of n-3 PUFAs (especially EPA and DHA) than 100 g of wild fish. Furthermore, quite high levels of (alpha-tocopherol in farmed fish can theoretically provide better EPA and DHA protection against peroxidation. Sensory analyses by trained consumer panels have not revealed any significant differences between wild and farmed fish. Moreover, fresh fish storage conditions (including the time from slaughtering to consumer sales) are more easily verifiable in the case of farmed fish, in which the content of potentially toxic heavy metals (a major health concern in certain areas) is also theoretically more easily controlled. Provided that they are raised under appropriate conditions, the nutritional content of farmed fish is at least as beneficial as that of wild fish (particularly

  5. Wild reindeer in Norway – population ecology, management and harvest

    Directory of Open Access Journals (Sweden)

    Eigil Reimers

    2007-04-01

    Full Text Available Wild reindeer in Norway, presently (winter 2005-06 numbering some 25 000 animals, are found in 23 more or less separated areas in the mountainous southern part of the country (see map in appendix. All herds are hunted and management is organized in close cooperation between owner organizations and state agencies. I will provide a historical review of the wild reindeer management and research in Norway and conclude with the present situation. We identify 3 types of wild reindeer on basis of their origin: (1 the original wild reindeer with minor influence from previous domestic reindeer herding activities (Snøhetta, Rondane and Sølenkletten, (2 wild reindeer with some influx of animals from past domestic reindeer herding in the area (Nordfjella, Hardangervidda, Setesdal-Ryfylke and (3 feral reindeer with a domesticated origin (reindeer released or escaped from past reindeer husbandry units; Forolhogna, Ottadalen North and Ottadalen South, Norefjell-Reinsjøfjell and several smaller areas. In Norway, genetic origin (wild or domesticated, body size and reproductive performance of reindeer differ among areas. Feral reindeer have higher body weights and enjoy higher reproductive rates than their originally wild counterparts. These differences may partially be explained by differences in food quality and availability among the populations. However, there is a growing suspicion that other explanatory factors are also involved. Wild reindeer are more vigilant and show longer fright and flight distances than feral reindeer. Number of animals harvested was 4817, or ca. 20% of the total population in 2005, but varies between 40% in feral reindeer areas to below 20% in some of the "wild" reindeer areas. Causal factors behind this variation include differences in age at maturation, postnatal calf mortality and herd structure. The Norwegian Institute for nature research (NINA in cooperation with the Directorate for nature management (DN allocate considerable

  6. Genomic Inbreeding and Relatedness in Wild Panda Populations.

    Science.gov (United States)

    Garbe, John R; Prakapenka, Dzianis; Tan, Cheng; Da, Yang

    2016-01-01

    Inbreeding and relatedness in wild panda populations are important parameters for panda conservation. Habitat loss and fragmentation are expected to increase inbreeding but the actual inbreeding levels in natural panda habitats were unknown. Using 150,025 SNPs and 14,926 SNPs selected from published whole-genome sequences, we estimated genomic inbreeding coefficients and relatedness of 49 pandas including 34 wild pandas sampled from six habitats. Qinling and Liangshan pandas had the highest levels of inbreeding and relatedness measured by genomic inbreeding and coancestry coefficients, whereas the inbreeding levels in Qionglai and Minshan were 28-45% of those in Qinling and Liangshan. Genomic coancestry coefficients between pandas from different habitats showed that panda populations from the four largest habitats, Minshan, Qionglai, Qinling and Liangshan, were genetically unrelated. Pandas between these four habitats on average shared 66.0-69.1% common alleles and 45.6-48.6% common genotypes, whereas pandas within each habitat shared 71.8-77.0% common alleles and 51.7-60.4% common genotypes. Pandas in the smaller populations of Qinling and Liangshan were more similarly to each other than pandas in the larger populations of Qionglai and Minshan according to three genomic similarity measures. Panda genetic differentiation between these habitats was positively related to their geographical distances. Most pandas separated by 200 kilometers or more shared no common ancestral alleles. The results provided a genomic quantification of the actual levels of inbreeding and relatedness among pandas in their natural habitats, provided genomic confirmation of the relationship between genetic diversity and geographical distances, and provided genomic evidence to the urgency of habitat protection.

  7. Genomic Inbreeding and Relatedness in Wild Panda Populations.

    Directory of Open Access Journals (Sweden)

    John R Garbe

    Full Text Available Inbreeding and relatedness in wild panda populations are important parameters for panda conservation. Habitat loss and fragmentation are expected to increase inbreeding but the actual inbreeding levels in natural panda habitats were unknown. Using 150,025 SNPs and 14,926 SNPs selected from published whole-genome sequences, we estimated genomic inbreeding coefficients and relatedness of 49 pandas including 34 wild pandas sampled from six habitats. Qinling and Liangshan pandas had the highest levels of inbreeding and relatedness measured by genomic inbreeding and coancestry coefficients, whereas the inbreeding levels in Qionglai and Minshan were 28-45% of those in Qinling and Liangshan. Genomic coancestry coefficients between pandas from different habitats showed that panda populations from the four largest habitats, Minshan, Qionglai, Qinling and Liangshan, were genetically unrelated. Pandas between these four habitats on average shared 66.0-69.1% common alleles and 45.6-48.6% common genotypes, whereas pandas within each habitat shared 71.8-77.0% common alleles and 51.7-60.4% common genotypes. Pandas in the smaller populations of Qinling and Liangshan were more similarly to each other than pandas in the larger populations of Qionglai and Minshan according to three genomic similarity measures. Panda genetic differentiation between these habitats was positively related to their geographical distances. Most pandas separated by 200 kilometers or more shared no common ancestral alleles. The results provided a genomic quantification of the actual levels of inbreeding and relatedness among pandas in their natural habitats, provided genomic confirmation of the relationship between genetic diversity and geographical distances, and provided genomic evidence to the urgency of habitat protection.

  8. Molecular genetic analysis of stomach contents reveals wild Atlantic cod feeding on piscine reovirus (PRV infected Atlantic salmon originating from a commercial fish farm.

    Directory of Open Access Journals (Sweden)

    Kevin Alan Glover

    Full Text Available In March 2012, fishermen operating in a fjord in Northern Norway reported catching Atlantic cod, a native fish forming an economically important marine fishery in this region, with unusual prey in their stomachs. It was speculated that these could be Atlantic salmon, which is not typical prey for cod at this time of the year in the coastal zone. These observations were therefore reported to the Norwegian Directorate of Fisheries as a suspected interaction between a local fish farm and this commercial fishery. Statistical analyses of genetic data from 17 microsatellite markers genotyped on 36 partially-degraded prey, samples of salmon from a local fish farm, and samples from the nearest wild population permitted the following conclusions: 1. The prey were Atlantic salmon, 2. These salmon did not originate from the local wild population, and 3. The local farm was the most probable source of these prey. Additional tests demonstrated that 21 of the 36 prey were infected with piscine reovirus. While the potential link between piscine reovirus and the disease heart and skeletal muscle inflammation is still under scientific debate, this disease had caused mortality of large numbers of salmon in the farm in the month prior to the fishermen's observations. These analyses provide new insights into interactions between domesticated and wild fish.

  9. Molecular genetic analysis of stomach contents reveals wild Atlantic cod feeding on piscine reovirus (PRV) infected Atlantic salmon originating from a commercial fish farm.

    Science.gov (United States)

    Glover, Kevin Alan; Sørvik, Anne Grete Eide; Karlsbakk, Egil; Zhang, Zhiwei; Skaala, Øystein

    2013-01-01

    In March 2012, fishermen operating in a fjord in Northern Norway reported catching Atlantic cod, a native fish forming an economically important marine fishery in this region, with unusual prey in their stomachs. It was speculated that these could be Atlantic salmon, which is not typical prey for cod at this time of the year in the coastal zone. These observations were therefore reported to the Norwegian Directorate of Fisheries as a suspected interaction between a local fish farm and this commercial fishery. Statistical analyses of genetic data from 17 microsatellite markers genotyped on 36 partially-degraded prey, samples of salmon from a local fish farm, and samples from the nearest wild population permitted the following conclusions: 1. The prey were Atlantic salmon, 2. These salmon did not originate from the local wild population, and 3. The local farm was the most probable source of these prey. Additional tests demonstrated that 21 of the 36 prey were infected with piscine reovirus. While the potential link between piscine reovirus and the disease heart and skeletal muscle inflammation is still under scientific debate, this disease had caused mortality of large numbers of salmon in the farm in the month prior to the fishermen's observations. These analyses provide new insights into interactions between domesticated and wild fish.

  10. Molecular Genetic Analysis of Stomach Contents Reveals Wild Atlantic Cod Feeding on Piscine Reovirus (PRV) Infected Atlantic Salmon Originating from a Commercial Fish Farm

    Science.gov (United States)

    Glover, Kevin Alan; Sørvik, Anne Grete Eide; Karlsbakk, Egil; Zhang, Zhiwei; Skaala, Øystein

    2013-01-01

    In March 2012, fishermen operating in a fjord in Northern Norway reported catching Atlantic cod, a native fish forming an economically important marine fishery in this region, with unusual prey in their stomachs. It was speculated that these could be Atlantic salmon, which is not typical prey for cod at this time of the year in the coastal zone. These observations were therefore reported to the Norwegian Directorate of Fisheries as a suspected interaction between a local fish farm and this commercial fishery. Statistical analyses of genetic data from 17 microsatellite markers genotyped on 36 partially-degraded prey, samples of salmon from a local fish farm, and samples from the nearest wild population permitted the following conclusions: 1. The prey were Atlantic salmon, 2. These salmon did not originate from the local wild population, and 3. The local farm was the most probable source of these prey. Additional tests demonstrated that 21 of the 36 prey were infected with piscine reovirus. While the potential link between piscine reovirus and the disease heart and skeletal muscle inflammation is still under scientific debate, this disease had caused mortality of large numbers of salmon in the farm in the month prior to the fishermen's observations. These analyses provide new insights into interactions between domesticated and wild fish. PMID:23620726

  11. Parasite infection and immune and health-state in wild fish exposed to marine pollution.

    Science.gov (United States)

    Sueiro, María Cruz; Bagnato, Estefanía; Palacios, María Gabriela

    2017-06-15

    Association between parasitism and immunity and health-state was investigated in wild Sebastes oculatus after having determined that pollution exposure is associated with altered immune and health-state parameters. Given the importance of the immune system in antiparasite defense we predicted: (i) parasite infection would be higher in pollution-exposed than in control fish and (ii) fish with lower immune and health-state parameters would show higher parasitism than fish in better condition. Metazoan parasite fauna was compared between pollution-exposed and non-exposed fish and parasitic indices were correlated with integrated measures of immunity and health-state. Results provided little support for the predictions; some parasite taxa increased, some decreased, and some were not affected in pollution-exposed fish despite their altered health and immunity. Furthermore, there was no link between individual immune and health-state parameters and parasitism. These findings highlight the complexity of host-parasite-environment interactions in relation to pollution in natural marine ecosystems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Potential risks of natural mercury levels to wild predator fish in an Amazon reservoir.

    Science.gov (United States)

    da Silva, Grazyelle Sebrenski; Filipak Neto, Francisco; Silva de Assis, Helena Cristina; Bastos, Wanderley Rodrigues; de Oliveira Ribeiro, Ciro Alberto

    2012-08-01

    Mercury (Hg) is a toxic metal that bioaccumulates in aquatic organisms and along food chain. Many studies have reported the problem of mercury exposure in aquatic systems from Amazon basin, but very few have focused on the potential risks to wild fish. The present study reports the bioaccumulation of mercury and alterations in target organs of the predator fish Hoplias malabaricus (traíra) from Samuel reservoir, Amazon basin, Northern Brazil. About 18% of fish had mercury levels in muscle exceeding the safe limit for ingestion through food, established by WHO (0.5 μg Hg g(-1)). Fish were separated in two groups according to mercury bioaccumulation in liver (0.2 μg Hg g(-1)-group II) for biomarker comparisons. Catalase activity and number of macrophage centers were statistically higher in group II, confirming the potential of Hg to interfere with redox balance and to recruit defense cells to the liver. Conversely, erythrocyte nuclear alterations were less frequent in group II, indicating a more rigorous selection of erythrocytes or hormesis pattern of response. Glutathione S-transferase activity, lipid peroxidation, and histopathological analyses were not statistically different in the liver and gills of both groups. Comparison of lipid peroxidation levels of these fish with others captured in Southern Brazil during another study and the high incidence of morphological alterations in the liver and gills suggest that the bioaccumulation of mercury during continuous exposure is posing potential risks to the species.

  13. On the dynamics of exploited fish populations

    National Research Council Canada - National Science Library

    Beverton, R. J. H; Holt, Sidney J

    1993-01-01

    ...-brooding cichlids, and viviparity in many sharks and toothcarps. Moreover, fish are of considerable importance to the survival of the human species in the form of nutritious, delicious and diverse food. Rational exploitation and management of our global stocks of fishes must rely upon a detailed and precise insight of their biology. The...

  14. Quantifying relative fishing impact on fish populations based on spatio-temporal overlap of fishing effort and stock density

    DEFF Research Database (Denmark)

    Vinther, Morten; Eero, Margit

    2013-01-01

    Evaluations of the effects of management measures on fish populations are usually based on the analyses of population dynamics and estimates of fishing mortality from stock assessments. However, this approach may not be applicable in all cases, in particular for data-limited stocks, which may...... GAM analyses to predict local cod densities and combine this with spatio-temporal data of fishing effort based on VMS (Vessel Monitoring System). To quantify local fishing impact on the stock, retention probability of the gears is taken into account. The results indicate a substantial decline...

  15. Inbreeding depression across the lifespan in a wild mammal population.

    Science.gov (United States)

    Huisman, Jisca; Kruuk, Loeske E B; Ellis, Philip A; Clutton-Brock, Tim; Pemberton, Josephine M

    2016-03-29

    Inbreeding depression is of major concern for the conservation of threatened species, and inbreeding avoidance is thought to be a key driver in the evolution of mating systems. However, the estimation of individual inbreeding coefficients in natural populations has been challenging, and, consequently, the full effect of inbreeding on fitness remains unclear. Genomic inbreeding coefficients may resolve the long-standing paucity of data on inbreeding depression in adult traits and total fitness. Here we investigate inbreeding depression in a range of life history traits and fitness in a wild population of red deer (Cervus elaphus) in Scotland using individual inbreeding coefficients derived from dense Single-Nucleotide Polymorphism (SNP) data (Fgrm). We find associations between[Formula: see text]and annual breeding success in both sexes, and between maternal inbreeding coefficient and offspring survival. We also confirm previous findings of inbreeding depression in birth weight and juvenile survival. In contrast, inbreeding coefficients calculated from a deep and comparatively complete pedigree detected inbreeding depression in juvenile survival, but not in any adult fitness component. The total effect of inbreeding on lifetime breeding success (LBS) was substantial in both sexes: for Fgrm = 0.125, a value resulting from a half-sib mating, LBS declined by 72% for females and 95% for males. Our results demonstrate that SNP-based estimates of inbreeding provide a powerful tool for evaluating inbreeding depression in natural populations, and suggest that, to date, the prevalence of inbreeding depression in adult traits may have been underestimated.

  16. Morphological distinctness despite large-scale phenotypic plasticity—analysis of wild and pond-bred juveniles of allopatric populations of Tropheus moorii

    Science.gov (United States)

    Kerschbaumer, Michaela; Postl, Lisbeth; Koch, Martin; Wiedl, Thomas; Sturmbauer, Christian

    2011-02-01

    Cichlids are an excellent model to study explosive speciation and adaptive radiation. Their evolutionary success has been attributed to their ability to undergo rapid morphological changes related to diet, and their particular breeding biology. Relatively minor changes in morphology allow for exploitation of novel food resources. The importance of phenotypic plasticity and genetically based differences for diversification was long recognized, but their relationship and relative magnitude remained unclear. We compared morphology of individuals of four wild populations of the Lake Tanganyika cichlid Tropheus moorii with their pond-raised F1 offspring. The magnitude of morphological change via phenotypic plasticity between wild and pond-bred F1 fish exceeds pairwise population differences by a factor of 2.4 (mean Mahalanobis distances). The genetic and environmental effects responsible for among population differentiation in the wild could still be recognized in the pond-bred F1 fish. All four pond populations showed the same trends in morphological change, mainly in mouth orientation, size and orientation of fins, and thickness of the caudal peduncle. As between population differentiation was lower in the wild than differentiation between pond-raised versus wild fish, we suggest the narrow ecological niche and intense interspecific competition in rock habitats is responsible for consistent shape similarity, even among long-term isolated populations.

  17. Population genetics and disease ecology of European wild boar

    NARCIS (Netherlands)

    Goedbloed, D.J.

    2013-01-01

    Welke factoren beïnvloeden de frequentie van de ziekten in wilde populaties? Het promotieonderzoek van Daniel Goedbloed beoordeelde de invloed van demografische, genetische en omgevingsfactoren op de frequentie van twee infectieziekten in Noordwest-Europese wilde zwijnen populaties.

  18. Hybrids between cultivated and wild carrots in natural populations in Denmark.

    Science.gov (United States)

    Magnussen, L S; Hauser, T P

    2007-08-01

    Many cultivated plant species are able to hybridize with related wild plants. However, it is not clear whether their hybrids are able to survive and reproduce outside managed fields, and if cultivar genes introgress into wild populations. In areas where wild carrots co-occur with carrot root-crops, pollen and seeds may flow from two different sources in the fields to the surrounding wild populations: from pure cultivar plants that occasionally flower, and from flowering 'bolters' that originate from hybridizations between wild (male) and cultivated carrots (female) in seed production fields in warmer regions of the world. To test whether hybrids are formed and survive in wild Danish populations, and whether prolonged hybridization has led to introgression of cultivar genes, we collected leaf material from adult individuals growing close to carrot fields and analysed their genotypic composition by AFLP. Four hybrids were identified among the 71 plants analysed, and these were most likely F(2) or backcross individuals, sired by pollen from hybrid bolters. Wild populations close to fields were genetically somewhat more similar to cultivars than wild populations far from fields, suggesting that neutral or beneficial cultivar alleles can introgress into the wild gene pool. Despite generations of improvement and adaptation of cultivar carrots to highly managed field conditions, hybrids can thus sometimes survive in wild populations close to carrot fields, and their genes transfer to wild populations by introgression.

  19. Phenotypic and genotypic heterogeneity among Streptococcus iniae isolates recovered from cultured and wild fish in North America, Central America and the Caribbean Islands

    Science.gov (United States)

    Streptococcus iniae, the etiological agent of streptococcosis in fish, is an important pathogen of cultured and wild fish worldwide. During the last decade outbreaks of streptococcosis have occurred in a wide range of cultured and wild fish in the Americas and Caribbean islands. To gain a better und...

  20. Resolving the effect of climate change on fish populations

    NARCIS (Netherlands)

    Rijnsdorp, A.D.; Peck, M.A.; Engelhard, G.H.; Moellmann, C.; Pinnegar, J.K.

    2009-01-01

    This paper develops a framework for the study of climate on fish populations based on first principles of physiology, ecology, and available observations. Environmental variables and oceanographic features that are relevant to fish and that are likely to be affected by climate change are reviewed.

  1. The presence of Bt-transgenic oilseed rape in wild mustard populations affects plant growth.

    Science.gov (United States)

    Liu, Yongbo; Stewart, C Neal; Li, Junsheng; Huang, Hai; Zhang, Xitao

    2015-12-01

    The adventitious presence of transgenic plants in wild plant populations is of ecological and regulatory concern, but the consequences of adventitious presence are not well understood. Here, we introduced Bacillus thuringiensis Cry1Ac (Bt)-transgenic oilseed rape (Bt OSR, Brassica napus) with various frequencies into wild mustard (Brassica juncea) populations. We sought to better understand the adventitious presence of this transgenic insecticidal crop in a wild-relative plant population. We assessed the factors of competition, resource availability and diamondback moth (Plutella xylostella) infestation on plant population dynamics. As expected, Bt OSR performed better than wild mustard in mixed populations under herbivore attack in habitats with enough resources, whereas wild mustard had higher fitness when Bt OSR was rarer in habitats with limited resources. Results suggest that the presence of insect-resistant transgenic plants could decrease the growth of wild mustard and Bt OSR plants and their populations, especially under high herbivore pressure.

  2. US Fish and Wildlife American Woodcock Population Status, 2004

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Singing-ground and Wing-collection surveys were conducted to assess the population status of the American woodcock (Scolopax minor). Singing-ground Survey data...

  3. The Genetic Structure of Wild Orobanche cumana Wallr. (Orobanchaceae Populations in Eastern Bulgaria Reflects Introgressions from Weedy Populations

    Directory of Open Access Journals (Sweden)

    Rocío Pineda-Martos

    2014-01-01

    Full Text Available Orobanche cumana is a holoparasitic plant naturally distributed from central Asia to south-eastern Europe, where it parasitizes wild Asteraceae species. It is also an important parasitic weed of sunflower crops. The objective of this research was to investigate genetic diversity, population structure, and virulence on sunflower of O. cumana populations parasitizing wild plants in eastern Bulgaria. Fresh tissue of eight O. cumana populations and mature seeds of four of them were collected in situ on wild hosts. Genetic diversity and population structure were studied with SSR markers and compared to weedy populations. Two main gene pools were identified in Bulgarian populations, with most of the populations having intermediate characteristics. Cross-inoculation experiments revealed that O. cumana populations collected on wild species possessed similar ability to parasitize sunflower to those collected on sunflower. The results were explained on the basis of an effective genetic exchange between populations parasitizing sunflower crops and those parasitizing wild species. The occurrence of bidirectional gene flow may have an impact on wild populations, as new physiological races continuously emerge in weedy populations. Also, genetic variability of wild populations may favour the ability of weedy populations to overcome sunflower resistance mechanisms.

  4. First isolation of an aquatic birnavirus from farmed and wild fish species in Australia.

    Science.gov (United States)

    Crane, M S; Hardy-Smith, P; Williams, L M; Hyatt, A D; Eaton, L M; Gould, A; Handlinger, J; Kattenbelt, J; Gudkovs, N

    2000-10-25

    During routine sampling and testing, as part of a systematic surveillance program (the Tasmanian Salmonid Health Surveillance Program), an aquatic birnavirus was isolated from 'pin-head' (fish exhibiting deficient acclimatisation on transfer to saltwater) Atlantic salmon Salmo salar, approximately 18 mo old, farmed in net-pens located in Macquarie Harbour on the west coast of Tasmania, Australia. The isolate grows readily in a range of fish cell lines including CHSE-214, RTG-2 and BF-2 and is neutralised by a pan-specific rabbit antiserum raised against infectious pancreatic necrosis virus (IPNV) Ab strain and by a commercial pan-specific IPNV-neutralising monoclonal antibody. Presence of the virus was not associated with gross clinical signs. Histopathological examination revealed a range of lesions particularly in pancreatic tissue. The virus was localised in pancreas sections by immunoperoxidase staining using the polyclonal antiserum and by electron microscopy. Examination by electron microscopy demonstrated that the virus isolated in cell culture (1) belongs to the family Birnaviridae, genus Aquabirnaviridae; (2) was ultrastructurally and antigenically similar to virus identified in the index fish; (3) is related to IPNV. Western blot analysis using the polyclonal rabbit antiserum confirmed the cross-reactions between various aquatic birnavirus isolates. In addition, PCR analysis of isolated viral nucleic acid from the index case indicated that the virus is more closely related to IPNV fr21 and N1 isolates than to other birnavirus isolates available for comparison. Sampling of other fish species within Macquarie Harbour has demonstrated that the virus is present in several other species of fish including farmed rainbow trout Oncorhynchus mykiss, wild flounder Rhombosolea tapirina, cod Pseudophycis sp., spiked dogfish Squalus megalops and ling Genypterus blacodes.

  5. Parasitism of Argulus japonicus in cultured and wild fish of Guangdong, China with new record of three hosts.

    Science.gov (United States)

    Alsarakibi, Muhamd; Wadeh, Hicham; Li, Guoqing

    2014-02-01

    This study aimed to demonstrate the ability of Argulus japonicus to infect a wide range of freshwater fishes, as well as to understand the effects of fish origin and host body size on the incidence of A. japonicus. Samples of cultured and wild fish were collected randomly from July 2010 to March 2013, using angling, long-lining, gill-netting, and trapping from rivers and fish farms in Guangdong province, South China. Eight fish species were found to be heavily infected including the common carp, the goldfish, the black carp, the silver carp, the brown trout, the rainbow trout, the mandarin fish, and the perch. Furthermore, the black carp, the brown trout, and the mandarin fish were recorded as new hosts for the first time. During the present study, a total of 2,271 fishes were examined, out of which 712 fishes were found to be infected by a total of 1,443 A. japonicus. Abundance and intensity of A. japonicus infection were significantly influenced by origin of fishes (cultured and wild) and total length (class I, 350 mm) of fish species, whereas varied impacts on prevalence of infection were observed. The correlation between total length of fishes and prevalence of A. japonicus infection was variable, where no significant correlation was observed in the black carp, the silver carp, the mandarin fish, and the perch. In spite of the weak negative correlation between body size of the silver carp and prevalence of infection, A. japonicus was the most abundant and intensive in the silver carp. Thus, aquaculturists should pay particular attention to the control of these fish lice due to its host biodiversity.

  6. Fish population dynamics in a seasonally varying wetland

    Science.gov (United States)

    DeAngelis, Donald L.; Trexler, Joel C.; Cosner, Chris; Obaza, Adam; Jopp, Fred

    2010-01-01

    Small fishes in seasonally flooded environments such as the Everglades are capable of spreading into newly flooded areas and building up substantial biomass. Passive drift cannot account for the rapidity of observed population expansions. To test the reaction-diffusion mechanism for spread of the fish, we estimated their diffusion coefficient and applied a reaction-diffusion model. This mechanism was also too weak to account for the spatial dynamics. Two other hypotheses were tested through modeling. The first--the 'refuge mechanism--hypothesizes that small remnant populations of small fishes survive the dry season in small permanent bodies of water (refugia), sites where the water level is otherwise below the surface. The second mechanism, which we call the 'dynamic ideal free distribution mechanism' is that consumption by the fish creates a prey density gradient and that fish taxis along this gradient can lead to rapid population expansion in space. We examined the two alternatives and concluded that although refugia may play an important role in recolonization by the fish population during reflooding, only the second, taxis in the direction of the flooding front, seems capable of matching empirical observations. This study has important implications for management of wetlands, as fish biomass is an essential support of higher trophic levels.

  7. FISH POPULATIONS OF THE POŽARNA RIVER

    Directory of Open Access Journals (Sweden)

    Enad Korjenić

    2013-10-01

    Full Text Available Ichthyofaunal research of the river Požarna was conducted during two seasons in the year 2006. The fish was caught with standard fish catching tools. On the field, the collected material was stored into 4% formaldehyde solution, and relocated in a laboratory for further analysis. Biosystematic determination of the caught fish was performed according to Vuković (15. The analysis of the total representative sample showed that the respective area was populated by the three species of fishes from the three different families. Specified were the River Trout - Salmo trutta m. fario (Linnaeus, 1758 from the Salmonidae family, Thymallus thymallus (Linnaeus, 1758 from the Thymallidae family. The Cottidae family was represented with Cottus gobio (Linnaeus, 1758. All three fish species were recorded in both sesons in the research area. Salmo trutta m. fario had the largest population size (91 or 68,42% of all caught fish. Such population size was also reflected in the contribution to the ichthyomass of 4.44 g or 78,46%. Key words: fish population, Požarna river

  8. Identification of learning mechanisms in a wild meerkat population.

    Directory of Open Access Journals (Sweden)

    Will Hoppitt

    Full Text Available Vigorous debates as to the evolutionary origins of culture remain unresolved due to an absence of methods for identifying learning mechanisms in natural populations. While laboratory experiments on captive animals have revealed evidence for a number of mechanisms, these may not necessarily reflect the processes typically operating in nature. We developed a novel method that allows social and asocial learning mechanisms to be determined in animal groups from the patterns of interaction with, and solving of, a task. We deployed it to analyse learning in groups of wild meerkats (Suricata suricatta presented with a novel foraging apparatus. We identify nine separate learning processes underlying the meerkats' foraging behaviour, in each case precisely quantifying their strength and duration, including local enhancement, emulation, and a hitherto unrecognized form of social learning, which we term 'observational perseverance'. Our analysis suggests a key factor underlying the stability of behavioural traditions is a high ratio of specific to generalized social learning effects. The approach has widespread potential as an ecologically valid tool to investigate learning mechanisms in natural groups of animals, including humans.

  9. Addressing wild turkey population declines using structured decision making

    Science.gov (United States)

    Robinson, Kelly F.; Fuller, Angela K.; Schiavone, Michael V.; Swift, Bryan L.; Diefenbach, Duane R.; Siemer, William F.; Decker, Daniel J.

    2017-01-01

    We present a case study from New York, USA, of the use of structured decision making (SDM) to identify fall turkey harvest regulations that best meet stakeholder objectives, in light of recent apparent declines in abundance of wild turkeys in the northeastern United States. We used the SDM framework to incorporate the multiple objectives associated with turkey hunting, stakeholder desires, and region-specific ecological and environmental factors that could influence fall harvest. We identified a set of 4 fall harvest regulations, composed of different season lengths and bag limits, and evaluated their relative achievement of the objectives. We used a stochastic turkey population model, statistical modeling, and expert elicitation to evaluate the consequences of each harvest regulation on each of the objectives. We conducted a statewide mail survey of fall turkey hunters in New York to gather the necessary information to evaluate tradeoffs among multiple objectives associated with hunter satisfaction. The optimal fall harvest regulation was a 2-week season and allowed for the harvest of 1 bird/hunter. This regulation was the most conservative of those evaluated, reflecting the concerns about recent declines in turkey abundance among agency wildlife biologists and the hunting public. Depending on the region of the state, the 2-week, 1-bird regulation was predicted to result in 7–32% more turkeys on the landscape after 5 years. The SDM process provided a transparent framework for setting fall turkey harvest regulations and reduced potential stakeholder conflict by explicitly taking the multiple objectives of different stakeholder groups into account.

  10. Identification of learning mechanisms in a wild meerkat population.

    Science.gov (United States)

    Hoppitt, Will; Samson, Jamie; Laland, Kevin N; Thornton, Alex

    2012-01-01

    Vigorous debates as to the evolutionary origins of culture remain unresolved due to an absence of methods for identifying learning mechanisms in natural populations. While laboratory experiments on captive animals have revealed evidence for a number of mechanisms, these may not necessarily reflect the processes typically operating in nature. We developed a novel method that allows social and asocial learning mechanisms to be determined in animal groups from the patterns of interaction with, and solving of, a task. We deployed it to analyse learning in groups of wild meerkats (Suricata suricatta) presented with a novel foraging apparatus. We identify nine separate learning processes underlying the meerkats' foraging behaviour, in each case precisely quantifying their strength and duration, including local enhancement, emulation, and a hitherto unrecognized form of social learning, which we term 'observational perseverance'. Our analysis suggests a key factor underlying the stability of behavioural traditions is a high ratio of specific to generalized social learning effects. The approach has widespread potential as an ecologically valid tool to investigate learning mechanisms in natural groups of animals, including humans.

  11. Population structure of the wild soybean (Glycine soja) in China: implications from microsatellite analyses.

    Science.gov (United States)

    Guo, Juan; Liu, Yifei; Wang, Yunsheng; Chen, Jianjun; Li, Yinghui; Huang, Hongwen; Qiu, Lijuan; Wang, Ying

    2012-09-01

    Wild soybean (Glycine soja), a native species of East Asia, is the closest wild relative of the cultivated soybean (G. max) and supplies valuable genetic resources for cultivar breeding. Analyses of the genetic variation and population structure of wild soybean are fundamental for effective conservation studies and utilization of this valuable genetic resource. In this study, 40 wild soybean populations from China were genotyped with 20 microsatellites to investigate the natural population structure and genetic diversity. These results were integrated with previous microsatellite analyses for 231 representative individuals from East Asia to investigate the genetic relationships of wild soybeans from China. Analysis of molecular variance (AMOVA) revealed that 43·92 % of the molecular variance occurred within populations, although relatively low genetic diversity was detected for natural wild soybean populations. Most of the populations exhibited significant effects of a genetic bottleneck. Principal co-ordinate analysis, construction of a Neighbor-Joining tree and Bayesian clustering indicated two main genotypic clusters of wild soybean from China. The wild soybean populations, which are distributed in north-east and south China, separated by the Huang-Huai Valley, displayed similar genotypes, whereas those populations from the Huang-Huai Valley were different. The previously unknown population structure of the natural populations of wild soybean distributed throughout China was determined. Two evolutionarily significant units were defined and further analysed by combining genetic diversity and structure analyses from Chinese populations with representative samples from Eastern Asia. The study suggests that during the glacial period there may have been an expansion route between south-east and north-east China, via the temperate forests in the East China Sea Land Bridge, which resulted in similar genotypes of wild soybean populations from these regions. Genetic

  12. Metal concentrations and pathological responses of wild native fish exposed to sewage discharge in a Mediterranean river

    Energy Technology Data Exchange (ETDEWEB)

    Maceda-Veiga, Alberto, E-mail: albertomaceda@gmail.com [Department of Animal Biology (Vertebrates) and Biodiversity Research Institute (IRBio), University of Barcelona, E-08028 Barcelona (Spain); Monroy, Mario; Navarro, Elisenda [Department of Animal Biology (Vertebrates) and Biodiversity Research Institute (IRBio), University of Barcelona, E-08028 Barcelona (Spain); Viscor, Ginés [Department of Animal Physiology (Faculty of Biology), University of Barcelona, E-08028 Barcelona (Spain); Sostoa, Adolfo de [Department of Animal Biology (Vertebrates) and Biodiversity Research Institute (IRBio), University of Barcelona, E-08028 Barcelona (Spain)

    2013-04-01

    sensitive and useful non-lethal diagnostic tool in wild fish populations. Highlights: ► Lethal and non-lethal diagnostic tools were employed to determine the health status of two fish species. ► Squalius laietanus appeared to have fewer pathological responses than B. meridionalis. ► Barbus meridionalis was the best sentinel species for the metals determined. ► Haematological variables become putative good diagnostic tools for these species.

  13. Waste feed from coastal fish farms: A trophic subsidy with compositional side-effects for wild gadoids

    Science.gov (United States)

    Fernandez-Jover, Damian; Martinez-Rubio, Laura; Sanchez-Jerez, Pablo; Bayle-Sempere, Just T.; Lopez Jimenez, Jose Angel; Martínez Lopez, Francisco Javier; Bjørn, Pål-Arne; Uglem, Ingebrigt; Dempster, Tim

    2011-03-01

    Aquaculture of carnivorous fish species in sea-cages typically uses artificial feeds, with a proportion of these feeds lost to the surrounding environment. This lost resource may provide a trophic subsidy to wild fish in the vicinity of fish farms, yet the physiological consequences of the consumption of waste feed by wild fish remain unclear. In two regions in Norway with intensive aquaculture, we tested whether wild saithe ( Pollachius virens) and Atlantic cod ( Gadus morhua) associated with fish farms (F assoc), where waste feed is readily available, had modified diets, condition and fatty acid (FA) compositions in their muscle and liver tissues compared to fish unassociated (UA) with farms. Stomach content analyses revealed that both cod and saithe consumed waste feed in the vicinity of farms (6-96% of their diet was composed of food pellets). This translated into elevated body and liver condition compared to fish caught distant from farms for cod at both locations and elevated body condition for saithe at one of the locations. As a consequence of a modified diet, we detected significantly increased concentrations of terrestrial-derived fatty acids (FAs) such as linoleic (18:2ω6) and oleic (18:1ω9) acids and decreased concentrations of DHA (22:6ω3) in the muscle and/or liver of F assoc cod and saithe when compared with UA fish. In addition, the ω3:ω6 ratio clearly differed between F assoc and UA fish. Linear discriminant analysis (LDA) correctly classified 97% of fish into F assoc or UA origin for both cod and saithe based on the FA composition of liver tissues, and 89% of cod and 86% of saithe into F assoc or UA origin based on the FA composition of muscle. Thus, LDA appears a useful tool for detecting the influence of fish farms on the FA composition of wild fish. Ready availability of waste feed with high protein and fat content provides a clear trophic subsidy to wild fish in coastal waters, yet whether the accompanying side-effect of altered fatty

  14. Total lipids and fatty acid profile in the liver of wild and farmed Catla catla fish

    Directory of Open Access Journals (Sweden)

    Hussain, Bilal

    2010-03-01

    Full Text Available This experimental work was aimed to study the moisture content, total lipids and fatty acid profile in the liver of wild and farmed freshwater major carp Catla catla of three different weight categories designated as W1 (601-900g, W2 (901- 1200g and W3 (1201-1500g. Seven fish specimens of each of the three weight categories of wild and farmed Catla catla were obtained from Trimu Head, Jhang and Fish Hatchery, Satiana Road and Faisalabad, respectively. The fish were dissected to remove the liver and after weighing, liver samples were prepared and subjected to chemical analysis. Wild Catla catla liver had a significantly (p Catla catla deposited significantly (p Catla catla. Saturated fatty acids C12:0, C14:0, C16:0, C18:0, C20:0 and C22:0 were identified with considerable percentages in the liver of Catla catla from both habitats and monounsaturated fatty acid C18:1 was found in considerable amounts in the liver of both major carp. Polyunsaturated fatty acids such as C18:3 (n-6 and C20: 2 (n-6 were detected in the liver of the wild fish of W2 and W3 and was similar in the W3 weight category of the farmed species.Este trabajo experimental tiene como objetivo estudiar el contenido de humedad, lípidos totales y perfil de ácidos grasos de hígado de carpa de agua dulce Catla catla de tres categorías con peso diferentes designadas como W1 (601- 900g, W2 (901-1200g and W3 (1201-1500g. Siete muestras de pescados por cada una de las tres categorías de peso para Catla catla salvajes y criados fueron obtenidos de Trimu Head, Jhang and Fish Hatchery, Satiana Road y Faisalabad, respectivamente. Los pescados fueron diseccionados para obtener el hígado y las muestras de hígado fueron preparadas y sujetas a análisis químico. Catla catla salvaje tuvo un contenido de humedad significativamente mayor (p Catla catla criadas se depositaron mayores contenidos de lípidos en el hígado. La proporción de ácidos grasos saturados vario irregularmente en los l

  15. Influence of age and rearing conditions of a fish on the chance to survive in the wild

    OpenAIRE

    Lyach, Roman

    2011-01-01

    The task of this thesis is to summarize all the most important biotic and abiotic factors that can influence chances of reared fish to survive in the wild. It contains some of the most frequently reared and popular fishes, such as Sander lucioperca (pike perch), Samo trutta (trout), Micropterus salmoides (largemouth bass), Esox lucius (northern pike), Esox masquinongy (muskellunge) and the hybrid of northern pike and muskellunge, the tiger muskellunge. Mainly the factors such as success, surv...

  16. Hybrids between cultivated and wild carrots in natural populations in Denmark

    DEFF Research Database (Denmark)

    Magnussen, L.S.; Hauser, Thure Pavlo

    2007-01-01

    in warmer regions of the world. To test whether hybrids are formed and survive in wild Danish populations, and whether prolonged hybridization has led to introgression of cultivar genes, we collected leaf material from adult individuals growing close to carrot fields and analysed their genotypic composition......Many cultivated plant species are able to hybridize with related wild plants. However, it is not clear whether their hybrids are able to survive and reproduce outside managed fields, and if cultivar genes introgress into wild populations. In areas where wild carrots co-occur with carrot root......-crops, pollen and seeds may flow from two different sources in the fields to the surrounding wild populations: from pure cultivar plants that occasionally flower, and from flowering 'bolters' that originate from hybridizations between wild (male) and cultivated carrots (female) in seed production fields...

  17. Developing a size indicator for fish populations

    Directory of Open Access Journals (Sweden)

    Yong Chen

    2008-06-01

    Full Text Available Monitoring temporal and/or spatial variations in fish size-at-age data can often provide fisheries managers with important information about the status of fish stocks and therefore help them identify necessary changes in management policies. However, due to the multivariate nature of size-at-age data, commonly used single-age-based approaches ignore covariance between sizes of different age groups. Different results may therefore be derived when evaluating temporal variations using different age groups for the comparison. The possibility of atypical errors in size-at-age data due to ageing and measurement errors further complicates the comparison. We propose a two-step approach for developing an indicator for monitoring temporal and/or spatial variation in size-at-age data. A robust approach, minimum volume ellipsoid analysis, is used to identify possible outliers in size-at-age data. Then a weighted principal component analysis is applied to the data with the identified outliers down-weighted. An indicator is defined from the resultant principal components for monitoring temporal/spatial variations in size-at-age data. We illustrate the proposed approach with size-at-age data for cod (Gadus morhua in the northwest Atlantic, NAFO subdivision 3Ps. The overall size-at-age indicator identified shows that the pre-1980 year classes tend to have a much higher size-at-age than the post-1980 year classes.

  18. Infections of nervous necrosis virus in wild and cage-reared marine fish from South China Sea with unexpected wide host ranges.

    Science.gov (United States)

    Liu, X D; Huang, J N; Weng, S P; Hu, X Q; Chen, W J; Qin, Z D; Dong, X X; Liu, X L; Zhou, Y; Asim, M; Wang, W M; He, J G; Lin, L

    2015-06-01

    The concerns about the impact of the nervous necrosis virus (NNV) infections in wild fish have been raised. This paper presents the results of quarterly surveys of NNV in wild and cage-reared marine fish from South China Sea. Samples of 892 wild fish belonging to 69 species and 381 cage-reared fish belonging to 11 species were collected and were detected by seminested PCR and nested PCR. In the case of seminested PCR, the positive signal was detected in 3.0% and 3.1% samples of wild and cage-reared fish, respectively. However, by nested RT-PCR, the positive signal was observed in 42.3% and 63.0% samples of wild and cage-reared fish, respectively. If the fish species were considered, the positive signal was detected in 21.7% and 72.7% species of wild and cage-reared fish by seminested PCR assay, respectively. However, by nested RT-PCR, the positive signal was observed in 65.2% and 100% species of wild and cage-reared fish, respectively. The nucleotide sequences of the nested PCR products were determined. Phylogenetic tree showed that all the obtained viral isolates belonged to the red-spotted grouper nervous necrosis virus (RGNNV) genotype. Thirty-five species of the marine fish were the new hosts of NNV. © 2014 John Wiley & Sons Ltd.

  19. Natural Chemical Composition of Commercial Fish Species: Characterisation of Pangasius, Wild and Farmed Turbot and Barramundi

    Directory of Open Access Journals (Sweden)

    Monika Manthey-Karl

    2016-08-01

    Full Text Available To comply with the relevant legal requirements and correct labelling, it is necessary for business operators and inspection authorities to know the natural characteristics of the raw material. This study gives a comprehensive overview of muscle flesh composition of farmed and wild Atlantic turbot (Scophthalmus maximus and barramundi (Lates calcarifer and of farmed pangasius (Pangasianodon hypophthalmus. The proximate composition, di- and triphosphates and citric acid values are presented in order to evaluate possible indicators for a hidden treatment during processing to fillets. All moisture contents were ≤80%. Even for pangasius, protein values for deep skinned fillets of ≥18% were determined. Only small quantities of naturally occurring citric acid (up to 0.03 g·kg−1 were detectable. The lipid content was the most varying main component within the different species, ranging between 1.2% to 2.0% and 0.3% to 3.0% for farmed turbot and barramundi, respectively. Pangasius flesh had a mean lipid content of 7.8%. Trimming and separation of the red layer reduced the lipid content of the commercially sold white-flesh fillets to 2.7% to 3.5%. Fatty acids profiles, free amino acids, and minerals were analysed to show the nutritional quality of the aquaculture fish species and compared to wild turbot and barramundi. Despite some natural variation, these components can be considered as comparable.

  20. Natural Chemical Composition of Commercial Fish Species: Characterisation of Pangasius, Wild and Farmed Turbot and Barramundi

    Science.gov (United States)

    Manthey-Karl, Monika; Lehmann, Ines; Ostermeyer, Ute; Schröder, Ute

    2016-01-01

    To comply with the relevant legal requirements and correct labelling, it is necessary for business operators and inspection authorities to know the natural characteristics of the raw material. This study gives a comprehensive overview of muscle flesh composition of farmed and wild Atlantic turbot (Scophthalmus maximus) and barramundi (Lates calcarifer) and of farmed pangasius (Pangasianodon hypophthalmus). The proximate composition, di- and triphosphates and citric acid values are presented in order to evaluate possible indicators for a hidden treatment during processing to fillets. All moisture contents were ≤80%. Even for pangasius, protein values for deep skinned fillets of ≥18% were determined. Only small quantities of naturally occurring citric acid (up to 0.03 g·kg−1) were detectable. The lipid content was the most varying main component within the different species, ranging between 1.2% to 2.0% and 0.3% to 3.0% for farmed turbot and barramundi, respectively. Pangasius flesh had a mean lipid content of 7.8%. Trimming and separation of the red layer reduced the lipid content of the commercially sold white-flesh fillets to 2.7% to 3.5%. Fatty acids profiles, free amino acids, and minerals were analysed to show the nutritional quality of the aquaculture fish species and compared to wild turbot and barramundi. Despite some natural variation, these components can be considered as comparable. PMID:28231154

  1. IMPLEMENTATION OF WAVELETS TO DETECTION OF FISH POPULATION

    Directory of Open Access Journals (Sweden)

    Yasemin KAHRAMANER

    2013-01-01

    Full Text Available The influence of climatic oscillations (based on NAO and ENSO on monthly catch rates of fish population such as blue fish and sea bass (pomatomus population between 1991-2008 were analyzed in Black Sea and Marmara Sea by wavelet transform (Wavelet 1-D and continuous wavelet 1-D with DMeyer for 7-Levels. Wavelet analysis is an efficient method of time series analysis to study non-stationary data. Wavelet analyses allowed us to quantify both the pattern of variability in the time series and non-stationary associations between fish population and climatic signals. Phase analyses were carried out to investigate dependency between the two signals. We reported strong relations between fish stock and climate series for the 4- and 5-yr periodic modes, i.e. the periodic band of the El Nino Southern Oscillation signal propagation in the Black and Marmara Seas. These associations were non-stationary, evidenced from 1995 to 2008. Warm episodes matched increases of longline catch rates of bigeye during the 1970-1990 time frames, whereas the strong 1997-1998 warm event matched a decrease of purse seine catch rates of yellowfin. We discussed these results in terms of changes in catchability for purse seine and longline. The results of this study were compared with former harmonic analyses to explain seasonal effects of NAO and ENSO on fish population.

  2. Fishborne trematodes in cultured Nile tilapia (Oreochromis niloticus) and wild-caught fish from Thailand

    DEFF Research Database (Denmark)

    Wiriya, Benjamaporn; Clausen, Jesper Hedegaard; Inpankaew, Tawin

    2013-01-01

    Fish-borne zoonotic trematode (FZT) infections affect the health of more than 18 million people around the world, particularly in Asian countries. Nile tilapia (Oreochromis niloticus) is a white meat fish that has an increasing national and international market. The objective of this study...... culture fish were 2.5% and 10% in pond culture fish. During the second sampling, metacercariae was found in 2.0% of tilapia from cage and none from the ponds. Of the 150 wild-caught fish, a total of 80 (53.3%) were found to be infected with metacercariae, mostly the zoonotic species Stellantchasmus...... for vigilance and good management practices by the aquaculture sector. Crown...

  3. Effects of fire on fish populations: Landscape perspectives on persistance of native fishes and nonnative fish invasions

    Science.gov (United States)

    Dunham, J.B.; Young, M.; Gresswell, Robert E.; Rieman, B.

    2003-01-01

    Our limited understanding of the short and long-term effects of fire on fish contributes to considerable uncertainty in assessments of the risks and benefits of fire management alternatives. A primary concern among the many potential effects of fire is the effects of fire and fire management on persistence of native fish populations. Limited evidence suggests vulnerability of fish to fire is contingent upon the quality of affected habitats, the amount and distribution of habitat (habitat fragmentation), and habitat specificity of the species in question. Species with narrow habitat requirements in highly degraded and fragmented systems are likely to be most vulnerable to fire and fire-related disturbance. In addition to effects of fire on native fish, there are growing concerns about the effects of fire on nonnative fish invasions. The role of fire in facilitating invasions by nonnative fishes is unknown, but experience with other species suggests some forms of disturbance associated with fire may facilitate invasion. Management efforts to promote persistence of fishes in fire-prone landscapes can take the form of four basic alternatives: (1) pre-fire management; (2) post-fire management; (3) managing fire itself (e.g. fire fighting); and (4) monitoring and adaptive management. Among these alternatives, pre-fire management is likely to be most effective. Effective pre-fire management activities will address factors that may render fish populations more vulnerable to the effects of fire (e.g. habitat degradation, fragmentation, and nonnative species). Post-fire management is also potentially important, but suffers from being a reactive approach that may not address threats in time to avert them. Managing fire itself can be important in some contexts, but negative consequences for fish populations are possible (e.g. toxicity of fire fighting chemicals to fish). Monitoring and adaptive management can provide important new information for evaluating alternatives, but

  4. Variation in otolith macrostructure of Japanese flounder ( Paralichthys olivaceus): A method to discriminate between wild and released fish

    Science.gov (United States)

    Katayama, S.; Isshiki, T.

    2007-02-01

    The main objective of this study was to develop a method to discriminate between wild and hatchery-produced Japanese flounder, Paralichthys olivaceus, based on variations in otolith macrostructure. Otoliths of wild flounder were more elliptical than those of hatchery-produced fish, whereas otolith area and marginal coarseness showed no clear differences. Otolith morphometry did not vary significantly with water temperature or feeding conditions in rearing experiments. Reduced ellipticity in the otoliths of hatchery-produced fish could be caused by biotic and abiotic conditions after release. Throughout the study, it was found that otoliths of Japanese flounder reared at 15 and 20 °C regimes showed opaque zones regardless of feeding condition, while otolith of fish reared at 25 °C had translucent zones. The potential of thermal marks and secondary zones as a new mass-marking system is presented.

  5. Spontaneous gene flow and population structure in wild and cultivated chicory, Cichorium intybus L

    DEFF Research Database (Denmark)

    Kiær, Lars Pødenphant; Felber, F.; Flavell, A.

    2009-01-01

    Spontaneous gene flow between wild and cultivated chicory, Cichorium intybus L., may have implications for the genetic structure and evolution of populations and varieties. One aspect of this crop-wild gene flow is the dispersal of transgenes from genetically modified varieties, e.g. gene flow from...... GM chicory to natural chicory could have unwanted consequences. With the purpose to identify and quantify crop-wild gene flow in chicory, we analysed introgression in 19 wild chicory populations and 16 accessions of chicory varieties and landraces distributed across Northern, Central...... and Mediterranean Europe. The analysis used 281 AFLP markers and 75 SSAP markers giving a total of 356 polymorphic markers. Results from model based assignments with the program STRUCTURE indicated many incidents of recent gene flow. Gene flow was observed both between cultivars and wild populations, between...

  6. Physiological response of wild rainbow trout to angling: Impact of angling duration, fish size, body condition, and temperature

    Science.gov (United States)

    Meka, Julie M.; McCormick, S.D.

    2005-01-01

    This study evaluated the immediate physiological response of wild rainbow trout to catch-and-release angling in the Alagnak River, southwest Alaska. Information was recorded on individual rainbow trout (n = 415) captured by angling including landing time and the time required to remove hooks (angling duration), the time to anesthetize fish in clove oil and withdraw blood, fish length and weight, and water temperature at capture locations. Plasma cortisol, glucose, ions (sodium, potassium, chloride), and lactate were analyzed to determine the effects of angling duration, fish size, body condition, and temperature. Levels of plasma ions did not change significantly during the observed physiological response and levels of plasma glucose were sometimes influenced by length (2000, 2001), body condition (2001), or temperature (2001). Levels of plasma cortisol and lactate in extended capture fish (angling duration greater than 2 min) were significantly higher than levels in rapid capture fish (angling duration less than 2 min). Rapid capture fish were significantly smaller than extended capture fish, reflecting that fish size influenced landing and handling times. Fish size was related to cortisol and lactate in 2002, which corresponded to the year when larger fish were captured and there were longer landing times. Body condition (i.e., weight/length regression residuals index), was significantly related to lactate in 2000 and 2001. Water temperatures were higher in 2001 (mean temperature ± S.E., 13 ± 2oC) than in 2002 (10 ± 2oC), and fish captured in 2001 had significantly higher cortisol and lactate concentrations than fish captured in 2002. The pattern of increase in plasma cortisol and lactate was due to the amount of time fish were angled, and the upper limit of the response was due to water temperature. The results of this study indicate the importance of minimizing the duration of angling in order to reduce the sublethal physiological disturbances in wild

  7. Spontaneous gene flow and population structure in wild and cultivated chicory, Cichorium intybus L.

    NARCIS (Netherlands)

    Kiaer, L.P.; Felber, F.; Flavell, A.; Guadagnuola, R.; Guiatti, D.; Hauser, T.P.; Olivieri, A.M.; Scotti, I.; Syed, N.; Vischi, M.; Wiel, van de C.C.M.; Jorgensen, R.B.

    2009-01-01

    Spontaneous gene flow between wild and cultivated chicory, Cichorium intybus L., may have implications for the genetic structure and evolution of populations and varieties. One aspect of this crop-wild gene flow is the dispersal of transgenes from genetically modified varieties, e.g. gene flow from

  8. Population growth in a wild bird is buffered against phenological mismatch

    NARCIS (Netherlands)

    Reed, T.; Grotan, V.; Jenouvrier, S.; Saether, B.E.; Visser, M.E.

    2013-01-01

    road-scale environmental changes are altering patterns of natural selection in the wild, but few empirical studies have quantified the demographic cost of sustained directional selection in response to these changes. We tested whether population growth in a wild bird is negatively affected by

  9. Effects of human population density and proximity to markets on coral reef fishes vulnerable to extinction by fishing.

    Science.gov (United States)

    Brewer, T D; Cinner, J E; Green, A; Pressey, R L

    2013-06-01

    Coral reef fisheries are crucial to the livelihoods of tens of millions of people; yet, widespread habitat degradation and unsustainable fishing are causing severe depletion of stocks of reef fish. Understanding how social and economic factors, such as human population density, access to external markets, and modernization interact with fishing and habitat degradation to affect fish stocks is vital to sustainable management of coral reef fisheries. We used fish survey data, national social and economic data, and path analyses to assess whether these factors explain variation in biomass of coral reef fishes among 25 sites in Solomon Islands. We categorized fishes into 3 groups on the basis of life-history characteristics associated with vulnerability to extinction by fishing (high, medium, and low vulnerability). The biomass of fish with low vulnerability was positively related to habitat condition. The biomass of fishes with high vulnerability was negatively related to fishing conducted with efficient gear. Use of efficient gear, in turn, was strongly and positively related to both population density and market proximity. This result suggests local population pressure and external markets have additive negative effects on vulnerable reef fish. Biomass of the fish of medium vulnerability was not explained by fishing intensity or habitat condition, which suggests these species may be relatively resilient to both habitat degradation and fishing. © 2012 Society for Conservation Biology.

  10. Association of health involvement and attitudes towards eating fish on farmed and wild fish consumption in Belgium, Norway and Spain

    NARCIS (Netherlands)

    Altintzoglou, T.; Vanhonacker, F.; Verbeke, W.; Luten, J.B.

    2011-01-01

    Consumers in many European countries do not equally meet the recommended daily intake levels for fish consumption. Various factors that can influence fish consumption behaviour have been identified but limited research has been performed on fish consumption behaviour, discriminating between farmed

  11. Population dynamics of the invasive fish, Gambusia affinis , in ...

    African Journals Online (AJOL)

    The alien invasive Gambusia affinis is one of the most widely introduced fish species on the planet, and has established in freshwater ecosystems across South Africa. The invasion ecology and, in particular, the population dynamics of the species in this country are, however, poorly understood. In this study the relative ...

  12. changes in population structures of the major fish species in ...

    African Journals Online (AJOL)

    of the intricacies within these isolated water bodies. The available data so far indicate that the fisheries within satellite lakes are declining (Katunzi and Msuku 2001,. Katunzi and Kishe 2002, Katunzi 2003) while little is known on the ecosystems and population structures. Heavy fishing pressure, free access to the fisheries,.

  13. Interactive Visualization of Video Data for Fish Population Monitoring

    NARCIS (Netherlands)

    E.M.A.L. Beauxis-Aussalet (Emmanuelle); L. Hardman (Lynda); D. van Leeuwen (Dennis); P.J. Stappers; M. H. Lamers; M.J.M.R. Thissen

    2014-01-01

    htmlabstractThe recent use of computer vision techniques for monitoring ecosystems has opened new perspectives for marine ecology research. These techniques can extract information about fish populations from in-situ cameras, without requiring ecologists to watch the videos. However, they

  14. Genomewide single nucleotide polymorphism discovery in Atlantic salmon (Salmo salar): validation in wild and farmed American and European populations.

    Science.gov (United States)

    Yáñez, J M; Naswa, S; López, M E; Bassini, L; Correa, K; Gilbey, J; Bernatchez, L; Norris, A; Neira, R; Lhorente, J P; Schnable, P S; Newman, S; Mileham, A; Deeb, N; Di Genova, A; Maass, A

    2016-07-01

    A considerable number of single nucleotide polymorphisms (SNPs) are required to elucidate genotype-phenotype associations and determine the molecular basis of important traits. In this work, we carried out de novo SNP discovery accounting for both genome duplication and genetic variation from American and European salmon populations. A total of 9 736 473 nonredundant SNPs were identified across a set of 20 fish by whole-genome sequencing. After applying six bioinformatic filtering steps, 200 K SNPs were selected to develop an Affymetrix Axiom(®) myDesign Custom Array. This array was used to genotype 480 fish representing wild and farmed salmon from Europe, North America and Chile. A total of 159 099 (79.6%) SNPs were validated as high quality based on clustering properties. A total of 151 509 validated SNPs showed a unique position in the genome. When comparing these SNPs against 238 572 markers currently available in two other Atlantic salmon arrays, only 4.6% of the SNP overlapped with the panel developed in this study. This novel high-density SNP panel will be very useful for the dissection of economically and ecologically relevant traits, enhancing breeding programmes through genomic selection as well as supporting genetic studies in both wild and farmed populations of Atlantic salmon using high-resolution genomewide information. © 2016 John Wiley & Sons Ltd.

  15. Teratogenic effects of selenium in natural populations of freshwater fish.

    Science.gov (United States)

    Lemly, A D

    1993-10-01

    The prevalence of abnormalities and associated tissue selenium residues were assessed for the fish population of Belews Lake, North Carolina, and two reference lakes in 1975, 1978, 1982, and 1992. Teratogenic defects identified included lordosis, kyphosis, scoliosis, and head, mouth, and fin deformities. Many fish exhibited multiple malformations and some were grossly deformed and distorted in appearance. Other abnormalities observed were edema, exophthalmus, and cataracts. Whole-body tissue residues of selenium in the fishes of Belews Lake were up to 130 times those in the reference lakes and the incidence of abnormalities was some 7 to 70 times greater. Teratogenic defects increased as selenium levels rose between 1975 and 1982 and fell with declining selenium levels between 1982 and 1992 as selenium inputs into Belews Lake were curtailed. The relationship between selenium residues and prevalence of malformations approximated an exponential function (R2 = 0.881, P selenium and 0-70% deformities. This relationship could be useful in evaluating the role of teratogenic effects in warm-water fish populations suspected of having selenium-related reproductive failure. Unique conditions may have existed in Belews Lake which led to the high frequency and persistence of deformities in juvenile and adult fish. In other, less-contaminated locations competition and predation may eliminate malformed individuals in all but the larval life stage. Teratogenesis could be an important, but easily overlooked phenomenon contributing to fishery reproductive failure in selenium-contaminated aquatic habitats.

  16. Selenium uptake and speciation in wild and caged fish downstream of a metal mining and milling discharge.

    Science.gov (United States)

    Phibbs, James; Wiramanaden, Cheryl I E; Hauck, Dominic; Pickering, Ingrid J; Liber, Karsten; Janz, David M

    2011-07-01

    The aim of this research was to evaluate the dominance of the feeding pathway with respect to selenium (Se) uptake and speciation in fish inhabiting the receiving waters downstream of a uranium processing mill in northern Saskatchewan, Canada. The experimental design included analysis of Se in the predominant fish species located in the study area, a caging validation study using wild, naïve (i.e., collected from a reference lake) lake chub (Couesius plumbeus) and spottail shiner (Notropis hudsonius), and a 21-day feeding cage study using wild naïve lake chub. Three exposure lakes located downstream of the uranium mill and one reference lake situated in an adjacent watershed were studied to investigate a gradient of Se exposure. Lake chub were identified as more suitable candidates for caging due to higher survival and condition factor at the completion of the 21-day trial. Analytical results indicated that lake chub caged in the exposure lakes had significantly greater whole-body Se concentrations after 21 days compared to fish caged in the reference lake. Selenium speciation results (obtained using X-ray absorption spectroscopy) from wild and caged lake chub indicated that organic Se modeled as selenomethionine was the dominant form of Se found in both wild and caged lake chub from the exposure lakes, and that selenomethionine (R-Se-R) acts as a marker of bioavailable Se exposure. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Modeling Disjunct Gray Wolf Populations in Semi-Wild Landscapes

    Science.gov (United States)

    Robert G. Haight; David J. Mladenoff; Adrian P. Wydeven

    1998-01-01

    Gray wolves (Canis lupus) in parts of the United States and Europe live in networks of disjunct populations, many of which are close to human settlement. Because wolf management goals include sustaining disjunct populations, it is important to ask what types of areas and protections are needed for population survival. To predict the effects of different levels of human...

  18. Comparative Bacteriological Study of Two Wild Boar Populations in Sierra Morena (Ja�n, Spain

    Directory of Open Access Journals (Sweden)

    Antonio NOTARIO

    2010-12-01

    Full Text Available The aim of this study was to investigate the presence of various bacterial species in the wild boar populations of Lugar Nuevo and Selladores-Contadero woodlands from Sierra Morena (Spain. Bacteriological analyses were carried out on a total of 229 wild boar individuals hunted in the period 2000-2003 in eleven experimental plots which are representative for the different biotopes of the area. The following species were detected: Brucella ovis, Clostridium sp., Corynebacterium sp., Streptococcus pneumoniae, Escherichia coli, Mycobacterium bovis, Mycobacterium avium subsp. paratuberculosis, Mannheimia haemolytica, Pasteurella multocida, Pseudomonas aeruginosa, Chlamydophila psittaci, Staphylococcus aureus and Staphylococcus sp. and the bacterial prevalence was estimated for each of them. The results provide useful indications of the health status of wild boar in both locations and highlight the potential of the wild boar populations to act as biological reservoirs of certain microorganisms that can be passed onto other vertebrate wild animals and humans.

  19. Comparison between wild and hatchery populations of Korean pen shell (Atrina pectinata) using microsatellite DNA markers.

    Science.gov (United States)

    An, Hye Suck; Kim, Byeong Hak; Lee, Jang Wook; Dong, Chun Mae; Kim, Shin Kwon; Kim, Yi Cheong

    2011-01-01

    Pen shell (Atrina pectinata) is a popular food source with a high commercial value in a number of Asian Pacific areas. The natural A. pectinata population has been declining continuously over the past several decades. Microsatellite DNA markers are a useful DNA-based tool for monitoring the genetic variation of pen shell populations. In this study, 20 polymorphic microsatellite (MS) DNA markers were identified from a partial genomic pen shell DNA library enriched in CA repeats, and used to compare allelic variation between wild and hatchery pen shell populations in Korea. A total of 438 alleles were detected at the 20 MS loci in the two populations. All loci were easily amplified and demonstrated allelic variability, with the number of alleles ranging from 5 to 35 in the wild population and from 5 to 22 in the farmed population. The average observed and expected heterozygosities were 0.69 and 0.82, respectively, in the hatchery samples and 0.69 and 0.83, respectively, in the wild samples. Statistical analysis of fixation index (F(ST)) and analysis of molecular variance (AMOVA) showed minor, but significant, genetic differences between the wild and hatchery populations (F(ST) = 0.0106, CI(95%) = 0.003-0.017). These microsatellite loci may be valuable for future aquaculture and population genetic studies for developing conservation and management plans. Further studies with additional pen shell samples are needed to conclusively determine the genetic diversity between the wild and hatchery populations.

  20. Evaluating genetic traceability methods for captive-bred marine fish and their applications in fisheries management and wildlife forensics

    OpenAIRE

    Bylemans, Jonas; Maes , Gregory E; Diopere, Eveline; Cariani, Alessia; Senn, Helen; Taylor, Martin I; Helyar, Sarah; Bargelloni, Luca; Bonaldo, Alessio; Carvalho, Gary; Guarniero, Ilaria; Komen, Hans; Martinsohn, Jann T.; Einar E. Nielsen; Tinti, Fausto

    2016-01-01

    Growing demands for marine fish products is leading to increased pressure on already depleted wild populations and a rise in aquaculture production. Consequently, more captive-bred fish are released into the wild through accidental escape or deliberate releases. The increased mixing of captive-bred and wild fish may affect the ecological and/or genetic integrity of wild fish populations. Unambiguous identification tools for captive-bred fish will be highly valuable to manage risks (fisheries ...

  1. Trans-generational effects on ageing in a wild bird population

    NARCIS (Netherlands)

    Bouwhuis, S.; Charmantier, A.; Verhulst, S.; Sheldon, B. C.

    Ageing, long thought to be too infrequent to study effectively in natural populations, has recently been shown to be ubiquitous, even in the wild. A major challenge now is to explain variation in the rates of ageing within populations. Here, using 49 years of data from a population of great tits

  2. Temporal change in genetic integrity suggests loss of local adaptation in a wild Atlantic salmon (Salmo salar) population following introgression by farmed escapees

    Science.gov (United States)

    Bourret, V; O'Reilly, P T; Carr, J W; Berg, P R; Bernatchez, L

    2011-01-01

    In some wild Atlantic salmon populations, rapid declines in numbers of wild returning adults has been associated with an increase in the prevalence of farmed salmon. Studies of phenotypic variation have shown that interbreeding between farmed and wild salmon may lead to loss of local adaptation. Yet, few studies have attempted to assess the impact of interbreeding at the genome level, especially among North American populations. Here, we document temporal changes in the genetic makeup of the severely threatened Magaguadavic River salmon population (Bay of Fundy, Canada), a population that might have been impacted by interbreeding with farmed salmon for nearly 20 years. Wild and farmed individuals caught entering the river from 1980 to 2005 were genotyped at 112 single-nucleotide polymorphisms (SNPs), and/or eight microsatellite loci, to scan for potential shifts in adaptive genetic variation. No significant temporal change in microsatellite-based estimates of allele richness or gene diversity was detected in the wild population, despite its precipitous decline in numbers over the last two decades. This might reflect the effect of introgression from farmed salmon, which was corroborated by temporal change in linkage-disequilibrium. Moreover, SNP genome scans identified a temporal decrease in candidate loci potentially under directional selection. Of particular interest was a SNP previously shown to be strongly associated with an important quantitative trait locus for parr mark number, which retained its genetic distinctiveness between farmed and wild fish longer than other outliers. Overall, these results indicate that farmed escapees have introgressed with wild Magaguadavic salmon resulting in significant alteration of the genetic integrity of the native population, including possible loss of adaptation to wild conditions. PMID:21224876

  3. Population genetic structure of Japanese wild soybean (Glycine soja) based on microsatellite variation.

    Science.gov (United States)

    Kuroda, Y; Kaga, A; Tomooka, N; Vaughan, D A

    2006-04-01

    The research objectives were to determine aspects of the population dynamics relevant to effective monitoring of gene flow in the soybean crop complex in Japan. Using 20 microsatellite primers, 616 individuals from 77 wild soybean (Glycine soja) populations were analysed. All samples were of small seed size ( 10 km) events among populations, and spatial autocorrelation analysis revealed that populations within a radius of 100 km showed a close genetic relationship to one another. When analysis of graphical ordination was applied to compare the microsatellite variation of wild soybean with that of 53 widely grown Japanese varieties of cultivated soybean (Glycine max), the primary factor of genetic differentiation was based on differences between wild and cultivated soybeans and the secondary factor was geographical differentiation of wild soybean populations. Admixture analysis revealed that 6.8% of individuals appear to show introgression from cultivated soybeans. These results indicated that population genetic structure of Japanese wild soybean is (i) strongly affected by the founder effect due to seed dispersal and inbreeding strategy, (ii) generally well differentiated from cultivated soybean, but (iii) introgression from cultivated soybean occurs. The implications of the results for the release of transgenic soybeans where wild soybeans grow are discussed.

  4. Lack of polymorphism at MC1R wild-type allele and evidence of domestic allele introgression across European wild boar populations

    DEFF Research Database (Denmark)

    Canu, Antonio; Vilaça, Sibelle T.; Iacolina, Laura

    2016-01-01

    Domestication promotes the emergence of novel phenotypic and behavioural traits in domesticated animals compared to their wild ancestors. We analysed variation at the melanocortin receptor I (MC1R) and nuclear receptor subfamily 6, group A, member 1 (NR6A1) genes in European wild boar populations...... of hybridization between wild and domestic forms. Most of the wild boars (94%) were homozygous for the European wild-type (E+) MC1R allele. We did not observe any synonymous substitution in the European E+ allele, confirming its monomorphism even in areas known to be hotspots of wild boar genetic diversity....... The remaining wild boars (6%) showed genetic introgression of three different European domestic alleles. No Asian MC1R allele was found in our sample. Furthermore, domestic NR6A1 alleles were observed in 6% of wild boars. Considering jointly the two loci analyzed, 11% of boars, sampled all over Europe, showed...

  5. Quantitative analysis of toxin extracts from various tissues of wild and cultured puffer fish by an electrophysiological method.

    Science.gov (United States)

    Sasaki, Keita; Takayama, Yasunori; Tahara, Tatsuo; Anraku, Kensaku; Ito, Yushi; Akaike, Norio

    2008-03-15

    We observed the effects of the toxin extracted from various tissues of wild and cultured puffer fish on voltage-dependent sodium current (I(Na)) using single rat CA1 neurons, and compared the results with that of tetrodotoxin (TTX). Toxin extracts from wild puffer fish inhibited I(Na) in a dilution-dependent manner, and toxin extracts from liver or ovary produced 300 times greater inhibition than that from muscle, and corresponded to about 65 microg TTX/g tissue. We also used puffer fish cultured in net cages or in tanks set up on land, in an attempt to isolate them from the food chain. The toxin extracts from cultured puffer fish also suppressed I(Na), but the inhibition was much weaker, and the effects of toxin extracts were almost the same in all tissues examined including liver, ovary, muscle, etc. We calculated the maximum edible amount for each tissue, assuming that the lethal dose of TTX is 1-10 microg/kg, and we found that the liver or ovary was edible in the case of cultured puffer fish.

  6. Susceptibility of juvenile sole Solea senegalensis to marine isolates of viral haemorrhagic septicaemia virus from wild and farmed fish.

    Science.gov (United States)

    López-Vázquez, C; Conde, M; Dopazo, C P; Barja, J L; Bandín, I

    2011-01-21

    The susceptibility of sole Solea senegalensis to infection with 3 viral haemorrhagic septicaemia virus (VHSV) strains obtained from wild Greenland halibut Reinhardtius hippoglossoides and farmed turbot Psetta maxima was demonstrated. Fish were infected by an intraperitoneal (i.p.), immersion or cohabitational route, and maintained at 16 degrees C. Infection trials showed that VHSV isolates were pathogenic for sole fingerlings by i.p. injection and waterborne exposure causing moderate levels of mortality (10 to 55%). In addition, the mortality observed in fish cohabitating with i.p.-infected sole confirms horizontal transmission of the virus. However, the low rates of mortality registered in this challenge suggest that there is a low dissemination of virus by the i.p.-infected sole, which results in lower secondary challenge of the cohabitating fish. External signs of disease included haemorrhaging of the ventral area and ascitic fluid in the body cavity. Dead fish were tested for VHSV by both cell culture and RT-PCR assay, using pools of kidney and spleen from 10 individuals. Virus was recovered from most of the pools composed of dead fish. The results obtained in this study not only demonstrate the susceptibility of sole to the VHSV strains employed but also indicate that wild VHSV marine isolates represent a potential risk for sole aquaculture.

  7. The evolutionary ecology of individual phenotypic plasticity in wild populations

    National Research Council Canada - National Science Library

    NUSSEY, D. H; WILSON, A. J; BROMMER, J. E

    2007-01-01

    The ability of individual organisms to alter morphological and life‐history traits in response to the conditions they experience is an example of phenotypic plasticity which is fundamental to any population's ability to deal with short...

  8. Individual-based approach to fish population dynamics: An overview

    Energy Technology Data Exchange (ETDEWEB)

    Van Winkle, W.; Rose, K.A. (Oak Ridge National Lab., TN (United States)); Chambers, R.C. (Huntsman Marine Science Centre, New Brunswick (Canada))

    1993-05-01

    Individual-based simulation modeling tracks the attributes of individual fish through time and aggregates them to generate insights into population function. By seeking to understand how fish of differing phenotypes respond to variations in physicochemical and biological environments, analysts hope to improve predictions of population trends. A review of eight accompanying papers highlights the promise and current limitations of the individual-based approach. Among the challenges to be faced are accurately representing feeding encounter rates, extending models to account for spatial heterogeneity and transgenerational responses, dealing with practical limits to the amount of data on individuals that can be measured and managed, more fully conceptionalizing natural processes, and acquiring appropriate field data with which to formulate and test the models. 16 refs., 1 tab.

  9. Improving the assessment of instream flow needs for fish populations

    Energy Technology Data Exchange (ETDEWEB)

    Sale, M.J. (Oak Ridge National Lab., TN (USA)); Otto, R.G. (Otto (R.G.) and Associates, Arlington, VA (USA))

    1991-01-01

    Instream flow requirements are one of the most frequent and most costly environmental issues that must be addressed in developing hydroelectric projects. Existing assessment methods for determining instream flow requirements have been criticized for not including all the biological response mechanisms that regulate fishery resources. A new project has been initiated to study the biological responses of fish populations to altered stream flows and to develop improved ways of managing instream flows. 21 refs., 3 figs.

  10. Strong selection barriers explain microgeographic adaptation in wild salamander populations.

    Science.gov (United States)

    Richardson, Jonathan L; Urban, Mark C

    2013-06-01

    Microgeographic adaptation occurs when populations evolve divergent fitness advantages across the spatial scales at which focal organisms regularly disperse. Although an increasing number of studies find evidence for microgeographic adaptation, the underlying causes often remain unknown. Adaptive divergence requires some combination of limited gene flow and strong divergent natural selection among populations. In this study, we estimated the relative influence of selection, gene flow, and the spatial arrangement of populations in shaping patterns of adaptive divergence in natural populations of the spotted salamander (Ambystoma maculatum). Within the study region, A. maculatum co-occur with the predatory marbled salamander (Ambystoma opacum) in some ponds, and past studies have established a link between predation risk and adaptive trait variation in A. maculatum. Using 14 microsatellite loci, we found a significant pattern of genetic divergence among A. maculatum populations corresponding to levels of A. opacum predation risk. Additionally, A. maculatum foraging rate was strongly associated with predation risk, genetic divergence, and the spatial relationship of ponds on the landscape. Our results indicate the sorting of adaptive genotypes by selection regime and strongly suggest that substantial selective barriers operate against gene flow. This outcome suggests that microgeographic adaptation in A. maculatum is possible because strong antagonistic selection quickly eliminates maladapted phenotypes despite ongoing and substantial immigration. Increasing evidence for microgeographic adaptation suggests a strong role for selective barriers in counteracting the homogenizing influence of gene flow. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  11. Coral reef fish populations can persist without immigration

    KAUST Repository

    Salles, Océane C.

    2015-11-18

    Determining the conditions under which populations may persist requires accurate estimates of demographic parameters, including immigration, local reproductive success, and mortality rates. In marine populations, empirical estimates of these parameters are rare, due at least in part to the pelagic dispersal stage common to most marine organisms. Here, we evaluate population persistence and turnover for a population of orange clownfish, Amphiprion percula, at Kimbe Island in Papua New Guinea. All fish in the population were sampled and genotyped on five occasions at 2-year intervals spanning eight years. The genetic data enabled estimates of reproductive success retained in the same population (reproductive success to self-recruitment), reproductive success exported to other subpopulations (reproductive success to local connectivity), and immigration and mortality rates of sub-adults and adults. Approximately 50% of the recruits were assigned to parents from the Kimbe Island population and this was stable through the sampling period. Stability in the proportion of local and immigrant settlers is likely due to: low annual mortality rates and stable egg production rates, and the short larval stages and sensory capacities of reef fish larvae. Biannual mortality rates ranged from 0.09 to 0.55 and varied significantly spatially. We used these data to parametrize a model that estimated the probability of the Kimbe Island population persisting in the absence of immigration. The Kimbe Island population was found to persist without significant immigration. Model results suggest the island population persists because the largest of the subpopulations are maintained due to having low mortality and high self-recruitment rates. Our results enable managers to appropriately target and scale actions to maximize persistence likelihood as disturbance frequencies increase.

  12. Coral reef fish populations can persist without immigration

    Science.gov (United States)

    Salles, Océane C.; Maynard, Jeffrey A.; Joannides, Marc; Barbu, Corentin M.; Saenz-Agudelo, Pablo; Almany, Glenn R.; Berumen, Michael L.; Thorrold, Simon R.; Jones, Geoffrey P.; Planes, Serge

    2015-01-01

    Determining the conditions under which populations may persist requires accurate estimates of demographic parameters, including immigration, local reproductive success, and mortality rates. In marine populations, empirical estimates of these parameters are rare, due at least in part to the pelagic dispersal stage common to most marine organisms. Here, we evaluate population persistence and turnover for a population of orange clownfish, Amphiprion percula, at Kimbe Island in Papua New Guinea. All fish in the population were sampled and genotyped on five occasions at 2-year intervals spanning eight years. The genetic data enabled estimates of reproductive success retained in the same population (reproductive success to self-recruitment), reproductive success exported to other subpopulations (reproductive success to local connectivity), and immigration and mortality rates of sub-adults and adults. Approximately 50% of the recruits were assigned to parents from the Kimbe Island population and this was stable through the sampling period. Stability in the proportion of local and immigrant settlers is likely due to: low annual mortality rates and stable egg production rates, and the short larval stages and sensory capacities of reef fish larvae. Biannual mortality rates ranged from 0.09 to 0.55 and varied significantly spatially. We used these data to parametrize a model that estimated the probability of the Kimbe Island population persisting in the absence of immigration. The Kimbe Island population was found to persist without significant immigration. Model results suggest the island population persists because the largest of the subpopulations are maintained due to having low mortality and high self-recruitment rates. Our results enable managers to appropriately target and scale actions to maximize persistence likelihood as disturbance frequencies increase. PMID:26582017

  13. Risk assessment and toxic effects of metal pollution in two cultured and wild fish species from highly degraded aquatic habitats.

    Science.gov (United States)

    Omar, Wael A; Zaghloul, Khalid H; Abdel-Khalek, Amr A; Abo-Hegab, S

    2013-11-01

    Lake Qaroun is an inland lake at the lowest part of El-Fayoum depression, Egypt. It receives agricultural and domestic non-treated drainage waters, which are also used for aquaculture in Qaroun area. The results of the present study aimed to provide comparable data between wild (collected from Lake Qaroun) and cultured (collected from Qaroun fish farms and the reference site) Nile tilapia Oreochromis niloticus and mullet Mugil cephalus, as indicators of natural and anthropogenic impacts on aquatic ecosystem as well as to evaluate the human hazard index associated with fish consumption. Metal concentrations in fish tissues showed a species-specific bioaccumulation pattern. Statistically significant differences were observed in the mean metal concentrations with lower bioavailability in M. cephalus compared with O. niloticus in internal vital organs (liver, kidney, and muscle) but much higher in external organs (gill and skin). Histopathological alterations and evident damages were observed in gill, liver, and kidney of both species collected from Lake Qaroun and Qaroun fish farms compared with those from the reference site. The results showed significant increase of plasma aspartate aminotransferase and alanine aminotransferase activity as well as creatinine and uric acid concentration in both fish species from polluted locations. The human health hazard index showed that the cumulative risk greatly increases with increasing fish consumption rate, thus yielding an alarming concern for consumer health.

  14. High Prevalence of Extended-Spectrum β-Lactamase-Producing Enterobacteriaceae in Wild Fish from the Mediterranean Sea in Algeria.

    Science.gov (United States)

    Brahmi, Soumia; Touati, Abdelaziz; Dunyach-Remy, Catherine; Sotto, Albert; Pantel, Alix; Lavigne, Jean-Philippe

    2017-08-14

    We investigated the prevalence of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae among wild fish from the coast of Bejaia (Algeria) in the Mediterranean Sea. From March 2012 to August 2013, gut and gill samples of wild fish were screened for the presence of ESBL-producing Enterobacteriaceae. Strains were characterized with regard to antibiotic resistance, β-lactamase content, plasmid-mediated quinolone resistance, aminoglycoside resistance genes, and clonality (repetitive sequence-based polymerase chain reaction profiles and multilocus sequence typing). Virulence traits were performed for Escherichia coli and Klebsiella pneumoniae isolates. Of the 300 fish studied, 64 (21.3%) isolates were screened as positive for ESBL producing by the double-disc method. The isolates corresponded to E. coli, K. pneumoniae, Enterobacter cloacae, Morganella morganii, Citrobacter freundii, and Proteus vulgaris. A predominance of blaCTX-M gene was observed with a prevalence of 60.5% (n = 46). Furthermore, our study describes the association of important coresistance and virulence factors in E. coli and K. pneumoniae. Twelve of the ESBL producers carried genes of the qnr family and oqxAB gene and six carried the aac(6')-Ib-cr gene. Our results highlight for the first time the diffusion of multidrug-resistant Enterobacteriaceae isolates carrying resistance and virulence genes in fish from the Mediterranean Sea in Algeria.

  15. Farmed Atlantic salmon Salmo salar L. parr may reduce early survival of wild fish.

    Science.gov (United States)

    Sundt-Hansen, L; Huisman, J; Skoglund, H; Hindar, K

    2015-06-01

    The study examined the density-mediated effects on growth, survival and dispersal of wild and farmed Atlantic salmon Salmo salar offspring in the period immediately following emergence, using a substitutive design. In small confined stream channels, wild parr coexisting with farmed parr had a significantly poorer survival, than wild parr alone. Density did not affect this relationship. In larger unconfined stream channels, wild parr coexisting with farmed parr entered a downstream trap in higher numbers than wild parr in allopatry. The results suggests that during the earliest life stages, farmed S. salar can outcompete wild S. salar, resulting in a reduced survival of wild S. salar. © 2015 The Fisheries Society of the British Isles.

  16. Linkage disequilibrium in wild and cultured populations of Pacific oyster ( Crassostrea gigas)

    Science.gov (United States)

    Guo, Xiang; Li, Qi; Kong, Lingfeng; Yu, Hong

    2016-04-01

    Linkage disequilibrium (LD) can be applied for mapping the actual genes responsible for variation of economically important traits through association mapping. The feasibility and efficacy of association studies are strongly dependent on the extent of LD which determines the number and density of markers in the studied population, as well as the experimental design for an association analysis. In this study, we first characterized the extent of LD in a wild population and a cultured mass-selected line of Pacific oyster ( Crassostrea gigas). A total of 88 wild and 96 cultured individuals were selected to assess the level of genome-wide LD with 53 microsatellites, respectively. For syntenic marker pairs, no significant association was observed in the wild population; however, three significant associations occurred in the cultured population, and the significant LD extended up to 12.7 cM, indicating that strong artificial selection is a key force for substantial increase of genome-wide LD in cultured population. The difference of LD between wild and cultured populations showed that association studies in Pacific oyster can be achieved with reasonable marker densities at a relatively low cost by choosing an association mapping population. Furthermore, the frequent occurrence of LD between non-syntenic loci and rare alleles encourages the joint application of linkage analysis and LD mapping when mapping genes in oyster. The information on the linkage disequilibrium in the cultured population is useful for future association mapping in oyster.

  17. The population structure of wild sorghum species in agro-ecological ...

    African Journals Online (AJOL)

    Whole population FIS, FST and FIT values were low at 0.15, 0.16 and 0.29, respectively indicating low level of inbreeding, low genetic differentiation of the population and low to moderate deviation from Hardy–Weinberg (HW) equilibrium respectively. The deviation from HW equilibrium was significant in some wild ...

  18. ECOLOGO-GENETIC MONITORING OF CULTIVATED AND WILD PLANT POPULATION

    Directory of Open Access Journals (Sweden)

    A. E. SHPAKOV

    2010-01-01

    Full Text Available Quantitative estimation of genotypic structure dynamic of three plant species: Nicotiana tabacum L., Anacamptus pyramidalis (L. Rich., Teucrium chamaedrys L. in different ecological conditions has been conducted. The effectiveness of systemic analyses of the trait complex with the aim of ecologo-genetic monitoring of the plant population has been established.

  19. Genetic differences between the wild and hatchery-produced populations of Korean short barbeled grunter (Hapalogenys nitens) determined with microsatellite markers.

    Science.gov (United States)

    An, H S; Kang, H W; Han, H S; Park, J Y; Hong, C G; Park, J; Myeong, J I; An, C M

    2014-10-31

    Short barbeled grunter, Hapalogenys nitens, is an economically important fishery resource. In Korea, this fish is in the early stage of domestication, and it has been regarded as the candidate marine fish species for prospective aquaculture diversification. This study presents a preliminary investigation of the future viability of sustainable fry production from short barbeled grunter. We used 12 polymorphic nuclear microsatellite DNA loci to analyze the possible genetic variability between the wild and hatchery-produced populations of short barbeled grunter from Korea and identified 91 alleles. Compared to the wild population, significant genetic changes including reduced genetic diversity (average allele number: 7.42 vs 3.75; average expected heterozygosity: 0.713 vs 0.598, Wilcoxon signed-rank test; P hatchery-produced population, as indicated by the observation of allele richness, unique allele, heterozygosity, FST, and results of molecular analysis of variance. These findings indicate that genetic drift may have promoted the differentiation between these 2 populations, which may have negative effects on sustainable fry production. Therefore, genetic variations of the wild and hatchery-produced populations should be monitored and subjected to control inbreeding through a commercial breeding program. The information presented by this paper would provide a useful genetic basis for future sustainable culturing planning and management of H. nitens.

  20. Differences in the metabolic rates of exploited and unexploited fish populations: a signature of recreational fisheries induced evolution?

    Directory of Open Access Journals (Sweden)

    Jan-Michael Hessenauer

    Full Text Available Non-random mortality associated with commercial and recreational fisheries have the potential to cause evolutionary changes in fish populations. Inland recreational fisheries offer unique opportunities for the study of fisheries induced evolution due to the ability to replicate study systems, limited gene flow among populations, and the existence of unexploited reference populations. Experimental research has demonstrated that angling vulnerability is heritable in Largemouth Bass Micropterus salmoides, and is correlated with elevated resting metabolic rates (RMR and higher fitness. However, whether such differences are present in wild populations is unclear. This study sought to quantify differences in RMR among replicated exploited and unexploited populations of Largemouth Bass. We collected age-0 Largemouth Bass from two Connecticut drinking water reservoirs unexploited by anglers for almost a century, and two exploited lakes, then transported and reared them in the same pond. Field RMR of individuals from each population was quantified using intermittent-flow respirometry. Individuals from unexploited reservoirs had a significantly higher mean RMR (6% than individuals from exploited populations. These findings are consistent with expectations derived from artificial selection by angling on Largemouth Bass, suggesting that recreational angling may act as an evolutionary force influencing the metabolic rates of fishes in the wild. Reduced RMR as a result of fisheries induced evolution may have ecosystem level effects on energy demand, and be common in exploited recreational populations globally.

  1. Resistance of barley landraces and wild barley populations to powdery mildew in Jordan

    Directory of Open Access Journals (Sweden)

    Adel Abdel-Ghani

    2008-10-01

    Full Text Available Eleven barley (Hordeum vulgare L. landraces and 12 wild barley (H. spontaneum populations, collected from diverse eco-geographical regions of Jordan, were screened for resistance to powdery mildew. The average powdery mildew disease score (based on a 0 to 4 severity scale was <1 in all tested barley landraces. Disease scores in wild barley populations ranged from 1.2 to 3.8. Most barley landraces of all tested lines were highly resistant to powdery mildew. The percentage of wild barley lines exhibiting high resistance was 19%, while 45% of the lines were moderately resistant and 36% susceptible to powdery mildew. There was no significant correlation between weather variables (precipitation, temperature and altitude and the disease scores of either the barley landraces or the wild barley populations. However, resistance in wild barley was more common in humid districts and at higher altitudes. Both barley landrace and wild barley accessions could serve as potential donors for powdery mildew resistance genes to be transferred to barley varieties improved by plant breeding.

  2. Suburbanization, estrogen contamination, and sex ratio in wild amphibian populations

    Science.gov (United States)

    Lambert, Max R.; Giller, Geoffrey S. J.; Barber, Larry B.; Fitzgerald, Kevin C.; Skelly, David K.

    2015-01-01

    Research on endocrine disruption in frog populations, such as shifts in sex ratios and feminization of males, has predominantly focused on agricultural pesticides. Recent evidence suggests that suburban landscapes harbor amphibian populations exhibiting similar levels of endocrine disruption; however the endocrine disrupting chemical (EDC) sources are unknown. Here, we show that sex ratios of metamorphosing frogs become increasingly female-dominated along a suburbanization gradient. We further show that suburban ponds are frequently contaminated by the classical estrogen estrone and a variety of EDCs produced by plants (phytoestrogens), and that the diversity of organic EDCs is correlated with the extent of developed land use and cultivated lawn and gardens around a pond. Our work also raises the possibility that trace-element contamination associated with human land use around suburban ponds may be contributing to the estrogenic load within suburban freshwaters and constitutes another source of estrogenic exposure for wildlife. These data suggest novel, unexplored pathways of EDC contamination in human-altered environments. In particular, we propose that vegetation changes associated with suburban neighborhoods (e.g., from forests to lawns and ornamental plants) increase the distribution of phytoestrogens in surface waters. The result of frog sex ratios varying as a function of human land use implicates a role for environmental modulation of sexual differentiation in amphibians, which are assumed to only have genetic sex determination. Overall, we show that endocrine disruption is widespread in suburban frog populations and that the causes are likely diverse.

  3. Increasing hydrologic variability threatens depleted anadromous fish populations.

    Science.gov (United States)

    Ward, Eric J; Anderson, Joseph H; Beechie, Tim J; Pess, George R; Ford, Michael J

    2015-01-29

    Predicting effects of climate change on species and ecosystems depend on understanding responses to shifts in means (such as trends in global temperatures), but also shifts in climate variability. To evaluate potential responses of anadromous fish populations to an increasingly variable environment, we performed a hierarchical analysis of 21 Chinook salmon populations from the Pacific Northwest, examining support for changes in river flows and flow variability on population growth. More than half of the rivers analyzed have already experienced significant increases in flow variability over the last 60 years, and this study shows that this increase in variability in freshwater flows has a more negative effect than any other climate signal included in our model. Climate change models predict that this region will experience warmer winters and more variable flows, which may limit the ability of these populations to recover. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

  4. Native fish population and habitat study, Santa Ana River, California

    Science.gov (United States)

    Wulff, Marissa L.; Brown, Larry R.; May, Jason

    2017-01-01

    Collection of additional data on the Santa Ana Sucker (Catostomus santaanae) and the Arroyo Chub (Gila orcutti) has been identified as a needed task to support development of the upper Santa Ana River Habitat Conservation Plan (HCP; http://www.uppersarhcp.com/). The ability to monitor population abundance and understanding the habitats used by species are important when developing such plans. The Santa Ana Sucker (Catostomus santaanae) is listed as a threatened species under federal legislation and is considered a species of special concern in California by the California Department of Fish and Wildlife (Moyle 2002). The Arroyo Chub (Gila orcutti) is considered a species of special concern in California by the California Department of Fish and Wildlife (Moyle 2002). Both species are present in the Santa Ana River watershed in the area being evaluated for establishment of the upper Santa Ana River Habitat Conservation Plan (HCP; http://www.uppersarhcp.com/). The HCP is a collaborative effort involving the water resource agencies of the Santa Ana River Watershed, the US Fish and Wildlife Service, California Department of Fish and Wildlife, and other government agencies and stakeholder organizations. The goals of the HCP are to: 1) enable the water resource agencies to provide a reliable water supply for human uses; 2) conserve and maintain natural rivers and streams that provide habitat for a diversity of unique and rare species; and 3) maintain recreational opportunities for activities such as hiking, fishing, and wildlife viewing, provided by the protection of these habitats and the river systems they depend on. The HCP will specify how species and their habitats will be protected and managed in the future and will provide the incidental take permits needed by the water resource agencies under the federal and State endangered species acts to maintain, operate, and improve their water resource infrastructure. Although the Santa Ana Sucker has been the subject of

  5. Population genomics of marine fishes: next generation prospects and challenges

    DEFF Research Database (Denmark)

    Hansen, Jakob Hemmer; Therkildsen, Nina Overgaard; Pujolar, J.M.

    2014-01-01

    Over the past few years, technological advances have facilitated giant leaps forward in our ability to generate genome-wide molecular data, offering exciting opportunities for gaining new insights into the ecology and evolution of species where genomic information is still limited. Marine fishes...... are valuable organisms for advancing our understanding of evolution on historical and contemporary time scales, and here we highlight areas in which research on these species is likely to be particularly important in the near future. These include possibilities for gaining insights into processes on ecological...... methods in marine fishes. Complications associated with fast decay of linkage disequilibrium, as expected for species with large effective population sizes, and the possibility that adaptation is associated with both soft selective sweeps and polygenic selection, leaving complex genomic signatures...

  6. Social barriers to pathogen transmission in wild animal populations

    Energy Technology Data Exchange (ETDEWEB)

    Loehle, C.

    1995-03-01

    Diseases and pathogens are receiving increasing recognition as sources of mortality in animal populations. Immune system strength is clearly important in fending off pathogen attack. Physical barriers to pathogen entry are also important. Various individual behaviors are efficacious in reducing contact with diseases and pests. This paper focuses on a fourth mode of defense: social barriers to transmission. Various social behaviors have pathogen transmission consequences. Selective pressures on these social behaviors may therefore exist. Effects on pathogen transmission of mating strategies, social avoidance, group size, group isolation, and other behaviors are explored. It is concluded that many of these behaviors may have been affected by selection pressures to reduce transmission of pathogens. 84 refs., 1 tab.

  7. Impact of naturally spawning captive-bred Atlantic salmon on wild populations: depressed recruitment and increased risk of climate-mediated extinction.

    Science.gov (United States)

    McGinnity, Philip; Jennings, Eleanor; DeEyto, Elvira; Allott, Norman; Samuelsson, Patrick; Rogan, Gerard; Whelan, Ken; Cross, Tom

    2009-10-22

    The assessment report of the 4th International Panel on Climate Change confirms that global warming is strongly affecting biological systems and that 20-30% of species risk extinction from projected future increases in temperature. It is essential that any measures taken to conserve individual species and their constituent populations against climate-mediated declines are appropriate. The release of captive bred animals to augment wild populations is a widespread management strategy for many species but has proven controversial. Using a regression model based on a 37-year study of wild and sea ranched Atlantic salmon (Salmo salar) spawning together in the wild, we show that the escape of captive bred animals into the wild can substantially depress recruitment and more specifically disrupt the capacity of natural populations to adapt to higher winter water temperatures associated with climate variability. We speculate the mechanisms underlying this seasonal response and suggest that an explanation based on bio-energetic processes with physiological responses synchronized by photoperiod is plausible. Furthermore, we predict, by running the model forward using projected future climate scenarios, that these cultured fish substantially increase the risk of extinction for the studied population within 20 generations. In contrast, we show that positive outcomes to climate change are possible if captive bred animals are prevented from breeding in the wild. Rather than imposing an additional genetic load on wild populations by releasing maladapted captive bred animals, we propose that conservation efforts should focus on optimizing conditions for adaptation to occur by reducing exploitation and protecting critical habitats. Our findings are likely to hold true for most poikilothermic species where captive breeding programmes are used in population management.

  8. Comparative analysis of selected semi-persistent and emerging pollutants in wild-caught fish and aquaculture associated fish using Bogue (Boops boops) as sentinel species.

    Science.gov (United States)

    Henríquez-Hernández, Luis Alberto; Montero, Daniel; Camacho, María; Ginés, Rafael; Boada, Luis D; Ramírez Bordón, Besay; Valerón, Pilar F; Almeida-González, Maira; Zumbado, Manuel; Haroun, Ricardo; Luzardo, Octavio P

    2017-03-01

    The marine environment acts as a sink for diverse anthropogenic pollutants, although the environmental contamination may be non-uniformly distributed. In recent decades, the aquaculture sector has experienced a steady growth postulating as a good alternative for seafood production. However, a social debate exits about the differential level of pollutants in wild and farmed species. This study was designed to evaluate the level of pollutants in a sentinel species: Bogue (Boops boops) associated and non-associated to fish-farm cages. A total of 82 chemical substances were determined by gas chromatography-mass spectrometry, including persistent (polychlorobiphenyls (PCBs) and organochlorine pesticides (OCPs)), semi-persistent (bromodiphenyl ethers (BDEs) and polycyclic aromatic hydrocarbons (PAHs)), and emerging pollutants (such as organophosphate flame retardants (OPFRs) and UV-filters). In general, aquaculture-associated bogues showed lower levels of semi-persistent and emerging pollutants than wild-caught fish, especially when sums were considered. Thus, sum of BDEs was significantly lower in the aquaculture group (p=0.01). A similar trend was also observed for benzo(a)anthracene, the UV-filter 2-ethylhexyl-p-methoxycinnamate and some OPFRs. In the case of persistent pollutants, the sum of dioxin-like PCBs and sum of DDTs were lower in the group of wild-caught bogues (p=0.034 and p=0.003, respectively) than in aquaculture-associated bogues, as previously described for some aquaculture species. Fish feed appear as an important factor in the uptake of such substances suggesting a diet intervention to reduce their levels in the aquaculture products. Another interesting result is that for almost all chemical substances analyzed, bogues captured near sewage outfalls showed the highest levels of pollutants, pointing out the need of stringent measures for wastewater treatment units discharging in coastal areas. On the light of these results, further research in specific

  9. Genetic variation in wild and hatchery population of Catla catla (Hamilton, 1822) analyzed through mtDNA cytochrome b region.

    Science.gov (United States)

    Behera, Bijay Kumar; Kunal, Swaraj Priyaranjan; Baisvar, Vishwamitra Singh; Meena, Dharmendra Kumar; Panda, Debarata; Pakrashi, Sudip; Paria, Prasenjit; Das, Pronob; Debnath, Dipesh; Parida, Pranaya Kumar; Das, Basanta Kumar; Jena, Joykrushna

    2018-01-01

    Catla (Catla catla) is a one of the most harvested Indian major carps and is widely cultured fish species in Indian subcontinent. In the present study, genetic variability between hatchery and wild stocks of Catla was surveyed using sequence data of mitochondrial DNA of partial 307 bp of cytochrome b region. A total of 174 Catla individuals were examined from three different river basins and hatcheries. Significant genetic heterogeneity was observed for the sequence data (FST = 0.308, p ≤ 0.001). However, analysis of molecular variance (AMOVA) resulted in insignificant genetic differentiation among the samples of three rivers and culture zones (FCT = -0.10, p = 0.44). The result suggested a significant genetic variation within different riverine system, low genetic differentiation among samples from river basins and a lack of genetic variation in hatchery populations.

  10. Evidence for Domesticated and Wild Populations of Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    2005-07-01

    Full Text Available Saccharomyces cerevisiae is predominantly found in association with human activities, particularly the production of alcoholic beverages. S. paradoxus, the closest known relative of S. cerevisiae, is commonly found on exudates and bark of deciduous trees and in associated soils. This has lead to the idea that S. cerevisiae is a domesticated species, specialized for the fermentation of alcoholic beverages, and isolates of S. cerevisiae from other sources simply represent migrants from these fermentations. We have surveyed DNA sequence diversity at five loci in 81 strains of S. cerevisiae that were isolated from a variety of human and natural fermentations as well as sources unrelated to alcoholic beverage production, such as tree exudates and immunocompromised patients. Diversity within vineyard strains and within saké strains is low, consistent with their status as domesticated stocks. The oldest lineages and the majority of variation are found in strains from sources unrelated to wine production. We propose a model whereby two specialized breeds of S. cerevisiae have been created, one for the production of grape wine and one for the production of saké wine. We estimate that these two breeds have remained isolated from one another for thousands of years, consistent with the earliest archeological evidence for winemaking. We conclude that although there are clearly strains of S. cerevisiae specialized for the production of alcoholic beverages, these have been derived from natural populations unassociated with alcoholic beverage production, rather than the opposite.

  11. Energetic and ecological constraints on population density of reef fishes.

    Science.gov (United States)

    Barneche, D R; Kulbicki, M; Floeter, S R; Friedlander, A M; Allen, A P

    2016-01-27

    Population ecology has classically focused on pairwise species interactions, hindering the description of general patterns and processes of population abundance at large spatial scales. Here we use the metabolic theory of ecology as a framework to formulate and test a model that yields predictions linking population density to the physiological constraints of body size and temperature on individual metabolism, and the ecological constraints of trophic structure and species richness on energy partitioning among species. Our model was tested by applying Bayesian quantile regression to a comprehensive reef-fish community database, from which we extracted density data for 5609 populations spread across 49 sites around the world. Our results indicate that population density declines markedly with increases in community species richness and that, after accounting for richness, energetic constraints are manifested most strongly for the most abundant species, which generally are of small body size and occupy lower trophic groups. Overall, our findings suggest that, at the global scale, factors associated with community species richness are the major drivers of variation in population density. Given that populations of species-rich tropical systems exhibit markedly lower maximum densities, they may be particularly susceptible to stochastic extinction. © 2016 The Author(s).

  12. Scaling in Free-Swimming Fish and Implications for Measuring Size-at-Time in the Wild

    Science.gov (United States)

    Broell, Franziska; Taggart, Christopher T.

    2015-01-01

    This study was motivated by the need to measure size-at-age, and thus growth rate, in fish in the wild. We postulated that this could be achieved using accelerometer tags based first on early isometric scaling models that hypothesize that similar animals should move at the same speed with a stroke frequency that scales with length-1, and second on observations that the speed of primarily air-breathing free-swimming animals, presumably swimming ‘efficiently’, is independent of size, confirming that stroke frequency scales as length-1. However, such scaling relations between size and swimming parameters for fish remain mostly theoretical. Based on free-swimming saithe and sturgeon tagged with accelerometers, we introduce a species-specific scaling relationship between dominant tail beat frequency (TBF) and fork length. Dominant TBF was proportional to length-1 (r2 = 0.73, n = 40), and estimated swimming speed within species was independent of length. Similar scaling relations accrued in relation to body mass-0.29. We demonstrate that the dominant TBF can be used to estimate size-at-time and that accelerometer tags with onboard processing may be able to provide size-at-time estimates among free-swimming fish and thus the estimation of growth rate (change in size-at-time) in the wild. PMID:26673777

  13. Genetic concepts and uncertainties in restoring fish populations and species

    Science.gov (United States)

    Reisenbichler, R.R.; Utter, F.M.; Krueger, C.C.

    2003-01-01

    Genetic considerations can be crucially important to the success of reintroductions of lotic species. Current paradigms for conservation and population genetics provide guidance for reducing uncertainties in genetic issues and for increasing the likelihood of achieving restoration. Effective restoration is facilitated through specific goals and objectives developed from the definition that a restored or healthy population is (i) genetically adapted to the local environment, (ii) self-sustaining at abundances consistent with the carrying capacity of the river system, (iii) genetically compatible with neighboring populations so that substantial outbreeding depression does not result from straying and interbreeding between populations, and (iv) sufficiently diverse genetically to accommodate environmental variability over many decades. Genetic principles reveal the importance of describing and adhering to the ancestral lineages for the species to be restored and enabling genetic processes to maintain diversity and fitness in the populations under restoration. Newly established populations should be protected from unnecessary human sources of mortality, gene flow from maladapted (e.g., hatchery) or exotic populations, and inadvertent selection by fisheries or other human activities. Such protection facilitates initial, rapid adaptation of the population to its environment and should enhance the chances for persistence. Various uncertainties about specific restoration actions must be addressed on a case-by-case basis. Such uncertainties include whether to allow natural colonization or to introduce fish, which populations are suitable as sources for reintroduction, appropriate levels of gene flow from other populations, appropriate levels of artificial production, appropriate minimum numbers of individuals released or maintained in the population, and the best developmental stages for releasing fish into the restored stream. Rigorous evaluation or

  14. Identification of the first glyphosate-resistant wild radish (Raphanus raphanistrum L.) populations.

    Science.gov (United States)

    Ashworth, Michael B; Walsh, Michael J; Flower, Ken C; Powles, Stephen B

    2014-09-01

    In Australia, glyphosate has been used routinely to control wild radish (Raphanus raphanistrum L.) for the past 40 years. This study focuses on two field-evolved glyphosate-resistant populations of wild radish collected from the grainbelt of Western Australia. Two wild radish biotypes were confirmed to be glyphosate resistant by comparing R/S of two suspected populations. Based on R/S from dose-response curves, the R1 and R2 populations were 2.3 and 3.2 times more resistant to glyphosate respectively. Dose response on glyphosate-selected progeny (>1080 g ha(-1)) demonstrated that the glyphosate resistance mechanism was heritable. When compared with the pooled mortality results of three known susceptible populations (S1, S2 and S3), the R1 and R2 subpopulations were 3.4-fold and 4.5-fold more resistant at the LD50 level respectively. Both populations were found to have multiple resistance to the phytoene desaturase inhibitor; diflufenican, the synthetic auxin; 2,4-D and the ALS inhibitors; chlorsulfuron, sulfometuron-methyl, imazethapyr and metosulam. This is the first report confirming glyphosate resistance evolution in wild radish and serves to re-emphasise the importance of diverse weed control strategies. Proactive and integrated measures for resistance management need to be developed to diversify control measures away from glyphosate and advance the use of non-herbicidal techniques. © 2014 Society of Chemical Industry.

  15. Patterns of population subdivision, gene flow and genetic variability in the African wild dog (Lycaon pictus).

    Science.gov (United States)

    Girman, D J; Vilà, C; Geffen, E; Creel, S; Mills, M G; McNutt, J W; Ginsberg, J; Kat, P W; Mamiya, K H; Wayne, R K

    2001-07-01

    African wild dogs are large, highly mobile carnivores that are known to disperse over considerable distances and are rare throughout much of their geographical range. Consequently, genetic variation within and differentiation between geographically separated populations is predicted to be minimal. We determined the genetic diversity of mitochondrial DNA (mtDNA) control region sequences and microsatellite loci in seven populations of African wild dogs. Analysis of mtDNA nucleotide diversity suggests that, historically, wild dog populations have been small relative to other large carnivores. However, population declines due to recent habitat loss have not caused a dramatic reduction in genetic diversity. We found one historical and eight recent mtDNA genotypes in 280 individuals that defined two highly divergent clades. In contrast to a previous, more limited, mtDNA analysis, sequences from these clades are not geographically restricted to eastern or southern African populations. Rather, we found a large admixture zone spanning populations from Botswana, Zimbabwe and south-eastern Tanzania. Mitochondrial and microsatellite differentiation between populations was significant and unique mtDNA genotypes and alleles characterized the populations. However, gene flow estimates (Nm) based on microsatellite data were generally greater than one migrant per generation. In contrast, gene flow estimates based on the mtDNA control region were lower than expected given differences in the mode of inheritance of mitochondrial and nuclear markers which suggests a male bias in long-distance dispersal.

  16. Ocean acidification alters fish populations indirectly through habitat modification

    Science.gov (United States)

    Nagelkerken, Ivan; Russell, Bayden D.; Gillanders, Bronwyn M.; Connell, Sean D.

    2016-01-01

    Ocean ecosystems are predicted to lose biodiversity and productivity from increasing ocean acidification. Although laboratory experiments reveal negative effects of acidification on the behaviour and performance of species, more comprehensive predictions have been hampered by a lack of in situ studies that incorporate the complexity of interactions between species and their environment. We studied CO2 vents from both Northern and Southern hemispheres, using such natural laboratories to investigate the effect of ocean acidification on plant-animal associations embedded within all their natural complexity. Although we substantiate simple direct effects of reduced predator-avoidance behaviour by fishes, as observed in laboratory experiments, we here show that this negative effect is naturally dampened when fish reside in shelter-rich habitats. Importantly, elevated CO2 drove strong increases in the abundance of some fish species through major habitat shifts, associated increases in resources such as habitat and prey availability, and reduced predator abundances. The indirect effects of acidification via resource and predator alterations may have far-reaching consequences for population abundances, and its study provides a framework for a more comprehensive understanding of increasing CO2 emissions as a driver of ecological change.

  17. Impacts of neonicotinoid use on long-term population changes in wild bees in England

    Science.gov (United States)

    Woodcock, Ben A.; Isaac, Nicholas J. B.; Bullock, James M.; Roy, David B.; Garthwaite, David G.; Crowe, Andrew; Pywell, Richard F.

    2016-08-01

    Wild bee declines have been ascribed in part to neonicotinoid insecticides. While short-term laboratory studies on commercially bred species (principally honeybees and bumblebees) have identified sub-lethal effects, there is no strong evidence linking these insecticides to losses of the majority of wild bee species. We relate 18 years of UK national wild bee distribution data for 62 species to amounts of neonicotinoid use in oilseed rape. Using a multi-species dynamic Bayesian occupancy analysis, we find evidence of increased population extinction rates in response to neonicotinoid seed treatment use on oilseed rape. Species foraging on oilseed rape benefit from the cover of this crop, but were on average three times more negatively affected by exposure to neonicotinoids than non-crop foragers. Our results suggest that sub-lethal effects of neonicotinoids could scale up to cause losses of bee biodiversity. Restrictions on neonicotinoid use may reduce population declines.

  18. Antipredator behavior QTL: differences in rainbow trout clonal lines derived from wild and hatchery populations.

    Science.gov (United States)

    Christensen, Kris A; Brunelli, Joseph P; Wheeler, Paul A; Thorgaard, Gary H

    2014-09-01

    Variation in antipredator behavior may partially explain the survival differences seen between wild and hatchery trout and salmon. Antipredator behavior is thought to change during the domestication process, along with other traits. Investigations of antipredator behavior could benefit conservation efforts and supplementation programs. Our goal was to characterize the antipredator behavior in clonal rainbow trout lines derived from either wild or hatchery populations and identify genetic loci associated with variation between lines. We identified several behaviors that varied between clonal lines and QTL for several behavioral and size traits. Characterizing genetic variation underlying these behaviors may prove valuable in future conservation efforts by enabling monitoring of allele frequencies of loci affecting predation in wild populations.

  19. The Domestication Syndrome in Phoenix dactylifera Seeds: Toward the Identification of Wild Date Palm Populations.

    Science.gov (United States)

    Gros-Balthazard, Muriel; Newton, Claire; Ivorra, Sarah; Pierre, Marie-Hélène; Pintaud, Jean-Christophe; Terral, Jean-Frédéric

    2016-01-01

    Investigating crop origins is a priority to understand the evolution of plants under domestication, develop strategies for conservation and valorization of agrobiodiversity and acquire fundamental knowledge for cultivar improvement. The date palm (Phoenix dactylifera L.) belongs to the genus Phoenix, which comprises 14 species morphologically very close, sometimes hardly distinguishable. It has been cultivated for millennia in the Middle East and in North Africa and constitutes the keystone of oasis agriculture. Yet, its origins remain poorly understood as no wild populations are identified. Uncultivated populations have been described but they might represent feral, i.e. formerly cultivated, abandoned forms rather than truly wild populations. In this context, this study based on morphometrics applied to 1625 Phoenix seeds aims to (1) differentiate Phoenix species and (2) depict the domestication syndrome observed in cultivated date palm seeds using other Phoenix species as a "wild" reference. This will help discriminate truly wild from feral forms, thus providing new insights into the evolutionary history of this species. Seed size was evaluated using four parameters: length, width, thickness and dorsal view surface. Seed shape was quantified using outline analyses based on the Elliptic Fourier Transform method. The size and shape of seeds allowed an accurate differentiation of Phoenix species. The cultivated date palm shows distinctive size and shape features, compared to other Phoenix species: seeds are longer and elongated. This morphological shift may be interpreted as a domestication syndrome, resulting from the long-term history of cultivation, selection and human-mediated dispersion. Based on seed attributes, some uncultivated date palms from Oman may be identified as wild. This opens new prospects regarding the possible existence and characterization of relict wild populations and consequently for the understanding of the date palm origins. Finally, we

  20. Current distribution and characterization of the wild grapevine populations in Andalusia (Spain).

    Science.gov (United States)

    Cantos, Manuel; Arroyo-García, Rosa; García, José Luis; Lara, Miguel; Morales, Ramón; López, María Ángeles; Gallardo, Antonio; Ocete, Carlos Alvar; Rodríguez, Álvaro; Valle, José Manuel; Vaca, Ramón; González-Maestro, Magdalena; Bánáti, Hajnalka; Ocete, Rafael

    2017-03-01

    For decades, human activities have gradually destroyed the natural habitats of wild grapevine, Vitis vinifera L. subsp. sylvestris (Gmelin) Hegi, and nowadays this species is endangered in southern Europe. In this paper, 94 populations of this species have been localized and characterized in the Andalusian region in the Iberian Peninsula between 1989 and 2013. Location, ecological aspects, and sanitary characteristics are described. Must properties and in vitro tolerance to calcareous conditions were also checked. The paper also contains a global description of female and male individuals. Two hundred individuals from six river basin populations have been sampled, and their genetic structure analyzed by using 25 nuclear microsatellites loci to investigate the gene diversity of wild grape populations in Andalusia at two levels: total individuals and at river basin populations. Also, the genetic relationship of wild and cultivated accessions has been tested. Wild grapevine is considered the ancestor of the cultivated varieties and should be preserved as this material could be used to start breeding programs of cultivated varieties and also to restore riverbank forests, which constitute one of the worst preserved ecosystems in the area. Copyright © 2017 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

  1. Latitudinal variation in wild populations of Drosophila melanogaster : heritabilities and reaction norms

    NARCIS (Netherlands)

    van't Land, J; van Putten, P; Zwaan, B; Kamping, A; van Delden, W

    Large amounts of genetic variation for wing length and wing area were demonstrated both within and between Drosophila melanogaster populations along a latitudinal gradient in South America. Wing length and wing area showed a strong positive correlation with latitude in both wild flies and

  2. Interactions between Behaviour and Genetics in Wild and Domestic Bird Populations

    NARCIS (Netherlands)

    Rodenburg, T.B.; Oers, van K.

    2010-01-01

    Personality traits can be favoured by both natural and artificial selection, if they result in increased fitness or productivity, and therefore play an important role in both wild and domestic populations. Here, we review how personality traits affect and are affected by natural and artificial

  3. Chloroplast DNA Variations in Wild Brassicas and Their Implication in Breeding and Population Genetics Studies

    Directory of Open Access Journals (Sweden)

    Bharti Sarin

    2015-01-01

    Full Text Available Evaluation of chloroplast DNA (cpDNA diversity in wild relatives of crop brassicas is important for characterization of cytoplasm and also for population genetics/phylogeographic analyses. The former is useful for breeding programs involving wide hybridization and synthesis of alloplasmic lines, while the latter is important for formulating conservation strategies. Therefore, PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism technique was applied to study cpDNA diversity in 14 wild brassicas (including 31 accessions which revealed a total of 219 polymorphic fragments. The combination of polymorphisms obtained by using only two primer pair-restriction enzyme combinations was sufficient to distinguish all 14 wild brassicas. Moreover, 11 primer pairs-restriction enzyme combinations revealed intraspecific polymorphisms in eight wild brassicas (including endemic and endangered species, B. cretica and B. insularis, resp.. Thus, even within a small number of accessions that were screened, intraspecific polymorphisms were observed, which is important for population genetics analyses in wild brassicas and consequently for conservation studies.

  4. Genetic diversity and population structure of an important wild berry crop

    Science.gov (United States)

    Zoratti, Laura; Palmieri, Luisa; Jaakola, Laura; Häggman, Hely

    2015-01-01

    The success of plant breeding in the coming years will be associated with access to new sources of variation, which will include landraces and wild relatives of crop species. In order to access the reservoir of favourable alleles within wild germplasm, knowledge about the genetic diversity and the population structure of wild species is needed. Bilberry (Vaccinium myrtillus) is one of the most important wild crops growing in the forests of Northern European countries, noted for its nutritional properties and its beneficial effects on human health. Assessment of the genetic diversity of wild bilberry germplasm is needed for efforts such as in situ conservation, on-farm management and development of plant breeding programmes. However, to date, only a few local (small-scale) genetic studies of this species have been performed. We therefore conducted a study of genetic variability within 32 individual samples collected from different locations in Iceland, Norway, Sweden, Finland and Germany, and analysed genetic diversity among geographic groups. Four selected inter-simple sequence repeat primers allowed the amplification of 127 polymorphic loci which, based on analysis of variance, made it possible to identify 85 % of the genetic diversity within studied bilberry populations, being in agreement with the mixed-mating system of bilberry. Significant correlations were obtained between geographic and genetic distances for the entire set of samples. The analyses also highlighted the presence of a north–south genetic gradient, which is in accordance with recent findings on phenotypic traits of bilberry. PMID:26483325

  5. Inbreeding avoidance influences the viability of reintroduced populations of African wild dogs (Lycaon pictus).

    Science.gov (United States)

    Becker, Penny A; Miller, Philip S; Gunther, Micaela Szykman; Somers, Michael J; Wildt, David E; Maldonado, Jesús E

    2012-01-01

    The conservation of many fragmented and small populations of endangered African wild dogs (Lycaon pictus) relies on understanding the natural processes affecting genetic diversity, demographics, and future viability. We used extensive behavioural, life-history, and genetic data from reintroduced African wild dogs in South Africa to (1) test for inbreeding avoidance via mate selection and (2) model the potential consequences of avoidance on population persistence. Results suggested that wild dogs avoided mating with kin. Inbreeding was rare in natal packs, after reproductive vacancies, and between sibling cohorts (observed on 0.8%, 12.5%, and 3.8% of occasions, respectively). Only one of the six (16.7%) breeding pairs confirmed as third-order (or closer) kin consisted of animals that were familiar with each other, while no other paired individuals had any prior association. Computer-simulated populations allowed to experience inbreeding had only a 1.6% probability of extinction within 100 years, whereas all populations avoiding incestuous matings became extinct due to the absence of unrelated mates. Populations that avoided mating with first-order relatives became extinct after 63 years compared with persistence of 37 and 19 years for those also prevented from second-order and third-order matings, respectively. Although stronger inbreeding avoidance maintains significantly more genetic variation, our results demonstrate the potentially severe demographic impacts of reduced numbers of suitable mates on the future viability of small, isolated wild dog populations. The rapid rate of population decline suggests that extinction may occur before inbreeding depression is observed.

  6. Inbreeding avoidance influences the viability of reintroduced populations of African wild dogs (Lycaon pictus.

    Directory of Open Access Journals (Sweden)

    Penny A Becker

    Full Text Available The conservation of many fragmented and small populations of endangered African wild dogs (Lycaon pictus relies on understanding the natural processes affecting genetic diversity, demographics, and future viability. We used extensive behavioural, life-history, and genetic data from reintroduced African wild dogs in South Africa to (1 test for inbreeding avoidance via mate selection and (2 model the potential consequences of avoidance on population persistence. Results suggested that wild dogs avoided mating with kin. Inbreeding was rare in natal packs, after reproductive vacancies, and between sibling cohorts (observed on 0.8%, 12.5%, and 3.8% of occasions, respectively. Only one of the six (16.7% breeding pairs confirmed as third-order (or closer kin consisted of animals that were familiar with each other, while no other paired individuals had any prior association. Computer-simulated populations allowed to experience inbreeding had only a 1.6% probability of extinction within 100 years, whereas all populations avoiding incestuous matings became extinct due to the absence of unrelated mates. Populations that avoided mating with first-order relatives became extinct after 63 years compared with persistence of 37 and 19 years for those also prevented from second-order and third-order matings, respectively. Although stronger inbreeding avoidance maintains significantly more genetic variation, our results demonstrate the potentially severe demographic impacts of reduced numbers of suitable mates on the future viability of small, isolated wild dog populations. The rapid rate of population decline suggests that extinction may occur before inbreeding depression is observed.

  7. Inbreeding Avoidance Influences the Viability of Reintroduced Populations of African Wild Dogs (Lycaon pictus)

    Science.gov (United States)

    Becker, Penny A.; Miller, Philip S.; Gunther, Micaela Szykman; Somers, Michael J.; Wildt, David E.; Maldonado, Jesús E.

    2012-01-01

    The conservation of many fragmented and small populations of endangered African wild dogs (Lycaon pictus) relies on understanding the natural processes affecting genetic diversity, demographics, and future viability. We used extensive behavioural, life-history, and genetic data from reintroduced African wild dogs in South Africa to (1) test for inbreeding avoidance via mate selection and (2) model the potential consequences of avoidance on population persistence. Results suggested that wild dogs avoided mating with kin. Inbreeding was rare in natal packs, after reproductive vacancies, and between sibling cohorts (observed on 0.8%, 12.5%, and 3.8% of occasions, respectively). Only one of the six (16.7%) breeding pairs confirmed as third-order (or closer) kin consisted of animals that were familiar with each other, while no other paired individuals had any prior association. Computer-simulated populations allowed to experience inbreeding had only a 1.6% probability of extinction within 100 years, whereas all populations avoiding incestuous matings became extinct due to the absence of unrelated mates. Populations that avoided mating with first-order relatives became extinct after 63 years compared with persistence of 37 and 19 years for those also prevented from second-order and third-order matings, respectively. Although stronger inbreeding avoidance maintains significantly more genetic variation, our results demonstrate the potentially severe demographic impacts of reduced numbers of suitable mates on the future viability of small, isolated wild dog populations. The rapid rate of population decline suggests that extinction may occur before inbreeding depression is observed. PMID:22615933

  8. Heavy metals in fish tissues/stomach contents in four marine wild commercially valuable fish species from the western continental shelf of South China Sea.

    Science.gov (United States)

    Gu, Yang-Guang; Lin, Qin; Huang, Hong-Hui; Wang, Liang-Gen; Ning, Jia-Jia; Du, Fei-Yan

    2017-01-30

    The concentrations of heavy metals (Cd, Pb, Cr, Ni, Cu and Zn) were determined in four commercially valuable fish species (Thunnus obesus, Decapterus lajang, Cubiceps squamiceps and Priacanthus macracanthus), collected in the western continental shelf of the South China Sea. Concentrations of Cd, Pb, Cr, Ni, Cu, and Zn in fish muscles were 0.006-0.050, 0.13-0.68, 0.18-0.85, 0.11-0.25, 0.12-0.77, and 2.41-4.73μg/g, wet weight, respectively. Concentrations of heavy metals in all species were below their acceptable daily upper limit, suggesting human consumption of these wild fish species may be safe, with health risk assessment based on the target hazard quotients (THQ) and total THQ, indicating no significant adverse health effects with consumption. The average concentrations of Zn were higher in gills than in stomach contents, backbones or muscle, while conversely, the other heavy metals had higher concentrations in stomach contents than in other tissues. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Identification of fish populations with particular reference to the pelagic fish stocks of the Indian Ocean region

    Digital Repository Service at National Institute of Oceanography (India)

    Dwivedi, S.N.

    The most essential step in any fishery management is the identification of discrete fish populations. This is particularly important for the development of Indian Ocean pelagic fisheries. The simple signal character analysis of meristic or metric...

  10. The Domestication Syndrome in Phoenix dactylifera Seeds: Toward the Identification of Wild Date Palm Populations

    Science.gov (United States)

    Gros-Balthazard, Muriel; Newton, Claire; Ivorra, Sarah; Pierre, Marie-Hélène; Terral, Jean-Frédéric

    2016-01-01

    Investigating crop origins is a priority to understand the evolution of plants under domestication, develop strategies for conservation and valorization of agrobiodiversity and acquire fundamental knowledge for cultivar improvement. The date palm (Phoenix dactylifera L.) belongs to the genus Phoenix, which comprises 14 species morphologically very close, sometimes hardly distinguishable. It has been cultivated for millennia in the Middle East and in North Africa and constitutes the keystone of oasis agriculture. Yet, its origins remain poorly understood as no wild populations are identified. Uncultivated populations have been described but they might represent feral, i.e. formerly cultivated, abandoned forms rather than truly wild populations. In this context, this study based on morphometrics applied to 1625 Phoenix seeds aims to (1) differentiate Phoenix species and (2) depict the domestication syndrome observed in cultivated date palm seeds using other Phoenix species as a “wild” reference. This will help discriminate truly wild from feral forms, thus providing new insights into the evolutionary history of this species. Seed size was evaluated using four parameters: length, width, thickness and dorsal view surface. Seed shape was quantified using outline analyses based on the Elliptic Fourier Transform method. The size and shape of seeds allowed an accurate differentiation of Phoenix species. The cultivated date palm shows distinctive size and shape features, compared to other Phoenix species: seeds are longer and elongated. This morphological shift may be interpreted as a domestication syndrome, resulting from the long-term history of cultivation, selection and human-mediated dispersion. Based on seed attributes, some uncultivated date palms from Oman may be identified as wild. This opens new prospects regarding the possible existence and characterization of relict wild populations and consequently for the understanding of the date palm origins. Finally, we

  11. Rapid Decrease in Populations of Wild Ring-Tailed Lemurs (Lemur catta) in Madagascar.

    Science.gov (United States)

    LaFleur, Marni; Clarke, Tara A; Reuter, Kim; Schaeffer, Toby

    2016-01-01

    Lemurs are the most threatened group of mammals on earth. Lemur catta (ring-tailed lemur) represents one of the most iconic lemur species and faces numerous anthropogenic threats in the wild. In this study, we present population estimates from 32 sites across the range of L. catta, collected from primary and secondary data sources, to assess the number of ring-tailed lemurs left in the wild. We estimate that there are approximately 2,220 individual L. catta remaining in the 32 sites considered. We note local extinctions of populations of L. catta in at least 12 of the 32 sites examined, and that significantly more extinctions occurred in areas without some form of protection. This decrease in extant populations could represent a decrease of more than 95% of all ring-tailed lemurs in Madagascar since the year 2000. While these results should be considered preliminary, we stress the rapid decline of the species and note that habitat loss, bushmeat hunting and the illegal pet trade are driving populations to local extinction. Based on the data presented here, urgent and immediate funding and conservation action are crucial to ensure the viability of the remaining wild populations of ring-tailed lemurs. © 2017 S. Karger AG, Basel.

  12. Genetic differentiation of wild and cultivated populations: diversity of Coffea canephora Pierre in Uganda.

    Science.gov (United States)

    Musoli, P; Cubry, P; Aluka, P; Billot, C; Dufour, M; De Bellis, F; Pot, D; Bieysse, D; Charrier, A; Leroy, T

    2009-07-01

    Coffea canephora Pierre ex Frohener is a perennial plant originated from Africa. Two main groups, Guinean and Congolese, have already been identified within this species. They correspond to main refugia in western and central Africa. In this paper we present the analysis of a region that has not yet been studied, Uganda. Two wild, one feral (once cultivated but abandoned for many years), and two cultivated populations of C. canephora from Uganda were evaluated using 24 microsatellite markers. Basic diversity, dissimilarity and genetic distances between individuals, genetic differentiation between populations, and structure within populations were analysed. Expected heterozygosity was high for wild compartments (0.48 to 0.54) and for cultivated and feral ones (0.57 to 0.59), with the number of private alleles ranging from 12 for cultivated genotypes to 37 for a wild compartment. The Ugandan samples show significant population structuring. We compared the Ugandan populations with a representative sample of known genetic diversity groups within the species using 18 markers. Coffea canephora of Ugandan origin was found to be genetically different from previously identified diversity groups, implying that it forms another diversity group within the species. Given its large distribution and extremely recent domestication, C. canephora can be used to understand the effect of refugia colonization on genetic diversity.

  13. Epidemiological characterization of VNNV in hatchery-reared and wild marine fish on Hainan Island, China, and experimental infection of golden pompano (Trachinotus ovatus) juveniles.

    Science.gov (United States)

    Ma, Hongling; Wen, Weigeng; Su, Youlu; Feng, Juan; Xu, Liwen; Peng, Chao; Guo, Zhixun

    2015-12-01

    The current epidemiological situation of viral nervous necrosis virus (VNNV) on Hainan Island was investigated. A total of 490 hatchery-reared fish and 652 wild fish were sampled for VNNV detection from March 2013 to May 2014. Positive detection rates of 84.53% (153/181) and 0.97 % (3/309) were obtained in diseased and healthy hatchery-reared samples, respectively, by conventional RT-PCR. However, using more-sensitive nested RT-PCR, the positive detection rates in healthy hatchery-reared fish reached up to 64.08% (198/309), suggesting that asymptomatic VNNV carriers commonly exist among larvae and juveniles breeding on Hainan Island. In wild-fish samples, 2.6% (17/652) and 34.2% (223/652) positive detection rates were observed using RT-PCR and nested RT-PCR, respectively, indicating that wild fish may be a potential reservoir for VNNV. Phylogenetic analysis showed that all 52 VNNV isolates from cultured fish belong to the RGNNV genotype, but 2 out of 48 VNNV isolates from wild fish samples were found to be of the SJNNV genotype. This study is the first to confirm the existence of SJNNV-genotype VNNV in China. Golden pompano, an important fish species for culture, was selected as a fish model to investigate the optimal conditions for RGNNV disease progression in artificial infection experiments. The effects of temperature, salinity, and fish size were evaluated. Results showed that 28 °C and 20 ‰ are the optimal infection temperature and salinity, respectively, and golden pompano juveniles with small body sizes are more susceptible to RGNNV. These findings are highly consistent with those conditions involved in the natural outbreak of RGNNV.

  14. Three decades of farmed escapees in the wild: a spatio-temporal analysis of Atlantic salmon population genetic structure throughout Norway.

    Directory of Open Access Journals (Sweden)

    Kevin A Glover

    Full Text Available Each year, hundreds of thousands of domesticated farmed Atlantic salmon escape into the wild. In Norway, which is the world's largest commercial producer, many native Atlantic salmon populations have experienced large numbers of escapees on the spawning grounds for the past 15-30 years. In order to study the potential genetic impact, we conducted a spatio-temporal analysis of 3049 fish from 21 populations throughout Norway, sampled in the period 1970-2010. Based upon the analysis of 22 microsatellites, individual admixture, F(ST and increased allelic richness revealed temporal genetic changes in six of the populations. These changes were highly significant in four of them. For example, 76% and 100% of the fish comprising the contemporary samples for the rivers Vosso and Opo were excluded from their respective historical samples at P=0.001. Based upon several genetic parameters, including simulations, genetic drift was excluded as the primary cause of the observed genetic changes. In the remaining 15 populations, some of which had also been exposed to high numbers of escapees, clear genetic changes were not detected. Significant population genetic structuring was observed among the 21 populations in the historical (global F(ST =0.038 and contemporary data sets (global F(ST =0.030, although significantly reduced with time (P=0.008. This reduction was especially distinct when looking at the six populations displaying temporal changes (global F(ST dropped from 0.058 to 0.039, P=0.006. We draw two main conclusions: 1. The majority of the historical population genetic structure throughout Norway still appears to be retained, suggesting a low to modest overall success of farmed escapees in the wild; 2. Genetic introgression of farmed escapees in native salmon populations has been strongly population-dependent, and it appears to be linked with the density of the native population.

  15. Scaling methane emissions in ruminants and global estimates in wild populations.

    Science.gov (United States)

    Pérez-Barbería, F J

    2017-02-01

    Methane (CH 4 ) emissions by human activities have more than doubled since the 1700s, and they contribute to global warming. One of the sources of CH 4 is produced by incomplete oxidation of feed in the ruminant's gut. Domestic ruminants produce most of the emissions from animal sources, but emissions by wild ruminants have been poorly estimated. This study (i) scales CH 4 against body mass in 503 experiments in ruminants fed herbage, and assesses the effect of different sources of variation, using published and new data; and (ii) it uses these models to produce global estimates of CH 4 emissions from wild ruminants. The incorporation of phylogeny, diet and technique of measuring in to a model that scales log 10 CH 4 gd -1 against log 10 body mass (kg), reduces the slope, from 1.075 to 0.868, making it not significantly steeper than the scaling coefficient of metabolic requirements to body mass. Scaling models that include dry matter intake (DMI) and dietary fiber indicate that although both increase CH 4 , dietary fiber depresses CH 4 as the levels of DMI increases. Cattle produces more CH 4 per unit of DMI than red deer, sheep or goat, and there are no significant differences between CH 4 produced by red deer and sheep. The average estimates of global emissions from wild ruminants calculated using different models are smaller (1.094-2.687Tgy -1 ) than those presented in the reports of the Intergovernmental Panel on Climate Change (15Tgyr -1 ). Potential causes to explain such discrepancy are the uncertainty on the world's wild ruminant population size, and the use of methane output from cattle, a high methane producer, as representative methane output of wild ruminants. The main limitation researchers' face in calculating accurate global CH 4 emissions from wild ungulates is a lack of reliable information on their population sizes. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Selection of reference genes for qRT-PCR examination of wild populations of Atlantic cod Gadus morhua

    Directory of Open Access Journals (Sweden)

    Lie Kai K

    2008-07-01

    Full Text Available Abstract Background Extensive sequencing efforts have been taking place for the Atlantic cod (Gadus morhua in recent years, the number of ESTs in the Genbank has reached more than 140.000. Despite its importance in North Atlantic fisheries and potential use in aquaculture, relatively few gene expression examination exists for this species, and systematic evaluations of reference gene stability in quantitative real-time RT-PCR (qRT-PCR studies are lacking. Results The stability of 10 potential reference genes was examined in six tissues of Atlantic cod obtained from four populations, to determine the most suitable genes to be used in qRT-PCR analyses. Relative transcription levels of genes encoding β-actin (ACTB, elongation factor 1A (EF1A, actin-related protein-2 (ARP-2, glyceraldehyde-3P-dehydrogenase (GAPDH, ubiquitin (Ubi, acidic ribosomal protein (ARP, ribosomal protein S9 (S9, ribosomal protein L4 (RPL4, RPL22 and RPL37 were quantified in gills, brain, liver, head kidney, muscle and middle intestine in six juvenile fish from three wild populations and from farmed Atlantic cod. Reference gene stability was investigated using the geNorm and NormFinder tools. Based on calculations performed with the geNorm, which determines the most stable genes from a set of tested genes in a given cDNA sample, ARP, Ubi, S9 and RPL37 were among the most stable genes in all tissues. When the same calculations were done with NormFinder, the same genes plus RPL4 and EF1A were ranked as the preferable genes. Conclusion Overall, this work suggests that the Ubi and ARP can be useful as reference genes in qRT-PCR examination of gene expression studying wild populations of Atlantic cod.

  17. Selection of reference genes for qRT-PCR examination of wild populations of Atlantic cod Gadus morhua.

    Science.gov (United States)

    Olsvik, Pål A; Søfteland, Liv; Lie, Kai K

    2008-07-16

    Extensive sequencing efforts have been taking place for the Atlantic cod (Gadus morhua) in recent years, the number of ESTs in the Genbank has reached more than 140.000. Despite its importance in North Atlantic fisheries and potential use in aquaculture, relatively few gene expression examination exists for this species, and systematic evaluations of reference gene stability in quantitative real-time RT-PCR (qRT-PCR) studies are lacking. The stability of 10 potential reference genes was examined in six tissues of Atlantic cod obtained from four populations, to determine the most suitable genes to be used in qRT-PCR analyses. Relative transcription levels of genes encoding beta-actin (ACTB), elongation factor 1A (EF1A), actin-related protein-2 (ARP-2), glyceraldehyde-3P-dehydrogenase (GAPDH), ubiquitin (Ubi), acidic ribosomal protein (ARP), ribosomal protein S9 (S9), ribosomal protein L4 (RPL4), RPL22 and RPL37 were quantified in gills, brain, liver, head kidney, muscle and middle intestine in six juvenile fish from three wild populations and from farmed Atlantic cod. Reference gene stability was investigated using the geNorm and NormFinder tools. Based on calculations performed with the geNorm, which determines the most stable genes from a set of tested genes in a given cDNA sample, ARP, Ubi, S9 and RPL37 were among the most stable genes in all tissues. When the same calculations were done with NormFinder, the same genes plus RPL4 and EF1A were ranked as the preferable genes. Overall, this work suggests that the Ubi and ARP can be useful as reference genes in qRT-PCR examination of gene expression studying wild populations of Atlantic cod.

  18. Genome re-sequencing of semi-wild soybean reveals a complex Soja population structure and deep introgression.

    Directory of Open Access Journals (Sweden)

    Jie Qiu

    Full Text Available Semi-wild soybean is a unique type of soybean that retains both wild and domesticated characteristics, which provides an important intermediate type for understanding the evolution of the subgenus Soja population in the Glycine genus. In this study, a semi-wild soybean line (Maliaodou and a wild line (Lanxi 1 collected from the lower Yangtze regions were deeply sequenced while nine other semi-wild lines were sequenced to a 3-fold genome coverage. Sequence analysis revealed that (1 no independent phylogenetic branch covering all 10 semi-wild lines was observed in the Soja phylogenetic tree; (2 besides two distinct subpopulations of wild and cultivated soybean in the Soja population structure, all semi-wild lines were mixed with some wild lines into a subpopulation rather than an independent one or an intermediate transition type of soybean domestication; (3 high heterozygous rates (0.19-0.49 were observed in several semi-wild lines; and (4 over 100 putative selective regions were identified by selective sweep analysis, including those related to the development of seed size. Our results suggested a hybridization origin for the semi-wild soybean, which makes a complex Soja population structure.

  19. Genome re-sequencing of semi-wild soybean reveals a complex Soja population structure and deep introgression.

    Science.gov (United States)

    Qiu, Jie; Wang, Yu; Wu, Sanling; Wang, Ying-Ying; Ye, Chu-Yu; Bai, Xuefei; Li, Zefeng; Yan, Chenghai; Wang, Weidi; Wang, Ziqiang; Shu, Qingyao; Xie, Jiahua; Lee, Suk-Ha; Fan, Longjiang

    2014-01-01

    Semi-wild soybean is a unique type of soybean that retains both wild and domesticated characteristics, which provides an important intermediate type for understanding the evolution of the subgenus Soja population in the Glycine genus. In this study, a semi-wild soybean line (Maliaodou) and a wild line (Lanxi 1) collected from the lower Yangtze regions were deeply sequenced while nine other semi-wild lines were sequenced to a 3-fold genome coverage. Sequence analysis revealed that (1) no independent phylogenetic branch covering all 10 semi-wild lines was observed in the Soja phylogenetic tree; (2) besides two distinct subpopulations of wild and cultivated soybean in the Soja population structure, all semi-wild lines were mixed with some wild lines into a subpopulation rather than an independent one or an intermediate transition type of soybean domestication; (3) high heterozygous rates (0.19-0.49) were observed in several semi-wild lines; and (4) over 100 putative selective regions were identified by selective sweep analysis, including those related to the development of seed size. Our results suggested a hybridization origin for the semi-wild soybean, which makes a complex Soja population structure.

  20. Population genetic structure of an estuarine and a reef fish species exploited by Brazilian artisanal fishing

    Directory of Open Access Journals (Sweden)

    Regina H.G. Priolli

    2016-11-01

    Full Text Available In this study, we used microsatellite markers to examine the genetic structures of Centropomus undecimalis (Bloch, 1792 and Epinephelus marginatus (Lowe, 1834 populations collected from artisanal fishing sites along a stretch of coastline in southeastern Brazil. Based on F-statistics, there was no significant genetic differentiation evident in any C. undecimalis samples (FST=0.012. However, Bayesian clustering, principal component analysis (PCA and discriminant analysis of principal components (DAPC results suggested that there were most likely two clusters, with no relation to geographic areas. The bottleneck results showed no significant values and the effective population sizes (Ne for the two genetically differentiated groups were large and similar. In contrast, for E. marginatus populations, the microsatellite loci showed no population subdivisions. The FST value was low and non-significant (FST=0.008, a Bayesian analysis indicated one cluster, and a PCA showed that all samples from different geographical sites shared the same genetic structure. The bottleneck results exhibited significant differences, and a low Ne was observed. The results of the genetic study of these two species along the southeastern Brazilian coast suggest that the distinct genetic structure of each species should be taken into account as management units for the conservation of their genetic diversities.

  1. How much gene flow is needed to avoid inbreeding depression in wild tiger populations?

    Science.gov (United States)

    Kenney, John; Allendorf, Fred W.; McDougal, Charles; Smith, James L. D.

    2014-01-01

    The number and size of tiger populations continue to decline owing to habitat loss, habitat fragmentation and poaching of tigers and their prey. As a result, tiger populations have become small and highly structured. Current populations have been isolated since the early 1970s or for approximately seven generations. The objective of this study is to explore how inbreeding may be affecting the persistence of remaining tiger populations and how dispersal, either natural or artificial, may reduce the potentially detrimental effect of inbreeding depression. We developed a tiger simulation model and used published levels of genetic load in mammals to simulate inbreeding depression. Following a 50 year period of population isolation, we introduced one to four dispersing male tigers per generation to explore how gene flow from nearby populations may reduce the negative impact of inbreeding depression. For the smallest populations, even four dispersing male tigers per generation did not increase population viability, and the likelihood of extinction is more than 90% within 30 years. Unless habitat connectivity is restored or animals are artificially introduced in the next 70 years, medium size wild populations are also likely to go extinct, with only four to five of the largest wild tiger populations likely to remain extant in this same period without intervention. To reduce the risk of local extinction, habitat connectivity must be pursued concurrently with efforts to increase population size (e.g. enhance habitat quality, increase habitat availability). It is critical that infrastructure development, dam construction and other similar projects are planned appropriately so that they do not erode the extent or quality of habitat for these populations so that they can truly serve as future source populations. PMID:24990671

  2. How much gene flow is needed to avoid inbreeding depression in wild tiger populations?

    Science.gov (United States)

    Kenney, John; Allendorf, Fred W; McDougal, Charles; Smith, James L D

    2014-08-22

    The number and size of tiger populations continue to decline owing to habitat loss, habitat fragmentation and poaching of tigers and their prey. As a result, tiger populations have become small and highly structured. Current populations have been isolated since the early 1970s or for approximately seven generations. The objective of this study is to explore how inbreeding may be affecting the persistence of remaining tiger populations and how dispersal, either natural or artificial, may reduce the potentially detrimental effect of inbreeding depression. We developed a tiger simulation model and used published levels of genetic load in mammals to simulate inbreeding depression. Following a 50 year period of population isolation, we introduced one to four dispersing male tigers per generation to explore how gene flow from nearby populations may reduce the negative impact of inbreeding depression. For the smallest populations, even four dispersing male tigers per generation did not increase population viability, and the likelihood of extinction is more than 90% within 30 years. Unless habitat connectivity is restored or animals are artificially introduced in the next 70 years, medium size wild populations are also likely to go extinct, with only four to five of the largest wild tiger populations likely to remain extant in this same period without intervention. To reduce the risk of local extinction, habitat connectivity must be pursued concurrently with efforts to increase population size (e.g. enhance habitat quality, increase habitat availability). It is critical that infrastructure development, dam construction and other similar projects are planned appropriately so that they do not erode the extent or quality of habitat for these populations so that they can truly serve as future source populations. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  3. Intersex in fishes and amphibians: population implications, prevalence, mechanisms and molecular biomarkers.

    Science.gov (United States)

    Abdel-Moneim, Ahmed; Coulter, David P; Mahapatra, Cecon T; Sepúlveda, Maria S

    2015-11-01

    Intersex is defined as the abnormal presence of both testicular and ovarian cells in gonads of gonochoristic animals. Its occurrence is widespread and reports on its presence in the gonads of vertebrates continues to increase. In this review, we use standardized terminology to summarize the current knowledge of intersex in gonochoristic fishes and amphibians. We describe the different indices that have been used to assess the severity of intersex and synthesize reports discussing the prevalence of intersex in relation to different types of pollutants. In addition, we evaluate the geographic distribution and chronology of the reported cases of intersex in fishes and amphibians, their pathological descriptions and severity and discuss species sensitivities. We also summarize molecular biomarkers that have been tested for early detection of intersex in wild populations and highlight additional biomarkers that target molecular pathways involved in gonadal development that require further investigation for use in the diagnosis of intersex. Finally, we discuss the needs for future research in this field. Copyright © 2015 John Wiley & Sons, Ltd.

  4. Potential effects of incorporating fertility control into typical culling regimes in wild pig populations

    Science.gov (United States)

    Davis, Amy J.; Cunningham, Fred L.; VerCauteren, Kurt C.; Eckery, Doug C.

    2017-01-01

    Effective management of widespread invasive species such as wild pigs (Sus scrofa) is limited by resources available to devote to the effort. Better insight of the effectiveness of different management strategies on population dynamics is important for guiding decisions of resource allocation over space and time. Using a dynamic population model, we quantified effects of culling intensities and time between culling events on population dynamics of wild pigs in the USA using empirical culling patterns and data-based demographic parameters. In simulated populations closed to immigration, substantial population declines (50–100%) occurred within 4 years when 20–60% of the population was culled annually, but when immigration from surrounding areas occurred, there was a maximum of 50% reduction, even with the maximum culling intensity of 60%. Incorporating hypothetical levels of fertility control with realistic culling intensities was most effective in reducing populations when they were closed to immigration and when intrinsic population growth rate was too high (> = 1.78) to be controlled by culling alone. However, substantial benefits from fertility control used in conjunction with culling may only occur over a narrow range of net population growth rates (i.e., where net is the result of intrinsic growth rates and culling) that varies depending on intrinsic population growth rate. The management implications are that the decision to use fertility control in conjunction with culling should rely on concurrent consideration of achievable culling intensity, underlying demographic parameters, and costs of culling and fertility control. The addition of fertility control reduced abundance substantially more than culling alone, however the effects of fertility control were weaker than in populations without immigration. Because these populations were not being reduced substantially by culling alone, fertility control could be an especially helpful enhancement to culling

  5. Potential effects of incorporating fertility control into typical culling regimes in wild pig populations.

    Science.gov (United States)

    Pepin, Kim M; Davis, Amy J; Cunningham, Fred L; VerCauteren, Kurt C; Eckery, Doug C

    2017-01-01

    Effective management of widespread invasive species such as wild pigs (Sus scrofa) is limited by resources available to devote to the effort. Better insight of the effectiveness of different management strategies on population dynamics is important for guiding decisions of resource allocation over space and time. Using a dynamic population model, we quantified effects of culling intensities and time between culling events on population dynamics of wild pigs in the USA using empirical culling patterns and data-based demographic parameters. In simulated populations closed to immigration, substantial population declines (50-100%) occurred within 4 years when 20-60% of the population was culled annually, but when immigration from surrounding areas occurred, there was a maximum of 50% reduction, even with the maximum culling intensity of 60%. Incorporating hypothetical levels of fertility control with realistic culling intensities was most effective in reducing populations when they were closed to immigration and when intrinsic population growth rate was too high (> = 1.78) to be controlled by culling alone. However, substantial benefits from fertility control used in conjunction with culling may only occur over a narrow range of net population growth rates (i.e., where net is the result of intrinsic growth rates and culling) that varies depending on intrinsic population growth rate. The management implications are that the decision to use fertility control in conjunction with culling should rely on concurrent consideration of achievable culling intensity, underlying demographic parameters, and costs of culling and fertility control. The addition of fertility control reduced abundance substantially more than culling alone, however the effects of fertility control were weaker than in populations without immigration. Because these populations were not being reduced substantially by culling alone, fertility control could be an especially helpful enhancement to culling for

  6. Tissue-specific bioaccumulation of human and veterinary antibiotics in bile, plasma, liver and muscle tissues of wild fish from a highly urbanized region.

    Science.gov (United States)

    Zhao, Jian-Liang; Liu, You-Sheng; Liu, Wang-Rong; Jiang, Yu-Xia; Su, Hao-Chang; Zhang, Qian-Qian; Chen, Xiao-Wen; Yang, Yuan-Yuan; Chen, Jun; Liu, Shuang-Shuang; Pan, Chang-Gui; Huang, Guo-Yong; Ying, Guang-Guo

    2015-03-01

    We investigated the bioaccumulation of antibiotics in bile, plasma, liver and muscle tissues of wild fish from four rivers in the Pearl River Delta region. In total, 12 antibiotics were present in at least one type of fish tissues from nine wild fish species in the four rivers. The mean values of log bioaccumulation factors (log BAFs) for the detected antibiotics in fish bile, plasma, liver, and muscle tissues were at the range of 2.06-4.08, 1.85-3.47, 1.41-3.51, and 0.48-2.70, respectively. As the digestion tissues, fish bile, plasma, and liver showed strong bioaccumulation ability for some antibiotics, indicating a different bioaccumulation pattern from hydrophobic organic contaminants. Human health risk assessment based on potential fish consumption indicates that these antibiotics do not appear to pose an appreciable risk to human health. To the best of our knowledge, this is first report of bioaccumulation patterns of antibiotics in wild fish bile and plasma. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. The temporal development in a hybridizing population of wild and cultivated chicory (Chicorium intybus L.)

    DEFF Research Database (Denmark)

    Sørensen, Bende Storgaard; Kiær, Lars Pødenphant; Bagger Jørgensen, Rikke

    2007-01-01

    on the persistence of the hybrids in a natural environment over time. To evaluate this, we studied an experimental hybridizing population of wild and cultivated chicories Wichorium intybus) relative to a previous study on the same population 2 years earlier. We compared the genetic composition, morphology......, no distinct fitness differences existed between the plants of 2004, probably due to most of the plants being intermediate. No hybridization barriers appeared to be present between wild and cultivated chicories beyond the F, generation, since F-2 hybrids and backcrosses were in abundance; in fact, hybrids...... of probably fourth or fifth generation were present. In conclusion, all results indicate that no barriers exist to the temporal persistence of chicory hybrids in a natural environment....

  8. Sampling Lake Alice NWR Fish Populations - 2014, North Dakota

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The USFWS and North Dakota Game and Fish Department sampled Northern pike, walleye, yellow perch and white bass within the boundary of Lake Alice NWR in North...

  9. Natural variation in grain selenium concentration of wild barley, Hordeum spontaneum, populations from Israel.

    Science.gov (United States)

    Yan, Jun; Wang, Fang; Qin, Haibo; Chen, Guoxiong; Eviatar, Nevo; Fahima, Tzion; Cheng, Jianping

    2011-09-01

    Wild barley (Hordeum spontaneum), the progenitor of cultivated barley, is an important genetic resource for cereal improvement. Selenium (Se) is an essential trace mineral for humans and animals with antioxidant, anticancer, antiarthropathy, and antiviral effects. In the current study, the grain Se concentration (GSeC) of 92 H. spontaneum genotypes collected from nine populations representing different habitats in Israel was investigated in the central area of Guizhou Province, China. Remarkable variations in GSeC were found between and within populations, ranging from 0 to 0.387 mg kg(-1) among the 92 genotypes with an average of 0.047 mg kg(-1). Genotype 20_C from the Sede Boqer population had the highest GSeC, while genotype 25_1 from the Atlit population had the lowest. The mean value of GSeC in each population varied from 0.010 to 0.105 mg kg(-1). The coefficient of variation for each population ranged from 12% to 163%. Significant correlations were found between GSeC and 12 ecogeographical factors out of 14 studied. Habitat soil type also significantly affected GSeC. The wild barley exhibited wider GSeC ranges and greater diversity than its cultivated counterparts. The higher Se grain concentrations found in H. spontaneum populations suggest that wild barley germplasm confer higher abilities for Se uptake and accumulation, which can be used for genetic studies of barley nutritional value and for further improvement of domesticated cereals.

  10. Population Structure of and Conservation Strategies for Wild Pyrus ussuriensis Maxim. in China

    Science.gov (United States)

    Wuyun, Tana; Amo, Hitomi; Xu, Jingshi; Ma, Teng; Uematsu, Chiyomi; Katayama, Hironori

    2015-01-01

    Pyrus ussriensis Maxim. is native to the northern part of China, but whose habitats are currently being destroyed by environmental changes and human deforestation. An investigation of population structure and genetic diversity of wild Ussurian pear is a priority in order to acquire fundamental knowledge for conservation. A total of 153 individuals of wild Ussurian pear from the main habitats, Heilongjiang, Jilin, and Inner Mongolia in China, possessed low genetic diversity as a result of habitat fragmentation. The genetic diversity of the populations in Inner Mongolia and north east of Heilongjiang was especially low and there was the possibility of inbreeding. Wild Ussurian pears were divided into 5 groups based on the Bayesian clustering method using 20 nuclear SSRs (nSSRs) and 5 groups by haplotype distributions using 16 chloroplast SSRs (cpSSRs), and the populations in Inner Mongolia and north east of Heilongjiang represented unique genotypes. AMOVA indicated there was a 20.05% variation in nSSRs and a 44.40% variation in cpSSRs among populations. These values are relatively high when compared to those of other tree species. Haplotype E, positioned in the center of the cpSSR analysis network and showed the largest number of connections with other haplotypes, represented the most important haplotype. Inner Mongolia and the north east of Heilongjiang are two areas that need urgent conservation because of their genetic vulnerability and peculiarity. We determined 4 conservation units based on the clustering by nSSRs and cpSSRs, and geographic factor. This information is helpful in deciding the conservation strategies for wild Ussurian pear in China. PMID:26252516

  11. It's a bear market: evolutionary and ecological effects of predation on two wild sockeye salmon populations.

    Science.gov (United States)

    Lin, J E; Hard, J J; Naish, K A; Peterson, D; Hilborn, R; Hauser, L

    2016-05-01

    Predation can affect both phenotypic variation and population productivity in the wild, but quantifying evolutionary and demographic effects of predation in natural environments is challenging. The aim of this study was to estimate selection differentials and coefficients associated with brown bear (Ursus arctos) predation in wild sockeye salmon (Oncorhynchus nerka) populations spawning in pristine habitat that is often subject to intense predation pressure. Using reconstructed genetic pedigrees, individual reproductive success (RS) was estimated in two sockeye salmon populations for two consecutive brood years with very different predation intensities across brood years. Phenotypic data on individual adult body length, body depth, stream entry timing and reproductive lifespan were used to calculate selection coefficients based on RS, and genetic variance components were estimated using animal models. Bears consistently killed larger and more recently arrived adults, although selection differentials were small. In both populations, mean RS was higher in the brood year experiencing lower predation intensity. Selection coefficients were similar across brood years with different levels of predation, often indicating stabilizing selection on reproductive lifespan as well as directional selection for longer reproductive lifespan. Despite these selection pressures, genetic covariation of morphology, phenology and lifespan appears to have maintained variation in spawner body size and stream entry timing in both populations. Our results therefore suggest considerable demographic but limited evolutionary effects of bear predation in the two study populations.

  12. A tool for tracking genetic contributions of wild Penaeus (Melicertus) plebejus broodstock to hatchery populations.

    Science.gov (United States)

    Chan, Jackie T; Sherwin, William B; Taylor, Matthew D

    2014-12-01

    Stock enhancement, restocking and sea ranching are being increasingly applied in both fisheries and conservation. The contribution of hatchery stock to fishery harvest and the maintenance of the genetic structure of stocked populations are both important considerations when releasing captive-bred organisms into natural systems. Use of wild-caught broodstock generally overcomes some of the genetic problems associated with domesticated hatchery populations, but there is still a need to ensure that a sufficient proportion of the natural population contribute to production of the stocked cohort to realise the genetic benefits of using wild-caught broodstock. Releases of Penaeus (Melicertus) plebejus are under investigation as a means of increasing prawn production in recruitment-limited areas. We used the highly variable mitochondrial control region (mtCR) to assign post-larvae to maternal lineages in the hatchery and also to investigate the reproductive performance of female broodstock in terms of contribution to the production of the cohorts of post-larvae in the hatchery. Our data showed that mtCR can be a useful tool for tracking lineages and provided genetic evidence that unequal contribution and underproducing females can occur even in wild-caught broodstock. This work therefore highlights the importance of monitoring the genetic composition of pre-release hatchery stocks. © 2014 Stichting International Foundation for Animal Genetics.

  13. CRISPR/Cas9 gene drives in genetically variable and nonrandomly mating wild populations.

    Science.gov (United States)

    Drury, Douglas W; Dapper, Amy L; Siniard, Dylan J; Zentner, Gabriel E; Wade, Michael J

    2017-05-01

    Synthetic gene drives based on CRISPR/Cas9 have the potential to control, alter, or suppress populations of crop pests and disease vectors, but it is unclear how they will function in wild populations. Using genetic data from four populations of the flour beetle Tribolium castaneum, we show that most populations harbor genetic variants in Cas9 target sites, some of which would render them immune to drive (ITD). We show that even a rare ITD allele can reduce or eliminate the efficacy of a CRISPR/Cas9-based synthetic gene drive. This effect is equivalent to and accentuated by mild inbreeding, which is a characteristic of many disease-vectoring arthropods. We conclude that designing such drives will require characterization of genetic variability and the mating system within and among targeted populations.

  14. Assessment of the pelagic fish populations using CEN multi-mesh gillnets: consequences for the characterization of the fish communities

    Directory of Open Access Journals (Sweden)

    C. Deceliere-Vergès

    2008-01-01

    Full Text Available The contribution of CEN standard pelagic nets to the assessment of fish communities is tested by comparing three metrics (species composition, species abundance, and size structures measured in accordance with the standard (i.e. using benthic nets only to those calculated from the total effort (i.e. including pelagic nets. Hydroacoustic surveys were used simultaneously to assess fish densities in the pelagic habitat. The results show that in most cases the pelagic nets did not provide any extra information about these three metrics. However, their inclusion in the calculation of CPUE and size structures may affect the picture of the fish communities, especially in lakes containing salmonid populations. This study highlights the need to sample pelagic fish when assessing fish communities in order to determine lake quality.

  15. Assessment of the pelagic fish populations using CEN multi-mesh gillnets: consequences for the characterization of the fish communities

    Directory of Open Access Journals (Sweden)

    Deceliere-Vergès C.

    2009-01-01

    Full Text Available The contribution of CEN standard pelagic nets to the assessment of fish communities is tested by comparing three metrics (species composition, species abundance, and size structures measured in accordance with the standard (i.e. using benthic nets only to those calculated from the total effort (i.e. including pelagic nets. Hydroacoustic surveys were used simultaneously to assess fish densities in the pelagic habitat. The results show that in most cases the pelagic nets did not provide any extra information about these three metrics. However, their inclusion in the calculation of CPUE and size structures may affect the picture of the fish communities, especially in lakes containing salmonid populations. This study highlights the need to sample pelagic fish when assessing fish communities in order to determine lake quality.

  16. Archaeological evidence of validity of fish populations on unexploited reefs as proxy targets for modern populations.

    Science.gov (United States)

    Longenecker, Ken; Chan, Yvonne L; Toonen, Robert J; Carlon, David B; Hunt, Terry L; Friedlander, Alan M; Demartini, Edward E

    2014-10-01

    Reef-fish management and conservation is hindered by a lack of information on fish populations prior to large-scale contemporary human impacts. As a result, relatively pristine sites are often used as conservation baselines for populations near sites affected by humans. This space-for-time approach can only be validated by sampling assemblages through time. We used archaeological remains to evaluate whether the remote, uninhabited Northwestern Hawaiian Islands (NWHI) might provide a reasonable proxy for a lightly exploited baseline in the Main Hawaiian Islands (MHI). We used molecular and morphological techniques to describe the taxonomic and size composition of the scarine parrotfish catches present in 2 archaeological assemblages from the MHI, compared metrics of these catches with modern estimates of reproductive parameters to evaluate whether catches represented by the archaeological material were consistent with sustainable fishing, and evaluated overlap between size structures represented by the archaeological material and modern survey data from the MHI and the NWHI to assess whether a space-for-time substitution is reasonable. The parrotfish catches represented by archaeological remains were consistent with sustainable fishing because they were dominated by large, mature individuals whose average size remained stable from prehistoric (AD approximately 1400-1700) through historic (AD 1700-1960) periods. The ancient catches were unlike populations in the MHI today. Overlap between the size structure of ancient MHI catches and modern survey data from the NWHI or the MHI was an order of magnitude greater for the NWHI comparison, a result that supports the validity of using the NWHI parrotfish data as a proxy for the MHI before accelerated, heavy human impacts in modern times. © 2014 Society for Conservation Biology.

  17. Micro-evolutionary divergence patterns of mandible shapes in wild house mouse (Mus musculus populations

    Directory of Open Access Journals (Sweden)

    Tautz Diethard

    2011-10-01

    Full Text Available Abstract Background Insights into the micro-evolutionary patterns of morphological traits require an assessment of the natural variation of the trait within and between populations and closely related species. The mouse mandible is a particularly suitable morphological trait for such an analysis, since it has long been used as a model to study the quantitative genetics of shape. In addition, many distinct populations, sub-species and closely related species are known for the house mouse. However, morphological comparisons among wild caught animals require an assessment in how far environmental and technical factors could interfere with the shape change measurements. Results Using geometric morphometrics, we have surveyed mandible shapes in 15 natural populations of the genus Mus, with a focus on the subspecies Mus musculus domesticus. In parallel we have carefully assessed possibly confounding technical and biological factors. We find that there are distinct differences on average between populations, subspecies and species, but these differences are smaller than differences between individuals within populations. Populations from summer-dry regions, although more ancestral, are less distinct from each other than are populations from the more recently colonized northern areas. Populations with especially distinct shapes occur in an area of sympatry of M. m. domesticus and M. spretus and on recently colonized sub-antarctic islands. We have also studied a number of inbred strains to assess in how far their mandible shapes resemble those from the wild. We find that they fall indeed into the shape space of natural variation between individuals in populations. Conclusions Although mandible shapes in natural populations can be influenced by environmental variables, these influences are insufficient to explain the average extent of shape differences between populations, such that evolutionary processes must be invoked to explain this level of diversity

  18. 137Cs monitoring in the meat of wild boar population in Slovakia

    Directory of Open Access Journals (Sweden)

    Katarina Beňová

    2016-06-01

    Full Text Available Currently, due to the elapsed time and the nature of the Chernobyl accident, the only artificial radionuclide present in the soil is 137Cs, with a physical half-life conversion of 30.17 years. The 137Cs is quickly integrated into a biological cycle, similar to potassium. Generally, radionuclides are characterized by their mobility in soil. Contamination of materials and food by radionuclides represent a serious problem and has a negative impact on human health. The threat of international terrorism and the inability to forestall the impact of natural disasters on nuclear energetic (Fukushima accident, are also reasons for continuous monitoring of food safety. According screening measurement performed in European countries, high radioactivity levels were reported in the wild boars muscles from Sumava (Czech Republic. Seasonal fluctuation of 137Cs activity in the wild boar meat samples was observed in the forests on the southern Rhineland. Monitoring of 137Cs activity in the wild boar meat samples in the hunting grounds in Slovakia was initiated based on the reports on exceeding limits of the content of radiocaesium in the meat of wild boar from the surrounding countries. The aim of this study was to determine the 137Cs post Chernobyl contamination of wild boars population in different hunting districts of Slovakia during 2013 - 2014. A total of 60 thigh muscle samples from wild boars of different age categories (4 months - 2 years were evaluated. 137Cs activity was measured by gamma spectrometry (Canberra. Despite the fact Slovakia is closer to Chernobyl as Czech Republic and Germany, the 137Cs activity measured was very low and far below the permitted limit. The highest radiocaesium activity level measured in muscle was 37.2 Bq.kg-1 ±4.7%. Wild boar originated from Zlate Moravce district. The measurement results show, that 137Cs contamination levels of game in Slovakia are low. Radiocaesium activity in examined samples was very low and

  19. Endogenous and exogenous constraints in the population changes of wild boar (sus scrofa Linnaeus, 1758)

    OpenAIRE

    Uzal Fernandez, Antonio; Nores, Carlos

    2004-01-01

    The population dynamics of wild boar (Sus scrofa) was studied in a time series over 26 years using\\ud data from the Regional Hunting Reserve of Somiedo (northern Spain). This population is controlled\\ud by a complex negative feedback system that acts with one (main) and two (secondary) years of delay\\ud (lags). The primary feedback might be explained by intraspecific competition for food resulting from\\ud fluctuations in mast production (acorns and beech), and the secondary feedback might be ...

  20. Differential modulation of human intestinal bifidobacterium populations after consumption of a wild blueberry (Vaccinium angustifolium) drink.

    Science.gov (United States)

    Guglielmetti, Simone; Fracassetti, Daniela; Taverniti, Valentina; Del Bo', Cristian; Vendrame, Stefano; Klimis-Zacas, Dorothy; Arioli, Stefania; Riso, Patrizia; Porrini, Marisa

    2013-08-28

    Bifidobacteria are gaining increasing interest as health-promoting bacteria. Nonetheless, the genus comprises several species, which can exert different effects on human host. Previous studies showed that wild blueberry drink consumption could selectively increase intestinal bifidobacteria, suggesting an important role for the polyphenols and fiber present in wild blueberries. This study evaluated the modulation of the most common and abundant bifidobacterial taxonomic groups inhabiting the human gut in the same fecal samples. The analyses carried out showed that B. adolescentis, B. breve, B. catenulatum/pseudocatelulatum, and B. longum subsp. longum were always present in the group of subjects enrolled, whereas B. bifidum and B. longum subsp. infantis were not. Furthermore, it was found that the most predominant bifidobacterial species were B. longum subsp. longum and B. adolescentis. The results obtained revealed a high interindividual variability; however, a significant increase of B. longum subsp. infantis cell concentration was observed in the feces of volunteers after the wild blueberry drink treatment. This bifidobacterial group was shown to possess immunomodulatory abilities and to relieve symptoms and promote the regression of several gastrointestinal disorders. Thus, an increased cell concentration of B. longum subsp. infantis in the human gut could be considered of potential health benefit. In conclusion, wild blueberry consumption resulted in a specific bifidogenic effect that could positively affect certain populations of bifidobacteria with demonstrated health-promoting properties.

  1. Application of nonparametric multivariate analyses to the authentication of wild and farmed European sea bass (Dicentrarchus labrax). Results of a survey on fish sampled in the retail trade.

    Science.gov (United States)

    Fasolato, Luca; Novelli, Enrico; Salmaso, Luigi; Corain, Livio; Camin, Federica; Perini, Matteo; Antonetti, Paolo; Balzan, Stefania

    2010-10-27

    The aim of this study was to apply biometric measurements and analyses of proximate composition, fatty acid composition, and ratios of stable isotopes of carbon (δ(13)C) and nitrogen (δ(15)N) in muscle tissue to reliably differentiate between wild and farmed European sea bass (Dicentrarchus labrax). Farmed (n = 20) and wild (n = 19) European sea bass were purchased between March and May 2008 and used as standard samples. In the same months, a survey was conducted to evaluate the truthfulness of the statements on the labels of European sea bass sold in retail markets (declared farmed n = 34 and declared wild n = 33). In addition, data from the literature (reference) were employed to build the profile type of wild and farmed European sea bass. Primarily, an exploration and comparison of the analytical data of the standard data set based on principal component analysis and permutation test were performed. Afterward, an inferential statistical approach based on nonparametric combination test methodology (NPC) was applied on standard samples to check its suitability in discriminating the production method. This multivariate statistical analysis selected 30 variables on a total of 36 available. The validation of standard fish data set was accomplished by a novel nonparametric rank-based method according to profile type (just 1 misclassification over 39 samples). Both the NPC test and nonparametric rank-based method were then applied to survey fishes using the selected variables with the aim to classify the individual European sea bass as "true farmed" or "true wild". The former test segregated 10 fishes over 33 declared wild, whereas the results obtained by the nonparametric rank-based method showed that 11 of 33 declared wild European sea bass samples could be unquestionably attributed to the wild cluster. Moreover, considering the comparative contribution of profile type, a few surveyed farmed samples were ascribed to the wild cluster.

  2. An Infectious Disease and Mortality Survey in a Population of Free-Ranging African Wild Dogs and Sympatric Domestic Dogs

    OpenAIRE

    Flacke, G.; Becker, P; Cooper, D; Szykman Gunther, M.; Robertson, I.; Holyoake, C.; Donaldson, R.; Warren, K

    2013-01-01

    Disease can cause declines in wildlife populations and significantly threaten their survival. Recent expansion of human and domestic animal populations has made wildlife more susceptible to transmission of pathogens from domestic animal hosts. We conducted a pathogen surveillance and mortality survey for the population of African wild dogs (Lycaon pictus) in KwaZulu-Natal (KZN), South Africa, from January 2006–February 2007. Samples were obtained from 24 wild dogs for canine distemper virus (...

  3. Raw material procurement for termite fishing tools by wild chimpanzees in the Issa valley, Western Tanzania.

    Science.gov (United States)

    Almeida-Warren, Katarina; Sommer, Volker; Piel, Alex K; Pascual-Garrido, Alejandra

    2017-10-01

    Chimpanzee termite fishing has been studied for decades, yet the selective processes preceding the manufacture of fishing tools remain largely unexplored. We investigate raw material selection and potential evidence of forward planning in the chimpanzees of Issa valley, western Tanzania. Using traditional archaeological methods, we surveyed the location of plants from where chimpanzees sourced raw material to manufacture termite fishing tools, relative to targeted mounds. We measured raw material abundance to test for availability and selection. Statistics included Chi-Squared, two-tailed Wilcoxon, and Kruskall-Wallace tests. Issa chimpanzees manufactured extraction tools only from bark, despite availability of other suitable materials (e.g., twigs), and selected particular plant species as raw material sources, which they often also exploit for food. Most plants were sourced 1-16 m away from the mound, with a maximum of 33 m. The line of sight from the targeted mound was obscured for a quarter of these plants. The exclusive use of bark tools despite availability of other suitable materials indicates a possible cultural preference. The fact that Issa chimpanzees select specific plant species and travel some distance to source them suggests some degree of selectivity and, potentially, forward planning. Our results have implications for the reconstruction of early hominin behaviors, particularly with regard to the use of perishable tools, which remain archaeologically invisible. © 2017 Wiley Periodicals, Inc.

  4. Genome sequence, population history, and pelage genetics of the endangered African wild dog (Lycaon pictus).

    Science.gov (United States)

    Campana, Michael G; Parker, Lillian D; Hawkins, Melissa T R; Young, Hillary S; Helgen, Kristofer M; Szykman Gunther, Micaela; Woodroffe, Rosie; Maldonado, Jesús E; Fleischer, Robert C

    2016-12-09

    The African wild dog (Lycaon pictus) is an endangered African canid threatened by severe habitat fragmentation, human-wildlife conflict, and infectious disease. A highly specialized carnivore, it is distinguished by its social structure, dental morphology, absence of dewclaws, and colorful pelage. We sequenced the genomes of two individuals from populations representing two distinct ecological histories (Laikipia County, Kenya and KwaZulu-Natal Province, South Africa). We reconstructed population demographic histories for the two individuals and scanned the genomes for evidence of selection. We show that the African wild dog has undergone at least two effective population size reductions in the last 1,000,000 years. We found evidence of Lycaon individual-specific regions of low diversity, suggestive of inbreeding or population-specific selection. Further research is needed to clarify whether these population reductions and low diversity regions are characteristic of the species as a whole. We documented positive selection on the Lycaon mitochondrial genome. Finally, we identified several candidate genes (ASIP, MITF, MLPH, PMEL) that may play a role in the characteristic Lycaon pelage.

  5. The genomic landscape of rapid repeated evolutionary adaptation to toxic pollution in wild fish

    Science.gov (United States)

    Atlantic killifish populations have rapidly adapted to normally lethal levels of pollution in four urban estuaries. Through analysis of 384 whole killifish genome sequences and comparative transcriptomics in four pairs of sensitive and tolerant populations, we identify the aryl h...

  6. Collapse and recovery of forage fish populations prior to commercial exploitation

    Science.gov (United States)

    McClatchie, S.; Hendy, I. L.; Thompson, A. R.; Watson, W.

    2017-02-01

    We use a new, well-calibrated 500 year paleorecord off southern California to determine collapse frequency, cross correlation, persistence, and return times of exploited forage fish populations. The paleorecord shows that "collapse" (defined as forage. Forage populations are resilient on the 500 year time scale, but their collapse and recovery cycle (based on the paleorecord) are suited to alternating periods of high fishing mortality and periods of little or no fishing.

  7. Putative Panmixia in Restricted Populations of Trypanosoma cruzi Isolated from Wild Triatoma infestans in Bolivia

    Science.gov (United States)

    Barnabe, Christian; Buitrago, Rosio; Bremond, Philippe; Aliaga, Claudia; Salas, Renata; Vidaurre, Pablo; Herrera, Claudia; Cerqueira, Frédérique; Bosseno, Marie-France; Waleckx, Etienne; Breniere, Simone Frédérique

    2013-01-01

    Trypanosoma cruzi, the causative agent of Chagas disease, is subdivided into six discrete typing units (DTUs; TcI–TcVI) of which TcI is ubiquitous and genetically highly variable. While clonality is the dominant mode of propagation, recombinant events play a significant evolutive role. Recently, foci of wild Triatoma infestans have been described in Bolivia, mainly infected by TcI. Hence, for the first time, we evaluated the level of genetic exchange within TcI natural potentially panmictic populations (single DTU, host, area and sampling time). Seventy-nine TcI stocks from wild T. infestans, belonging to six populations were characterized at eight microsatellite loci. For each population, Hardy-Weinberg equilibrium (HWE), linkage disequilibrium (LD), and presence of repeated multilocus genotypes (MLG) were analyzed by using a total of seven statistics, to test the null hypothesis of panmixia (H0). For three populations, none of the seven statistics allowed to rejecting H0; for another one the low size did not allow us to conclude, and for the two others the tests have given contradictory results. Interestingly, apparent panmixia was only observed in very restricted areas, and was not observed when grouping populations distant of only two kilometers or more. Nevertheless it is worth stressing that for the statistic tests of "HWE", in order to minimize the type I error (i. e. incorrect rejection of a true H0), we used the Bonferroni correction (BC) known to considerably increase the type II error ( i. e. failure to reject a false H0). For the other tests (LD and MLG), we did not use BC and the risk of type II error in these cases was acceptable. Thus, these results should be considered as a good indicator of the existence of panmixia in wild environment but this must be confirmed on larger samples to reduce the risk of type II error. PMID:24312410

  8. CHARACTERIZING POPULATIONS OF THE ESTUARINE FISH FUNDULUS HETEROCLITUS INDIGENOUS TO SITES WITH DIFFERING ENVIRONMENTAL QUALITY

    Science.gov (United States)

    Populations of the non-migratory estuarine fish Fundulus heteroclitus were collected from New Bedford Harbor and distant clean sites to investigate whether indigenous populations have adapted genetically to the harbor's contamination. New Bedford Harbor, a major port in southe...

  9. A survey of wild marine fish identifies a potential origin of an outbreak of viral haemorrhagic septicaemia in wrasse, Labridae, used as cleaner fish on marine Atlantic salmon, Salmo salar L., farms.

    Science.gov (United States)

    Wallace, I S; Donald, K; Munro, L A; Murray, W; Pert, C C; Stagg, H; Hall, M; Bain, N

    2015-06-01

    Viral haemorrhagic septicaemia virus (VHSV) was isolated from five species of wrasse (Labridae) used as biological controls for parasitic sea lice predominantly, Lepeophtheirus salmonis (Krøyer, 1837), on marine Atlantic salmon, Salmo salar L., farms in Shetland. As part of the epidemiological investigation, 1400 wild marine fish were caught and screened in pools of 10 for VHSV using virus isolation. Eleven pools (8%) were confirmed VHSV positive from: grey gurnard, Eutrigla gurnardus L.; Atlantic herring, Clupea harengus L.; Norway pout, Trisopterus esmarkii (Nilsson); plaice, Pleuronectes platessa L.; sprat, Sprattus sprattus L. and whiting, Merlangius merlangus L. The isolation of VHSV from grey gurnard is the first documented report in this species. Nucleic acid sequencing of the partial nucleocapsid (N) and glycoprotein (G) genes was carried out for viral characterization. Sequence analysis confirmed that all wild isolates were genotype III the same as the wrasse and there was a close genetic similarity between the isolates from wild fish and wrasse on the farms. Infection from these local wild marine fish is the most likely source of VHSV isolated from wrasse on the fish farms. © 2014 Crown Copyright. Journal of Fish Diseases © 2014 John Wiley & Sons Ltd.

  10. Encountering a bait is necessary but insufficient to explain individual variability in vulnerability to angling in two freshwater benthivorous fish in the wild

    Science.gov (United States)

    Monk, Christopher Thomas; Arlinghaus, Robert

    2017-01-01

    Fish personality traits, such as swimming activity, or personality related emergent behavioural properties, such as the degree of space use shown by an individual fish, should affect encounter rates between individual fish and fishing gear. Increased encounters should in turn drive vulnerability to capture by passively operated gears. However, empirical evidence documenting a relationship between activity-based behaviours and vulnerability to capture by passive fishing gear in the wild is limited. Using whole-lake acoustic telemetry, we first documented significant repeatabilities over several months in a suite of encounter rate-associated behaviours (swimming distance, activity space size, time on baited feeding sites, switching frequency among baited feeding sites, distance to the lake bottom) in two recreationally important benthivorous cyprinid species, the common carp (Cyprinus carpio) and tench (Tinca tinca). We then experimentally targeted both species using stationary angling on baited feeding sites. Individual fish regularly visited the angling sites, documenting that the fishes encountered the angling baits. When attempting to explain individual variation in vulnerability as a function of repeatable behavioural traits, we found no evidence of a significant relationship among various encounter-based behaviours and vulnerability to angling for both species. There was also no evidence for size selection or for energetically less conditioned fish to be more vulnerable. The data cumulatively suggest that fine-scale behaviours after encountering a bait (e.g., frequency of bait intake) may be ultimately decisive for determining vulnerability to angling in benthivorous fish. Based on our work, fishing-induced selection on encounter-based behaviours in recreational angling for benthivorous fish in the wild appears unlikely. PMID:28301558

  11. Additional treatment of wastewater reduces endocrine disruption in wild fish--a comparative study of tertiary and advanced treatments.

    Science.gov (United States)

    Baynes, Alice; Green, Christopher; Nicol, Elizabeth; Beresford, Nicola; Kanda, Rakesh; Henshaw, Alan; Churchley, John; Jobling, Susan

    2012-05-15

    Steroid estrogens are thought to be the major cause of feminization (intersex) in wild fish. Widely used wastewater treatment technologies are not effective at removing these contaminants to concentrations thought to be required to protect aquatic wildlife. A number of advanced treatment processes have been proposed to reduce the concentrations of estrogens entering the environment. Before investment is made in such processes, it is imperative that we compare their efficacy in terms of removal of steroid estrogens and their feminizing effects with other treatment options. This study assessed both steroid removal and intersex induction in adult and early life stage fish (roach, Rutilus rutilus). Roach were exposed directly to either secondary (activated sludge process (ASP)), tertiary (sand filtrated (SF)), or advanced (chlorine dioxide (ClO(2)), granular activated charcoal (GAC)) treated effluents for six months. Surprisingly, both the advanced GAC and tertiary SF treatments (but not the ClO(2) treatment) significantly removed the intersex induction associated with the ASP effluent; this was not predicted by the steroid estrogen measurements, which were higher in the tertiary SF than either the GAC or the ClO(2). Therefore our study highlights the importance of using both biological and chemical analysis when assessing new treatment technologies.

  12. Wild Water Buffalo Bubalus arnee in Koshi Tappu Wildlife Reserve, Nepal: status, population and conservation importance

    Directory of Open Access Journals (Sweden)

    T.B. Khatri

    2012-11-01

    Full Text Available The Asiatic Wild Water Buffalo Bubalus arnee is an endangered species restricted to South and Southeast Asia. Nepal’s only population survives in the Koshi Tappu Wildlife Reserve which is located on the floodplain of the Koshi River, a tributary of Ganga. This species is under threat due to high anthropogenic pressure ranging from habitat deterioration to hybridization with domestic buffalo. Yet, the population has grown from 63 in 1976 to 219 in 2009, despite the decline in the calf/cow ratio. The present study conducted in 2009 used the block count method. The count showed the presence of a backcrossed population of 74 in addition to the total of 219 individuals. At present, a number of conservation and livelihood interventions have been undertaken to safeguard the biodiversity, particularly the wild buffalo population in the Koshi Tappu Wildlife Reserve. The community-based sustainable management approach benefiting both conservation and livelihood of local people is necessary to ensure the long term conservation of the species

  13. Epidemiology of the emergent disease Paridae pox in an intensively studied wild bird population.

    Directory of Open Access Journals (Sweden)

    Shelly Lachish

    Full Text Available Paridae pox, a novel avipoxvirus infection, has recently been identified as an emerging infectious disease affecting wild tit species in Great Britain. The incursion of Paridae pox to a long-term study site where populations of wild tits have been monitored in detail for several decades provided a unique opportunity to obtain information on the local-scale epidemiological characteristics of this novel infection during a disease outbreak. Using captures of >8000 individual birds, we show that, within two years of initial emergence, Paridae pox had become established within the population of great tits (Parus major reaching relatively high peak prevalence (10%, but was far less prevalent (<1% in sympatric populations of several other closely related, abundant Paridae species. Nonlinear smoothing models revealed that the temporal pattern of prevalence among great tits was characterised by within-year fluctuations indicative of seasonal forcing of infection rates, which was likely driven by multiple environmental and demographic factors. There was individual heterogeneity in the course of infection and, although recovery was possible, diseased individuals were far less likely to be recaptured than healthy individuals, suggesting a survival cost of infection. This study demonstrates the value of long-term monitoring for obtaining key epidemiological data necessary to understand disease dynamics, spread and persistence in natural populations.

  14. Genetic structure of wild Spanish populations of Castanea sativa as revealed by isozyme analysis

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Lopez, J.; Monteagudo, A. B.

    2010-07-01

    The genetic variability within and among 17 wild Spanish chestnut stands was examined by isozyme analysis, with the goals of describing their geographic structure and designing conservation and management strategies. Measures of genetic diversity such as allelic richness, heterozygosity, polymorphism, F-statistics, D-statistics, gene flow and the contributions of each stand to diversity and allelic richness were calculated, clustering using Nei's genetic distances and a method based on an Monte Carlo Markov Chain algorithm were used. Wild Spanish chestnut populations displayed heterogeneity of allele frequencies between them, high levels of genetic diversity and high differentiation (Fst = 0.15) compared with populations from other western European countries. Two clustering methods allowed identification of three clusters: The highest heterozygosity and allelic richness were found in the North and especially in the Galician cluster close to Portugal. These results indicate that probably the northern chestnut populations are relictual originated from a North Iberian refuge. Several areas can be recommended for inclusion in the network of Conservation Units: Fraga de Catasos, representing the southern Galician cluster; Fragas do Eume, representing the northern Spanish cluster; and Hervas or El Tiemblo, representing the Mediterranean cluster. Key words: relict populations, diversity, allelic richness, conservation. (Author)

  15. The environmental dependence of inbreeding depression in a wild bird population.

    Directory of Open Access Journals (Sweden)

    Marta Szulkin

    2007-10-01

    Full Text Available Inbreeding depression occurs when the offspring produced as a result of matings between relatives show reduced fitness, and is generally understood as a consequence of the elevated expression of deleterious recessive alleles. How inbreeding depression varies across environments is of importance for the evolution of inbreeding avoidance behaviour, and for understanding extinction risks in small populations. However, inbreeding-by-environment (IxE interactions have rarely been investigated in wild populations.We analysed 41 years of breeding events from a wild great tit (Parus major population and used 11 measures of the environment to categorise environments as relatively good or poor, testing whether these measures influenced inbreeding depression. Although inbreeding always, and environmental quality often, significantly affected reproductive success, there was little evidence for statistically significant I x E interactions at the level of individual analyses. However, point estimates of the effect of the environment on inbreeding depression were sometimes considerable, and we show that variation in the magnitude of the I x E interaction across environments is consistent with the expectation that this interaction is more marked across environmental axes with a closer link to overall fitness, with the environmental dependence of inbreeding depression being elevated under such conditions. Hence, our analyses provide evidence for an environmental dependence of the inbreeding x environment interaction: effectively an I x E x E.Overall, our analyses suggest that I x E interactions may be substantial in wild populations, when measured across relevant environmental contrasts, although their detection for single traits may require very large samples, or high rates of inbreeding.

  16. Structural differences between wild-type and fish eye disease mutant of lecithin:cholesterol acyltransferase.

    Science.gov (United States)

    Reshetnyak, Yana; Tchedre, Kissaou T; Nair, Maya P; Pritchard, P Haydn; Lacko, Andras G

    2006-08-01

    Fluorescence spectroscopy has been used to investigate the conformational changes that occur upon binding of wild type (WT) and mutant (Thr123Ile) lecithin:cholesterol acyltransferase (LCAT) to the potential substrates (dioleoyl-phosphatidyl choline [DOPC] and high density lipoprotein [HDL]). For a detailed analysis of structural differences between WT and mutant LCAT, we performed decompositional analysis of a set of tryptophan fluorescence spectra, measured at increasing concentrations of external quenchers (acrylamide and KI). The data obtained show that Thr123Ile mutation in LCAT leads to a conformation that is likely to be more rigid (less mobile/flexible) than that of the WT protein with a redistribution of charged residues around exposed tryptophan fluorophores. We propose that the redistribution of charged residues in mutant LCAT may be a major factor responsible for the dramatically reduced activity of the enzyme with HDL and reconstituted high density lipoprotein (rHDL).

  17. Fish collagen is an important panallergen in the Japanese population.

    Science.gov (United States)

    Kobayashi, Y; Akiyama, H; Huge, J; Kubota, H; Chikazawa, S; Satoh, T; Miyake, T; Uhara, H; Okuyama, R; Nakagawara, R; Aihara, M; Hamada-Sato, N

    2016-05-01

    Collagen was identified as a fish allergen in early 2000s. Although its allergenic potential has been suggested to be low, risks associated with collagen as a fish allergen have not been evaluated to a greater extent. In this study, we aimed to clarify the importance of collagen as a fish allergen. Our results showed that 50% of Japanese patients with fish allergy had immunoglobulin E (IgE) against mackerel collagen, whereas 44% had IgE against mackerel parvalbumin. IgE inhibition assay revealed high cross-reactivity of mackerel collagen to 22 fish species (inhibition rates: 87-98%). Furthermore, a recently developed allergy test demonstrated that collagen triggered IgE cross-linking on mast cells. These data indicate that fish collagen is an important and very common panallergen in fish consumed in Japan. The high rate of individuals' collagen allergy may be attributable to the traditional Japanese custom of raw fish consumption. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Diseases and parasites of laboratory reared and wild population of banded pearl spot Etroplus suratensis (Cichlidae) in Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Rattan, P.; Parulekar, A.H.

    Banded Pearl spot Etroplus suratensis, the inhabitant of coastal backwaters and lagoons is one among the few finfish species identified for brackishwater farming. Common diseases and parasites from the wild population of Goa and from the laboratory...

  19. THE EFFECT OF NUTRIENT MEDIA IN MICROPROPAGATION AND IN VITRO CONSERVATION OF WILD POPULATION OF MAHALEB CHERRY (PRUNUS MAHALEB L.)

    National Research Council Canada - National Science Library

    Valbona Sota; Efigjeni Kongjika

    2014-01-01

      Shoot tips of Prunus mahaleb L. isolated from wild populations of Zejmen (Lezhe), promising as rootstocks for sweet cherry cultivars, were submitted to in vitro culture to test if micropropagation could be used for their rapid production...

  20. Reproductive ageing and sexual selection on male body size in a wild population of antler flies (Protopiophila litigata)

    National Research Council Canada - National Science Library

    BONDURIANSKY, R; BRASSIL, C. E

    2005-01-01

    Little is known about the importance of trade‐offs between ageing and other life history traits, or the effects of ageing on sexual selection, particularly in wild populations suffering high extrinsic mortality rates...

  1. Differences in survival and growth in hatchery and stream environments, and in maturation of residuls in a stream, between progeny of hatchery and wild steelhead (Study sites: Brushy Fork Creek and Dworshak Hatchery; Stocks:Dworshak hatchery and Fish Creek wild; Year classes: 1992 and 1993): Chapter 1

    Science.gov (United States)

    Rubin, Stephen P.; Reisenbichler, Reginald R.; Wetzel, Lisa A.; Hensleigh, Jay E.; Leonetti,; Rubin, Stephen P.; Reisenbichler, Reginald R.; Wetzel, Lisa A.; Hayes, Michael C.

    2012-01-01

    Freshwater survival in hatchery and natural rearing environments was compared between progeny of hatchery (H) and wild (W) steelhead Oncorhynchus mykiss from the Clearwater River drainage in Idaho. Adults from Dworshak National Fish Hatchery and wild adults from Fish Creek fish were artificially spawned, and their progeny were genetically marked at the PEPA allozyme locus and released together as unfed fry in production facilities at the hatchery and in Brushy Fork Creek, also in the Clearwater River drainage, in a common garden design. Survival was higher for H than for W progeny at the hatchery but lower for H than for W progeny in Brushy Fork, indicating reduced fitness of the hatchery population for natural rearing and suggesting domestication as the cause. Survival at the hatchery was lower than is typical due to disease outbreaks. Survival of the first year-class of experimental fish to smolt release was only 18%. Survival of H fish was 3.8 times that of W fish under these poor survival conditions. All fish from the second year-class died halfway through the scheduled 10 month rearing period. Survival of H fish was 5.2 times that of W fish to when 1% of the initial fry were still alive indicating that W fish succumbed to the epizootic sooner than did H fish. Emigrants from the Brushy Fork study reach were sampled for three years and fish residing in the study reach were sampled for six years following fry release. Most emigrants were one or two years old and too small to be smolts (mean fork length at age-2 = 93 mm). Survival in Brushy Fork was lower for H than for W fish of the first year-class. Survival of the second year-class was higher for H than for W fish during the first two months in the stream but was lower for H than for W fish thereafter, and net survival from release to ages 3 and older was also lower for H than for W fish if our emigrant samples were representative (periods of inoperative emigrant traps prevented certainty about this

  2. Genetic variation of wild and hatchery populations of the catla Indian major carp (Catla catla Hamilton 1822: Cypriniformes, Cyprinidae revealed by RAPD markers

    Directory of Open Access Journals (Sweden)

    S.M. Zakiur Rahman

    2009-01-01

    Full Text Available Genetic variation is a key component for improving a stock through selective breeding programs. Randomly amplified polymorphic DNA (RAPD markers were used to assess genetic variation in three wild population of the catla carp (Catla catla Hamilton 1822 in the Halda, Jamuna and Padma rivers and one hatchery population in Bangladesh. Five decamer random primers were used to amplify RAPD markers from 30 fish from each population. Thirty of the 55 scorable bands were polymorphic, indicating some degree of genetic variation in all the populations. The proportion of polymorphic loci and gene diversity values reflected a relatively higher level of genetic variation in the Halda population. Sixteen of the 30 polymorphic loci showed a significant (p < 0.05, p < 0.01, p < 0.001 departure from homogeneity and the F ST values in the different populations indicated some degree of genetic differentiation in the population pairs. Estimated genetic distances between populations were directly correlated with geographical distances. The unweighted pair group method with averages (UPGMA dendrogram showed two clusters, the Halda population forming one cluster and the other populations the second cluster. Genetic variation of C. catla is a useful trait for developing a good management strategy for maintaining genetic quality of the species.

  3. Heavy metals in wild marine fish from South China Sea: levels, tissue- and species-specific accumulation and potential risk to humans.

    Science.gov (United States)

    Liu, Jin-Ling; Xu, Xiang-Rong; Ding, Zhen-Hua; Peng, Jia-Xi; Jin, Ming-Hua; Wang, You-Shao; Hong, Yi-Guo; Yue, Wei-Zhong

    2015-10-01

    Heavy metal pollution in marine fish has become an important worldwide concern, not only because of the threat to fish in general, but also due to human health risks associated with fish consumption. To investigate the occurrence of heavy metals in marine fish species from the South China Sea, 14 fish species were collected along the coastline of Hainan China during the spring of 2012 and examined for species- and tissue-specific accumulation. The median concentrations of Cd, Cr, Cu, Zn, Pb and As in muscle tissue of the examined fish species were not detectable (ND), 2.02, 0.24, 2.64, 0.025, and 1.13 mg kg(-1) wet weight, respectively. Levels of Cu, Zn, Cd and Cr were found to be higher in the liver and gills than in muscle, while Pb was preferentially accumulated in the gills. Differing from other heavy metals, As did not exhibit tissue-specific accumulation. Inter-species differences of heavy metal accumulation were attributed to the different habitat and diet characteristics of marine fish. Human dietary exposure assessment suggested that the amounts of both Cr and As in marine wild fish collected from the sites around Hainan, China were not compliant with the safety standard of less than 79.2 g d(-1) for wild marine fish set by the Joint FAO/WHO Expert Committee on Food Additives. Further research to identify the explicit sources of Cr and As in marine fish from South China Sea should be established.

  4. Essential oil composition and variability of Hypericum perforatum L. from wild population in Kosovo

    Directory of Open Access Journals (Sweden)

    Hajdari Avni

    2014-06-01

    Full Text Available Aerial parts of Hypericum perforatum L. (Hypericaceae were collected from five wild populations in Kosovo, with aim to investigate the chemical composition and natural variation of essential oils between wild populations. This species could be considered of economic potential as it is widespread in Kosovo, on the other hand H. perforatum is one of the best-known medicinal herbs used in Kosovo folk medicine. Essential oils were obtained by steam distillation and analysed by GC-FID and GC-MS. Sixty-seven components were identified. The yields of essential oils differed depending on the population and ranged from 0.04 to 0.26% based on dry weight. The aerial parts of H. perforatum were characterized by the following main constituents: 2-methyl-octane (1.1-15.5%, α-pinene (3.7-36.5%, β-caryophyllene (1.2-12.4%, caryophyllene oxide (3.3-17.7% and n-tetradecanol (3.6- 10.4%. Hierarchical cluster analysis revealed that the concentration of components depends on the origin of the plant populations, thus α-pinene and 2-methyl-octane were present in the highest concentration in population originating from Gjakove, Prizren and Ferizaj, whereas in the populations originating from Peje and Prishtine the most abundant constituents were caryophyllene oxide, β-caryophyllene and n-tetradecanol. Further investigation is needed to establish the natural variability and chemopolymorphism of this species in the territory of Kosovo, which should be supported by molecular level analyses.

  5. Niche segregation and genetic structure of Campylobacter jejuni populations from wild and agricultural host species.

    Science.gov (United States)

    Sheppard, Samuel K; Colles, Frances M; McCarthy, Noel D; Strachan, Norval J C; Ogden, Iain D; Forbes, Ken J; Dallas, John F; Maiden, Martin C J

    2011-08-01

    Bacterial populations can display high levels of genetic structuring but the forces that influence this are incompletely understood. Here, by combining modelling approaches with multilocus sequence data for the zoonotic pathogen Campylobacter, we investigated how ecological factors such as niche (host) separation relate to population structure. We analysed seven housekeeping genes from published C. jejuni and C. coli isolate collections from a range of food and wild animal sources as well as abiotic environments. By reconstructing genetic structure and the patterns of ancestry, we quantified C. jejuni host association, inferred ancestral populations, investigated genetic admixture in different hosts and determined the host origin of recombinant C. jejuni alleles found in hybrid C. coli lineages. Phylogenetically distinct C. jejuni lineages were associated with phylogenetically distinct wild birds. However, in the farm environment, phylogenetically distant host animals shared several C. jejuni lineages that could not be segregated according to host origin using these analyses. Furthermore, of the introgressed C. jejuni alleles found in C. coli lineages, 73% were attributed to genotypes associated with food animals. Our results are consistent with an evolutionary scenario where distinct Campylobacter lineages are associated with different host species but the ecological factors that maintain this are different in domestic animals such that phylogenetically distant animals can harbour closely related strains. © 2011 Blackwell Publishing Ltd.

  6. Pervasive Mitochondrial Sequence Heteroplasmy in Natural Populations of Wild Carrot, Daucus carota spp. carota L.

    Directory of Open Access Journals (Sweden)

    Jennifer R Mandel

    Full Text Available Exceptions to the generally accepted rules that plant mitochondrial genomes are strictly maternally inherited and that within-individual sequence diversity in those genomes, i.e., heteroplasmy, should be minimal are becoming increasingly apparent especially with regard to sequence-level heteroplasmy. These findings raise questions about the potential significance of such heteroplasmy for plant mitochondrial genome evolution. Still studies quantifying the amount and consequences of sequence heteroplasmy in natural populations are rare. In this study, we report pervasive sequence heteroplasmy in natural populations of wild carrot, a close relative of the cultivated crop. In order to assay directly for this heteroplasmy, we implemented a quantitative PCR assay that can detect and quantify intra-individual SNP variation in two mitochondrial genes (Cox1 and Atp9. We found heteroplasmy in > 60% of all wild carrot populations surveyed and in > 30% of the 140 component individuals that were genotyped. Heteroplasmy ranged from a very small proportion of the total genotype (e.g., 0.995:0.005 to near even mixtures (e.g., 0.590:0.410 in some individuals. These results have important implications for the role of intra-genomic recombination in the generation of plant mitochondrial genome genotypic novelty. The consequences of such recombination are evident in the results of this study through analysis of the degree of linkage disequilibrium (LD between the SNP sites at the two genes studied.

  7. Development of a spatially distributed model of fish population density for habitat assessment of rivers

    Science.gov (United States)

    Sui, Pengzhe; Iwasaki, Akito; Ryo, Masahiro; Saavedra, Oliver; Yoshimura, Chihiro

    2013-04-01

    Flow conditions play an important role in sustaining biodiversity of river ecosystem. However, their relations to freshwater fishes, especially to fish population density, have not been clearly described. This study, therefore, aimed to propose a new methodology to quantitatively link habitat conditions, including flow conditions and other physical conditions, to population density of fish species. We developed a basin-scale fish distribution model by integrating the concept of habitat suitability assessment with a distributed hydrological model (DHM) in order to estimate fish population density with particular attention to flow conditions. Generalized linear model (GLM) was employed to evaluate the relationship between population density of fish species and major environmental factors. The target basin was Sagami River in central Japan, where the river reach was divided into 10 sections by estuary, confluences of tributaries, and river-crossing structures (dams, weirs). The DHM was employed to simulate river discharge from 1998 to 2005, which was used to calculate 10 flow indices including mean discharge, 25th and 75th percentile discharge, duration of low and high flows, number of floods. In addition, 5 water quality parameters and 13 other physical conditions (such as basin area, river width, mean diameter of riverbed material, and number of river-crossing structures upstream and downstream) of each river section were considered as environmental variables. In case of Sagami River, 10 habitat variables among them were then selected based on their correlations to avoid multicollinearity. Finally, the best GLM was developed for each species based on Akaike's information criterion. As results, population densities of 16 fish species in Sagami River were modelled, and correlation coefficients between observed and calculated population densities for 10 species were more than 0.70. The key habitat factors for population density varied among fish species. Minimum

  8. Creating a sanctuary for wild Steelhead Trout through hatchery operations

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Deschutes River basin in north-central Oregon supports a wild population of threatened summer steelhead (Oncorhynchus mykiss). The basin has seen large increases...

  9. Individual and population-level impacts of an emerging poxvirus disease in a wild population of great tits.

    Directory of Open Access Journals (Sweden)

    Shelly Lachish

    Full Text Available Emerging infectious diseases of wildlife can have severe effects on host populations and constitute a pressing problem for biodiversity conservation. Paridae pox is an unusually severe form of avipoxvirus infection that has recently been identified as an emerging infectious disease particularly affecting an abundant songbird, the great tit (Parus major, in Great Britain. In this study, we study the invasion and establishment of Paridae pox in a long-term monitored population of wild great tits to (i quantify the impact of this novel pathogen on host fitness and (ii determine the potential threat it poses to population persistence. We show that Paridae pox significantly reduces the reproductive output of great tits by reducing the ability of parents to fledge young successfully and rear those young to independence. Our results also suggested that pathogen transmission from diseased parents to their offspring was possible, and that disease entails severe mortality costs for affected chicks. Application of multistate mark-recapture modelling showed that Paridae pox causes significant reductions to host survival, with particularly large effects observed for juvenile survival. Using an age-structured population model, we demonstrate that Paridae pox has the potential to reduce population growth rate, primarily through negative impacts on host survival rates. However, at currently observed prevalence, significant disease-induced population decline seems unlikely, although pox prevalence may be underestimated if capture probability of diseased individuals is low. Despite this, because pox-affected model populations exhibited lower average growth rates, this emerging infectious disease has the potential to reduce the resilience of populations to other environmental factors that reduce population size.

  10. The effects of urbanization on population density, occupancy, and detection probability of wild felids.

    Science.gov (United States)

    Lewis, Jesse S; Logan, Kenneth A; Alldredge, Mat W; Bailey, Larissa L; VandeWoude, Sue; Crooks, Kevin R

    2015-10-01

    Urbanization is a primary driver of landscape conversion, with far-reaching effects on landscape pattern and process, particularly related to the population characteristics of animals. Urbanization can alter animal movement and habitat quality, both of which can influence population abundance and persistence. We evaluated three important population characteristics (population density, site occupancy, and species detection probability) of a medium-sized and a large carnivore across varying levels of urbanization. Specifically, we studied bobcat and puma populations across wildland, exurban development, and wildland-urban interface (WUI) sampling grids to test hypotheses evaluating how urbanization affects wild felid populations and their prey. Exurban development appeared to have a greater impact on felid populations than did habitat adjacent to a major urban area (i.e., WUI); estimates of population density for both bobcats and pumas were lower in areas of exurban development compared to wildland areas, whereas population density was similar between WUI and wildland habitat. Bobcats and pumas were less likely to be detected in habitat as the amount of human disturbance associated with residential development increased at a site, which was potentially related to reduced habitat quality resulting from urbanization. However, occupancy of both felids was similar between grids in both study areas, indicating that this population metric was less sensitive than density. At the scale of the sampling grid, detection probability for bobcats in urbanized habitat was greater than in wildland areas, potentially due to restrictive movement corridors and funneling of animal movements in landscapes influenced by urbanization. Occupancy of important felid prey (cottontail rabbits and mule deer) was similar across levels of urbanization, although elk occupancy was lower in urbanized areas. Our study indicates that the conservation of medium- and large-sized felids associated with

  11. Comparative genetic diversity of wild and hatchery-produced populations of tongue sole (Cynoglossus semilaevis) using multiplex PCR assays with polymorphic microsatellite markers

    National Research Council Canada - National Science Library

    An, H S; Kim, E-M; Kang, H W; Han, H S; Lee, J W; Park, J Y; Myeong, J I; An, C M

    2013-01-01

    .... Specifically, possible differences in genetic variability between wild populations of tongue sole from Korea and hatchery-produced populations of tongue sole from China were assessed using multiplex...

  12. Diversity of parasites in wild Astronotus ocellatus (Perciformes, Cichlidae, an ornamental and food fish in Brazil

    Directory of Open Access Journals (Sweden)

    MARCOS TAVARES-DIAS

    2017-10-01

    Full Text Available ABSTRACT The community composition of parasites was characterized in Astronotus ocellatus from a tributary of the Amazon River, northern Brazil. The prevalence was 87.9%, and a total of 526,052 parasites were collected, with a mean of 15,941 parasites per host. Nine taxa of ecto- and endo-parasites were identified, but Ichthyophthirius multifiliis was the dominant species, while Piscinoodinium pillulare, Clinostomum marginatum and Argulus multicolor were the least prevalent parasites. The parasite community was characterized by a low species richness, low diversity and low evenness. Host body size was not found to influence the composition of the parasite community, and there was no significant correlation between abundance of any parasite species and host body size. Papers published concerning the presence of parasites in this host in different hydrographic basins within Brazil indicate that 22 species of parasites are known to infect A. ocellatus, including species of ectoparasites and endoparasites. In Brazil, ectoparasites species, particularly crustaceans, have been found to parasitize A. ocellatus in relatively high numbers. This predominance of ectoparasites is typical of fish of lentic ecosystems. Finally, the presence of different endoparasites taxa suggest that A. ocellatus acts as an intermediate or definitive host.

  13. Halogenated phenolic compounds in wild fish from Canadian Areas of Concern.

    Science.gov (United States)

    Gilroy, Ève A M; Muir, Derek C G; McMaster, Mark E; Darling, Colin; Campbell, Linda M; Alaee, Mehran; Brown, Scott B; Sherry, James P

    2017-09-01

    Concentrations of halogenated phenolic compounds were measured in the plasma of brown bullhead (Ameiurus nebulosus) from 4 Canadian Areas of Concern (AOCs), to assess exposure to suspected thyroid-disrupting chemicals. Hydroxylated polychlorinated biphenyls (OH-PCBs) were detected in every sample collected in 3 of the AOCs; the detection frequency was lower in samples from the Detroit River AOC. The OH-PCBs most frequently detected were pentachloro, hexachloro, and heptachloro congeners, which are structurally similar to thyroid hormones. Pentachlorophenol (PCP) was detected at highest concentrations (1.8 ng/g) in fish from Prince Edward Bay, the Bay of Quinte Lake reference site, and Hillman Marsh (the Wheatley Harbour reference site), suggesting local sources of contamination. Elevated PCP concentrations were also detected in the plasma of brown bullhead from exposed sites in the Toronto and Region AOC (0.4-0.6 ng/g). Triclosan was consistently detected in the Toronto and Region AOC (0.05-0.9 ng/g), consistent with wastewater emission. Greater concentrations were occasionally detected in the plasma of brown bullhead from the Bay of Quinte AOC. Concentrations of polybrominated diphenyl ethers were highest in the Toronto and Region AOC, and at 2 of the Bay of Quinte AOC exposed sites near Trenton and Belleville. Distribution patterns reflected the properties and usage of the compounds under investigation and the characteristics of each AOC. Environ Toxicol Chem 2017;36:2266-2273. © 2017 SETAC. © 2017 SETAC.

  14. Diversity of parasites in wild Astronotus ocellatus (Perciformes, Cichlidae), an ornamental and food fish in Brazil.

    Science.gov (United States)

    Tavares-Dias, Marcos; Neves, Ligia R

    2017-01-01

    The community composition of parasites was characterized in Astronotus ocellatus from a tributary of the Amazon River, northern Brazil. The prevalence was 87.9%, and a total of 526,052 parasites were collected, with a mean of 15,941 parasites per host. Nine taxa of ecto- and endo-parasites were identified, but Ichthyophthirius multifiliis was the dominant species, while Piscinoodinium pillulare, Clinostomum marginatum and Argulus multicolor were the least prevalent parasites. The parasite community was characterized by a low species richness, low diversity and low evenness. Host body size was not found to influence the composition of the parasite community, and there was no significant correlation between abundance of any parasite species and host body size. Papers published concerning the presence of parasites in this host in different hydrographic basins within Brazil indicate that 22 species of parasites are known to infect A. ocellatus, including species of ectoparasites and endoparasites. In Brazil, ectoparasites species, particularly crustaceans, have been found to parasitize A. ocellatus in relatively high numbers. This predominance of ectoparasites is typical of fish of lentic ecosystems. Finally, the presence of different endoparasites taxa suggest that A. ocellatus acts as an intermediate or definitive host.

  15. Distribution and numbers of the wild boar population in south eastern Poland

    Directory of Open Access Journals (Sweden)

    Fonseca, C.

    2002-12-01

    Full Text Available By using both plot sampling and line intercept snow track index, the population density and numbers of wild boar in Bieszczady Mountains and Bieszczady Foothills was estimated during February 2000. The total number of wild boar inhabiting the study area (140.4 thousands ha of forest was equal to 655 animals with an average population density of 4.66 wild boar per 1000 ha, ranging from 0.0 (Forest Districts of Cisna and Wetlina to 23.21 individuals/1000 ha (Krasiczyn Forest District. The low density of wild boar in Bieszczady Mountains is caused by the high wolf prédation and overharvest rate. The recomendation is to stop wild boar hunting in Bieszczady Mountains during the next 4 hunting seasons, and to use the harvest rate equal to 30% of the population size in February.

    [fr]
    En février 2000, nous avons estimé la densité de population et le nombre de sangliers sauvages dans les montagnes Bieszczady et les collines Bieszczady. Pour cela, un index des empreintes sur la neige interceptant une ligne ainsi que des parcelles d'échantillonage ont été utilisées. Le nombre total de sangliers habitant dans la zone d'étude -140.400 ha de forêts- s'élevait à 655 animais; la densité moyenne de population était de 4,66 sangliers sauvages par 1000 ha, chiffre oscillant entre 0,0 (Districts Forestiers de Cisna et Wetlina et 23,21 individus par 1000 ha (District de Krasiczyn. La très basse densité de sangliers sauvages dans les Montagnes Bieszczady est sans doute la conséquence de la forte prédation par le loup et de la chasse importante. Les auteurs proposent d'arrêter la chasse dans les Montagnes Bieszczady durant les 4 saisons suivantes et de limiter le taux d'extraction à 30% du niveau de la population en février.
    [es]
    Durante febrero de 2000, en las montañas Bieszczady y sus estribaciones, se estimó la densidad poblacional y número de jabalíes por medio del índice de intercepción lineal de huellas en nieve

  16. Intake Levels of Fish in the UK Paediatric Population

    OpenAIRE

    Kranz, Sibylle; Nicholas R V Jones; Monsivais, Pablo

    2017-01-01

    The United Kingdom (UK) is an island and its culture, including diet, is heavily influenced by the maritime resources. Dietary guidance in the UK recommends intake of fish, which provides important nutrients, such as long-chain omega-3 polyunsaturated fatty acids (n-3 PUFA). This study was designed to describe the fish intake habits of UK children using a nationally representative sample. Dietary and socio-demographic data of children 2?18 (N = 2096) in the National Diet and Nutrition Survey ...

  17. Notes on wild dog Lycaon pictus and lion Panthera leo population trends during a drought in the Kruger National Park

    Directory of Open Access Journals (Sweden)

    M.G.L. Mills

    1995-09-01

    Full Text Available Wild dog Lycaon pictus and lion Panthera leo populations in the Kruger National Park appeared to undergo an increase during a drought period in the early 1990s. Newly established packs, high adult survival and pup productivity contributed to an increase in the wild dog population and evidence for high predation success during the height of the drought is presented. An increase in the lion density between 1989 and 1993 on the northern basalt plains, as well as changes in the structure of the population, seem to be related to changes in prey populations, particularly to a decline in numbers and condition of buffalo Syncerus cafer.

  18. Multilocus Sex Determination Revealed in Two Populations of Gynodioecious Wild Strawberry, Fragaria vesca subsp. bracteata.

    Science.gov (United States)

    Ashman, Tia-Lynn; Tennessen, Jacob A; Dalton, Rebecca M; Govindarajulu, Rajanikanth; Koski, Matthew H; Liston, Aaron

    2015-10-19

    Gynodioecy, the coexistence of females and hermaphrodites, occurs in 20% of angiosperm families and often enables transitions between hermaphroditism and dioecy. Clarifying mechanisms of sex determination in gynodioecious species can thus illuminate sexual system evolution. Genetic determination of gynodioecy, however, can be complex and is not fully characterized in any wild species. We used targeted sequence capture to genetically map a novel nuclear contributor to male sterility in a self-pollinated hermaphrodite of Fragaria vesca subsp. bracteata from the southern portion of its range. To understand its interaction with another identified locus and possibly additional loci, we performed crosses within and between two populations separated by 2000 km, phenotyped the progeny and sequenced candidate markers at both sex-determining loci. The newly mapped locus contains a high density of pentatricopeptide repeat genes, a class commonly involved in restoration of fertility caused by cytoplasmic male sterility. Examination of all crosses revealed three unlinked epistatically interacting loci that determine sexual phenotype and vary in frequency between populations. Fragaria vesca subsp. bracteata represents the first wild gynodioecious species with genomic evidence of both cytoplasmic and nuclear genes in sex determination. We propose a model for the interactions between these loci and new hypotheses for the evolution of sex determining chromosomes in the subdioecious and dioecious Fragaria. Copyright © 2015 Ashman et al.

  19. Prevalence and effects of West Nile virus on wild American kestrel (Falco sparverius) populations in Colorado

    Science.gov (United States)

    Dusek, Robert J.; Iko, William M.; Hofmeister, Erik K.; Paul, Ellen

    2012-01-01

    To assess the potential impacts of West Nile virus (WNV) on a wild population of free-ranging raptors, we investigated the prevalence and effects of WNV on American Kestrels (Falco sparverius) breeding along the Front Range of the Rocky Mountains in northern Colorado. We monitored kestrel nesting activity at 131 nest boxes from March to August 2004. Of 81 nest attempts, we obtained samples from 111 adults and 250 young. We did not detect WNV in sera; however, 97.3% (108/111) of adults tested positive for WNV neutralizing antibodies, which possibly represented passive transfer of maternal antibodies. Clutch size, hatching, and fledging success in our study did not differ from that previously reported for this species, suggesting that previous WNV exposure in kestrels did not have an effect on reproductive parameters measured in the breeding populations we studied in 2004.

  20. Characterization of F1 interspecific hybrids between wild Helianthus annuus L. populations and cultivated sunflower

    Directory of Open Access Journals (Sweden)

    Terzić Sreten

    2006-01-01

    Full Text Available Phenotype, chromosomes pairing and pollen vitality were compared between parental populations and F1 hybrids of interspecific cross between Helianthus annuus L. and cultivated sunflower. The investigation of the simple sequence repeats (SSR polymorphism was also used to test the hybrid nature of F1 populations. The phenotypic traits of F1 hybrid plants were either closer to the wild species or intermediate. Irregular chromosome pairing was found in only 0 to 10% of meiocytes in the meiosis of F1 hybrid plants. Interspecific crosses were confirmed with SSR markers in all hybrid combinations. Alleles that were not present in parental DNA were frequently observed in F1 hybrids. That is additional evidence that those hybrid combinations were not produced by self-fertilization. The results suggest that SSR markers can be efficiently used for the F1 hybrid characterization in crosses between closely related species, in which, the changes of phenotype, meiosis and pollen vitality are not always significant.

  1. Climate change effects on North American inland fish populations and assemblages

    Science.gov (United States)

    Lynch, Abigail J.; Myers, Bonnie; Chu, Cindy; Eby, Lisa A.; Falke, Jeffrey A.; Kovach, Ryan P.; Krabbenhoft, Trevor J.; Kwak, Thomas J.; Lyons, John; Paukert, Craig P.; Whitney, James E.

    2016-01-01

    Climate is a critical driver of many fish populations, assemblages, and aquatic communities. However, direct observational studies of climate change impacts on North American inland fishes are rare. In this synthesis, we (1) summarize climate trends that may influence North American inland fish populations and assemblages, (2) compile 31 peer-reviewed studies of documented climate change effects on North American inland fish populations and assemblages, and (3) highlight four case studies representing a variety of observed responses ranging from warmwater systems in the southwestern and southeastern United States to coldwater systems along the Pacific Coast and Canadian Shield. We conclude by identifying key data gaps and research needs to inform adaptive, ecosystem-based approaches to managing North American inland fishes and fisheries in a changing climate.

  2. First record of intestinal parasites in a wild population of jaguar in the Brazilian Atlantic Forest

    Directory of Open Access Journals (Sweden)

    Ana Carolina Srbek-Araujo

    Full Text Available Small and isolated wildlife populations may be more susceptible to disease, which makes illness an important issue to investigate regarding the conservation of large carnivores. Here, we present the results of the first investigation of intestinal parasites in one of the last remaining populations of jaguars in the Brazilian Atlantic Forest. We studied parasites from fecal samples using three different techniques for parasitological examination: floatation in saturated sodium chloride solution, sedimentation and formalin-ether centrifugation. Intestinal parasites were detected in 70% of the analyzed samples, and seven taxa (mean = 3.7 taxa/sample were identified. All the groups of parasites that were identified have been recorded in previous jaguar studies. However, the records of Class Trematoda and nematodes Trichuridae are the first evidence of these groups of worms in free-ranging jaguars in Brazil. Although our results do not provide conclusive evidence on the health of this jaguar population, given its very small size (approximately 20 animals we stress the need to properly understand the dynamics of disease in this wild population and to evaluate the risk of contracting new diseases from domestic species inhabiting the neighboring areas. These represent imperative actions for the successful conservation of this threatened population of jaguar.

  3. Demographic study of a wild house sparrow population by DNA fingerprinting.

    Science.gov (United States)

    Wetton, J H; Carter, R E; Parkin, D T; Walters, D

    Over the past twenty years, several techniques from biochemical and molecular genetics, such as enzyme electrophoresis and isoelectric focusing, have been widely and successfully applied to the study of population differentiation and evolution. However, they have been less applicable to demographic problems such as assigning parentage to individuals within a population. This stems from a general weakness of data derived from enzyme loci: allele frequencies at polymorphic loci are sufficiently skewed that the majority of individuals are of one or two genotypes. Many enzyme systems can only be examined post mortem, so that the loci are of little use if the animals are to be studied in the wild. The search for new and more sensitive techniques for detecting genetic variation has continued, and recently a major discovery has come from molecular biology. Jeffreys et al. have reported the detection of a type of hypervariable 'minisatellite' DNA that is extraordinarily polymorphic in human populations. We have applied their technique to several bird species and particularly to a population of house sparrows (Passer domesticus) near Nottingham. We report here that one of the human minisatellite clones is a suitable probe for sparrow DNA and that it reveals variation as extensive as that found in man. These results suggest that analysis of minisatellite DNA will be a powerful tool in the study of demographic population genetics.

  4. Serologic evidence of West Nile virus infection in three wild raptor populations.

    Science.gov (United States)

    Stout, William E; Cassini, Andrew G; Meece, Jennifer K; Papp, Joseph M; Rosenfield, Robert N; Reed, Kurt D

    2005-09-01

    We assayed for West Nile virus (WNV) antibodies to determine the presence and prevalence of WNV infection in three raptor populations in southeast Wisconsin during 2003-04. This study was conducted in the framework of ongoing population studies that started before WNV was introduced to the study area. For 354 samples, 88% of 42 adult Cooper's hawks (Accipiter cooperii), 2.1% of 96 nestling Cooper's hawks, 9.2% of 141 nestling red-tailed hawks (Buteo jamaicensis), and 12% of 73 nestling great horned owls (Bubo virginianus) tested positive for WNV antibodies by the constant virus-serum dilution neutralization test. Samples that tested positive for WNV antibodies were collected across a wide variety of habitat types, including urban habitats (both high and low density), roads, parking areas, recreational areas, croplands, pastures, grasslands, woodlands, and wetlands. Based on the increased prevalence and significantly higher WNV antibody titers in adults compared with nestlings, we suggest that nestlings with detectable antibody levels acquired these antibodies through passive transmission from the mother during egg production. Low levels of WNV antibodies in nestlings could serve as a surrogate marker of exposure in adult raptor populations. Based on breeding population densities and reproductive success over the past 15 yr, we found no apparent adverse effects of WNV infections on these wild raptor populations.

  5. Population Dynamics Among six Major Groups of the Oryza rufipogon Species Complex, Wild Relative of Cultivated Asian Rice.

    Science.gov (United States)

    Kim, HyunJung; Jung, Janelle; Singh, Namrata; Greenberg, Anthony; Doyle, Jeff J; Tyagi, Wricha; Chung, Jong-Wook; Kimball, Jennifer; Hamilton, Ruaraidh Sackville; McCouch, Susan R

    2016-12-01

    Understanding population structure of the wild progenitor of Asian cultivated rice (O. sativa), the Oryza rufipogon species complex (ORSC), is of interest to plant breeders and contributes to our understanding of rice domestication. A collection of 286 diverse ORSC accessions was evaluated for nuclear variation using genotyping-by-sequencing (113,739 SNPs) and for chloroplast variation using Sanger sequencing (25 polymorphic sites). Six wild subpopulations were identified, with 25 % of accessions classified as admixed. Three of the wild groups were genetically and geographically closely related to the O. sativa subpopulations, indica, aus and japonica, and carried O. sativa introgressions; the other three wild groups were genetically divergent, had unique chloroplast haplotypes, and were located at the geographical extremes of the species range. The genetic subpopulations were significantly correlated (r 2  = 0.562) with traditional species designations, O. rufipogon (perennial) and O. nivara (annual), differentiated based on morphology and life history. A wild diversity panel of 95 purified (inbred) accessions was developed for future genetic studies. Our results suggest that the cultivated aus subpopulation is most closely related to an annual wild relative, japonica to a perennial wild relative, and indica to an admixed population of diverse annual and perennial wild ancestors. Gene flow between ORSC and O. sativa is common in regions where rice is cultivated, threatening the identity and diversity of wild ORSC populations. The three geographically isolated ORSC populations harbor variation rarely seen in cultivated rice and provide a unique window into the genetic composition of ancient rice subpopulations.

  6. Economic impacts of changes in population dynamics of fish on the fisheries in the Barents Sea

    NARCIS (Netherlands)

    Link, P.M.; Tol, R.S.J.

    2006-01-01

    A bioeconomic simulation model of the two interacting fish species cod (Gadus morhua) and capelin (Mallotus villosus) and their fisheries is presented and applied to assess the consequences of changes in the population dynamics of these important fish stocks in the Barents Sea. In each scenario, the

  7. Marine foraging and annual fish consumption of a south polar Skua population in the maritime Antarctic

    NARCIS (Netherlands)

    Hahn, S.M.; Ritz, M.S.; Reinhardt, K.

    2008-01-01

    Pelagic fish are an important component of Antarctic food webs but few quantitative data exist on energy transfer from fish to seabirds for the Seasonal Pack-ice Zone. We studied a local population of south polar, skuas Catharacta maccormicki during a whole breeding cycle and estimated its entire

  8. Reproductive ecology and genetic variability in natural populations of the wild potato, Solanum kurtzianum.

    Science.gov (United States)

    Marfil, C F; Masuelli, R W

    2014-03-01

    The cultivated potato (Solanum tuberosum ssp. tuberosum) has more than 200 related wild species distributed along the Andes, adapted to a wide range of geographical and ecological areas. Since the last century, several collection expeditions were carried out to incorporate genetic variability into the potato germplasm around the world. However, little is known about the reproductive ecology and genetic population structure of natural potato population from field studies. The aim of this work is to study, in the field, the genetic variability and reproductive strategies of populations of one of the most widely distributed potato species in Argentina, Solanum kurtzianum, growing in Mendoza province. AFLP markers showed that the genetic variability is mainly present among plants within populations, indicating that in the sampled populations, sexual reproduction is more relevant than clonal multiplication (by tubers). Additional evidence was obtained evaluating the genetic diversity in populations with a distribution in patches, where several genotypes were always detected. From a field study performed in the Villavicencio Natural Reserve, we found that the average number of plump seeds per fruit was 94.3, identified and calculated the foraging distance of four insect pollinators, and demonstrated the seed dispersal by storm water channels. We argue that the breeding system, the two modes of reproduction and the ecological interaction described here may have a prominent role in determining the genetic structure of S. kurtzianum populations, and discuss the importance of field studies on population genetics, reproductive biology and ecology to design collections and conservation strategies. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  9. An Infectious Disease and Mortality Survey in a Population of Free-Ranging African Wild Dogs and Sympatric Domestic Dogs

    Directory of Open Access Journals (Sweden)

    G. Flacke

    2013-01-01

    Full Text Available Disease can cause declines in wildlife populations and significantly threaten their survival. Recent expansion of human and domestic animal populations has made wildlife more susceptible to transmission of pathogens from domestic animal hosts. We conducted a pathogen surveillance and mortality survey for the population of African wild dogs (Lycaon pictus in KwaZulu-Natal (KZN, South Africa, from January 2006–February 2007. Samples were obtained from 24 wild dogs for canine distemper virus (CDV and canine parvovirus (CPV serological testing. Data were collected on the presence of CDV, CPV, and rabies virus in the KZN domestic dog (Canis familiaris population from 2004–06. The presence of these pathogens was confirmed in domestic dogs throughout KZN. Wild dogs exhibited 0% and 4.2% prevalence for CDV and CPV antibodies, respectively. In 2006 the largest wild dog pack in KZN was reduced from 26 individuals to a single animal; disease due to rabies virus was considered the most probable cause. This study provides evidence that CDV, CPV and rabies are potential threats to African wild dog conservation in KZN. The most economical and practical way to protect wild dogs from canine pathogens may be via vaccination of sympatric domestic dogs; however, such programmes are currently limited.

  10. Alaska Department of Fish and Game Juneau, Alaska: South Central Moose Population Studies

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A study aiming to delineate populations and subpopulations of moose on the west side of the lower Susitna Valley and to assess their seasonal movement patterns

  11. Muskrat population estimates for Fish Springs NWR, Utah : An assessment of techniques

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Completion report for a study of muskrat population dynamics and vegetation utilization, being led by Utah State University for a doctorate dissertation. The study...

  12. Contaminants as a limiting factor of fish and wildlife populations in the Santa Cruz River, Arizona

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Declining populations of the endangered Gila topminnow in the Santa Cruz River prompted a 1997 study to assess contaminant levels in water, sediment, invertebrates,...

  13. Footprints of directional selection in wild Atlantic salmon populations: evidence for parasite-driven evolution?

    Science.gov (United States)

    Zueva, Ksenia J; Lumme, Jaakko; Veselov, Alexey E; Kent, Matthew P; Lien, Sigbjørn; Primmer, Craig R

    2014-01-01

    Mechanisms of host-parasite co-adaptation have long been of interest in evolutionary biology; however, determining the genetic basis of parasite resistance has been challenging. Current advances in genome technologies provide new opportunities for obtaining a genome-scale view of the action of parasite-driven natural selection in wild populations and thus facilitate the search for specific genomic regions underlying inter-population differences in pathogen response. European populations of Atlantic salmon (Salmo salar L.) exhibit natural variance in susceptibility levels to the ectoparasite Gyrodactylus salaris Malmberg 1957, ranging from resistance to extreme susceptibility, and are therefore a good model for studying the evolution of virulence and resistance. However, distinguishing the molecular signatures of genetic drift and environment-associated selection in small populations such as land-locked Atlantic salmon populations presents a challenge, specifically in the search for pathogen-driven selection. We used a novel genome-scan analysis approach that enabled us to i) identify signals of selection in salmon populations affected by varying levels of genetic drift and ii) separate potentially selected loci into the categories of pathogen (G. salaris)-driven selection and selection acting upon other environmental characteristics. A total of 4631 single nucleotide polymorphisms (SNPs) were screened in Atlantic salmon from 12 different northern European populations. We identified three genomic regions potentially affected by parasite-driven selection, as well as three regions presumably affected by salinity-driven directional selection. Functional annotation of candidate SNPs is consistent with the role of the detected genomic regions in immune defence and, implicitly, in osmoregulation. These results provide new insights into the genetic basis of pathogen susceptibility in Atlantic salmon and will enable future searches for the specific genes involved.

  14. Genetic Diversity and Population Structure of Wild Olives from the North-western Mediterranean Assessed by SSR Markers

    Science.gov (United States)

    Belaj, Angjelina; Muñoz-Diez, Concepción; Baldoni, Luciana; Porceddu, Andrea; Barranco, Diego; Satovic, Zlatko

    2007-01-01

    Background and Aims This study examines the pattern of genetic variability and genetic relationships of wild olive (Olea europaea subsp. europaea var. sylvestris) populations in the north-western Mediterranean. Recent bottleneck events are also assessed and an investigation is made of the underlying population structure of the wild olive populations. Methods The genetic variation within and between 11 wild olive populations (171 individuals) was analysed with eight microsatellite markers. Conventional and Bayesian-based analyses were applied to infer genetic structure and define the number of gene pools in wild olive populations. Key Results Bayesian model-based clustering identified four gene pools, which was in overall concordance with the Factorial Correspondence Analysis and Fitch–Margoliash tree. Two gene pools were predominantly found in southern Spain and Italian islands, respectively, in samples gathered from undisturbed forests of the typical Mediterranean climate. The other two gene pools were mostly detected in the north-eastern regions of Spain and in continental Italy and belong to the transition region between the temperate and Mediterranean climate zones. Conclusions On the basis of these results, it can be assumed that the population structure of wild olives from the north-western Mediterranean partially reflects the evolutionary history of these populations, although hybridization between true oleasters and cultivated varieties in areas of close contact between the two forms must be assumed as well. The study indicates a degree of admixture in all the populations, and suggests some caution regarding genetic differentiation at the population level, making it difficult to identify clear-cut genetic boundaries between candidate areas containing either genuinely wild or feral germplasm. PMID:17613587

  15. Hematodinium spp. infections in wild and cultured populations of marine crustaceans along the coast of China.

    Science.gov (United States)

    Wang, Jin-Feng; Li, Meng; Xiao, Jie; Xu, Wen-Jun; Li, Cai-Wen

    2017-05-11

    The parasitic dinoflagellate Hematodinium spp. infects a broad range of marine crustaceans. Its epidemics have impacted wild populations of various commercial fishery species around the world and the sustainability of mariculture in China. To study the epidemiology of Hematodinium spp. in marine crustaceans along the coast of China, we conducted a broad survey of wild and cultured stocks of major crustacean species in 2013 to 2015. Hematodinium sp. infections were identified in wild stocks of Portunus trituberculatus from Huludao, Laizhou, Qingdao, Yangtze River Estuary and Zhoushan, and Scylla paramamosain from Shantou; and cultured stocks of Portunus trituberculatus and Penaeus monodon from a polyculture pond in Qingdao. In the polyculture pond, Hematodinium sp. infections were observed in Portunus trituberculatus from June until October, with peak prevalence (up to 90%) observed in late July to early August. Furthermore, Hematodinium sp. infection was identified for the first time in the giant tiger prawn Penaeus monodon in the polyculture system during the disease outbreak. Phylogenetic analysis indicated that the Hematodinium isolate infecting Penaeus monodon was identical to the isolate infecting the co-cultured Portunus trituberculatus, and it was grouped into H. perezi genotype II together with the other isolates reported in China. The Hematodinium sp. isolated from Portunus trituberculatus appeared to have similar life stages as the H. perezi genotype III isolated from the American blue crab Callinectes sapidus. Our study indicates that outbreaks of Hematodinium disease can be a significant threat to the widely used polyculture system for decapods in China that may be particularly vulnerable to such generalist pathogens.

  16. Resistance to the Whitefly, Aleurotrachelus socialis, in Wild Populations of Cassava, Manihot Tristis

    Science.gov (United States)

    Carabalí, A.; Bellotti, A. C.; Montoya-Lerma, J.; Fregene, Martin

    2010-01-01

    The levels of resistance in the wild species of cassava, Manihot tristis Muell-Arg. (Malpighiales: Euphorbiaceae), to the whitefly, Aleurotrachelus socialis Bondar (Hemiptera: Alelyrodidae), the most important economic pest in cassava, Manihot esculenta Crantz (Malpighiales: Euphorbiaceae) crops in South America, were estimated under glasshouse conditions. The parameters of the life history of A. socialis were studied on TST-26 and TST-18 accessions of the wild parent and compared with the susceptible (CMC-40) and resistant (MEcu-72) cultivars. The average longevity on the wild accessions (TST-26, 4.1; TST-18, 4.6 days) and oviposition rates (TST-26, 2.0; TST-18, 1.6 eggs/female/2 days) of the A. socialis females were not significantly different from those of MEcu-72 (5.1 days and 3.4 eggs/female/2days). The longevity and oviposition rates on CMC-40 were highest (11 days and 8.6 eggs/female/2days). Analyses of the demographic parameters (Ro, rm; DT) showed a significant impact of the M. tristis accessions on the potential growth of A. socialis. The average survival time of adults that fed on TST-26, TST-18, and MEcu-72 were significantly different from those recorded on the susceptible genotype. Results from this study revealed important levels of resistance to the whitefly A. socialis on the TST-26 and TST-18 accessions due to the marked differences found for longevity and reproduction, which influenced and were consistent with the differences found in the net reproduction rate (Ro), intrinsic growth rate (rm) and population doubling time (DT). The combined effect of these parameters indicated that M. tristis accessions were inappropriate hosts for A. socialis. PMID:21062208

  17. Resistance to the whitefly, Aleurotrachelus socialis, in wild populations of cassava, Manihot tristis.

    Science.gov (United States)

    Carabalí, A; Bellotti, A C; Montoya-Lerma, J; Fregene, Martin

    2010-01-01

    The levels of resistance in the wild species of cassava, Manihot tristis Muell-Arg. (Malpighiales: Euphorbiaceae), to the whitefly, Aleurotrachelus socialis Bondar (Hemiptera: Alelyrodidae), the most important economic pest in cassava, Manihot esculenta Crantz (Malpighiales: Euphorbiaceae) crops in South America, were estimated under glasshouse conditions. The parameters of the life history of A. socialis were studied on TST-26 and TST-18 accessions of the wild parent and compared with the susceptible (CMC-40) and resistant (MEcu-72) cultivars. The average longevity on the wild accessions (TST-26, 4.1; TST-18, 4.6 days) and oviposition rates (TST-26, 2.0; TST-18, 1.6 eggs/female/2 days) of the A. socialis females were not significantly different from those of MEcu-72 (5.1 days and 3.4 eggs/female/2 days). The longevity and oviposition rates on CMC-40 were highest (11 days and 8.6 eggs/female/2 days). Analyses of the demographic parameters (Ro, r(m); DT) showed a significant impact of the M. tristis accessions on the potential growth of A. socialis. The average survival time of adults that fed on TST-26, TST-18, and MEcu-72 were significantly different from those recorded on the susceptible genotype. Results from this study revealed important levels of resistance to the whitefly A. socialis on the TST-26 and TST-18 accessions due to the marked differences found for longevity and reproduction, which influenced and were consistent with the differences found in the net reproduction rate (Ro), intrinsic growth rate (r(m)) and population doubling time (DT). The combined effect of these parameters indicated that M. tristis accessions were inappropriate hosts for A. socialis.

  18. Estimating Consumption to Biomass Ratio in Non-Stationary Harvested Fish Populations.

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    Rodrigo Wiff

    Full Text Available The food consumption to biomass ratio (C is one of the most important population parameters in ecosystem modelling because its quantifies the interactions between predator and prey. Existing models for estimating C in fish populations are per-recruit cohort models or empirical models, valid only for stationary populations. Moreover, empirical models lack theoretical support. Here we develop a theory and derive a general modelling framework to estimate C in fish populations, based on length frequency data and the generalised von Bertalanffy growth function, in which models for stationary populations with a stable-age distributions are special cases. Estimates using our method are compared with estimates from per-recruit cohort models for C using simulated harvested fish populations of different lifespans. The models proposed here are also applied to three fish populations that are targets of commercial fisheries in southern Chile. Uncertainty in the estimation of C was evaluated using a resampling approach. Simulations showed that stationary and non-stationary population models produce different estimates for C and those differences depend on the lifespan, fishing mortality and recruitment variations. Estimates of C using the new model exhibited smoother inter-annual variation in comparison with a per-recruit model estimates and they were also smaller than C predicted by the empirical equations in all population assessed.

  19. Estimating Consumption to Biomass Ratio in Non-Stationary Harvested Fish Populations

    Science.gov (United States)

    Wiff, Rodrigo; Roa-Ureta, Ruben H.; Borchers, David L.; Milessi, Andrés C.; Barrientos, Mauricio A.

    2015-01-01

    The food consumption to biomass ratio (C) is one of the most important population parameters in ecosystem modelling because its quantifies the interactions between predator and prey. Existing models for estimating C in fish populations are per-recruit cohort models or empirical models, valid only for stationary populations. Moreover, empirical models lack theoretical support. Here we develop a theory and derive a general modelling framework to estimate C in fish populations, based on length frequency data and the generalised von Bertalanffy growth function, in which models for stationary populations with a stable-age distributions are special cases. Estimates using our method are compared with estimates from per-recruit cohort models for C using simulated harvested fish populations of different lifespans. The models proposed here are also applied to three fish populations that are targets of commercial fisheries in southern Chile. Uncertainty in the estimation of C was evaluated using a resampling approach. Simulations showed that stationary and non-stationary population models produce different estimates for C and those differences depend on the lifespan, fishing mortality and recruitment variations. Estimates of C using the new model exhibited smoother inter-annual variation in comparison with a per-recruit model estimates and they were also smaller than C predicted by the empirical equations in all population assessed. PMID:26528721

  20. Chemical diversity among the essential oils of wild populations of Stachys lavandulifolia VAHL (Lamiaceae) from Iran.

    Science.gov (United States)

    Aghaei, Yaqub; Hossein Mirjalili, Mohammad; Nazeri, Vahideh

    2013-02-01

    The variation of the essential-oil composition among ten wild populations of Stachys lavandulifolia VAHL (Lamiaceae), collected from different geographical regions of Iran, was assessed by GC-FID and GC/MS analyses, and their intraspecific chemical variability was determined. Altogether, 49 compounds were identified in the oils, and a relatively high variation in their contents was found. The major compounds of the essential oils were myrcene (0.0-26.2%), limonene (0.0-24.5%), germacrene D (4.2-19.3%), bicyclogermacrene (1.6-18.0%), δ-cadinene (6.5-16.0%), pulegone (0.0-15.1%), (Z)-hex-3-enyl tiglate (0.0-15.1%), (E)-caryophyllene (0.0-12.9), α-zingiberene (0.2-12.2%), and spathulenol (1.6-11.1%). For the determination of the chemotypes and the chemical variability, the essential-oil components were subjected to cluster analysis (CA). The five different chemotypes characterized were Chemotype I (germacrene D/bicyclogermacrene), Chemotype II (germacrene D/spathulenol), Chemotype III (limonene/δ-cadinene), Chemotype IV (pulegone), and Chemotype V (α-zingiberene). The high chemical variation among the populations according to their geographical and bioclimatic distribution imposes that conservation strategies of populations should be made appropriately, taking into account these factors. The in situ and ex situ conservation strategies should concern all populations representing the different chemotypes. Copyright © 2013 Verlag Helvetica Chimica Acta AG, Zürich.

  1. Saccharomyces cerevisiae: population divergence and resistance to oxidative stress in clinical, domesticated and wild isolates.

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    Stephanie Diezmann

    Full Text Available BACKGROUND: Saccharomyces cerevisiae has been associated with human life for millennia in the brewery and bakery. Recently it has been recognized as an emerging opportunistic pathogen. To study the evolutionary history of S. cerevisiae, the origin of clinical isolates and the importance of a virulence-associated trait, population genetics and phenotypic assays have been applied to an ecologically diverse set of 103 strains isolated from clinics, breweries, vineyards, fruits, soil, commercial supplements and insect guts. METHODOLOGY/PRINCIPAL FINDINGS: DNA sequence data from five nuclear DNA loci were analyzed for population structure and haplotype distribution. Additionally, all strains were tested for survival of oxidative stress, a trait associated with microbial pathogenicity. DNA sequence analyses identified three genetic subgroups within the recombining S. cerevisiae strains that are associated with ecology, geography and virulence. Shared alleles suggest that the clinical isolates contain genetic contribution from the fruit isolates. Clinical and fruit isolates exhibit high levels of recombination, unlike the genetically homogenous soil isolates in which no recombination was detected. However, clinical and soil isolates were more resistant to oxidative stress than any other population, suggesting a correlation between survival in oxidative stress and yeast pathogenicity. CONCLUSIONS/SIGNIFICANCE: Population genetic analyses of S. cerevisiae delineated three distinct groups, comprising primarily the (i human-associated brewery and vineyard strains, (ii clinical and fruit isolates (iii and wild soil isolates from eastern U.S. The interactions between S. cerevisiae and humans potentiate yeast evolution and the development of genetically, ecologically and geographically divergent groups.

  2. Saccharomyces cerevisiae: population divergence and resistance to oxidative stress in clinical, domesticated and wild isolates.

    Science.gov (United States)

    Diezmann, Stephanie; Dietrich, Fred S

    2009-01-01

    Saccharomyces cerevisiae has been associated with human life for millennia in the brewery and bakery. Recently it has been recognized as an emerging opportunistic pathogen. To study the evolutionary history of S. cerevisiae, the origin of clinical isolates and the importance of a virulence-associated trait, population genetics and phenotypic assays have been applied to an ecologically diverse set of 103 strains isolated from clinics, breweries, vineyards, fruits, soil, commercial supplements and insect guts. DNA sequence data from five nuclear DNA loci were analyzed for population structure and haplotype distribution. Additionally, all strains were tested for survival of oxidative stress, a trait associated with microbial pathogenicity. DNA sequence analyses identified three genetic subgroups within the recombining S. cerevisiae strains that are associated with ecology, geography and virulence. Shared alleles suggest that the clinical isolates contain genetic contribution from the fruit isolates. Clinical and fruit isolates exhibit high levels of recombination, unlike the genetically homogenous soil isolates in which no recombination was detected. However, clinical and soil isolates were more resistant to oxidative stress than any other population, suggesting a correlation between survival in oxidative stress and yeast pathogenicity. Population genetic analyses of S. cerevisiae delineated three distinct groups, comprising primarily the (i) human-associated brewery and vineyard strains, (ii) clinical and fruit isolates (iii) and wild soil isolates from eastern U.S. The interactions between S. cerevisiae and humans potentiate yeast evolution and the development of genetically, ecologically and geographically divergent groups.

  3. Modeling Possible Cooling-Water Intake System Impacts on Ohio River Fish Populations

    OpenAIRE

    Perry, Elgin; Seegert, Greg; Vondruska, Joe; Lohner, Timothy; Lewis, Randy

    2002-01-01

    To assess the possible impacts caused by cooling-water intake system entrainment and impingement losses, populations of six target fish species near power plants on the Ohio River were modeled. A Leslie matrix model was constructed to allow an evaluation of bluegill, freshwater drum, emerald shiner, gizzard shad, sauger, and white bass populations within five river pools. Site-specific information on fish abundance and length-frequency distribution was obtained from long-term Ohio River Ecolo...

  4. First report of widespread wild populations of Triatoma infestans (Reduviidae, Triatominae) in the valleys of La Paz, Bolivia.

    Science.gov (United States)

    Buitrago, Rosio; Waleckx, Etienne; Bosseno, Marie-France; Zoveda, Faustine; Vidaurre, Pablo; Salas, Renata; Mamani, Elio; Noireau, François; Brenière, Simone Frédérique

    2010-04-01

    Wild populations of Triatoma infestans, the main vector of Chagas disease in the Southern Cone countries, may be involved in reinfestation of human dwellings, limiting the success of vector-control campaigns in Bolivia. Knowledge of the distribution of these populations remains incomplete. We report here the detection of T. infestans wild populations in large areas in the department of La Paz, Bolivia. Among 18 sylvatic areas investigated, 17 were positive with T. infestans specimens. The infection rate of captured T. infestans with Trypanosoma cruzi was 85.7% in adult specimens. These results expand the geographical distribution of wild populations of T. infestans; it may be distributed throughout the Inter-Andean Dry Forest eco-region of Bolivia. The current information allows us to propose the hypothesis that a sylvatic origin of the reinfestation is located in the valleys of La Paz.

  5. First Report of Widespread Wild Populations of Triatoma infestans (Reduviidae, Triatominae) in the Valleys of La Paz, Bolivia

    Science.gov (United States)

    Buitrago, Rosio; Waleckx, Etienne; Bosseno, Marie-France; Zoveda, Faustine; Vidaurre, Pablo; Salas, Renata; Mamani, Elio; Noireau, François; Brenière, Simone Frédérique

    2010-01-01

    Wild populations of Triatoma infestans, the main vector of Chagas disease in the Southern Cone countries, may be involved in reinfestation of human dwellings, limiting the success of vector-control campaigns in Bolivia. Knowledge of the distribution of these populations remains incomplete. We report here the detection of T. infestans wild populations in large areas in the department of La Paz, Bolivia. Among 18 sylvatic areas investigated, 17 were positive with T. infestans specimens. The infection rate of captured T. infestans with Trypanosoma cruzi was 85.7% in adult specimens. These results expand the geographical distribution of wild populations of T. infestans; it may be distributed throughout the Inter-Andean Dry Forest eco-region of Bolivia. The current information allows us to propose the hypothesis that a sylvatic origin of the reinfestation is located in the valleys of La Paz. PMID:20348501

  6. [Impact of trawl fishing on fisheries population components in East China Sea].

    Science.gov (United States)

    Fan, Wei; Zhou, Sufang; Cui, Xuesen; Cheng, Yanhong

    2003-10-01

    Based on the recent 50 years two-boats trawl fishing data of some state-owned fisheries companies and recent 7 years single-boat fishing data of some areas in East China Sea, the trophic index(TI) and composition indexs of fishes of two-boats trawl and single-boat trawl were calculated and analyzed, which indicated that TI increased before 1974 and decreased rapidly thereafter, while composition index decreased from the end of 1970s, but SD increased. The results of single-boat trawl also indicated that TI decreased gradually. Long-term over-fishing of trawl was one of the main reasons of the change of fisheries population structure in East China Sea. All of these showed that there was an over-fishing in East China Sea, and the robust of fisheries population was lower.

  7. Variability of total flavonoid and mucilage content of wild growing chamomile (Matricaria recutita L. populations

    Directory of Open Access Journals (Sweden)

    Gosztola, Beáta

    2016-07-01

    Full Text Available During our investigation 50 wild growing chamomile populations’ active substance content, among them total flavonoid content and swelling index referring to mucilage content were examined in 2009 in the main chamomile collection areas of Hungary. Swelling index was determined according to the general and specified descriptions of Althaeae folium monograph of European Pharmacopoeia, while total flavonoid content was measured by the method described in the monograph of Crataegi folium cum flore. The 50 Hungarian wild growing chamomile populations proved to be very heterogeneous in terms of the examined features. The swelling index of their flower drug samples changed between 15.8 and 80.8 and their total flavonoid content varied from 0.94 to 2.28 %. Significant correlation was also found between meteorological conditions and evaluated characteristics: there was medium strong positive correlation between spring total heat unit (sum of daily 10 °C higher average temperatures of the period lasted from 1st of March, 2009 until the day before flower collection as well as total heat unit of 10 days before harvest and swelling index (r = 0.50-0.56, furthermore medium strong negative connection could be seen between total heat units and total flavonoid content (r = -0.60-0.65. Based on these findings it can be ascertained that raising temperature affects the mucilage accumulation positively, however, it has a negative effect on the amount of flavonoids.

  8. Vitamin D status predicts reproductive fitness in a wild sheep population.

    Science.gov (United States)

    Handel, Ian; Watt, Kathryn A; Pilkington, Jill G; Pemberton, Josephine M; Macrae, Alastair; Scott, Philip; McNeilly, Tom N; Berry, Jacqueline L; Clements, Dylan N; Nussey, Daniel H; Mellanby, Richard J

    2016-01-13

    Vitamin D deficiency has been associated with the development of many human diseases, and with poor reproductive performance in laboratory rodents. We currently have no idea how natural selection directly acts on variation in vitamin D metabolism due to a total lack of studies in wild animals. Here, we measured serum 25 hydroxyvitamin D (25(OH)D) concentrations in female Soay sheep that were part of a long-term field study on St Kilda. We found that total 25(OH)D was strongly influenced by age, and that light coloured sheep had higher 25(OH)D3 (but not 25(OH)D2) concentrations than dark sheep. The coat colour polymorphism in Soay sheep is controlled by a single locus, suggesting vitamin D status is heritable in this population. We also observed a very strong relationship between total 25(OH)D concentrations in summer and a ewe's fecundity the following spring. This resulted in a positive association between total 25(OH)D and the number of lambs produced that survived their first year of life, an important component of female reproductive fitness. Our study provides the first insight into naturally-occurring variation in vitamin D metabolites, and offers the first evidence that vitamin D status is both heritable and under natural selection in the wild.

  9. Long telomeres are associated with clonality in wild populations of the fissiparous starfish Coscinasterias tenuispina.

    Science.gov (United States)

    Garcia-Cisneros, A; Pérez-Portela, R; Almroth, B C; Degerman, S; Palacín, C; Sköld, H Nilsson

    2015-11-01

    Telomeres usually shorten during an organism's lifespan and have thus been used as an aging and health marker. When telomeres become sufficiently short, senescence is induced. The most common method of restoring telomere length is via telomerase reverse transcriptase activity, highly expressed during embryogenesis. However, although asexual reproduction from adult tissues has an important role in the life cycles of certain species, its effect on the aging and fitness of wild populations, as well as its implications for the long-term survival of populations with limited genetic variation, is largely unknown. Here we compare relative telomere length of 58 individuals from four populations of the asexually reproducing starfish Coscinasterias tenuispina. Additionally, 12 individuals were used to compare telomere lengths in regenerating and non-regenerating arms, in two different tissues (tube feet and pyloric cecum). The level of clonality was assessed by genotyping the populations based on 12 specific microsatellite loci and relative telomere length was measured via quantitative PCR. The results revealed significantly longer telomeres in Mediterranean populations than Atlantic ones as demonstrated by the Kruskal-Wallis test (K=24.17, significant value: P-value<0.001), with the former also characterized by higher levels of clonality derived from asexual reproduction. Telomeres were furthermore significantly longer in regenerating arms than in non-regenerating arms within individuals (pyloric cecum tissue: Mann-Whitney test, V=299, P-value<10(-6); and tube feet tissue Student's t=2.28, P-value=0.029). Our study suggests that one of the mechanisms responsible for the long-term somatic maintenance and persistence of clonal populations is telomere elongation.

  10. Sampling characteristics and calibration of snorkel counts to estimate stream fish populations

    Science.gov (United States)

    Weaver, D.; Kwak, Thomas J.; Pollock, Kenneth

    2014-01-01

    Snorkeling is a versatile technique for estimating lotic fish population characteristics; however, few investigators have evaluated its accuracy at population or assemblage levels. We evaluated the accuracy of snorkeling using prepositioned areal electrofishing (PAE) for estimating fish populations in a medium-sized Appalachian Mountain river during fall 2008 and summer 2009. Strip-transect snorkel counts were calibrated with PAE counts in identical locations among macrohabitats, fish species or taxa, and seasons. Mean snorkeling efficiency (i.e., the proportion of individuals counted from the true population) among all taxa and seasons was 14.7% (SE, 2.5%), and the highest efficiencies were for River Chub Nocomis micropogon at 21.1% (SE, 5.9%), Central Stoneroller Campostoma anomalum at 20.3% (SE, 9.6%), and darters (Percidae) at 17.1% (SE, 3.7%), whereas efficiencies were lower for shiners (Notropis spp., Cyprinella spp., Luxilus spp.) at 8.2% (SE, 2.2%) and suckers (Catostomidae) at 6.6% (SE, 3.2%). Macrohabitat type, fish taxon, or sampling season did not significantly explain variance in snorkeling efficiency. Mean snorkeling detection probability (i.e., probability of detecting at least one individual of a taxon) among fish taxa and seasons was 58.4% (SE, 6.1%). We applied the efficiencies from our calibration study to adjust snorkel counts from an intensive snorkeling survey conducted in a nearby reach. Total fish density estimates from strip-transect counts adjusted for snorkeling efficiency were 7,288 fish/ha (SE, 1,564) during summer and 15,805 fish/ha (SE, 4,947) during fall. Precision of fish density estimates is influenced by variation in snorkeling efficiency and sample size and may be increased with additional sampling effort. These results demonstrate the sampling properties and utility of snorkeling to characterize lotic fish assemblages with acceptable efficiency and detection probability, less effort, and no mortality, compared with traditional

  11. Agriculture modifies the seasonal decline of breeding success in a tropical wild bird population

    Science.gov (United States)

    Cartwright, Samantha J; Nicoll, Malcolm A C; Jones, Carl G; Tatayah, Vikash; Norris, Ken

    2014-01-01

    Habitat conversion for agriculture is a major driver of biodiversity loss, but our understanding of the demographic processes involved remains poor. We typically investigate the impacts of agriculture in isolation even though populations are likely to experience multiple, concurrent changes in the environment (e.g. land and climate change). Drivers of environmental change may interact to affect demography, but the mechanisms have yet to be explored fully in wild populations. Here, we investigate the mechanisms linking agricultural land use with breeding success using long-term data for the formerly Critically Endangered Mauritius kestrel Falco punctatus, a tropical forest specialist that also occupies agricultural habitats. We specifically focused on the relationship between breeding success, agriculture and the timing of breeding because the latter is sensitive to changes in climatic conditions (spring rainfall) and enables us to explore the interactive effects of different (land and climate) drivers of environmental change. Breeding success, measured as egg survival to fledging, declines seasonally in this population, but we found that the rate of this decline became increasingly rapid as the area of agriculture around a nest site increased. If the relationship between breeding success and agriculture was used in isolation to estimate the demographic impact of agriculture, it would significantly under-estimate breeding success in dry (early) springs and over-estimate breeding success in wet (late) springs. Analysis of prey delivered to nests suggests that the relationship between breeding success and agriculture might be due, in part, to spatial variation in the availability of native, arboreal geckos. Synthesis and applications. Agriculture modifies the seasonal decline in breeding success in this population. As springs are becoming wetter in our study area and since the kestrels breed later in wetter springs, the impact of agriculture on breeding success will

  12. Genetic wealth, population health: Major histocompatibility complex variation in captive and wild ring-tailed lemurs (Lemur catta).

    Science.gov (United States)

    Grogan, Kathleen E; Sauther, Michelle L; Cuozzo, Frank P; Drea, Christine M

    2017-10-01

    Across species, diversity at the major histocompatibility complex (MHC) is critical to individual disease resistance and, hence, to population health; however, MHC diversity can be reduced in small, fragmented, or isolated populations. Given the need for comparative studies of functional genetic diversity, we investigated whether MHC diversity differs between populations which are open, that is experiencing gene flow, versus populations which are closed, that is isolated from other populations. Using the endangered ring-tailed lemur (Lemur catta) as a model, we compared two populations under long-term study: a relatively "open," wild population (n = 180) derived from Bezà Mahafaly Special Reserve, Madagascar (2003-2013) and a "closed," captive population (n = 121) derived from the Duke Lemur Center (DLC, 1980-2013) and from the Indianapolis and Cincinnati Zoos (2012). For all animals, we assessed MHC-DRB diversity and, across populations, we compared the number of unique MHC-DRB alleles and their distributions. Wild individuals possessed more MHC-DRB alleles than did captive individuals, and overall, the wild population had more unique MHC-DRB alleles that were more evenly distributed than did the captive population. Despite management efforts to maintain or increase genetic diversity in the DLC population, MHC diversity remained static from 1980 to 2010. Since 2010, however, captive-breeding efforts resulted in the MHC diversity of offspring increasing to a level commensurate with that found in wild individuals. Therefore, loss of genetic diversity in lemurs, owing to small founder populations or reduced gene flow, can be mitigated by managed breeding efforts. Quantifying MHC diversity within individuals and between populations is the necessary first step to identifying potential improvements to captive management and conservation plans.

  13. How to induce defense responses in wild plant populations? Using bilberry (Vaccinium myrtillus) as example.

    Science.gov (United States)

    Seldal, Tarald; Hegland, Stein Joar; Rydgren, Knut; Rodriguez-Saona, Cesar; Töpper, Joachim Paul

    2017-03-01

    Inducible plant defense is a beneficial strategy for plants, which imply that plants should allocate resources from growth and reproduction to defense when herbivores attack. Plant ecologist has often studied defense responses in wild populations by biomass clipping experiments, whereas laboratory and greenhouse experiments in addition apply chemical elicitors to induce defense responses. To investigate whether field ecologists could benefit from methods used in laboratory and greenhouse studies, we established a randomized block-design in a pine-bilberry forest in Western Norway. We tested whether we could activate defense responses in bilberry ( Vaccinium myrtillus ) by nine different treatments using clipping (leaf tissue or branch removal) with or without chemical treatment by methyljasmonate (MeJA). We subsequently measured consequences of induced defenses through vegetative growth and insect herbivory during one growing season. Our results showed that only MeJA-treated plants showed consistent defense responses through suppressed vegetative growth and reduced herbivory by leaf-chewing insects, suggesting an allocation of resources from growth to defense. Leaf tissue removal reduced insect herbivory equal to the effect of the MeJa treatments, but had no negative impact on growth. Branch removal did not reduce insect herbivory or vegetative growth. MeJa treatment and clipping combined did not give an additional defense response. In this study, we investigated how to induce defense responses in wild plant populations under natural field conditions. Our results show that using the chemical elicitor MeJA, with or without biomass clipping, may be a better method to induce defense response in field experiments than clipping of leaves or branches that often has been used in ecological field studies.

  14. Survey and comparison of major intestinal flora in captive and wild ring-tailed lemur (Lemur catta) populations.

    Science.gov (United States)

    Villers, Lynne M; Jang, Spencer S; Lent, Cheryl L; Lewin-Koh, Sock-Cheng; Norosoarinaivo, Jeanne Aimée

    2008-02-01

    A survey to identify the major intestinal species of aerobic bacteria, protozoa and helminths was conducted on captive and wild populations of ring-tailed lemurs (Lemur catta). Samples were collected from 50 captive lemurs at 11 zoological institutions in the United States. In Madagascar, 98 aerobic bacteria samples and 99 parasite samples were collected from eight sites chosen to cover a variety of populations across the species range. Identical collection, preservation and lab techniques were used for captive and wild populations. The predominant types of aerobic bacteria flora were identified via five separate tests. The tests for parasites conducted included flotation, sedimentation and FA/GC. Twenty-seven bacteria unique to either the captive or wild populations were cultured with eight of these being statistically significantly different. Fourteen bacteria common to both populations were cultured, of which six differed significantly. Entamoeba coli was the only parasite common to both the captive and wild populations. Giardia spp., Isospora spp., strongyles-type ova, Entamoeba spp. and Entamoeba polecki were found only in captive samples. Cryptosporidium, Balantidium coli, pinworm-type ova, and two fluke-like ova were seen only in wild samples. In addition, samples were compared for both bacteria and parasites from three unique field sites in Madagascar. In this three-site comparison, six types of bacteria were statistically significantly different. No significant differences regarding parasites were seen. Significant differences were found between the captive and wild populations, whereas fewer differences were found between sites within Madagascar. Although we isolated Campylobacter and Giardia, all animals appeared clinically healthy. (c) 2007 Wiley-Liss, Inc.

  15. A Review of the Current Status of Relevant Zoonotic Pathogens in Wild Swine (Sus scrofa) Populations: Changes Modulating the Risk of Transmission to Humans.

    Science.gov (United States)

    Ruiz-Fons, F

    2017-02-01

    Many wild swine populations in different parts of the World have experienced an unprecedented demographic explosion that may result in increased exposure of humans to wild swine zoonotic pathogens. Interactions between humans and wild swine leading to pathogen transmission could come from different ways, being hunters and game professionals the most exposed to acquiring infections from wild swine. However, increasing human settlements in semi-natural areas, outdoor activities, socio-economic changes and food habits may increase the rate of exposure to wild swine zoonotic pathogens and to potentially emerging pathogens from wild swine. Frequent and increasing contact rate between humans and wild swine points to an increasing chance of zoonotic pathogens arising from wild swine to be transmitted to humans. Whether this frequent contact could lead to new zoonotic pathogens emerging from wild swine to cause human epidemics or emerging disease outbreaks is difficult to predict, and assessment should be based on thorough epidemiologic surveillance. Additionally, several gaps in knowledge on wild swine global population dynamics trends and wild swine-zoonotic pathogen interactions should be addressed to correctly assess the potential role of wild swine in the emergence of diseases in humans. In this work, viruses such as hepatitis E virus, Japanese encephalitis virus, Influenza virus and Nipah virus, and bacteria such as Salmonella spp., Shiga toxin-producing Escherichia coli, Campylobacter spp. and Leptospira spp. have been identified as the most prone to be transmitted from wild swine to humans on the basis of geographic spread in wild swine populations worldwide, pathogen circulation rates in wild swine populations, wild swine population trends in endemic areas, susceptibility of humans to infection, transmissibility from wild swine to humans and existing evidence of wild swine-human transmission events. © 2015 Blackwell Verlag GmbH.

  16. An exposure assessment of methyl mercury via fish consumption for the Japanese population.

    Science.gov (United States)

    Zhang, Ying; Nakai, Satoshi; Masunaga, Shigeki

    2009-09-01

    The objective of this article was to propose an exposure assessment model to describe the relationship between fish consumption and body methyl mercury (MeHg) levels in the Japanese population. Individual MeHg intake was estimated by the summation of species-specific fish consumption multiplied by species-specific fish MeHg levels. The distribution of fish consumed by individuals and the MeHg level in each fish species were assigned based on published data from Japanese government institutions. The probability of MeHg intake for a population was accomplished through a Monte Carlo simulation by the random sampling of fish consumption and species-specific MeHg levels. Internal body MeHg levels in blood and hair were estimated using a one-compartment model. Overall, the mean value of MeHg intake for the Japanese population was estimated to be 6.76 microg/day or 0.14 microg/kg body weight per day (bw/day), while the mean value for the hair mercury level was 2.02 microg/g. Compared with the survey data that tabulated hair mercury levels in a cross-section of the Japanese population, the simulation results matched the hair mercury survey data very well for women, but somewhat underestimated for men and all of the population. This exposure assessment model is a useful attempt at further risk assessment with respect to a risk-benefit analysis.

  17. Field survey on Tamaraw (Bubalus mindorensis - Present population size and herd behavior in wild

    Directory of Open Access Journals (Sweden)

    Y. Kanai

    2010-02-01

    Full Text Available Tamaraw, an endemic species on the Philippine island of Mindoro, is a critically endangered animal listed by IUCN. Although the population size of tamaraw has been monitored by the Department of Environment and Natural Resources of the Philippines annually from 1999, there is no academic report on the wild tamaraw population. Therefore, we investigated the present tamaraw population size and herd behavior in their natural habitat. The study area covered about 4,000 ha of natural grassland located in Mts. Iglit-Baco National Park, with 16 strategically located observation sites. The tamaraw population was counted using the Intensive Concentration Count Method or Simultaneous Multi Vantage Point Counts for five consecutive days in April, 2006. Fresh fecal samples of tamaraws were also collected from seven observation sites to determine prevalence of endoparasites. A total of 263 individuals were observed, consisting of 162 adult (62%, 52 juveniles (estimated ages of 1-4 years: 20% and 49 yearlings (19%. Out of the 263 individuals, 29 (11% were observed solitary, of which the majority were adult males (15/29. On the other hand, the remaining 234 tamaraws formed 71 groups consisting of 2-7 head per group. Out of 65 groups successfully sexed for adult animals, 63 (93% had one or two adult cows with or without calves and 36 (55% had one adult bull. From 15 fresh fecal samples, Coccidia eggs were detected in 10 cases and Fasciola eggs in 3 cases. These results demonstrated that 1 the tamaraw population is still in the critical ranges and there is a considerable deviation in the sex ratio of adult animals and in the proportion of juveniles to yearlings, 2 the tamaraw usually form families consisting of one bull with one or two cows, with the consequence of some solitary bulls, and 3 further analysis is required on the prevalence of endoparasites in the tamaraw.

  18. Successional change in the Lake Superior fish community: population trends in ciscoes, rainbow smelt, and lake trout, 1958-2008

    Science.gov (United States)

    Gorman, Owen T.

    2012-01-01

    The Lake Superior fish community underwent massive changes in the second half of the 20th century. Those changes are largely reflected in changes in abundance of the adults of principal prey species, the ciscoes (Coregonus spp.), the invasive rainbow smelt (Osmerus mordax), and the principal predator, lake trout (Salvelinus namaycush). To better understand changes in species abundances, a comprehensive series of gillnet and bottom trawl data collected from 1958 to 2008 were examined. In the late 1950s/early 1960s, smelt abundance was at its maximum, wild lake trout was at its minimum, and an abundance of hatchery lake trout was increasing rapidly. The bloater (Coregonus hoyi) was the prevalent cisco in the lake; abundance was more than 300% greater than the next most abundant cisco, shortjaw cisco (C. zenithicus), followed by kiyi (C. kiyi) and lake cisco (C. artedi). By the mid-1960s, abundance of hatchery lake trout was nearing maximum, smelt abundance was beginning to decline, and abundances of all ciscoes declined, but especially that of shortjaw cisco and kiyi. By the late 1970s, recovery of wild lake trout stocks was well underway and abundances of hatchery lake trout and smelt were declining and the ciscoes were reaching their nadir. During 1980–1990, the fish community underwent a dramatic shift in organization and structure. The rapid increase in abundance of wild lake trout, concurrent with a rapid decline in hatchery lake trout, signaled the impending recovery. Rainbow smelt abundance dropped precipitously and within four years, lake cisco and bloater populations rebounded on the heels of a series of strong recruitment events. Kiyi populations showed signs of recovery by 1989, and shortjaw by 2000, though well below historic maximum abundances. High abundance of adult smelt prior to 1980 appears to be the only factor linked to recruitment failure in the ciscoes. Life history traits of the cisco species were examined to better understand their different

  19. The genetic basis of adaptive population differentiation: A quantitative trait locus analysis of fitness traits in two wild barley populations from contrasting habitats

    NARCIS (Netherlands)

    Verhoeven, K.J.F.; Vanhala, T.K.; Biere, A.; Nevo, E.; Damme, van J.M.M.

    2004-01-01

    We used a quantitative trait locus (QTL) approach to study the genetic basis of population differentiation in wild barley, Hordeum spontaneum. Several ecotypes are recognized in this model species, and population genetic studies and reciprocal transplant experiments have indicated the role of local

  20. Fishery-independent data reveal negative effect of human population density on Caribbean predatory fish communities.

    Directory of Open Access Journals (Sweden)

    Christopher D Stallings

    Full Text Available BACKGROUND: Understanding the current status of predatory fish communities, and the effects fishing has on them, is vitally important information for management. However, data are often insufficient at region-wide scales to assess the effects of extraction in coral reef ecosystems of developing nations. METHODOLOGY/PRINCIPAL FINDINGS: Here, I overcome this difficulty by using a publicly accessible, fisheries-independent database to provide a broad scale, comprehensive analysis of human impacts on predatory reef fish communities across the greater Caribbean region. Specifically, this study analyzed presence and diversity of predatory reef fishes over a gradient of human population density. Across the region, as human population density increases, presence of large-bodied fishes declines, and fish communities become dominated by a few smaller-bodied species. CONCLUSIONS/SIGNIFICANCE: Complete disappearance of several large-bodied fishes indicates ecological and local extinctions have occurred in some densely populated areas. These findings fill a fundamentally important gap in our knowledge of the ecosystem effects of artisanal fisheries in developing nations, and provide support for multiple approaches to data collection where they are commonly unavailable.

  1. Fishery-Independent Data Reveal Negative Effect of Human Population Density on Caribbean Predatory Fish Communities

    Science.gov (United States)

    Stallings, Christopher D.

    2009-01-01

    Background Understanding the current status of predatory fish communities, and the effects fishing has on them, is vitally important information for management. However, data are often insufficient at region-wide scales to assess the effects of extraction in coral reef ecosystems of developing nations. Methodology/Principal Findings Here, I overcome this difficulty by using a publicly accessible, fisheries-independent database to provide a broad scale, comprehensive analysis of human impacts on predatory reef fish communities across the greater Caribbean region. Specifically, this study analyzed presence and diversity of predatory reef fishes over a gradient of human population density. Across the region, as human population density increases, presence of large-bodied fishes declines, and fish communities become dominated by a few smaller-bodied species. Conclusions/Significance Complete disappearance of several large-bodied fishes indicates ecological and local extinctions have occurred in some densely populated areas. These findings fill a fundamentally important gap in our knowledge of the ecosystem effects of artisanal fisheries in developing nations, and provide support for multiple approaches to data collection where they are commonly unavailable. PMID:19421312

  2. Population genetic structure of wild and hatchery black rockfish Sebastes inermis in Korea, assessed using cross-species microsatellite markers.

    Science.gov (United States)

    An, H S; Kim, E-M; Lee, J-H; Noh, J K; An, C M; Yoon, S J; Park, K D; Myeong, J-I

    2011-10-13

    The population structure of the black rockfish, Sebastes inermis (Sebastidae), was estimated using 10 microsatellite loci developed for S. schlegeli on samples of 174 individuals collected from three wild and three hatchery populations in Korea. Reduced genetic variation was detected in hatchery strains [overall number of alleles (N(A)) = 8.07; allelic richness (A(R)) = 7.37; observed heterozygosity (H(O)) = 0.641] compared with the wild samples (overall N(A) = 8.43; A(R) = 7.83; H(O) = 0.670), but the difference was not significant. Genetic differentiation among the populations was significant (overall F(ST) = 0.0237, P hatchery strains and between wild and hatchery strains, but not among the wild populations, indicating high levels of gene flow along the southern coast of Korea, even though the black rockfish is a benthic, non-migratory marine species. Genetic differentiation among the hatchery strains could reflect genetic drift due to intensive breeding practices. Thus, in the interests of optimal resource management, genetic variation should be monitored and inbreeding controlled within stocks in commercial breeding programs. Information on genetic population structure based on cross-species microsatellite markers can aid in the proper management of S. inermis populations.

  3. Modeling Possible Cooling-Water Intake System Impacts on Ohio River Fish Populations

    Directory of Open Access Journals (Sweden)

    Elgin Perry

    2002-01-01

    Full Text Available To assess the possible impacts caused by cooling-water intake system entrainment and impingement losses, populations of six target fish species near power plants on the Ohio River were modeled. A Leslie matrix model was constructed to allow an evaluation of bluegill, freshwater drum, emerald shiner, gizzard shad, sauger, and white bass populations within five river pools. Site-specific information on fish abundance and length-frequency distribution was obtained from long-term Ohio River Ecological Research Program and Ohio River Sanitation Commission (ORSANCO electrofishing monitoring programs. Entrainment and impingement data were obtained from 316(b demonstrations previously completed at eight Ohio River power plants. The model was first run under a scenario representative of current conditions, which included fish losses due to entrainment and impingement. The model was then rerun with these losses added back into the populations, representative of what would happen if all entrainment and impingement losses were eliminated. The model was run to represent a 50-year time period, which is a typical life span for an Ohio River coal-fired power plant. Percent changes between populations modeled with and without entrainment and impingement losses in each pool were compared to the mean interannual coefficient of variation (CV, a measure of normal fish population variability. In 6 of the 22 scenarios of fish species and river pools that were evaluated (6 species × 5 river pools, minus 8 species/river pool combinations that could not be evaluated due to insufficient fish data, the projected fish population change was greater than the expected variability of the existing fish population, indicating a possible adverse environmental impact. Given the number of other variables affecting fish populations and the conservative modeling approach, which assumed 100% mortality for all entrained fish and eggs, it was concluded that the likelihood of impact was

  4. Modeling possible cooling-water intake system impacts on Ohio River fish populations.

    Science.gov (United States)

    Perry, Elgin; Seegert, Greg; Vondruska, Joe; Lohner, Timothy; Lewis, Randy

    2002-04-26

    To assess the possible impacts caused by cooling-water intake system entrainment and impingement losses, populations of six target fish species near power plants on the Ohio River were modeled. A Leslie matrix model was constructed to allow an evaluation of bluegill, freshwater drum, emerald shiner, gizzard shad, sauger, and white bass populations within five river pools. Site-specific information on fish abundance and length-frequency distribution was obtained from long-term Ohio River Ecological Research Program and Ohio River Sanitation Commission (ORSANCO) electrofishing monitoring programs. Entrainment and impingement data were obtained from 316(b) demonstrations previously completed at eight Ohio River power plants. The model was first run under a scenario representative of current conditions, which included fish losses due to entrainment and impingement. The model was then rerun with these losses added back into the populations, representative of what would happen if all entrainment and impingement losses were eliminated. The model was run to represent a 50-year time period, which is a typical life span for an Ohio River coal-fired power plant. Percent changes between populations modeled with and without entrainment and impingement losses in each pool were compared to the mean interannual coefficient of variation (CV), a measure of normal fish population variability. In 6 of the 22 scenarios of fish species and river pools that were evaluated (6 species x 5 river pools, minus 8 species/river pool combinations that could not be evaluated due to insufficient fish data), the projected fish population change was greater than the expected variability of the existing fish population, indicating a possible adverse environmental impact. Given the number of other variables affecting fish populations and the conservative modeling approach, which assumed 100% mortality for all entrained fish and eggs, it was concluded that the likelihood of impact was by no means

  5. Age and sex-specific mortality of wild and captive populations of a monogamous pair-bonded primate (Aotus azarae)

    DEFF Research Database (Denmark)

    Larson, Sam; Colchero, Fernando; Jones, Owen

    2016-01-01

    In polygynous primates, a greater reproductive variance in males has been linked to their reduced life expectancy relative to females. The mortality patterns of monogamous pair-bonded primates, however, are less clear. We analyzed the sex differences in mortality within wild (NMales = 70, NFemales...... = 73) and captive (NMales = 25, NFemales = 29) populations of Azara's owl monkeys (Aotus azarae), a socially and genetically monogamous primate exhibiting bi-parental care. We used Bayesian Survival Trajectory Analysis (BaSTA) to test age-dependent models of mortality. The wild and captive populations...

  6. Length-Based Assessment of Coral Reef Fish Populations in the Main and Northwestern Hawaiian Islands: e0133960

    National Research Council Canada - National Science Library

    Marc O Nadon; Jerald S Ault; Ivor D Williams; Steven G Smith; Gerard T DiNardo

    2015-01-01

      The coral reef fish community of Hawaii is composed of hundreds of species, supports a multimillion dollar fishing and tourism industry, and is of great cultural importance to the local population...

  7. Population size structure of non-native fishes along longitudinal gradients in a highly regulated Mediterranean basin.

    Directory of Open Access Journals (Sweden)

    Fátima Amat-Trigo

    2015-10-01

    Documented changes in fish size metrics at population levels can demonstrate trends in non-native fishes at basin scale, however, the collinearity with spatial gradients and the species-specific response could make it a difficult undertaking.

  8. Length-based assessment of coral reef fish populations in the main and northwestern Hawaiian islands.

    Directory of Open Access Journals (Sweden)

    Marc O Nadon

    Full Text Available The coral reef fish community of Hawaii is composed of hundreds of species, supports a multimillion dollar fishing and tourism industry, and is of great cultural importance to the local population. However, a major stock assessment of Hawaiian coral reef fish populations has not yet been conducted. Here we used the robust indicator variable "average length in the exploited phase of the population ([Formula: see text]", estimated from size composition data from commercial fisheries trip reports and fishery-independent diver surveys, to evaluate exploitation rates for 19 Hawaiian reef fishes. By and large, the average lengths obtained from diver surveys agreed well with those from commercial data. We used the estimated exploitation rates coupled with life history parameters synthesized from the literature to parameterize a numerical population model and generate stock sustainability metrics such as spawning potential ratios (SPR. We found good agreement between predicted average lengths in an unfished population (from our population model and those observed from diver surveys in the largely unexploited Northwestern Hawaiian Islands. Of 19 exploited reef fish species assessed in the main Hawaiian Islands, 9 had SPRs close to or below the 30% overfishing threshold. In general, longer-lived species such as surgeonfishes, the redlip parrotfish (Scarus rubroviolaceus, and the gray snapper (Aprion virescens had the lowest SPRs, while short-lived species such as goatfishes and jacks, as well as two invasive species (Lutjanus kasmira and Cephalopholis argus, had SPRs above the 30% threshold.

  9. Length-based assessment of coral reef fish populations in the main and northwestern Hawaiian islands.

    Science.gov (United States)

    Nadon, Marc O; Ault, Jerald S; Williams, Ivor D; Smith, Steven G; DiNardo, Gerard T

    2015-01-01

    The coral reef fish community of Hawaii is composed of hundreds of species, supports a multimillion dollar fishing and tourism industry, and is of great cultural importance to the local population. However, a major stock assessment of Hawaiian coral reef fish populations has not yet been conducted. Here we used the robust indicator variable "average length in the exploited phase of the population ([Formula: see text])", estimated from size composition data from commercial fisheries trip reports and fishery-independent diver surveys, to evaluate exploitation rates for 19 Hawaiian reef fishes. By and large, the average lengths obtained from diver surveys agreed well with those from commercial data. We used the estimated exploitation rates coupled with life history parameters synthesized from the literature to parameterize a numerical population model and generate stock sustainability metrics such as spawning potential ratios (SPR). We found good agreement between predicted average lengths in an unfished population (from our population model) and those observed from diver surveys in the largely unexploited Northwestern Hawaiian Islands. Of 19 exploited reef fish species assessed in the main Hawaiian Islands, 9 had SPRs close to or below the 30% overfishing threshold. In general, longer-lived species such as surgeonfishes, the redlip parrotfish (Scarus rubroviolaceus), and the gray snapper (Aprion virescens) had the lowest SPRs, while short-lived species such as goatfishes and jacks, as well as two invasive species (Lutjanus kasmira and Cephalopholis argus), had SPRs above the 30% threshold.

  10. Ocean Acidification Effects on Atlantic Cod Larval Survival and Recruitment to the Fished Population.

    Science.gov (United States)

    Stiasny, Martina H; Mittermayer, Felix H; Sswat, Michael; Voss, Rüdiger; Jutfelt, Fredrik; Chierici, Melissa; Puvanendran, Velmurugu; Mortensen, Atle; Reusch, Thorsten B H; Clemmesen, Catriona

    2016-01-01

    How fisheries will be impacted by climate change is far from understood. While some fish populations may be able to escape global warming via range shifts, they cannot escape ocean acidification (OA), an inevitable consequence of the dissolution of anthropogenic carbon dioxide (CO2) emissions in marine waters. How ocean acidification affects population dynamics of commercially important fish species is critical for adapting management practices of exploited fish populations. Ocean acidification has been shown to impair fish larvae's sensory abilities, affect the morphology of otoliths, cause tissue damage and cause behavioural changes. Here, we obtain first experimental mortality estimates for Atlantic cod larvae under OA and incorporate these effects into recruitment models. End-of-century levels of ocean acidification (~1100 μatm according to the IPCC RCP 8.5) resulted in a doubling of daily mortality rates compared to present-day CO2 concentrations during the first 25 days post hatching (dph), a critical phase for population recruitment. These results were consistent under different feeding regimes, stocking densities and in two cod populations (Western Baltic and Barents Sea stock). When mortality data were included into Ricker-type stock-recruitment models, recruitment was reduced to an average of 8 and 24% of current recruitment for the two populations, respectively. Our results highlight the importance of including vulnerable early life stages when addressing effects of climate change on fish stocks.

  11. Genetic evidence of population structuring in the neotropical freshwater fish Brycon hilarii (Valenciennes, 1850

    Directory of Open Access Journals (Sweden)

    A Sanches

    Full Text Available Brycon hilarii is a migratory fish widely distributed throughout the Paraguay River Basin. It is appreciated in sport fishing and for its superior meat quality. It is also the main species for tourist attraction in the Bonito region (State of Mato Grosso do Sul, Brazil. Considering the lack of information on the genetic structure of the fish of this species, the aim of the present study was to detect the genetic variability of Brycon hilarii through RAPD markers. A total of eighty specimens collected in different seasons at four sites of the Miranda River sub-basin (Paraguay River Basin, Brazil were used for analysis. The results of genetic similarity, Shannon diversity, and AMOVA revealed differences between the sampling sites. Through AMOVA, differences between populations were more evident among the animals collected during the non-reproductive season, corresponding to a time of less movement of these fish. A population structuring model in which B. hilarii appears organized into genetically differentiated reproductive units that coexist and co-migrate through the studied system was suggested, contrasting the currently accepted idea that freshwater migratory fish form large panmictic populations in a determined hydrographic system. Despite the lack of a complete picture regarding the distribution of B. hilarii in the studied region, this initial idea on its population genetic structure could be an important contribution to providing aid for management and conservation programs of these fish.

  12. Pathogen exposure varies widely among sympatric populations of wild and domestic felids across the United States.

    Science.gov (United States)

    Carver, Scott; Bevins, Sarah N; Lappin, Michael R; Boydston, Erin E; Lyren, Lisa M; Alldredge, Mathew; Logan, Kenneth A; Sweanor, Linda L; Riley, Seth P D; Serieys, Laurel E K; Fisher, Robert N; Vickers, T Winston; Boyce, Walter; Mcbride, Roy; Cunningham, Mark C; Jennings, Megan; Lewis, Jesse; Lunn, Tamika; Crooks, Kevin R; Vandewoude, Sue

    2016-03-01

    Understanding how landscape, host, and pathogen traits contribute to disease exposure requires systematic evaluations of pathogens within and among host species and geographic regions. The relative importance of these attributes is critical for management of wildlife and mitigating domestic animal and human disease, particularly given rapid ecological changes, such as urbanization. We screened > 1000 samples from sympatric populations of puma (Puma concolor), bobcat (Lynx rufus), and domestic cat (Felis catus) across urban gradients in six sites, representing three regions, in North America for exposure to a representative suite of bacterial, protozoal, and viral pathogens (Bartonella sp., Toxoplasma gondii, feline herpesvirus-1, feline panleukopenea virus, feline calicivirus, and feline immunodeficiency virus). We evaluated prevalence within each species, and examined host trait and land cover determinants of exposure; providing an unprecedented analysis of factors relating to potential for infections in domesticated and wild felids. Prevalence differed among host species (highest for puma and lowest for domestic cat) and was greater for indirectly transmitted pathogens. Sex was inconsistently predictive of exposure to directly transmitted pathogens only, and age infrequently predictive of both direct and indirectly transmitted pathogens. Determinants of pathogen exposure were widely divergent between the wild felid species. For puma, suburban land use predicted increased exposure to Bartonella sp. in southern California, and FHV-1 exposure increased near urban edges in Florida. This may suggest interspecific transmission with domestic cats via flea vectors (California) and direct contact (Florida) around urban boundaries. Bobcats captured near urban areas had increased exposure to T. gondii in Florida, suggesting an urban source of prey Bobcats captured near urban areas in Colorado and Florida had higher FIV exposure, possibly suggesting increased intraspecific

  13. Pathogen exposure varies widely among sympatric populations of wild and domestic felids across the United States

    Science.gov (United States)

    Carver, Scott; Bevins, Sarah N.; Lappin, Michael R.; Boydston, Erin E.; Lyren, Lisa M.; Alldredge, Mathew W.; Logan, Kenneth A.; Sweanor, Linda L.; Riley, Seth P.D.; Serieys, Laurel E.K.; Fisher, Robert N.; Vickers, T. Winston; Boyce, Walter M.; McBride, Roy; Cunnigham, Mark C.; Jennings, Megan; Lewis, Jesse S.; Lunn, Tamika; Crooks, Kevin R.; VandeWoude, Sue

    2016-01-01

    Understanding how landscape, host, and pathogen traits contribute to disease exposure requires systematic evaluations of pathogens within and among host species and geographic regions. The relative importance of these attributes is critical for management of wildlife and mitigating domestic animal and human disease, particularly given rapid ecological changes, such as urbanization. We screened >1,000 samples from sympatric populations of puma (Puma concolor), bobcat (Lynx rufus) and domestic cat (Felis catus) across urban gradients in six sites, representing three regions, in North America for exposure to a representative suite of bacterial, protozoal and viral pathogens (Bartonella sp., Toxoplasma gondii, feline herpesvirus-1, feline panleukopenea virus, feline calicivirus, feline immunodeficiency virus). We evaluated prevalence within each species, and examined host trait and land cover determinants of exposure-providing an unprecedented analysis of factors relating to potential for infections in domesticated and wild felids. Prevalence differed among host species (highest for puma and lowest for domestic cat) and was greater for indirectly transmitted pathogens. Sex was inconsistently predictive of exposure to directly transmitted pathogens only, and age infrequently predictive of both direct and indirectly transmitted pathogens. Determinants of pathogen exposure were widely divergent between the wild felid species. For puma, suburban landuse predicted increased exposure to Bartonella sp. in southern California, and FHV-1 exposure increased near urban edges in Florida. This may suggest inter-specific transmission with domestic cats via flea vectors (California) and direct contact (Florida) around urban boundaries. Bobcats captured near urban areas had increased exposure to T. gondii in Florida, suggesting an urban source of prey. Bobcats captured near urban areas in Colorado and Florida had higher FIV exposure, possibly suggesting increased intra

  14. Population dynamics, intervention and survival in African wild dogs (Lycaon pictus).

    Science.gov (United States)

    Burrows, R; Hofer, H; East, M L

    1995-11-22

    The demography of Serengeti wild dog study packs and their extinction in 1991 was documented by Burrows et al. (1994). One explanation for pack loss compatible with demographic evidence was viral disease induced by stress caused by intervention (vaccination, immobilization and radio-collaring). Several studies claim to reject this hypothesis. However, cortisol levels measured in immobilized Lycaon, whose pathogen exposure is unknown, do not demonstrate that interventions in the Serengeti were benign. The analysis of survivorship in Lycaon in other ecosystems minimized the chance of demonstrating any effect of intervention and failed to consider vaccinations as intervention. There is now evidence that intervention significantly decreased survivorship of Masai Mara Lycaon. Further simulations of the likelihood of population extinction in Serengeti Lycaon, evidence of limited population variability and a small scaling factor in Serengeti Lycaon strengthen Burrows et al.'s conclusion that the extinction was unlikely to be due to chance alone. Although some studies claim that Lycaon conservation is doomed without intervention, to date vaccinations, blood sampling and radio-telemetry have contributed little to Lycaon conservation. All studies fail to disprove the Burrows hypothesis or provide convincing alternatives.

  15. Testing for a genetic response to sexual selection in a wild Drosophila population.

    Science.gov (United States)

    Gosden, T P; Thomson, J R; Blows, M W; Schaul, A; Chenoweth, S F

    2016-06-01

    In accordance with the consensus that sexual selection is responsible for the rapid evolution of display traits on macroevolutionary scales, microevolutionary studies suggest sexual selection is a widespread and often strong form of directional selection in nature. However, empirical evidence for the contemporary evolution of sexually selected traits via sexual rather than natural selection remains weak. In this study, we used a novel application of quantitative genetic breeding designs to test for a genetic response to sexual selection on eight chemical display traits from a field population of the fly, Drosophila serrata. Using our quantitative genetic approach, we were able to detect a genetically based difference in means between groups of males descended from fathers who had either successfully sired offspring or were randomly collected from the same wild population for one of these display traits, the diene (Z,Z)-5,9-C27 : 2 . Our experimental results, in combination with previous laboratory studies on this system, suggest that both natural and sexual selection may be influencing the evolutionary trajectories of these traits in nature, limiting the capacity for a contemporary evolutionary response. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

  16. Analysis of anthocyanin variation in wild populations of bilberry (Vaccinium myrtillus L.) in Finland.

    Science.gov (United States)

    Lätti, Anja K; Riihinen, Kaisu R; Kainulainen, Pirjo S

    2008-01-09

    The berries of Vaccinium myrtillus L. are characterized by 15 anthocyanins. To study the variation in the anthocyanins on a south-north axis of about 1000 km in Finland, the berries from 179 individual bilberry plants in 20 populations were analyzed using an optimized RP-HPLC-DAD method. The mean content of the total anthocyanins was 2878 mg/100 g dry weight. There was extensive variation in the anthocyanin contents within and between the populations, suggesting differences in berry raw material. A significantly lower content of the total anthocyanins was observed in the berries of the southern region compared to those in the central and northern regions. Differences in the proportions of anthocyanins were also observed. The delphinidin glycosides dominated in the northern berries whereas the cyanidin glycosides were most common in the southern ones. Exceptional bilberry individuals were found mainly from eastern Finland with very low amounts of anthocyanidin glucosides. This is the first systematic study to reveal the extremely high variation in the content and distribution of anthocyanins in wild bilberries.

  17. The wild tomato species Solanum chilense shows variation in pathogen resistance between geographically distinct populations

    Directory of Open Access Journals (Sweden)

    Remco Stam

    2017-01-01

    Full Text Available Wild tomatoes are a valuable source of disease resistance germplasm for tomato (Solanum lycopersicum breeders. Many species are known to possess a certain degree of resistance against certain pathogens; however, evolution of resistance traits is yet poorly understood. For some species, like Solanum chilense, both differences in habitat and within species genetic diversity are very large. Here we aim to investigate the occurrence of spatially heterogeneous coevolutionary pressures between populations of S. chilense. We investigate the phenotypic differences in disease resistance within S. chilense against three common tomato pathogens (Alternaria solani, Phytophthora infestans and a Fusarium sp. and confirm high degrees of variability in resistance properties between selected populations. Using generalised linear mixed models, we show that disease resistance does not follow the known demographic patterns of the species. Models with up to five available climatic and geographic variables are required to best describe resistance differences, confirming the complexity of factors involved in local resistance variation. We confirm that within S. chilense, resistance properties against various pathogens show a mosaic pattern and do not follow environmental patterns, indicating the strength of local pathogen pressures. Our study can form the basis for further investigations of the genetic traits involved.

  18. The diet of otters ( Lutra lutra L.) in Danish freshwater habitats : comparisons of prey fish populations

    DEFF Research Database (Denmark)

    Taastrom, H.M.; Jacobsen, Lene

    1999-01-01

    variations were found in the diet corresponding to the availability of prey. Non-fish prey categories, such as frogs, birds, mammals and invertebrates, were most frequently taken in spring and summer, but only frogs made an important contribution to the diet (0-21%). The results of analysing 978 otter......Otter spraints from five Danish freshwater localities were analysed. In all localities fish was the main prey (76-99% of estimated bulk), especially in winter. Depending on locality, the prey fish mainly consisted of cyprinids (Cyprinidae), percids (Percidae) or salmonids (Salmonidae). Seasonal...... spraints were compared with prey fish populations as estimated by electrofishing. It was concluded that the fish species composition in the otter diet generally reflected that of the foraging area, however, with the exception of a negative preference for trout (Salmo sp.) and a preference for sticklebacks...

  19. Scent-marking behaviour and social dynamics in a wild population of Eurasian lynx Lynx lynx.

    Science.gov (United States)

    Vogt, Kristina; Zimmermann, Fridolin; Kölliker, Mathias; Breitenmoser, Urs

    2014-07-01

    Scent-marking is widespread among mammals and has been observed in many felid species. Although the behaviour is well-described, little is known about its function in wild felid populations. We investigated patterns of scent-marking and its role in intra- and intersexual communication among resident and non-resident Eurasian lynx Lynx lynx by observing interactions among wild lynx at natural marking sites by means of infrared camera traps. Marking activity of resident animals showed a peak during the mating season and was lowest during the time when females gave birth and lactated. Both sexes scent-marked, but male lynx visited marking sites much more often than females and marked relatively more often when visiting a site. Most visits to marking sites were by residents but we also observed scent-marking by non-residents. Juveniles were never observed marking. We found no evidence of lynx regularly renewing scent-marks after a certain 'expiry date' but the presence of a strange scent-mark triggered over-marking. Males responded similarly to the presence of another individual's scent-mark, irrespective of whether it was the top- or the underlying scent-mark in a mixture of scent-marks they encountered. Our results suggest that marking sites could serve as 'chemical bulletin boards', where male lynx advertise their presence and gain information on ownership relationships in a given area. Females placed their urine marks on top of the ones left by resident males, but further studies are needed to explain the functions of over-marking in females. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Genetic diversity and population structure in cultivated sunflower and a comparison to its wild progenitor, Helianthus annuus L.

    Science.gov (United States)

    Mandel, J R; Dechaine, J M; Marek, L F; Burke, J M

    2011-09-01

    Crop germplasm collections are valuable resources for ongoing plant breeding efforts. To fully utilize such collections, however, researchers need detailed information about the amount and distribution of genetic diversity present within collections. Here, we report the results of a population genetic analysis of the primary gene pool of sunflower (Helianthus annuus L.) based on a broad sampling of 433 cultivated accessions from North America and Europe, as well as a range-wide collection of 24 wild sunflower populations. Gene diversity across the cultivars was 0.47, as compared with 0.70 in the wilds, indicating that cultivated sunflower harbors roughly two-thirds of the total genetic diversity present in wild sunflower. Population structure analyses revealed that wild sunflower can be subdivided into four genetically distinct population clusters throughout its North American range, whereas the cultivated sunflower gene pool could be split into two main clusters separating restorer lines from the balance of the gene pool. Use of a maximum likelihood method to estimate the contribution of the wild gene pool to the cultivated sunflower germplasm revealed that the bulk of the cultivar diversity is derived from two wild sunflower population genetic clusters that are primarily composed of individuals from the east-central United States, the same general region in which sunflower domestication is believed to have occurred. We also identified a nested subset of accessions that capture as much of the allelic diversity present within the sampled cultivated sunflower germplasm collection as possible. At the high end, a core set of 288 captured nearly 90% of the alleles present in the full set of 433, whereas a core set of just 12 accessions was sufficient to capture nearly 50% of the total allelic diversity present within this sample of cultivated sunflower.

  1. Mechanics of anisotropic inclusions applied to mica fish populations

    Science.gov (United States)

    Mulchrone, K.

    2009-04-01

    An analytical solution is derived for the mechanical behaviour of a linear viscous anisotropic elliptical inclusion immersed in a linear viscous isotropic fluid. By assuming that the internal anisotropy deforms passively a system of three differential equations describe the rate of change of ellipse long axis orientation, anisotropy orientation and ellipse aspect ratio. Taking appropriate limits, the model can be adapted to represent the behaviour of mica fish which deform only by glide along the basal plane. Simulation studies indicate that ellipse long axes tend towards a stable orientation of approximately 15 degrees, whereas anisotropy orientations tend to show a fatter and more asymmetric distribution. This is consistent with published natural data.

  2. Size at hatching determines population dynamics and response to harvesting in cannibalistic fish

    NARCIS (Netherlands)

    Kooten, van T.; Andersson, J.; Bystrom, P.; Persson, L.; Roos, A.M.

    2010-01-01

    We hypothesize that size at hatching strongly affects population dynamics of cannibalistic fish species and is a crucial determinant of how populations respond to selective removal of large individuals (harvesting). We use a mechanistic mathematical model to study the relation between hatching size

  3. The social and ecological integration of captive-raised adolescent male African elephants (Loxodonta africana) into a wild population.

    Science.gov (United States)

    Evans, Kate; Moore, Randall; Harris, Stephen

    2013-01-01

    A rapid rise in the number of captive African elephants (Loxodonta africana) used in the tourism industry in southern Africa and orphaned elephants in human care has led to concerns about their long-term management, particularly males. One solution is to release them into the wild at adolescence, when young males naturally leave their herd. However, this raises significant welfare concerns: little is known about how well released elephants integrate into wild populations and whether they pose a greater threat to humans than wild elephants. We document the release of three captive-raised adolescent male African elephants in the Okavango Delta, Botswana. Despite having been part of a herd of working elephants for at least eight years, the three males progressively integrated into the complex fission-fusion society of wild bull elephants. In the three years following release, they showed no tendency to be closer to human habitation, and there were no significant differences between wild and captive-raised adolescent males in the total number of social interactions, size of ranges and habitat use. However, the captive-raised elephants sparred less and vocalised more, and spent more time alone and in smaller social groups. Thereafter the released elephants continued to expand their ranges and interact with both mixed-sex herds and males. One male was shot by farmers 94 months after release, along with ten wild elephants, on a ranch outside the protected area. We show that captive-raised adolescent male elephants can integrate into a wild population. Long-term studies are required to determine the longevity, breeding success, and eventual fate of released male elephants, but we identified no significant short-term welfare problems for the released elephants or recipient population. Release of captive-raised mammals with complex social systems is a husbandry option that should be explored further.

  4. [Study of genetic diversity and spatial structure of the wild soybean (Glycine soja Sieb. & Zucc.) population from the Ekaterinovka in the south of Primorskii krai].

    Science.gov (United States)

    Tikhonov, A V; Nedoluzhko, A V; Martynov, V V; Dorokhov, D B

    2011-03-01

    Data are presented on the genetic diversity and spatial structure of the natural wild soybean population from the neighborhood of the settlement of Ekaterinovka in Primorskii krai and on the relationship between the genetic structure of this population and its spatial organization. These data are discussed in comparison with the results of studies of wild soybean populations in the Far East region of the Russian Federation and China. Recommendations are given concerning the collection of genetic wild soybean resources.

  5. Kelp forest fish populations in marine reserves and adjacent exploited areas of central California

    Science.gov (United States)

    Paddack, M.J.; Estes, J.A.

    2000-01-01

    Population structure (density and size distribution) of 10 species of epibenthic kelp forest fishes was compared between three marine reserves and adjacent exploited areas in central California. We also contrasted substrate relief, algal turf cover, and kelp population density among these areas. Densities of fishes were 12-35% greater within the reserves, but this difference was not statistically) significant. Habitat features explained only 4% of the variation in fish density and did not vary consistently between reserves and nonreserves. The average length of rockfish (genus Sebastes) was significantly greater in two of the three reserve sites, as was the proportion of larger fish. Population density and size differences combined to produce substantially greater biomass and, therefore, greater reproductive potential per unit of area within the reserves. The magnitude of these effects seems to be influenced by the reserve's age. Our findings demonstrate that current levels of fishing pressure influence kelp forest rockfish populations and suggest that this effect is widespread in central California. Existing marine reserves in central California kelp forests may help sustain exploited populations both through adult emigration and larval pool augmentation. The magnitude of these effects remains uncertain, however, because the spatial scale of both larval and adult dispersal relative to the size of existing reserves is unknown.

  6. Population structure in an anadromous fish Tenualosa ilisha using ...

    African Journals Online (AJOL)

    WATER INDIA

    2013-05-29

    May 29, 2013 ... tuna but in skipjack tuna no genetic differentiation was observed due to large population sizes (Ely et al., 2005). In Engraulis japonica from Yellow Sea and East China. Sea, cytochrome b gene fragment studies showed no significant genetic variation in its populations, the biological factors of anchovy such ...

  7. Effect of Large Wild Herbivore Populations on the Forage-Livestock Balance in the Source Region of the Yellow River

    Directory of Open Access Journals (Sweden)

    Fan Yang

    2018-01-01

    Full Text Available Unmanned aerial vehicle surveys were conducted in the summer season of 2016 and the winter season of 2017 to investigate the large wild herbivore population, including kiangs, Tibetan gazelles and bharals, in Madoi County; the source region of the Yellow River. The study generated forage grass production data in 30 m spatial resolution in Madoi County in 2016 using a downscaling algorithm; estimated a forage-livestock balance including wild animals and domestic animals; and analyzed the effect of the large wild herbivore population on the balance between forage grass and herbivory in Madoi County. The large wild herbivore population was estimated based on the density of the animals in the survey sample strip and compared and verified with available statistical data and the two survey results from the summer season of 2016 and winter season of 2017. The results showed that: (1 in the winter season of 2017, the populations of kiang, Tibetan gazelle and bharal were 17,100, 16,000 and 9300, respectively, while the populations of domestic yak, Tibetan sheep and horse were 70,800, 102,200 and 1200, respectively. The total population of large wild herbivores and domestic animals was 475,000 (sheep units. The ratio (in sheep units between large wild herbivores and domestic animals was 1:4.5; (2 When only considering domestic animals, the grazing pressure index was 1.13, indicating slight overloading of the grassland. When considering domestic animals and large wild herbivores (kiang, Tibetan gazelle and bharal, the grazing pressure index was 1.38, suggesting moderate overloading of the grassland; (3 If large wild herbivores are not taken into consideration when the forage-livestock balance is calculated, the grazing pressure will be under-estimated by 22%. Overgrazing is the major cause of grassland degradation in Madoi County. An additional 79,000 tons of hay or a 30% reduction in domestic animals is required to maintain a forage-livestock balance in

  8. Changes in habitat of fish populations: An inverse problem.

    Science.gov (United States)

    Levere, Kimberly M

    2016-08-01

    Mathematical modelling applies to a wide variety of application areas, and is an active area of research in many disciplines. It is often the case that accurate depiction of real-world phenomena require increasingly complex models. Unfortunately, this increased complexity in a model causes great difficulty when seeking solutions. What is more, developing a model with known parameters that produces results consistent with observed behaviors may prove to be a difficult or even impossible task. These difficulties have brought about an interest in inverse problems. In this paper we utilize a collage-based approach to solve an inverse problem for a model for the migration of three fish species through floodplain waters. A derivation of the mathematical model is presented and a generalized collage method is discussed and applied to this model to recover diffusion parameters. Theoretical and numerical particulars are discussed and results are presented. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Population Structure and Domestication Revealed by High-Depth Resequencing of Korean Cultivated and Wild Soybean Genomes†

    Science.gov (United States)

    Chung, Won-Hyong; Jeong, Namhee; Kim, Jiwoong; Lee, Woo Kyu; Lee, Yun-Gyeong; Lee, Sang-Heon; Yoon, Woongchang; Kim, Jin-Hyun; Choi, Ik-Young; Choi, Hong-Kyu; Moon, Jung-Kyung; Kim, Namshin; Jeong, Soon-Chun

    2014-01-01

    Despite the importance of soybean as a major crop, genome-wide variation and evolution of cultivated soybeans are largely unknown. Here, we catalogued genome variation in an annual soybean population by high-depth resequencing of 10 cultivated and 6 wild accessions and obtained 3.87 million high-quality single-nucleotide polymorphisms (SNPs) after excluding the sites with missing data in any accession. Nuclear genome phylogeny supported a single origin for the cultivated soybeans. We identified 10-fold longer linkage disequilibrium (LD) in the wild soybean relative to wild maize and rice. Despite the small population size, the long LD and large SNP data allowed us to identify 206 candidate domestication regions with significantly lower diversity in the cultivated, but not in the wild, soybeans. Some of the genes in these candidate regions were associated with soybean homologues of canonical domestication genes. However, several examples, which are likely specific to soybean or eudicot crop plants, were also observed. Consequently, the variation data identified in this study should be valuable for breeding and for identifying agronomically important genes in soybeans. However, the long LD of wild soybeans may hinder pinpointing causal gene(s) in the candidate regions. PMID:24271940

  10. Effects of spearfishing on reef fish populations in a multi-use conservation area.

    Science.gov (United States)

    Frisch, Ashley J; Cole, Andrew J; Hobbs, Jean-Paul A; Rizzari, Justin R; Munkres, Katherine P

    2012-01-01

    Although spearfishing is a popular method of capturing fish, its ecological effects on fish populations are poorly understood, which makes it difficult to assess the legitimacy and desirability of spearfishing in multi-use marine reserves. Recent management changes within the Great Barrier Reef Marine Park (GBRMP) fortuitously created a unique scenario by which to quantify the effects of spearfishing on fish populations. As such, we employed underwater visual surveys and a before-after-control-impact experimental design to investigate the effects of spearfishing on the density and size structure of target and non-target fishes in a multi-use conservation park zone (CPZ) within the GBRMP. Three years after spearfishing was first allowed in the CPZ, there was a 54% reduction in density and a 27% reduction in mean size of coral trout (Plectropomus spp.), the primary target species. These changes were attributed to spearfishing because benthic habitat characteristics and the density of non-target fishes were stable through time, and the density and mean size of coral trout in a nearby control zone (where spearfishing was prohibited) remained unchanged. We conclude that spearfishing, like other forms of fishing, can have rapid and substantial negative effects on target fish populations. Careful management of spearfishing is therefore needed to ensure that conservation obligations are achieved and that fishery resources are harvested sustainably. This is particularly important both for the GBRMP, due to its extraordinarily high conservation value and world heritage status, and for tropical island nations where people depend on spearfishing for food and income. To minimize the effects of spearfishing on target species and to enhance protection of functionally important fishes (herbivores), we recommend that fishery managers adjust output controls such as size- and catch-limits, rather than prohibit spearfishing altogether. This will preserve the cultural and social

  11. Effects of spearfishing on reef fish populations in a multi-use conservation area.

    Directory of Open Access Journals (Sweden)

    Ashley J Frisch

    Full Text Available Although spearfishing is a popular method of capturing fish, its ecological effects on fish populations are poorly understood, which makes it difficult to assess the legitimacy and desirability of spearfishing in multi-use marine reserves. Recent management changes within the Great Barrier Reef Marine Park (GBRMP fortuitously created a unique scenario by which to quantify the effects of spearfishing on fish populations. As such, we employed underwater visual surveys and a before-after-control-impact experimental design to investigate the effects of spearfishing on the density and size structure of target and non-target fishes in a multi-use conservation park zone (CPZ within the GBRMP. Three years after spearfishing was first allowed in the CPZ, there was a 54% reduction in density and a 27% reduction in mean size of coral trout (Plectropomus spp., the primary target species. These changes were attributed to spearfishing because benthic habitat characteristics and the density of non-target fishes were stable through time, and the density and mean size of coral trout in a nearby control zone (where spearfishing was prohibited remained unchanged. We conclude that spearfishing, like other forms of fishing, can have rapid and substantial negative effects on target fish populations. Careful management of spearfishing is therefore needed to ensure that conservation obligations are achieved and that fishery resources are harvested sustainably. This is particularly important both for the GBRMP, due to its extraordinarily high conservation value and world heritage status, and for tropical island nations where people depend on spearfishing for food and income. To minimize the effects of spearfishing on target species and to enhance protection of functionally important fishes (herbivores, we recommend that fishery managers adjust output controls such as size- and catch-limits, rather than prohibit spearfishing altogether. This will preserve the cultural

  12. Associations between omega-3 fatty acids, selenium content, and mercury levels in wild-harvested fish from the Dehcho Region, Northwest Territories, Canada.

    Science.gov (United States)

    Reyes, Ellen S; Aristizabal Henao, Juan J; Kornobis, Katherine M; Hanning, Rhona M; Majowicz, Shannon E; Liber, Karsten; Stark, Ken D; Low, George; Swanson, Heidi K; Laird, Brian D

    2017-01-01

    To better understand the risks and benefits of eating wild-harvested fish from the Northwest Territories, Canada, levels of total mercury (HgT) and selenium (Se) and composition of omega-3 fatty acid (n-3 FA) were measured in muscle tissue of fish harvested from lakes in the Dehcho Region, Northwest Territories, Canada. Average HgT levels ranged from 0.057 mg/kg (cisco) to 0.551 mg/kg (northern pike), while average n-3 FA concentrations ranged from 101 mg/100 g (burbot) to 1,689 mg/100 g (lake trout). In contrast to HgT and n-3 FA, mean Se concentrations were relatively similar among species. Consequently, species such as lake whitefish, cisco, and longnose sucker displayed the highest nutrient levels relative to HgT content. Levels of HgT tended to increase with fish size, while Se and n-3 FA levels were typically not associated with fork length or fish weight. Interestingly, HgT concentration was occasionally inversely related to tissue nutrient content. Significant negative correlations were observed between Hg and n-3 FA for lake trout, northern pike, and walleye. There were also significant negative correlations between Hg and Se noted for lake whitefish, cisco, and northern pike. Samples with the highest nutritional content displayed, on occasion, lower levels of HgT. This study provides valuable information for the design of probabilistic models capable of refining public health messaging related to minimizing Hg risks and maximizing nutrient levels in wild-harvested fish in the Canadian subarctic.

  13. Social carry-over effects underpin trans-seasonally linked structure in a wild bird population.

    Science.gov (United States)

    Firth, Josh A; Sheldon, Ben C

    2016-11-01

    Spatial structure underpins numerous population processes by determining the environment individuals' experience and which other individuals they encounter. Yet, how the social landscape influences individuals' spatial decisions remains largely unexplored. Wild great tits (Parus major) form freely moving winter flocks, but choose a single location to establish a breeding territory over the spring. We demonstrate that individuals' winter social associations carry-over into their subsequent spatial decisions, as individuals breed nearer to those they were most associated with during winter. Further, they also form territory boundaries with their closest winter associates, irrespective of breeding distance. These findings were consistent across years, and among all demographic classes, suggesting that such social carry-over effects may be general. Thus, prior social structure can shape the spatial proximity, and fine-scale arrangement, of breeding individuals. In this way, social networks can influence a wide range of processes linked to individuals' breeding locations, including other social interactions themselves. © 2016 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

  14. Testing yawning hypotheses in wild populations of two strepsirrhine species: Propithecus verreauxi and Lemur catta.

    Science.gov (United States)

    Zannella, Alessandra; Norscia, Ivan; Stanyon, Roscoe; Palagi, Elisabetta

    2015-11-01

    Yawning, although easily recognized, is difficult to explain. Traditional explanations stressed physiological mechanisms, but more recently, behavioral processes have received increasing attention. This is the first study to test a range of hypotheses on yawning in wild primate populations. We studied two sympatric strepsirrhine species, Lemur catta, and Propithecus verreauxi, of the Ankoba forest (24.99°S, 46.29°E, Berenty reserve) in southern Madagascar. Sexual dimorphism is lacking in both species. However, their differences in ecological and behavioral characteristics facilitate comparative tests of hypotheses on yawning. Our results show that within each species males and females yawned with similar frequencies supporting the Dimorphism Hypothesis, which predicts that low sexual dimorphism leads to little inter-sexual differences in yawning. In support of the State Changing Hypothesis yawning frequencies was linked to the sleep-wake cycle and punctuated transitions from one behavior to another. Accordingly, yawning frequencies were significantly higher in L. catta than in P. verreauxi, because L. catta has a higher basal level of activity and consequently a higher number of behavioral transitions. In agreement with the Anxiety Hypothesis, yawning increased significantly in the 10 min following predatory attacks or aggression. Our findings provide the first empirical evidence of a direct connection between anxiety and yawning in lemurs. Our results show that yawning in these two strepsirrhines occurs in different contexts, but more research will be necessary to determine if yawns are a single, unitary behavior. © 2015 Wiley Periodicals, Inc.

  15. A comparison of pectoral fin contact between two different wild dolphin populations

    Science.gov (United States)

    Dudzinski, K.M.; Gregg, J.D.; Ribic, C.A.; Kuczaj, S.A.

    2009-01-01

    Contact behaviour involving the pectoral fin has been documented in a number of dolphin species, and various explanations about its function have been offered. Pectoral fin contact can take a variety of forms, and involves a number of body parts and movements, likely differing depending upon social or ecological context. For this study, we compare the pectoral fin contact behaviour of two species of wild dolphins: Indo-Pacific bottlenose dolphins (Tursiops aduncus) from around Mikura Island, Japan, and Atlantic spotted dolphins (Stenella frontalis) from The Bahamas. The two study populations exhibit surprising similarity in the ways in which pectoral fin contacts are used, despite differences in species and environmental conditions at the two sites. Differences in contact rates for calves between the two sites suggest that calf-focused aggression from adult dolphins is more prevalent at Mikura than in The Bahamas. Our results suggest that pectoral fin contact behaviour seems to be driven primarily by social pressures, and may be similar in function to allogrooming described in primates. ?? 2008 Elsevier B.V.

  16. Epidemiology of viral haemorrhagic disease and myxomatosis in a free-living population of wild rabbits.

    Science.gov (United States)

    Calvete, C; Estrada, R; Villafuerte, R; Osácar, J J; Lucientes, J

    2002-06-22

    From January 1993 to June 1996, the epidemiology of myxomatosis and viral haemorrhagic disease (VHD) was studied in a free-living population of wild rabbits (Oryctolagus cuniculus) in Spain by means of serological surveys and radiotracking. Myxomatosis was endemic and associated with the breeding period. Its serological pattern was characterised by a 100 per cent prevalence of antibodies in adult rabbits and a rapid increase in antibodies in young rabbits in their first year. No mortality from myxomatosis was detected in adults, and mortality in young rabbits could not be estimated because of interference by predators and scavengers and the deaths of many radiotagged rabbits inside their burrows. VHD was also an endemic disease associated with the breeding period. Adults had a higher prevalence of antibodies against VHD than young rabbits, reaching values of 80 to 90 per cent. During the study, there was an increase in rabbit numbers as a result of a decrease in mortality from predation which was associated with an increase in mortality due to VHD and in the prevalence of antibodies to VHD. Mortality from VHD was lower in rabbits with VHD antibodies than in seronegative rabbits, but some mortality from the disease was also detected in seropositive rabbits. The annual mean mortality rate due to VHD in adult rabbits was estimated to be 21.8 per cent.

  17. CHEMICAL COMPOSITION VARIABILITY IN THE Uncaria tomentosa (cat’s claw WILD POPULATION

    Directory of Open Access Journals (Sweden)

    Evelyn Maribel Condori Peñaloza

    2015-03-01

    Full Text Available Uncaria tomentosa (cat's claw is a vine widely distributed throughout the South-American rainforest. Many studies investigating the chemical composition of cat's claw have focused on the pentacyclic (POA and tetracyclic oxindole alkaloids (TOA, quinovic acid glycosides (QAG, and polyphenols (PPH. Nevertheless, it is still uncertain how environmental factors affect chemical groups. The aim of this work was to better understand the influence of environmental factors (geographic origin, altitude, and season on cat's claw chemical composition. Stem bark, branches and leaf samples were extracted and analyzed by HPLC-PDA. The data obtained were explored by multivariate analysis (HCA and PCA. Higher amounts of oxindole alkaloids and PPH were found in leaves, followed by stem bark and branches. No clear relationship was verified among geographic origin or altitude and chemical composition, which remained unchanged regardless of season (dry or rainy. However, three oxindole alkaloid chemotypes were clearly recognized: chemotype I (POA with cis D/E ring junction; chemotype II (POA with trans D/E ring junction; and chemotype III (TOA. Thus, environmental factors appear to have only a minor influence on the chemical heterogeneity of the cat's claw wild population. Nevertheless, the occurrence of different chemotypes based on alkaloid profiles seems to be clear.

  18. Dietary fish intake and sleep quality: a population-based study.

    Science.gov (United States)

    Del Brutto, Oscar H; Mera, Robertino M; Ha, Jung-Eun; Gillman, Jennifer; Zambrano, Mauricio; Castillo, Pablo R

    2016-01-01

    Due to the content of omega-3 and vitamin D, fish consumption is likely to be associated with better sleep. However, current data are limited to a single study that is not representative of the population at large. The present study aimed to assess the effects of oily fish consumption on sleep quality in community dwelling adults living in rural coastal Ecuador. Atahualpa residents aged ≥40 years and who were identified during a door-to-door survey were interviewed with field instruments directed at assessing cardiovascular risk factors, sleep quality, and fish consumption. Using parametric regression and generalized linear models adjusted for demographics and cardiovascular risk factors, the study evaluated whether oily fish consumption is associated with a lower Pittsburgh sleep quality index (PSQI). Out of 721 eligible people, 677 (94%) were enrolled. Mean oily fish consumption was 9 ± 6 servings per week (one serving = 140 grams). Poor sleep quality was noticed in 187 (28%) individuals. Oily fish intake was higher in individuals with good sleep quality (p = 0.013). There was an inverse association between the PSQI score and oily fish servings per week in both parametric regression (β = -0.040; 95% CI -0.690 to -0.011, p = 0.007) and the adjusted generalized linear model (β = -0.032; 95% CI -0.605 to -0.004, p = 0.025). Oily fish consumption is associated with better sleep quality. Even in people who ingest more than the recommended amount of fish, an increase in fish intake is associated with further improvement in the quality of sleep. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Distribution and phylogeny of Wolbachia strains in wild mosquito populations in Sri Lanka.

    Science.gov (United States)

    Nugapola, N W Nalaka P; De Silva, W A Priyanka P; Karunaratne, S H P Parakrama

    2017-05-10

    Wolbachia are a group of maternally inherited intracellular bacteria known to be widespread among arthropods. Infections with Wolbachia cause declines of host populations, and also induce host resistance to a wide range of pathogens. Over the past few decades, researchers were curious to use Wolbachia as a biological tool to control mosquito vectors. During the present study, assessment of the prevalence of Wolbachia infections among wild mosquito populations in Sri Lanka where mosquito-borne diseases are a major health concern, was carried out for the first time. DNA was extracted from the abdomens of mosquitoes, collected from seven provinces, and screened for the presence of Wolbachia by PCR using wsp and groE primers. Group-specific and strain-specific primers were used to classify Wolbachia into the supergroups A and B, and into the strains Mel, AlbA and Pip. A total of 330 individual mosquitoes belonging to 22 species and 7 genera were screened. Eighty-seven mosquitoes (26.36%) belonging to four species (i.e. Aedes albopictus, Culex quinquefasciatus, Armigeres subalbatus and Mansonia uniformis) were positive for Wolbachia infections. Primary vector of the dengue fever, Ae. aegypti was negative for Wolbachia infections while the secondary vector, Ae. albopictus, showed a very high infection rate. The filarial vector C. quinquefasciatus had a relatively high rate of infection. Japanese encephalitis vectors C. gelidus and C. triteaneorynchus, and the Anopheles vectors of malaria were negative for Wolbachia infections. Nine sequences of Wolbachia-positive PCR products were deposited in the GenBank and compared with other available data. Aedes albopictus was infected with both Wolbachia strains A (AlbA) and B (Pip) supergroups. Phylogenetic analysis of the wsp sequences showed two major branches confirming identities obtained from the PCR screening with strain-specific primers. Wolbachia infections were found only among four mosquito species in Sri Lanka: Aedes

  20. Introgression Between Cultivars and Wild Populations of Momordica charantia L. (Cucurbitaceae in Taiwan

    Directory of Open Access Journals (Sweden)

    Yu-Chung Chiang

    2012-05-01

    Full Text Available The landrace strains of Momordica charantia are widely cultivated vegetables throughout the tropics and subtropics, but not in Taiwan, a continental island in Southeast Asia, until a few hundred years ago. In contrast, the related wild populations with smaller fruit sizes are native to Taiwan. Because of the introduction of cultivars for agricultural purposes, these two accessions currently exhibit a sympatric or parapatric distribution in Taiwan. In this study, the cultivars and wild samples from Taiwan, India, and Korea were collected for testing of their hybridization and evolutionary patterns. The cpDNA marker showed a clear distinction between accessions of cultivars and wild populations of Taiwan and a long divergence time. In contrast, an analysis of eight selectively neutral nuclear microsatellite loci did not reveal a difference between the genetic structures of these two accessions. A relatively short divergence time and frequent but asymmetric gene flows were estimated based on the isolation-with-migration model. Historical and current introgression from cultivars to wild populations of Taiwan was also inferred using MIGRATE-n and BayesAss analyses. Our results showed that these two accessions shared abundant common ancestral polymorphisms, and the timing of the divergence and colonization of the Taiwanese wild populations is consistent with the geohistory of the Taiwan Strait land bridge of the Last Glacial Maximum (LGM. Long-term and recurrent introgression between accessions indicated the asymmetric capacity to receive foreign genes from other accessions. The modern introduction of cultivars of M. charantia during the colonization of Taiwan by the Han Chinese ethnic group enhanced the rate of gene replacement in the native populations and resulted in the loss of native genes.

  1. AN ANALYSIS OF THE FISH POPULATIONS BY USING ANN AND WAVELET TECHNIQUES

    Directory of Open Access Journals (Sweden)

    Guven OZDEMİR

    2013-01-01

    Full Text Available Air – sea climate, environmental and biological conditions show various differences on several spatio-temporal scales. Climate change associated with anthropogenic activity and natural global multi-decadal climate variations effects on air-sea interactions and water surface–atmosphere–biosphere climate system. In the first part of this paper is related with Artificial Neuro Network analyses for prediction of fish stocks in Marmara and Black Sea. The second part of this study is based on wavelet analyses and, the results were compared with former wavelet and harmonic analyses to explain seasonal effects of NAO and ENSO on fish population. The influence of climatic oscillations (based on NAO and ENSO on monthly catch rates of fish population such as sea bass, Atlantic bonito,blue fish sea (pomatomus population between 1991-2012 in Black Sea and Marmara have been analyzed by discrete wavelet transform (DWT with Meyer and Daubechie's. Wavelet analysis is an efficient method of time series analysis to study non-stationary data. Wavelet analyses allowed us to quantify both the pattern of variability in the time series and non-stationary associations between fish population and climatic signals. Phase analyses were carried out to investigate dependency between the two signals. We reported strong relations between fish stock and climate series for the 4- and 5-yr periodic modes, i.e. the periodic band of the El Niño Southern Oscillation signal propagation in the Black Sea and Marmara Sea. These associations were non-stationary, evidenced from 1995 to 2012. It is recognized that other factors in small, meso and large scales may modulate fish stocks beginning from 1995 and more clearly from 2005

  2. Spatially resolved fish population analysis for designing MPAs

    DEFF Research Database (Denmark)

    Christensen, Asbjørn; Mosegaard, Henrik; Jensen, Henrik

    2009-01-01

    habitats for settled sandeels, combined with a life-cycle model for survival, growth, and reproduction, and a three-dimensional hydrodynamic model for describing larval transport between the network of habitats. SPAM couples stock dynamics to ecosystem and anthropogenic forcing via well-defined drivers......The sandeel population analysis model (SPAM) is presented as a simulation tool for exploring the efficiency of Marine Protected Areas (MPAs) for sandeel stocks. SPAM simulates spatially resolved sandeel population distributions, based on a high-resolution map of all fishery-established sandbank...

  3. Dispersal capacity predicts both population genetic structure and species richness in reef fishes.

    Science.gov (United States)

    Riginos, Cynthia; Buckley, Yvonne M; Blomberg, Simon P; Treml, Eric A

    2014-07-01

    Dispersal is a fundamental species characteristic that should directly affect both rates of gene flow among spatially distributed populations and opportunities for speciation. Yet no single trait associated with dispersal has been demonstrated to affect both micro- and macroevolutionary patterns of diversity across a diverse biological assemblage. Here, we examine patterns of genetic differentiation and species richness in reef fishes, an assemblage of over 7,000 species comprising approximately one-third of the extant bony fishes and over one-tenth of living vertebrates. In reef fishes, dispersal occurs primarily during a planktonic larval stage. There are two major reproductive and parental investment syndromes among reef fishes, and the differences between them have implications for dispersal: (1) benthic guarding fishes lay negatively buoyant eggs, typically guarded by the male parent, and from these eggs hatch large, strongly swimming larvae; in contrast, (2) pelagic spawning fishes release small floating eggs directly into the water column, which drift unprotected before small weakly swimming larvae hatch. Using phylogenetic comparative methods, we show that benthic guarders have significantly greater population structure than pelagic spawners and additionally that taxonomic families of benthic guarders are more species rich than families of pelagic spawners. Our findings provide a compelling case for the continuity between micro- and macroevolutionary processes of biological diversification and underscore the importance of dispersal-related traits in influencing the mode and tempo of evolution.

  4. Estimating the population density of Iberian wild goat Capra pyrenaica and mouflon Ovis aries in a Mediterranean forest environment

    Directory of Open Access Journals (Sweden)

    Rita Tinoco Torres

    2014-04-01

    Full Text Available Aim of study: To manage and conserve wild populations effectively, a good understating of population density is critical. During 2010, the density of Iberian wild goat Capra pyrenaica and mouflon Ovis aries were estimated.Area of study: The area is situated in Muela de Cortes Game Reservation (Spain, a Mediterranean forest plateau, after a mange Sarcoptes scabiei outbreak that affected both species. Material and methods: To measure the abundance, sex ratio and productivity of the Iberian wild goat and mouflon. Field work was conducted during spring (after parturition and autumn (during rut by walking along itineraries, using a Distance Sampling approach. Main results: Based on DS, the best relative fit of model and adjustment term for Iberian wild goat was hazard-rate cosine, based on the lowest AIC score. The average density for Iberian wild goat was 4 km-2 (95% CI: 2,3 – 6,9 (after parturition and 3,6 km-2 (95% CI: 2 – 6.6 (during rut. Average estimation was 1,422 goats (95% CI: 813 – 2,487 after parturition and 1,308 during rut (95% CI: 725 – 2,362. Mouflon best relative fit of model and adjustment term was uniform cosine after parturition, based on the lowest AIC score. The best relative fit of model and adjustment term for mouflon was hazard-rate cosine, based on the lowest AIC score. The average density was 6.8 mouflon km-2 (95% CI: 4.7 – 9,9 after parturition and 7,4 mouflon km-2 (95% CI: 4,4 – 12,5 during rut. Average estimation was 2,440 mouflon after parturition (95% CI: 1,673 – 3,558 and 2,678 during rut (95% CI: 1,589 – 4,515. Research highlights: The area represents one of the largest continental free-living populations of mouflon in Europe and a relevant area for Iberian wild goat, where it has survived for centuries and spread into the East Iberia. This study suggests that the survey methods used are suitable and sustainable with available field personnel for quantifying changes in wild goat and mouflon populations

  5. Contact rates of wild-living and domestic dog populations in Australia: a new approach.

    Science.gov (United States)

    Sparkes, Jessica; Ballard, Guy; Fleming, Peter J S; van de Ven, Remy; Körtner, Gerhard

    2016-12-01

    Dogs (Canis familiaris) can transmit pathogens to other domestic animals, humans and wildlife. Both domestic and wild-living dogs are ubiquitous within mainland Australian landscapes, but their interactions are mostly unquantified. Consequently, the probability of pathogen transfer among wild-living and domestic dogs is unknown. To address this knowledge deficit, we established 65 camera trap stations, deployed for 26,151 camera trap nights, to quantify domestic and wild-living dog activity during 2 years across eight sites in north-east New South Wales, Australia. Wild-living dogs were detected on camera traps at all sites, and domestic dogs recorded at all but one. No contacts between domestic and wild-living dogs were recorded, and limited temporal overlap in activity was observed (32 %); domestic dogs were predominantly active during the day and wild-living dogs mainly during the night. Contact rates between wild-living and between domestic dogs, respectively, varied between sites and over time (range 0.003-0.56 contacts per camera trap night). Contact among wild-living dogs occurred mainly within social groupings, and peaked when young were present. However, pup emergence occurred throughout the year within and between sites and consequently, no overall annual cycle in contact rates could be established. Due to infrequent interactions between domestic and wild-living dogs, there are likely limited opportunities for pathogen transmission that require direct contact. In contrast, extensive spatial overlap of wild and domestic dogs could facilitate the spread of pathogens that do not require direct contact, some of which may be important zoonoses.

  6. Comparison of the genetic variation of captive ring-tailed lemurs with a wild population in Madagascar.

    Science.gov (United States)

    Pastorini, Jennifer; Sauther, Michelle L; Sussman, Robert W; Gould, Lisa; Cuozzo, Frank P; Fernando, Prithiviraj; Nievergelt, Caroline M; Mundy, Nicholas I

    2015-01-01

    Genetic variability among captive and wild ring-tailed lemurs (Lemur catta) was assessed using mitochondrial and nuclear DNA data. A 529 bp segment of mtDNA was sequenced and 9 microsatellite loci were genotyped for 286 ring-tailed lemurs. Samples were obtained from the well-studied L. catta population at the Bezà Mahafaly Special Reserve and from captive animals at six institutions worldwide. We found evidence of possible patrilineal contribution but the absence of matrilineal contribution from the Bezà area, and haplotypes not found in Bezà but present in Ambohimahavelona, Andringitra Massif, and other unknown locations, in the sampled captive population, indicating that the founders of the captive population originated from a wide geographic range. Total genetic variation and relatedness in captive L. catta in the six institutions were similar in extent to that of the wild population in Bezà. Based on the diverse origins of the captive population founders our results suggest the erosion of genetic diversity in the captive population. Sampled individuals from the same institution were more closely related to each other than members of a social group in the wild. Individuals housed at different institutions were less closely related than those of different social groups at Bezà, indicating lower genetic exchange between captive institutions than between social groups in a locality in the wild. Our findings underscore the usefulness of genotyping in determining the geographic origin of captive population founders, obtaining pedigree information if paternity is uncertain, and in maximizing preservation of extant genetic diversity in captivity. © 2015 Wiley Periodicals, Inc.

  7. Compensatory mechanisms in fish populations: Literature reviews: Volume 1, Critical evaluation of case histories of fish populations experiencing chronic exploitation or impact: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Saila, S.B.; Chen, X.; Erzini, K.; Martin, B.

    1987-05-01

    This study includes case histories of certain fish species which are experiencing chronic perturbations and related literature pertaining to compensation processes. ''Compensation'' has been defined as the ability of fish to offset the population reduction caused by natural or man-induced stresses. Certain compensation methods are widely accepted, and include cannibalism, competition, disease, growth and predation, among others. These compensation methods are examined in relation to each fish species included in the study. Stock-recruit relationships and empirical observations of changes in growth and mortality have been the focus of much of the background on compensation. One of the conclusions drawn from this study is that a significant amount of recruitment variability exists and can be attributed to environmental (rather than compensatory) factors. The stock-recruitment problem appears to be the most significant scientific problem related to compensation in the types of fish included in this study. Results of the most recent studies of the American shad support this theory. Life histories, breeding biology and other pertinent data relating to each species included in the study will be found in the appendices.

  8. Disease associated population effects of commercial fish and shellfish species (ToR g)

    DEFF Research Database (Denmark)

    Lang, T.; Alfjorden, A.; Feist, S.W.

    2015-01-01

    marine gastropods, bivalves, crustaceans, and fishes. The report provides in-formation on the types of diseases, together with data on diagnostic criteria, causative agents, geographical ranges and effects at the individual and population level. A dis-cussion of the significance of the findings...... and references to key publications are pro-vided. The overview shows that the effects of diseases may occur at various life stages of affected hosts. The extent to which these effects lead to measurable popula-tion changes (e.g., in growth, reproduction, mortality, recruitment, population de...... larger role in population performance and dynamics in marine fish and shellfish than previously recognised. Therefore, methods for incorporating disease data into population/stock assessment models should be further explored. In the first instance, this will be rele-vant for commercial species, for which...

  9. New fish populations as evidence of climate chage in former dry areas of the Pampa Region ( Southern South America).

    OpenAIRE

    Gómez, Sergio Enrique; Trenti, Patricia S.; Menni, Roberto C.

    2004-01-01

    Water bodies located at 34º 58' S, 62º 58' W formed after 1980 by 30 % increasing rainfall during the last half century, were colonized by ten fish species which are a subset of the commonest species living in the pampasic lagunas. These new populations imply a displacement of the West of Pampasian fishes to areas of the western basins previously lacking fish.

  10. Bottom-up effects of climate on fish populations: data from the Continuous Plankton Recorder

    DEFF Research Database (Denmark)

    Pitois, S.G.; Lynam, C.P.; Jansen, Teunis

    2012-01-01

    a unique opportunity to investigate long-term changes over decadal scales in the abundance and distribution of fish larvae in relation to physical and biological factors. A principal component analysis (PCA) using 7 biotic and abiotic parameters is applied to investigate the impact of environmental changes...... in the plankton ecosystem, while the larvae of migratory species such as Atlantic mackerel responded more to hydrographic changes. Climate variability seems more likely to influence fish populations through bottom-up control via a cascading effect from changes in the North Atlantic Oscillation (NAO) impacting...... on the hydro dynamic features of the North Sea, in turn impacting on the plankton available as prey for fish larvae. The responses and adaptability of fish larvae to changing environmental conditions, parti cularly to changes in prey availability, are complex and species-specific. This complexity is enhanced...

  11. Prevalence and population structure of Vibrio vulnificus on fishes from the northern Gulf of Mexico.

    Science.gov (United States)

    Tao, Zhen; Larsen, Andrea M; Bullard, Stephen A; Wright, Anita C; Arias, Covadonga R

    2012-11-01

    The prevalence of Vibrio vulnificus on the external surfaces of fish from the northern Gulf of Mexico was determined in this study. A collection of 242 fish comprising 28 species was analyzed during the course of 12 sampling trips over a 16-month period. The prevalence of V. vulnificus was 37% but increased up to 69% in summer. A positive correlation was found between the percentages of V. vulnificus-positive fish and water temperatures, while salinity and V. vulnificus-positive fish prevalence were inversely correlated. A general lineal model (percent V. vulnificus-positive fish = 0.5930 - 0.02818 × salinity + 0.01406 × water temperature) was applied to best fit the data. Analysis of the population structure was carried out using 244 isolates recovered from fish. Ascription to 16S rRNA gene types indicated that 157 isolates were type A (62%), 72 (29%) were type B, and 22 (9%) were type AB. The percentage of type B isolates, considered to have greater virulence potential, was higher than that previously reported in oyster samples from the northern Gulf of Mexico. Amplified fragment length polymorphism (AFLP) was used to resolve the genetic diversity within the species. One hundred twenty-one unique AFLP profiles were found among all analyzed isolates, resulting in a calculated Simpson's index of diversity of 0.991. AFLP profiles were not grouped on the basis of collection date, fish species, temperature, or salinity, but isolates were clustered into two main groups that correlated precisely with 16S rRNA gene type. The population of V. vulnificus associated with fishes from the northern Gulf of Mexico is heterogeneous and includes strains of great virulence potential.

  12. Twelve years of repeated wild hog activity promotes population maintenance of an invasive clonal plant in a coastal dune ecosystem.

    Science.gov (United States)

    Oldfield, Callie A; Evans, Jonathan P

    2016-04-01

    Invasive animals can facilitate the success of invasive plant populations through disturbance. We examined the relationship between the repeated foraging disturbance of an invasive animal and the population maintenance of an invasive plant in a coastal dune ecosystem. We hypothesized that feral wild hog (Sus scrofa) populations repeatedly utilized tubers of the clonal perennial, yellow nutsedge (Cyperus esculentus) as a food source and evaluated whether hog activity promoted the long-term maintenance of yellow nutsedge populations on St. Catherine's Island, Georgia, United States. Using generalized linear mixed models, we tested the effect of wild hog disturbance on permanent sites for yellow nutsedge culm density, tuber density, and percent cover of native plant species over a 12-year period. We found that disturbance plots had a higher number of culms and tubers and a lower percentage of native live plant cover than undisturbed control plots. Wild hogs redisturbed the disturbed plots approximately every 5 years. Our research provides demographic evidence that repeated foraging disturbances by an invasive animal promote the long-term population maintenance of an invasive clonal plant. Opportunistic facultative interactions such as we demonstrate in this study are likely to become more commonplace as greater numbers of introduced species are integrated into ecological communities around the world.

  13. Lysogenic Streptococcus suis isolate SS2-4 containing prophage SMP showed increased mortality in zebra fish compared to the wild-type isolate.

    Directory of Open Access Journals (Sweden)

    Fang Tang

    Full Text Available Streptococcus suis (S. suis infection is considered to be a major problem in the swine industry worldwide. Based on the capsular type, 33 serotypes of S. suis have been described, with serotype 2 (SS2 being the most frequently isolated from diseased piglets. Little is known, however, about the pathogenesis and virulence factors of S. suis. Research on bacteriophages highlights a new area in S. suis research. A S. suis serotype 2 bacteriophage, designated SMP, has been previously isolated in our laboratory. Here, we selected a lysogenic isolate in which the SMP phage was integrated into the chromosome of strain SS2-4. Compared to the wild-type isolate, the lysogenic strain showed increased mortality in zebra fish. Moreover the sensitivity of the lysogenic strain to lysozyme was seven times higher than that of the wild-type.

  14. Population survey of phytoseiid mites and spider mites on peach leaves and wild plants in Japanese peach orchard.

    Science.gov (United States)

    Wari, David; Yamashita, Jun; Kataoka, Yoko; Kohara, Yoko; Hinomoto, Norihide; Kishimoto, Hidenari; Toyoshima, Shingo; Sonoda, Shoji

    2014-07-01

    A population survey of phytoseiid mites and spider mites was conducted on peach leaves and wild plants in Japanese peach orchards having different pesticide practices. The phytoseiid mite species composition on peach leaves and wild plants, as estimated using quantitative sequencing, changed during the survey period. Moreover, it varied among study sites. The phytoseiid mite species compositions were similar between peach leaves and some wild plants, such as Veronica persica, Paederia foetida, Persicaria longiseta, and Oxalis corniculata with larger quantities of phytoseiid mites, especially after mid-summer. A PCR-based method to detect the ribosomal ITS sequences of Tetranychus kanzawai and Panonychus mori from phytoseiid mites was developed. Results showed that Euseius sojaensis (specialized pollen feeder/generalist predator) uses both spider mites as prey in the field.

  15. Comparisons of genetic diversity in captive versus wild populations of the federally endangered Quino checkerspot butterfly (Euphydryas editha quino Behr; Lepidoptera: Nymphalidae)

    Science.gov (United States)

    Miller, Mark P.; Pratt, Gordon F.; Mullins, Thomas D.; Haig, Susan M.

    2014-01-01

    Captive populations can play a significant role in threatened and endangered species management. An important consideration when developing and managing captive populations, however, is the maintenance of genetic diversity to ensure that adequate variation exists to avoid the negative consequences of inbreeding. In this investigation, we compared genetic diversity patterns within captive and wild populations of the federally endangered Quino checkerspot butterfly (Euphydryas editha quino Behr [Lepidoptera: Nymphalidae]), a taxon with a restricted distribution to chaparral and sage shrublands within Riverside and San Diego counties, California. Our analyses revealed that medium to high-frequency alleles from the wild populations were also present in the captive populations. While there was no significant difference in genetic diversity as quantified by expected heterozygosity, the captive populations showed tendencies toward significantly lower allelic richness than their wild counterparts. Given that alleles from the wild populations were occasionally not detected in captive populations, periodic incorporation of new wild specimens into the captive population would help ensure that allelic diversity is maintained to the extent possible. If performed in advance, genetic surveys of wild populations may provide the clearest insights regarding the number of individuals needed in captivity to adequately reflect wild populations.

  16. Patterns of connectivity among populations of a coral reef fish

    Science.gov (United States)

    Chittaro, P. M.; Hogan, J. D.

    2013-06-01

    Knowledge of the patterns and scale of connectivity among populations is essential for the effective management of species, but our understanding is still poor for marine species. We used otolith microchemistry of newly settled bicolor damselfish ( Stegastes partitus) in the Mesoamerican Reef System (MRS), Western Caribbean, to investigate patterns of connectivity among populations over 2 years. First, we assessed spatial and temporal variability in trace elemental concentrations from the otolith edge to make a `chemical map' of potential source reef(s) in the region. Significant otolith chemical differences were detected at three spatial scales (within-atoll, between-atolls, and region-wide), such that individuals were classified to locations with moderate (52 % jackknife classification) to high (99 %) accuracy. Most sites at Turneffe Atoll, Belize showed significant temporal variability in otolith concentrations on the scale of 1-2 months. Using a maximum likelihood approach, we estimated the natal source of larvae recruiting to reefs across the MRS by comparing `natal' chemical signatures from the otolith of recruits to the `chemical map' of potential source reef(s). Our results indicated that populations at both Turneffe Atoll and Banco Chinchorro supply a substantial amount of individuals to their own reefs (i.e., self-recruitment) and thus emphasize that marine conservation and management in the MRS region would benefit from localized management efforts as well as international cooperation.

  17. Fish parasites

    DEFF Research Database (Denmark)

    This book contains 22 chapters on some of the most important parasitic diseases in wild and farmed fish. International experts give updated reviews and provide solutions to the problems......This book contains 22 chapters on some of the most important parasitic diseases in wild and farmed fish. International experts give updated reviews and provide solutions to the problems...

  18. Evidence of bovine viral diarrhea virus infection in three species of sympatric wild ungulates in Nevada: life history strategies may maintain endemic infections in wild populations

    Directory of Open Access Journals (Sweden)

    Peregrine Lee Wolff

    2016-03-01

    Full Text Available Evidence for bovine viral diarrhea virus (BVDV infection was detected in 2009-10 while investigating a pneumonia die-off in Rocky Mountain bighorn sheep (Ovis canadensis canadensis, and sympatric mountain goats (Oreamnos americanum in adjacent mountain ranges in Elko County, Nevada. Seroprevalence to BVDV-1 was 81% (N=32 in the bighorns and 100% (N=3 in the mountain goats. Serosurveillance from 2011 to 2015 of surviving bighorns and mountain goats as well as sympatric mule deer (Odocoileus hemionus, indicated a prevalence of 72% (N=45, 45% (N=51, and 51% (N=342 respectively. All species had antibody titers to BVDV1 and BVDV2. BVDV1 was isolated in cell culture from three bighorn sheep and a mountain goat kid. BVDV2 was isolated from two mule deer. Six deer (N=96 sampled in 2013 were positive for BVDV by antigen-capture ELISA on ear notch. Wild ungulates and cattle concurrently graze public and private lands in these two mountain ranges, thus providing potential for interspecies viral transmission. Like cattle, mule deer, mountain goats, and bighorn sheep can be infected with BVDV and can develop clinical disease including immunosuppression. Winter migration patterns that increase densities and species interaction during the first and second trimester of gestation may contribute to the long term maintenance of the virus in these wild ungulates. More studies are needed to determine the population level impacts of BVDV infection on these three species.

  19. An examination of the population dynamics of syngnathid fishes within Tampa Bay, Florida, USA

    Directory of Open Access Journals (Sweden)

    Heather D. MASONJONES, Emily ROSE, Lori Benson McRAE,Danielle L. DIXSON

    2010-02-01

    Full Text Available Seagrass ecosystems worldwide have been declining, leading to a decrease in associated fish populations, especially those with low mobility such as syngnathids (pipefish and seahorses. This two-year pilot study investigated seasonal patterns in density, growth, site fidelity, and population dynamics of Tampa Bay (FL syngnathid fishes at a site adjacent to two marinas under construction. Using a modified mark-recapture technique, fish were collected periodically from three closely located sites that varied in seagrass species (Thalassia spp., Syringodium spp., and mixed-grass sites and their distance from open water, but had consistent physical/chemical environmental characteristics. Fish were marked, photographed for body size and gender measurements, and released the same day at the capture site. Of the 5695 individuals surveyed, 49 individuals were recaptured, indicating a large, flexible population. Population density peaks were observed in July of both years, with low densities in late winter and late summer. Spatially, syngnathid densities were highest closest to the mouth of the bay and lowest near the shoreline. Seven species of syngnathid fishes were observed, and species-specific patterns of seagrass use emerged during the study. However, only two species, Syngnathus scovelli and Hippocampus zosterae, were observed at high frequencies. For these two species, body size decreased across the study period, but while S. scovelli’s population density decreased, H. zosterae’s increased. Across six of the seven species, population size declined over the course of this preliminary study; however, seasonal shifts were impossible to distinguish from potential anthropogenic effects of construction [Current Zoology 56 (1: 118–133, 2010].

  20. Wild and semi-domesticated reindeer in Russia: status, population dynamics and trends under the present social and economic conditions

    Directory of Open Access Journals (Sweden)

    Eugene E. Syroechkovski

    2000-03-01

    Full Text Available At present (in 1999 there are approximately 1.5 million semi-domesticated and 1.3 million wild reindeer in Russia. The co-existence of these two forms remains a major problem. Reindeer herding has declined while the number of wild reindeer has increased during the last 10 years. The main causes of these changes are social and economic. The 1960s and 1970s were characterised by a deliberate attempt to eradicate the nomadic way of life of reindeer herders. It was relatively easy to introduce public (kolkhoz or sovkhoz reindeer herding in the Nenets, Chukchi and Komi-Izhem areas where large-scale reindeer herding was typical and, as a result, there were almost 1 million reindeer in collectives in the extreme north-eastern part of the USSR. At the same time reindeer herding deteriorated among the Khanty, Mansi, Evenk, Even, Selkup peoples. Perestroika in the 1990s resulted in the formation of a market economy. Collective reindeer herding declined and the number of semi-domesticated reindeer decreased during a period of gradual return to private ownership of reindeer. The largest region of reindeer herding is now the Nenets tegion in the north-west of Russia. Successful sympatric existence of wild and semi-domesticated reindeer is not possible. The Taimyr wild reindeer population numbers about 500-600 000 reindeer. From 1971 to 1981 not less than 700 000 reindeer in this population were shot. Ecological and economic control over them has now been lost. There are approximately 200 000 animals in Yakutia. The number of wild reindeer here has grown following the decline of reindeer husbandry. Yakut and Even reindeer herders believe that the decline has been due to wild reindeer drawing semi-domesticated teindeer away. At present 13 aboriginal peoples in northern Russia engage in reindeer herding. Five former reindeer herding peoples have given up herding but thete are signs of improvement in the situation among those peoples which have retained reindeer

  1. Distribution of naphthenic acids in tissues of laboratory-exposed fish and in wild fishes from near the Athabasca oil sands in Alberta, Canada.

    Science.gov (United States)

    Young, Rozlyn F; Michel, Lorelei Martínez; Fedorak, Phillip M

    2011-05-01

    Naphthenic acids, which have a variety of commercial applications, occur naturally in conventional crude oil and in highly biodegraded petroleum such as that found in the Athabasca oil sands in Alberta, Canada. Oil sands extraction is done using a caustic aqueous extraction process. The alkaline pH releases the naphthenic acids from the oil sands and dissolves them into water as their soluble naphthenate forms, which are anionic surfactants. These aqueous extracts contain concentrations of naphthenates that are acutely lethal to fishes and other aquatic organisms. Previous research has shown that naphthenic acids can be taken up by fish, but the distribution of these acids in various tissues of the fish has not been determined. In this study, rainbow trout (Oncorhynchus mykiss) were exposed to commercial (Merichem) naphthenic acids in the laboratory. After a 10-d exposure to approximately 3mg naphthenic acids/L, the fish were dissected and samples of gills, heart, liver, kidney, muscle, and eggs were extracted and analyzed for free (unconjugated) naphthenic acids by a gas chromatography-mass spectrometry method. Each of the tissues contained naphthenic acids and non-parametric statistical analyses showed that gills and livers contained higher concentrations than the muscles and that the livers had higher concentrations than the hearts. Four different species of fish (two fish of each species) were collected from the Athabasca River near two oil sands mining and extraction operations. No free naphthenic acids were detected in the muscle or liver of these fish. Copyright © 2010 Elsevier Inc. All rights reserved.

  2. Resistance to the Whitefly, Aleurotrachelus socialis, in Wild Populations of Cassava, Manihot Tristis

    OpenAIRE

    Carabal?, A.; Bellotti, A. C.; Montoya-Lerma,J; Fregene, Martin

    2010-01-01

    The levels of resistance in the wild species of cassava, Manihot tristis Muell-Arg. (Malpighiales: Euphorbiaceae), to the whitefly, Aleurotrachelus socialis Bondar (Hemiptera: Alelyrodidae), the most important economic pest in cassava, Manihot esculenta Crantz (Malpighiales: Euphorbiaceae) crops in South America, were estimated under glasshouse conditions. The parameters of the life history of A. socialis were studied on TST-26 and TST-18 accessions of the wild parent and compared with the su...

  3. Estimating multi-factor cumulative watershed effects on fish populations with an individual-based model

    Science.gov (United States)

    Bret C. Harvey; Steven F. Railsback

    2007-01-01

    While the concept of cumulative effects is prominent in legislation governing environmental management, the ability to estimate cumulative effects remains limited. One reason for this limitation is that important natural resources such as fish populations may exhibit complex responses to changes in environmental conditions, particularly to alteration of multiple...

  4. Natural variants of AtHKT1 enhance Na+ accumulation in two wild populations of Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Ana Rus

    2006-12-01

    Full Text Available Plants are sessile and therefore have developed mechanisms to adapt to their environment, including the soil mineral nutrient composition. Ionomics is a developing functional genomic strategy designed to rapidly identify the genes and gene networks involved in regulating how plants acquire and accumulate these mineral nutrients from the soil. Here, we report on the coupling of high-throughput elemental profiling of shoot tissue from various Arabidopsis accessions with DNA microarray-based bulk segregant analysis and reverse genetics, for the rapid identification of genes from wild populations of Arabidopsis that are involved in regulating how plants acquire and accumulate Na(+ from the soil. Elemental profiling of shoot tissue from 12 different Arabidopsis accessions revealed that two coastal populations of Arabidopsis collected from Tossa del Mar, Spain, and Tsu, Japan (Ts-1 and Tsu-1, respectively, accumulate higher shoot levels of Na(+ than do Col-0 and other accessions. We identify AtHKT1, known to encode a Na(+ transporter, as being the causal locus driving elevated shoot Na(+ in both Ts-1 and Tsu-1. Furthermore, we establish that a deletion in a tandem repeat sequence approximately 5 kb upstream of AtHKT1 is responsible for the reduced root expression of AtHKT1 observed in these accessions. Reciprocal grafting experiments establish that this loss of AtHKT1 expression in roots is responsible for elevated shoot Na(+. Interestingly, and in contrast to the hkt1-1 null mutant, under NaCl stress conditions, this novel AtHKT1 allele not only does not confer NaCl sensitivity but also cosegregates with elevated NaCl tolerance. We also present all our elemental profiling data in a new open access ionomics database, the Purdue Ionomics Information Management System (PiiMS; http://www.purdue.edu/dp/ionomics. Using DNA microarray-based genotyping has allowed us to rapidly identify AtHKT1 as the casual locus driving the natural variation in shoot Na

  5. Host races of the cotton aphid, Aphis gossypii, in asexual populations from wild plants of taro and brinjal.

    Science.gov (United States)

    Agarwala, B K; Choudhury, Parichita Ray

    2013-01-01

    Worldwide, several studies have shown that adaptation to different host plants in phytophagous insects can promote speciation. The cotton aphid, Aphis gossypii Glover (Homoptera: Aphididae: Aphidini), is a highly polyphagous species, but its populations increase by parthenogenetic reproduction alone in Indian subcontinent. This study showed that genotypes living in wild plants of taro, Colocasia esculenta var. esculenta (L.) Schott (Alismatales: Araceae), and brinjal, Solanum torvum Swartz (Solanales: Solanaceae), behave as distinct host races. Success rates of colonization after reciprocal host transfers were very poor. Clones of A. gossypii from wild taro partly survived in the first generation when transferred to wild brinjal, but nymph mortality was 100% in the second generation. In contrast, brinjal clones, when transferred to taro, could not survive even in the first generation. Significant differences between the clones from two host species were also recorded in development time, generation time, fecundity, intrinsic rate of increase, net reproductive rate, and mean relative growth rate. Morphologically, aphids of wild taro clones possessed longer proboscis and fore-femora than the aphids of the brinjal clones. The results showed that A. gossypii exists as distinct host races with different abilities of colonizing host plants, and its populations appear to have more potential of sympatic evolution than previously regarded.

  6. Oceanography and life history predict contrasting genetic population structure in two Antarctic fish species

    OpenAIRE

    Young, E. F.; Belchier, M.; Hauser, L; Horsburgh, G.J.; Meredith, M. P.; Murphy, E.J.; Pascoal, S.; Rock, J; Tysklind, N.; Carvalho, G R

    2015-01-01

    Understanding the key drivers of population connectivity in the marine environment is essential for the effective management of natural resources. Although several different approaches to evaluating connectivity have been used, they are rarely integrated quantitatively. Here, we use a ?seascape genetics? approach, by combining oceanographic modelling and microsatellite analyses, to understand the dominant influences on the population genetic structure of two Antarctic fishes with contrasting ...

  7. Steelhead returns to Warm Springs National Fish Hatchery, 1978 - 2003

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Warm Springs River is a major tributary of the Deschutes River in north-central Oregon, and supports a population of wild summer steelhead (Oncorhynchusmykiss)....

  8. Trophic status and helminth infracommunities of fish populations in Kashmir Himalayan lakes.

    Science.gov (United States)

    Shah, H B; Yousuf, A R; Chishti, M Z; Shahnaz, S; Ahmad, F

    2014-09-01

    The present study considers the influence of the trophic status of three Kashmir Himalayan lakes on the patterns of helminth infracommunities in populations of three species of fish during 2006 to 2008. Data were collected from three lakes of differing trophic status in the Kashmir Himalayas, namely Anchar, a hyper(eu)trophic lake; Dal, a eutrophic lake; and Manasbal, a meso(eu)trophic lake. Three species of fish examined included the native fish Schizothorax niger Heckel and two exotic species--Carassius carassius (Linnaeus) and Cyprinus carpio Linnaeus. The analysis of data showed a clear habitat effect on the abundance pattern of helminth species, thus revealing lake-specific differences in parasite infracommunities of both S. niger and C. carassius. Helminth infracommunity richness was the highest in host populations from the Anchar lake compared to other two lakes. Low values in the Manasbal lake emphasize the low diversity of their helminth infracommunities. On the other hand, there was no observed pattern of community structure in the case of C. carpio in the three lake sites. However due to bias in sampling there was no distinct effect of fish body size on parasite infracommunity structure, although the present results do show that fish parasite data can be meaningful in diagnosing changes in the trophic condition of eutrophic lakes.

  9. Evaluation of population-level ecological risks of fish-eating birds to dioxinlike PCBs exposure

    Energy Technology Data Exchange (ETDEWEB)

    Naito, Wataru; Yoshida, Kikuo [National Institute of Advanced Industrial Science and Technology, Research Center for Chemical Risk Management, Tsukuba (Japan); Murata, Mariko [National Institute of Technology and Evaluation, Tokyo (Japan)

    2004-09-15

    Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/DFs) and some non- and monoortho- polychlorinated biphenyl congeners that can attain planar configuration (dioxinlike PCBs), which are chemically stable and persistent, are thought to be biomagnified via foodchain. Many studies have revealed that higher levels of these compounds have been observed in fish-eating birds, a top consumer in aquatic biota. Among these compounds, Dioxinlike PCBs has contributed more than 80% of the total TEQs found in eggs of fish-eating birds. In order to evaluate the effects of these compounds on fish-eating birds, therefore, it is important to elucidate exposure pathways and characteristics of dioxinlike PCBs. The conventional ecological risk assessment method of chemicals entails comparing the predicted no effect concentration (PNEC) determined from laboratory toxicity tests with the predicted or observed concentration in a target organism or a surrounding environmental media. Utilizing such a result of simplistic individual-level effect to draw conclusions regarding chemical effects on population is, however, questionable. Since risk management decisions should be based on protecting populations, the methods for population-level ecological risk assessment of chemicals have been of increasing interest for risk assessors and managers. In this study, a population-level ecological risk assessment of dioxinlike PCBs on fish-eating birds was performed to judge the need for risk management measures to protect aquatic wildlife from dioxinlike PCBs contamination in Japan. Egg mortality risk and the changes in population growth rate, {lambda}, in relation to the contamination levels of dioxinlike PCBs in eggs of four different types of fish-eating birds were determined by integrating the results from both bioaccumulation and life-history models.

  10. Morphological and Molecular Data Reveal Three Distinct Populations of Indian Wild Rice Oryza rufipogon Griff. Species Complex

    Directory of Open Access Journals (Sweden)

    Balwant Singh

    2018-02-01

    Full Text Available Wild relatives of crops possess adaptive mutations for agronomically important traits, which could play significant role in crop improvement for sustainable agriculture. However, global climate change and human activities pose serious threats to the natural habitats leading to erosion of genetic diversity of wild rice populations. The purpose of this study was to explore and characterize India’s huge untapped wild rice diversity in Oryza rufipogon Griff. species complex from a wide range of ecological niches. We made strategic expeditions around diversity hot spots in 64 districts of nine different agro-climatic zones of the country and collected 418 wild rice accessions. Significant variation was observed among the accessions for 46 morphological descriptors, allowing classification into O. nivara, O. rufipogon, and O. sativa f. spontanea morpho-taxonomic groups. Genome-specific pSINE1 markers confirmed all the accessions having AA genome, which were further classified using ecotype-specific pSINE1 markers into annual, perennial, intermediate, and an unknown type. Principal component analysis revealed continuous variation for the morphological traits in each ecotype group. Genetic diversity analysis based on multi-allelic SSR markers clustered these accessions into three major groups and analysis of molecular variance for nine agro-climatic zones showed that 68% of the genetic variation was inherent amongst individuals while only 11% of the variation separated the zones, though there was significant correlation between genetic and spatial distances of the accessions. Model based population structure analysis using genome wide bi-allelic SNP markers revealed three sub-populations designated ‘Pro-Indica,’ ‘Pro-Aus,’ and ‘Mid-Gangetic,’ which showed poor correspondence with the morpho-taxonomic classification or pSINE1 ecotypes. There was Pan-India distribution of the ‘Pro-Indica’ and ‘Pro-Aus’ sub-populations across agro

  11. Prevalence of Salmonella strains in wild animals from a highly populated area of north-eastern Italy.

    Science.gov (United States)

    Rubini, Silva; Ravaioli, Cinzia; Previato, Sara; D'Incau, Mario; Tassinari, Massimo; Guidi, Enrica; Lupi, Silvia; Merialdi, Giuseppe; Bergamini, Mauro

    2016-01-01

    Salmonella is a ubiquitous pathogen that can infect host species, like wild birds, rodents, and/or arthropods, which may transmit infection to domestic animals and human population. In order to assess the related risk, a cross-sectional study was performed on 1114 carcasses of wild animals from a north-eastern area of the Emilia-Romagna Region, Italy. During post mortem examination, intestine samples were cultured. A statistical analysis demonstrated that there is no correlation between the presence of sub-clinically infected animals and greater human population density. In contrast, a significant correlation between the number of carcasses positive for Salmonella spp. and greater spatial density of pig, poultry, and cattle farms was observed (p animals with omnivorous feeding habits are particularly exposed to Salmonella colonization and, consequently, to spreading the organism. Regarding drug resistance, this study confirms the resistance to antimicrobials is increasing in commensal and environmental isolates.

  12. Response of fish population dynamics to mitigation activities in a large regulated river

    Science.gov (United States)

    Watkins, Carson J.; Ross, Tyler J.; Quist, Michael C.; Hardy, Ryan S.

    2017-01-01

    Extensive water development in large rivers has precipitated many negative ecological effects on native fish populations. Mitigation for such development often focuses on restoring biological integrity through remediation of the physical and chemical properties of regulated rivers. However, evaluating and defining the success of those programs can be difficult. We modeled the influence of mitigation-related environmental factors on growth and recruitment of two ecologically important native fish species (Largescale Sucker Catostomus macrocheilus and Mountain Whitefish Prosopium williamsoni) in the Kootenai River, Idaho. Artificial nutrient (phosphorus) addition best predicted the variability in annual growth of both species. Nutrient addition was positively related to Largescale Sucker growth but negatively related to Mountain Whitefish growth. The best model explained 82% of the annual variability in incremental growth for Largescale Suckers and 61% of the annual variability for Mountain Whitefish. Year-class strength of Largescale Suckers was not closely related to any of the environmental variables evaluated; however, year-class strength of Mountain Whitefish was closely associated with nutrient addition, discharge, and temperature. Most research has focused on biotic assemblages to evaluate the effects of mitigation activities on fishes, but there is an increased need to identify the influence of rehabilitation activities on fish population dynamics within those assemblages. Here, we demonstrate how fish growth can serve as an indicator of rehabilitation success in a highly regulated large river. Future fish restoration projects can likely benefit from a change in scope and from consideration of an evaluation framework involving the response of population rate functions to mitigation.

  13. Importance of the habitat choice behavior assumed when modeling the effects of food and temperature on fish populations

    Science.gov (United States)

    Wildhaber, Mark L.; Lamberson, Peter J.

    2004-01-01

    Various mechanisms of habitat choice in fishes based on food and/or temperature have been proposed: optimal foraging for food alone; behavioral thermoregulation for temperature alone; and behavioral energetics and discounted matching for food and temperature combined. Along with development of habitat choice mechanisms, there has been a major push to develop and apply to fish populations individual-based models that incorporate various forms of these mechanisms. However, it is not known how the wide variation in observed and hypothesized mechanisms of fish habitat choice could alter fish population predictions (e.g. growth, size distributions, etc.). We used spatially explicit, individual-based modeling to compare predicted fish populations using different submodels of patch choice behavior under various food and temperature distributions. We compared predicted growth, temperature experience, food consumption, and final spatial distribution using the different models. Our results demonstrated that the habitat choice mechanism assumed in fish population modeling simulations was critical to predictions of fish distribution and growth rates. Hence, resource managers who use modeling results to predict fish population trends should be very aware of and understand the underlying patch choice mechanisms used in their models to assure that those mechanisms correctly represent the fish populations being modeled.

  14. An integrative approach to assess ecological risks of surface water contamination for fish populations.

    Science.gov (United States)

    Santos, Raphael; Joyeux, Aude; Besnard, Aurélien; Blanchard, Christophe; Halkett, Cédric; Bony, Sylvie; Sanchez, Wilfried; Devaux, Alain

    2017-01-01

    Contamination of aquatic ecosystems is considered as one of the main threats to global freshwater biodiversity. Within the European Water Framework Directive (EU-WFD) a particular attention is dedicated to assess ecological risks of surface water contamination and mitigation of chemical pressures on aquatic ecosystems. In this work, we evaluated ecological risks of surface water contamination for fish populations in four EU-WFD rivers through an integrative approach investigating three Lines of Evidence (chemical contamination, biomarker responses as early warning signals of contamination impacting individuals and ecological analyses as an indicator of fish community disturbances). This work illustrates through 4 case studies the complementary role of biomarkers, chemical and ecological analyses which, used in combination, provide fundamental information to understand impacts of chemical pressures that can affect fish population dynamics. We discuss the limitations of this approach and future improvements needed within the EU-WFD to assess ecological risk of river contamination for fish populations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. The effects of adult sex ratio on mating competition in male and female guppies (Poecilia reticulata) in two wild populations.

    Science.gov (United States)

    Chuard, Pierre J C; Brown, Grant E; Grant, James W A

    2016-08-01

    When competing for mates, males typically exhibit higher rates of intrasexual aggression and courtship than females. Operational sex ratio, represented here by adult sex ratio (ASR) as a proxy, is likely the best predictor of this competition, which typically increases between members of one sex as members of the opposite sex become rarer. Moreover, in populations subject to high predation, males often decrease mating competitive behaviour due to predation risk. We explored the combined effects of ASR and population of origin (low vs. high ambient predation risk) on mating competition in male and female wild-caught Trinidadian guppies. Both male and female aggression rates increased with ASR, but the increase for males was only significant in the low-predation population. In regard to male mating tactics, courtship propensity was unaffected by ASR, while the propensity to sneak increased at male-biased ASRs. Guppies from a high predation population had lower aggression rates than their low predation counterpart, but male courtship and sneaking attempts did not differ between populations. Surprisingly, females were just as aggressive as males when competing for mates. These results highlight the trade-offs between antipredator and agonistic behaviour, which may affect sexual selection pressures in wild populations. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Population genomics of marine fishes: next-generation prospects and challenges.

    Science.gov (United States)

    Hemmer-Hansen, Jakob; Therkildsen, Nina Overgaard; Pujolar, José Martin

    2014-10-01

    Over the past few years, technological advances have facilitated giant leaps forward in our ability to generate genome-wide molecular data, offering exciting opportunities for gaining new insights into the ecology and evolution of species where genomic information is still limited. Marine fishes are valuable organisms for advancing our understanding of evolution on historical and contemporary time scales, and here we highlight areas in which research on these species is likely to be particularly important in the near future. These include possibilities for gaining insights into processes on ecological time scales, identifying genomic signatures associated with population divergence under gene flow, and determining the genetic basis of phenotypic traits. We also consider future challenges pertaining to the implementation of genome-wide coverage through next-generation sequencing and genotyping methods in marine fishes. Complications associated with fast decay of linkage disequilibrium, as expected for species with large effective population sizes, and the possibility that adaptation is associated with both soft selective sweeps and polygenic selection, leaving complex genomic signatures in natural populations, are likely to challenge future studies. However, the combination of high genome coverage and new statistical developments offers promising solutions. Thus, the next generation of studies is likely to truly facilitate the transition from population genetics to population genomics in marine fishes. This transition will advance our understanding of basic evolutionary processes and will offer new possibilities for conservation and management of valuable marine resources. © 2014 Marine Biological Laboratory.

  17. Context dependency of trait repeatability and its relevance for management and conservation of fish populations

    Science.gov (United States)

    Killen, S. S.; Adriaenssens, B.; Marras, S.; Claireaux, G.; Cooke, S. J.

    2016-01-01

    Repeatability of behavioural and physiological traits is increasingly a focus for animal researchers, for which fish have become important models. Almost all of this work has been done in the context of evolutionary ecology, with few explicit attempts to apply repeatability and context dependency of trait variation toward understanding conservation-related issues. Here, we review work examining the degree to which repeatability of traits (such as boldness, swimming performance, metabolic rate and stress responsiveness) is context dependent. We review methods for quantifying repeatability (distinguishing between within-context and across-context repeatability) and confounding factors that may be especially problematic when attempting to measure repeatability in wild fish. Environmental factors such temperature, food availability, oxygen availability, hypercapnia, flow regime and pollutants all appear to alter trait repeatability in fishes. This suggests that anthropogenic environmental change could alter evolutionary trajectories by changing which individuals achieve the greatest fitness in a given set of conditions. Gaining a greater understanding of these effects will be crucial for our ability to forecast the effects of gradual environmental change, such as climate change and ocean acidification, the study of which is currently limited by our ability to examine trait changes over relatively short time scales. Also discussed are situations in which recent advances in technologies associated with electronic tags (biotelemetry and biologging) and respirometry will help to facilitate increased quantification of repeatability for physiological and integrative traits, which so far lag behind measures of repeatability of behavioural traits. PMID:27382470

  18. Context dependency of trait repeatability and its relevance for management and conservation of fish populations.

    Science.gov (United States)

    Killen, S S; Adriaenssens, B; Marras, S; Claireaux, G; Cooke, S J

    2016-01-01

    Repeatability of behavioural and physiological traits is increasingly a focus for animal researchers, for which fish have become important models. Almost all of this work has been done in the context of evolutionary ecology, with few explicit attempts to apply repeatability and context dependency of trait variation toward understanding conservation-related issues. Here, we review work examining the degree to which repeatability of traits (such as boldness, swimming performance, metabolic rate and stress responsiveness) is context dependent. We review methods for quantifying repeatability (distinguishing between within-context and across-context repeatability) and confounding factors that may be especially problematic when attempting to measure repeatability in wild fish. Environmental factors such temperature, food availability, oxygen availability, hypercapnia, flow regime and pollutants all appear to alter trait repeatability in fishes. This suggests that anthropogenic environmental change could alter evolutionary trajectories by changing which individuals achieve the greatest fitness in a given set of conditions. Gaining a greater understanding of these effects will be crucial for our ability to forecast the effects of gradual environmental change, such as climate change and ocean acidification, the study of which is currently limited by our ability to examine trait changes over relatively short time scales. Also discussed are situations in which recent advances in technologies associated with electronic tags (biotelemetry and biologging) and respirometry will help to facilitate increased quantification of repeatability for physiological and integrative traits, which so far lag behind measures of repeatability of behavioural traits.

  19. Population structure and recruitment of the ectoparasite Argulus coregoni Thorell (Crustacea: Branchiura) on a fish farm.

    Science.gov (United States)

    Hakalahti, T; Valtonen, E T

    2003-07-01

    The population structure and recruitment of Argulus coregoni was monitored at a Finnish fish farm during the open water periods of 1999 and 2001 by weekly sampling of attached argulids. In 2001 the numbers of rainbow trout examined increased in the autumn when the A. coregoni population was declining. When the water temperature exceeded 10 degrees C, at the end of May, A. coregoni egg hatching commenced. A mean number of 98 (S.D. +/- 5.4) juvenile A. coregoni was recorded on each fish, before the start of female egg laying in July 1999. The abundance of lice was lower in 2001. The main recruitment of A. coregoni juveniles occurred in early summer, but the hatching of eggs continued until September. However, no pulses of hatching were recorded later in the summer and the numbers of lice on fish substantially decreased after mid-July in both years. On average, only 0.6 (S.D. +/- 0.72) parasites/fish were found between August and late October 2001 and none in November. We suggest that there is 1 main A. coregoni generation annually in Central Finland. Environmental conditions, especially temperature, affects the population cycle of A. coregoni: we found a more synchronous and intense population cycle during the summer 1999, when the early summer was warmer than in 2001. The overall sex ratio (female:male) of A. coregoni was nearly 1:1 in June 1999, but was male biased (1:1.4) in June 2001. It was also shown that from July onwards, many females detached from the fish host in order to lay their eggs on the bottom of the pond. Large males were often bigger than the largest females between mid-July and early September 2001, when as many as 3.7 (s.r. +/- 1.48) times more males than females were present in the lice samples.

  20. Narcissus late season yellows virus and Vallota speciosa virus found infecting domestic and wild populations of Narcissus species in Australia.

    Science.gov (United States)

    Wylie, S J; Nouri, S; Coutts, B A; Jones, M G K

    2010-07-01

    Isolates of Narcissus late season yellows virus (NLSYV) were identified from domestic and wild Narcissus populations at incidences of 66 and 49%, respectively. NLSYV was also detected in one plant of Clivea miniata. Comparisons of nucleotide and amino acid sequences of the coat protein genes of NLSYV isolates showed that they formed three distinct phylogenetic groups, including one not seen before. Vallota speciosa virus was detected in one domestic population of Narcissus sp. where it infected 70% of the plants. This is the first report of these viruses in Australia, and of NLSYV infecting C. miniata.

  1. Molecular epidemiology reveals emergence of a virulent infectious hematopoietic necrosis (IHN) virus strain in wild salmon and its transmission to hatchery fish

    Science.gov (United States)

    Anderson, Eric D.; Engelking, H. Mark; Emmenegger, Eveline J.; Kurath, Gael

    2000-01-01

    Infectious hematopoietic necrosis virus (IHNV) has been known to be a significant salmonid pathogen in the Pacific Northwest of North America for decades. The goal of this study was to characterize the IHNV genetic heterogeneity and viral traffic over time at a study site in the Deschutes River watershed in Oregon, with an emphasis on the epidemiology of IHNV types causing epidemics in wild kokanee Oncorhynchus nerkabetween 1991 and 1995. The study site included kokanee spawning grounds in the Metolius River and Lake Billy Chinook downstream, in which the IHNV epidemics occurred in 2- and 3-year-old kokanee, and the Round Butte Fish Hatchery at the outflow of the lake. Forty-two IHNV isolates collected from this area between 1975 and 1995 were characterized on a genetic basis by ribonuclease (RNase) protection fingerprint analyses of the virus nucleocapsid, glycoprotein, and nonvirion genes. Analysis of the 16 identified composite haplotypes suggested that both virus evolution and introduction of new IHNV strains contributed to the genetic diversity observed. The results indicated that the 1991–1995 epidemics in kokanee from Lake Billy Chinook were due to a newly introduced IHNV type that was first detected in spawning adult kokanee in 1988 and that this virus type was transmitted from the wild kokanee to hatchery fish downstream in 1991. Twelve IHNV haplotypes were found at Round Butte Fish Hatchery, indicating a series of virus displacement events during the 20-year period examined. This work shows that IHNV traffic can be much more complex than was previously recognized, and the results have implications for fisheries management at the hatchery and throughout the watershed.

  2. Senescence or selective disappearance? Age trajectories of body mass in wild and captive populations of a small-bodied primate

    Science.gov (United States)

    Hämäläinen, Anni; Dammhahn, Melanie; Aujard, Fabienne; Eberle, Manfred; Hardy, Isabelle; Kappeler, Peter M.; Perret, Martine; Schliehe-Diecks, Susanne; Kraus, Cornelia

    2014-01-01

    Classic theories of ageing consider extrinsic mortality (EM) a major factor in shaping longevity and ageing, yet most studies of functional ageing focus on species with low EM. This bias may cause overestimation of the influence of senescent declines in performance over condition-dependent mortality on demographic processes across taxa. To simultaneously investigate the roles of functional senescence (FS) and intrinsic, extrinsic and condition-dependent mortality in a species with a high predation risk in nature, we compared age trajectories of body mass (BM) in wild and captive grey mouse lemurs (Microcebus murinus) using longitudinal data (853 individuals followed through adulthood). We found evidence of non-random mortality in both settings. In captivity, the oldest animals showed senescence in their ability to regain lost BM, whereas no evidence of FS was found in the wild. Overall, captive animals lived longer, but a reversed sex bias in lifespan was observed between wild and captive populations. We suggest that even moderately condition-dependent EM may lead to negligible FS in the wild. While high EM may act to reduce the average lifespan, this evolutionary process may be counteracted by the increased fitness of the long-lived, high-quality individuals. PMID:25100693

  3. Probabilistic estimation of dietary exposure of the general Japanese population to dioxins in fish, using region-specific fish monitoring data.

    Science.gov (United States)

    Cao, Hongbin; Suzuki, Noriyuki; Sakurai, Takeo; Matsuzaki, Kanae; Shiraishi, Hiroaki; Morita, Masatoshi

    2008-05-01

    Many studies show that dietary consumption of fish is the greatest contributor to dioxin exposure of humans in Japan. To establish a link between ocean contamination and human exposure to dioxins in fish, we proposed a method of estimating exposure by integrating region-specific measured concentrations of dioxins in fish samples and information on the production and import-export volumes of fish. The advantage over "total diet studies" (TDS) was that the proposed method could analyze the impact of the geographical variability of ocean contamination on human exposure to dioxins in fish; this may help us to apply more effective measures against dioxin exposure. Probabilistic distributions (probability density functions (PDFs)) were assigned to express the variability in the results of monitoring dioxin concentrations in fish from coastal areas divided according to prefecture, and from offshore and distant waters and imported sources. The Monte Carlo technique was applied for probabilistic estimation of dietary exposure of the general Japanese population to dioxins in fish. The mean and 5th to 95th percentile range of dietary exposure were estimated, respectively, as 67.12 and 22.65-184.35 pg toxic equivalent per day. Sensitivity analysis showed that some specific coastal areas with higher dioxin levels in fish and some with larger production volumes of fish impacted more than others to total exposure and may thus attract priority in the implementation of dioxin abatement measures.

  4. Evaluating genetic traceability methods for captive-bred marine fish and their applications in fisheries management and wildlife forensics

    DEFF Research Database (Denmark)

    Bylemans, Jonas; Maes, Gregory E.; Diopere, Eveline

    2016-01-01

    -bred and wild fish may affect the ecological and/or genetic integrity of wild fish populations. Unambiguous identification tools for captive-bred fish will be highly valuable to manage risks (fisheries management) and tracing of escapees and seafood products (wildlife forensics). Using single nucleotide...... to monitor the effects of deliberate releases of captive-bred fish on wild populations. Population assignment proved to be more efficient after several generations of captive breeding, which makes it a useful method in forensic applications for well-established aquaculture species. We suggest...

  5. Evolution under domestication: ongoing artificial selection and divergence of wild and managed Stenocereus pruinosus (Cactaceae) populations in the Tehuacan Valley, Mexico.

    Science.gov (United States)

    Parra, Fabiola; Casas, Alejandro; Peñaloza-Ramírez, Juan Manuel; Cortés-Palomec, Aurea C; Rocha-Ramírez, Víctor; González-Rodríguez, Antonio

    2010-09-01

    The Tehuacán Valley in Mexico is a principal area of plant domestication in Mesoamerica. There, artificial selection is currently practised on nearly 120 native plant species with coexisting wild, silvicultural and cultivated populations, providing an excellent setting for studying ongoing mechanisms of evolution under domestication. One of these species is the columnar cactus Stenocereus pruinosus, in which we studied how artificial selection is operating through traditional management and whether it has determined morphological and genetic divergence between wild and managed populations. Semi-structured interviews were conducted with 83 households of three villages to investigate motives and mechanisms of artificial selection. Management effects were studied by comparing variation patterns of 14 morphological characters and population genetics (four microsatellite loci) of 264 plants from nine wild, silvicultural and cultivated populations. Variation in fruit characters was recognized by most people, and was the principal target of artificial selection directed to favour larger and sweeter fruits with thinner or thicker peel, fewer spines and pulp colours other than red. Artificial selection operates in agroforestry systems favouring abundance (through not felling plants and planting branches) of the preferred phenotypes, and acts more intensely in household gardens. Significant morphological divergence between wild and managed populations was observed in fruit characters and plant vigour. On average, genetic diversity in silvicultural populations (H(E) = 0.743) was higher than in wild (H(E) = 0.726) and cultivated (H(E) = 0.700) populations. Most of the genetic variation (90.58 %) occurred within populations. High gene flow (Nm(FST) > 2) was identified among almost all populations studied, but was slightly limited by mountains among wild populations, and by artificial selection among wild and managed populations. Traditional management of S. pruinosus involves

  6. Evolution under domestication: ongoing artificial selection and divergence of wild and managed Stenocereus pruinosus (Cactaceae) populations in the Tehuacán Valley, Mexico

    Science.gov (United States)

    Parra, Fabiola; Casas, Alejandro; Peñaloza-Ramírez, Juan Manuel; Cortés-Palomec, Aurea C.; Rocha-Ramírez, Víctor; González-Rodríguez, Antonio

    2010-01-01

    Background and Aims The Tehuacán Valley in Mexico is a principal area of plant domestication in Mesoamerica. There, artificial selection is currently practised on nearly 120 native plant species with coexisting wild, silvicultural and cultivated populations, providing an excellent setting for studying ongoing mechanisms of evolution under domestication. One of these species is the columnar cactus Stenocereus pruinosus, in which we studied how artificial selection is operating through traditional management and whether it has determined morphological and genetic divergence between wild and managed populations. Methods Semi-structured interviews were conducted with 83 households of three villages to investigate motives and mechanisms of artificial selection. Management effects were studied by comparing variation patterns of 14 morphological characters and population genetics (four microsatellite loci) of 264 plants from nine wild, silvicultural and cultivated populations. Key Results Variation in fruit characters was recognized by most people, and was the principal target of artificial selection directed to favour larger and sweeter fruits with thinner or thicker peel, fewer spines and pulp colours others than red. Artificial selection operates in agroforestry systems favouring abundance (through not felling plants and planting branches) of the preferred phenotypes, and acts more intensely in household gardens. Significant morphological divergence between wild and managed populations was observed in fruit characters and plant vigour. On average, genetic diversity in silvicultural populations (HE = 0·743) was higher than in wild (HE = 0·726) and cultivated (HE = 0·700) populations. Most of the genetic variation (90·58 %) occurred within populations. High gene flow (NmFST > 2) was identified among almost all populations studied, but was slightly limited by mountains among wild populations, and by artificial selection among wild and managed populations. Conclusions

  7. Insights into the mechanisms underlying mercury-induced oxidative stress in gills of wild fish (Liza aurata) combining {sup 1}H NMR metabolomics and conventional biochemical assays

    Energy Technology Data Exchange (ETDEWEB)

    Cappello, Tiziana, E-mail: tcappello@unime.it [Department of Biological and Environmental Sciences, University of Messina, 98166 Messina (Italy); Brandão, Fátima, E-mail: fatimabrandao@ua.pt [Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro (Portugal); Guilherme, Sofia; Santos, Maria Ana [Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro (Portugal); Maisano, Maria; Mauceri, Angela [Department of Biological and Environmental Sciences, University of Messina, 98166 Messina (Italy); Canário, João [Centro de Química Estrutural, Instítuto Superíor Técnico, Universidade de Lisboa, 1049-001 Lisbon (Portugal); Pacheco, Mário; Pereira, Patrícia [Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro (Portugal)

    2016-04-01

    be sensitive and effective towards a mechanistically based assessment of Hg toxicity in gills of wild fish, providing new insights into the toxicological pathways underlying the oxidative stress. - Highlights: • Mercury-induced oxidative stress was investigated in gills of wild fish Liza aurata. • {sup 1}H NMR-based metabolomics and oxidative stress biomarkers were applied. • Hg interfered with the antioxidant protection but lipid peroxidation was prevented. • Activation of membrane repair processes suggested cell membrane ability to recover. • The combined approach is a sensitive and effective tool in ecotoxicological studies.

  8. Indicators of the ‘wild seafood’ provisioning ecosystem service based on the surplus production of commercial fish stocks

    NARCIS (Netherlands)

    Piet, G.J.; Overzee, van H.M.J.; Miller, D.C.M.; Gelabert, E.R.

    2017-01-01

    The ‘Wild Seafood’ Provisioning Service (WSPS), on which commercial fisheries rely, is probably one of the best studied marine ecosystem services due to its economic relevance and because extensive information sources exist for assessment purposes. Yet, the indicators often proposed are not

  9. Chemical Composition of Juniperus communis L. Cone Essential Oil and Its Variability among Wild Populations in Kosovo.

    Science.gov (United States)

    Hajdari, Avni; Mustafa, Behxhet; Nebija, Dashnor; Miftari, Elheme; Quave, Cassandra L; Novak, Johannes

    2015-11-01

    Ripe cones of Juniperus communis L. (Cupressaceae) were collected from five wild populations in Kosovo, with the aim of investigating the chemical composition and natural variation of essential oils between and within wild populations. Ripe cones were collected, air dried, crushed, and the essential oils obtained by hydrodistillation. The essential-oil constituents were identified by GC-FID and GC/MS analyses. The yield of essential oil differed depending on the population origins and ranged from 0.4 to 3.8% (v/w, based on the dry weight). In total, 42 compounds were identified in the essential oils of all populations. The principal components of the cone-essential oils were α-pinene, followed by β-myrcene, sabinene, and D-limonene. Taking into consideration the yield and chemical composition, the essential oil originating from various collection sites in Kosovo fulfilled the minimum requirements for J. communis essential oils of the European Pharmacopoeia. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) were used to determine the influence of the geographical variations on the essential-oil composition. These statistical analyses suggested that the clustering of populations was not related to their geographic location, but rather appeared to be linked to local selective forces acting on the chemotype diversity. Copyright © 2015 Verlag Helvetica Chimica Acta AG, Zürich.

  10. Population Structure of Rat-Derived Pneumocystis carinii in Danish Wild Rats

    DEFF Research Database (Denmark)

    Palmer, Robert J.; Settnes, Osvald P.; Lodal, Jens

    2000-01-01

    The rat model of Pneumocystis carinii pneumonia is frequently used to study human P. carinii infection, but there are many differences between the rat and human infections. We studied naturally acquired P. carinii in wild rats to examine the relevance of the rat model for human infection. P. cari...

  11. Fungal Endophytes of Wild Barley and their Effects on Diuraphis noxia Population Development

    Science.gov (United States)

    S.L. Clement; A. Dan Wilson; D.G. Lester; C.M. Davitt

    1997-01-01

    Laboratory experiments were conducted to compare the expression of Diuraphis noxia (Mordvilko) (Homoptera: Aphididae) resistance in four plant introduction (PI) lines of wild barley (Hordeum) infected with different species or strains of endophytic fungi (tribe Balansieae, family Clavicipitaceae, Neotyphodium gen. nov. [formerly...

  12. A moving target--incorporating knowledge of the spatial ecology of fish into the assessment and management of freshwater fish populations.

    Science.gov (United States)

    Cooke, Steven J; Martins, Eduardo G; Struthers, Daniel P; Gutowsky, Lee F G; Power, Michael; Doka, Susan E; Dettmers, John M; Crook, David A; Lucas, Martyn C; Holbrook, Christopher M; Krueger, Charles C

    2016-04-01

    Freshwater fish move vertically and horizontally through the aquatic landscape for a variety of reasons, such as to find and exploit patchy resources or to locate essential habitats (e.g., for spawning). Inherent challenges exist with the assessment of fish populations because they are moving targets. We submit that quantifying and describing the spatial ecology of fish and their habitat is an important component of freshwater fishery assessment and management. With a growing number of tools available for studying the spatial ecology of fishes (e.g., telemetry, population genetics, hydroacoustics, otolith microchemistry, stable isotope analysis), new knowledge can now be generated and incorporated into biological assessment and fishery management. For example, knowing when, where, and how to deploy assessment gears is essential to inform, refine, or calibrate assessment protocols. Such information is also useful for quantifying or avoiding bycatch of imperiled species. Knowledge of habitat connectivity and usage can identify critically important migration corridors and habitats and can be used to improve our understanding of variables that influence spatial structuring of fish populations. Similarly, demographic processes are partly driven by the behavior of fish and mediated by environmental drivers. Information on these processes is critical to the development and application of realistic population dynamics models. Collectively, biological assessment, when informed by knowledge of spatial ecology, can provide managers with the ability to understand how and when fish and their habitats may be exposed to different threats. Naturally, this knowledge helps to better evaluate or develop strategies to protect the long-term viability of fishery production. Failure to understand the spatial ecology of fishes and to incorporate spatiotemporal data can bias population assessments and forecasts and potentially lead to ineffective or counterproductive management actions.

  13. A moving target—incorporating knowledge of the spatial ecology of fish into the assessment and management of freshwater fish populations

    Science.gov (United States)

    Cooke, Steven J.; Martins, Eduardo G; Struthers, Daniel P; Gutowsky, Lee F G; Powers, Michael H.; Doka, Susan E; Dettmers, John M.; Crook, David A; Lucas, Martyn C.; Holbrook, Christopher; Krueger, Charles C.

    2016-01-01

    Freshwater fish move vertically and horizontally through the aquatic landscape for a variety of reasons, such as to find and exploit patchy resources or to locate essential habitats (e.g., for spawning). Inherent challenges exist with the assessment of fish populations because they are moving targets. We submit that quantifying and describing the spatial ecology of fish and their habitat is an important component of freshwater fishery assessment and management. With a growing number of tools available for studying the spatial ecology of fishes (e.g., telemetry, population genetics, hydroacoustics, otolith microchemistry, stable isotope analysis), new knowledge can now be generated and incorporated into biological assessment and fishery management. For example, knowing when, where, and how to deploy assessment gears is essential to inform, refine, or calibrate assessment protocols. Such information is also useful for quantifying or avoiding bycatch of imperiled species. Knowledge of habitat connectivity and usage can identify critically important migration corridors and habitats and can be used to improve our understanding of variables that influence spatial structuring of fish populations. Similarly, demographic processes are partly driven by the behavior of fish and mediated by environmental drivers. Information on these processes is critical to the development and application of realistic population dynamics models. Collectively, biological assessment, when informed by knowledge of spatial ecology, can provide managers with the ability to understand how and when fish and their habitats may be exposed to different threats. Naturally, this knowledge helps to better evaluate or develop strategies to protect the long-term viability of fishery production. Failure to understand the spatial ecology of fishes and to incorporate spatiotemporal data can bias population assessments and forecasts and potentially lead to ineffective or counterproductive management actions.

  14. High population density enhances recruitment and survival of a harvested coral reef fish.

    Science.gov (United States)

    Wormald, Clare L; Steele, Mark A; Forrester, Graham E

    2013-03-01

    A negative relationship between population growth and population density (direct density dependence) is necessary for population regulation and is assumed in most models of harvested populations. Experimental tests for density dependence are lacking for large-bodied, harvested fish because of the difficulty of manipulating population density over large areas. We studied a harvested coral reef fish, Lutjanus apodus (schoolmaster snapper), using eight large, isolated natural reefs (0.4-1.6 ha) in the Bahamas as replicates. An initial observational test for density dependence was followed by a manipulation of population density. The manipulation weakened an association between density and shelter-providing habitat features and revealed a positive effect of population density on recruitment and survival (inverse density dependence), but no effect of density on somatic growth. The snappers on an individual reef were organized into a few shoals, and we hypothesize that large shoals on high-density reefs were less vulnerable to large piscivores (groupers and barracudas) than the small shoals on low-density reefs. Reductions in predation risk for individuals in large social groups are well documented, but because snapper shoals occupied reefs the size of small marine reserves, these ecological interactions may influence the outcome of management actions.

  15. Plasma vitellogenin in male teleost fish from 43 rivers worldwide is correlated with upstream human population size

    Energy Technology Data Exchange (ETDEWEB)

    Desforges, Jean-Pierre W.; Peachey, Brendan D.L.; Sanderson, Pauline M. [Department of Biology, University of Ottawa, 30 Marie Curie Street, K1N 6N5, Ottawa, Ontario (Canada); White, Paul A. [Environmental Health Sciences and Research Bureau, Health Canada, Ottawa, Ontario (Canada); Blais, Jules M., E-mail: jules.blais@uottawa.c [Department of Biology, University of Ottawa, 30 Marie Curie Street, K1N 6N5, Ottawa, Ontario (Canada)

    2010-10-15

    It has been previously demonstrated that vitellogenin (VTG) - a precursor egg yolk protein - is produced in male fish exposed to estrogenic compounds in wastewater treatment plant (WWTP) effluent. However, little attention has been given to examine whether any patterns of male VTG production exists across fish species on a global scale. We hypothesized that a composite measure of human population size over river discharge would best explain variations of protein levels in male fish. We compiled VTG data in 13 fish species from 43 rivers receiving municipal WWTP effluent on 3 continents. We found that human population size explained 28% of the variation in male VTG concentrations, whereas population/flow rate failed to significantly correlate with VTG. We suggest this result may be explained by the low solubility of estrogenic compounds, resulting in localized contamination near WWTP outfalls, rather than dilution by river water. - Concentrations of vitellogenin in riverine teleost fish were related to population size.

  16. Phenotypic plasticity of Vaccinium meridionale (Ericaceae in wild populations of mountain forests in Colombia

    Directory of Open Access Journals (Sweden)

    Gustavo A Ligarreto

    2011-06-01

    Full Text Available Vaccinium meridionale is a promising crop for the Andean region of South America and is currently available only in the wild. Spontaneous populations of this plant are found across the Colombian mountains, but very few published records on this plant morphology are available. A zonification study of V. meridionale was conducted in four principal areas of a low mountain forest of Colombia (Provinces of Boyacá, Cundinamarca, Santander and Nariño in 2007. A total of 20 populations and 100 plants of V. meridionale were individually characterized and surveyed, using a list of 26 characters of morphological variables (9 quantitative and 17 qualitative characters. Our results indicated that natural populations of V. meridionale might be found in the tropical forest under a highly heterogeneous climate and microclimate conditions, at different mountain regions between 2 357 and 3 168masl. The shrubs of V. meridionale exhibited a high level of intra-population variation in several quantitative (plant height, stem diameter and qualitative (growth habit, ramification density, presence of anthocyanins in stems morphological characters, suggesting an environmentally induced phenotypic plasticity. Plant height, stem diameter and foliar density were the most variable morphological traits, with coefficients of variation higher than 50%. However, several quantitative characters of its reproductive potential, such as berry dimensions, rachis length and number of flowers per inflorescence, resulted with low plasticity with coefficients of variation lower than 30.2%, indicating that these characters were genetically determined. The highest correlation coefficients (pVaccinium meridionale es una planta promisoria para la región Andina de Sudamérica y está disponible actualmente sólo en forma silvestre. Las poblaciones espontáneas de esta planta se encuentran en las montañas colombianas y existen muy pocos reportes publicados respecto a su morfología. Se

  17. The prevalence of beak and feather disease virus infection in wild populations of parrots and cockatoos in New Zealand.

    Science.gov (United States)

    Ha, H J; Anderson, I L; Alley, M R; Springett, B P; Gartrell, B D

    2007-10-01

    To determine the prevalence of beak and feather disease virus (BFDV) infection in exotic parrots and cockatoos in the wild in New Zealand. Eastern rosellas (Platycercus eximius, n=162) were caught from Te Puke, Wellington and Dunedin, using mistnets, between April 2004 and February 2006, and sulphur crested cockatoos (Cacatua galerita, n=255) were captured for pet-trading from November 2001 to September 2004. Feathers from both species were tested for BFDV, using an established polymerase chain reaction (PCR) test. Post-mortem examinations were conducted on some of the eastern rosellas, and selected tissues from 24 birds positive for BFDV were examined using routine histological methods for the presence of characteristic inclusion bodies. Of the eastern rosellas, 24/162 (14.8%) were positive for BFDV, and the 95% confidence interval (CI) for true prevalence was estimated as 8.6-20.4%, which varied between regions. Eastern rosellas that were positive for BFDV showed no clinical or histological signs of disease or inclusion bodies. Of the sulphur-crested cockatoos, 70/255 (28%) were positive for BFDV, and the 95% CI for true prevalence was calculated as 22-33%. The surprisingly high prevalence of BFDV in wild eastern rosellas and sulphur-crested cockatoos has serious implications for the conservation of native parrots and the export of wild-trapped parrots and cockatoos from New Zealand. Serological studies for BFDV in wild exotic parrots, and molecular studies of virus genotype, are recommended to further characterise the origin and epidemiology of the disease in populations of wild exotic parrots and cockatoos in New Zealand.

  18. Spatio-temporal genetic variation in populations of wild emmer wheat, Triticum turgidum ssp. dicoccoides, as revealed by AFLP analysis.

    Science.gov (United States)

    Ozbek, O; Millet, E; Anikster, Y; Arslan, O; Feldman, M

    2007-06-01

    Genetic structure of natural populations of wild crop relatives has been the subject of many studies. Yet, most of them focused on the assessment of spatial genetic diversity, while information on long-term variation, affected by yearly changes, has been considered only in few cases. The present study aimed therefore, to estimate the spatio-temporal genetic variation in populations of wild emmer wheat, the progenitor of domesticated wheat, and to assess the contribution of spatial versus temporal factors to the maintenance of genetic variation in a population. Single spikes were collected in the years 1988 and 2002 from plants that grew in the same sampling points, from six different habitats in the Ammiad conservation site, Eastern Galilee, Israel. Seeds were planted in a nursery and DNA was extracted from each plant and analyzed by the AFLP method. Fourteen primer combinations yielded 1,545 bands of which 50.0 and 48.8% were polymorphic in the years 1988 and 2002, respectively. Genetic diversity was much larger within populations than between populations and the temporal genetic diversity was considerably smaller than the spatial one. Nevertheless, population genetic structure may vary to some degree in different years, mainly due to fluctuations in population size because of yearly rainfall variations. This may lead to predominance of different genotypes in different years. Clustering the plants by their genetic distances grouped them according to their habitats, indicating the existence of genotype-environment affinities. The significance of the results in relation to factors affecting the maintenance of polymorphism in natural populations is discussed.

  19. Morphological, physiological and biochemical responses to soil water deficit in seedlings of three populations of wild pear tree (Pyrus boisseriana

    Directory of Open Access Journals (Sweden)

    Zarafshar, M.

    2014-01-01

    Full Text Available Water shortage limits the production of fruit orchards, such as pear, in arid and semi-arid regions. The identification of wild pear germplasm for potential use as rootstock would be valuable for pear cultivation in semi-arid regions. The relative drought tolerance of wild pear germplasm (Pyrus boisseriana from three different populations distributed along an elevational gradient ('semi-arid 1,000', 'semi-wet 1,350' and 'semi-wet 1,600' populations was evaluated in a greenhouse trial. Established container-grown seedlings were exposed to 18 days of simulated drought, or not, followed by a seven day recovery period. Biomass allocation and accumulation, physiological (stomatal conductance, photosynthesis, transpiration, xylem water potential and biochemical parameters (leaf pigments, free proline, malondialdehyde and hydrogen peroxide production were evaluated. Although all populations were able to recover from water shortage, thereby proving to be relatively drought tolerant, some differences between populations were detected for gas exchange parameters, biomass accumulation and proline concentration in favor of the 'semi-arid 1,000' elevation population, which was more drought tolerant. This population showed the most rapid and complete recovery of physiological activity (stomatal conductance and carbon fixation. In addition, all populations showed an increase in carotenoid content in the leaves. Overall, we showed that plants from the 'semi-arid 1,000' elevation had greater tolerance to drought than those from the higher elevations (semi-wet populations. It therefore appears that plants from the 'semi-arid 1,000' elevation represent a promising source of material to be tested as rootstock for commercial scions of pear in field conditions in areas prone to suffer from water deficit.

  20. Distance, dams and drift: What structures populations of an endangered, benthic stream fish?

    Science.gov (United States)

    Roberts, James H.; Angermeier, Paul; Hallerman, Eric M.

    2013-01-01

    Spatial population structure plays an important role in species persistence, evolution and conservation. Benthic stream fishes are diverse and frequently imperilled, yet the determinants and spatial scaling of their population structure are understudied. We investigated the range-wide population genetic structure of Roanoke logperch (Percina rex), an endangered, benthic stream fish of the eastern United States. Fish were sampled from 35 sites and analysed at 11 microsatellite DNA loci. Clustering models were used to sort individuals into genetically cohesive groups and thereby estimate the spatial scaling of population structure. We then used Bayesian generalized linear mixed models (BGLMMs) to test alternative hypotheses about the environmental factors most responsible for generating structure, as measured by the differentiation statistic FST. Clustering models delineated seven discrete populations, whose boundaries coincided with agents of fragmentation, including hydroelectric dams and tailwaters. In the absence of hydrological barriers, gene flow was extensive throughout catchments, whereas there was no evidence for contemporary dispersal between catchments across barriers. In the best-supported BGLMM, FST was positively related to the spatial distance and degree of hydrological alteration between sites and negatively related to genetic diversity within sites. Whereas the effect of tailwaters was equivocal, dams strongly influenced differentiation: the effect of a dam on FST was comparable to that of a between-site distance of over 1200 km of unimpounded river. Overall, the effect of distance-mediated dispersal was negligible compared to the combined effects of fragmentation and genetic drift. The contemporary population structure of P. rex comprises a few geographically extensive ‘islands’ that are fragmented by hydroelectric projects. This information clarifies the importance of a catchment-scale perspective on conserving the species and

  1. Status and trends of prey fish populations in Lake Michigan, 2008

    Science.gov (United States)

    Bunnell, David B.; Madenjian, Charles P.; Holuszko, Jeffrey D.; Desorcie, Timothy J.; Adams, Jean V.

    2009-01-01

    The Great Lakes Science Center (GLSC) has conducted lake-wide surveys of the fish community in Lake Michigan each fall since 1973 using standard 12-m bottom trawls towed along contour at depths of 9 to 110 m at each of seven index transects. The resulting data on relative abundance, size structure, and condition of individual fishes are used to estimate various population parameters that are in turn used by state and tribal agencies in managing Lake Michigan fish stocks. All seven established index transects of the survey were completed in 2008. The survey provides relative abundance and biomass estimates between the 5-m and 114-m depth contours of the lake (herein, lake-wide) for prey fish populations, as well as burbot, yellow perch, and the introduced dreissenid mussels. Lake-wide biomass of alewives in 2008 was estimated at 8.27 kilotonnes (kt) (1 kt = 1000 metric tons), which was the smallest biomass estimate in the entire time series and 29% lower than the 2007 estimate. Lake-wide biomass of bloater in 2008 was estimated at 3.33 kt, which was the lowest estimate since 1977 and 38% lower than the 2007 estimate. Rainbow smelt lake-wide biomass equaled 0.89 kt, which was only 0.01 kt higher than 2007, which is the lowest estimate in the time series. Deepwater sculpin lake-wide biomass equaled 5.23 kt, which is the fourth straight year of declining biomass. The 2008 estimate is the second smallest in the time series, and 39% lower than the 2007 estimate. Slimy sculpin lake-wide biomass remained relatively high in 2008 (2.75 kt), increasing 25% over 2007. Ninespine stickleback lake-wide biomass equaled only 0.50 kt in 2008, which was 79% lower than the 2007 estimate. The final prey fish, exotic round goby, increased two orders of magnitude between 2007 and 2008, from 0.02 to 4.65 kt. Round gobies now represent 18% of the prey fish biomass. Burbot lake-wide biomass (0.91 kt in 2008) has remained fairly constant since 2002. Numeric density of age-0 yellow perch (i

  2. Evaluation of Fish Movements, Migration Patterns and Populations Abundance with Streamwidth PIT Tag Interrogation Systems, Final Report 2002.

    Energy Technology Data Exchange (ETDEWEB)

    Zydlewski, Gayle B.; Casey, Sean

    2003-02-01

    (approximately 5,400). All species used the faster moving/deeper section of the creek at both SPIs. A backpack PIT tag detector was also developed and used as another remote ''recapture'' for additional accuracy in estimating population survival and recapture probability. This unit was used at an approximate efficiency of 24% to survey the creek after the Spring migration. Twenty-five individual fish were re-located. All PIT tag data were used to calculate survival and recapture probabilities using the Cormack-Jolly-Seber population model. Survival for steelhead was high and recapture probability depended greatly on season. Probability of recapture was highest in Spring (29.5%) and relatively low in all other seasons (< 7% in Fall, Winter, and Summer). Wild steelhead PIT tagged in the field and returned to the laboratory had a tag retention rate of 97.6%. A laboratory study was designed to determine the effects of 3-sized PIT tags (12 mm, 20 mm, and 23 mm) on survival and growth of individuals. Survival from surgical implantation of 23 mm PIT tags was > 98% for fish (coho salmon and steelhead). Retention of 23 mm PIT tags was 100% for coho salmon and 89% for steelhead. For both coho and steelhead, growth rates during the first month were affected by tagging, but by the end of 2 months growth effects equalized for all tag sizes. Life history characteristics quantified with SPI techniques are comparable to standard techniques. For example, peaks of Spring migration for steelhead and cutthroat were amazingly similar to those reported from the screw trap. These techniques will enable application of less laborious methods which are more accurate at estimating life history parameters.

  3. Evaluation of Fish Movements, Migration Patterns, and Population Abundance with Streamwidth PIT Tag Interrogation Systems, Final Report 2002.

    Energy Technology Data Exchange (ETDEWEB)

    Zydlewski, Gayle; Winter, Christiane; McClanahan, Dee

    2003-02-01

    (approximately 5,400). All species used the faster moving/deeper section of the creek at both SPIs. A backpack PIT tag detector was also developed and used as another remote 'recapture' for additional accuracy in estimating population survival and recapture probability. This unit was used at an approximate efficiency of 24% to survey the creek after the Spring migration. Twenty-five individual fish were re-located. All PIT tag data were used to calculate survival and recapture probabilities using the Cormack-Jolly-Seber population model. Survival for steelhead was high and recapture probability depended greatly on season. Probability of recapture was highest in Spring (29.5%) and relatively low in all other seasons (< 7% in Fall, Winter, and Summer). Wild steelhead PIT tagged in the field and returned to the laboratory had a tag retention rate of 97.6%. A laboratory study was designed to determine the effects of 3-sized PIT tags (12 mm, 20 mm, and 23 mm) on survival and growth of individuals. Survival from surgical implantation of 23 mm PIT tags was > 98% for fish (coho salmon and steelhead). Retention of 23 mm PIT tags was 100% for coho salmon and 89% for steelhead. For both coho and steelhead, growth rates during the first month were affected by tagging, but by the end of 2 months growth effects equalized for all tag sizes. Life history characteristics quantified with SPI techniques are comparable to standard techniques. For example, peaks of Spring migration for steelhead and cutthroat were amazingly similar to those reported from the screw trap. These techniques will enable application of less laborious methods which are more accurate at estimating life history parameters.

  4. Modulation of the stress response in wild fish is associated with variation in dissolved nitrate and nitrite.

    Science.gov (United States)

    Pottinger, Tom G

    2017-06-01

    Disruption of non-reproductive endocrine systems in wildlife by chemicals has received little attention but represents a potentially significant problem. Nitrate is a major anthropogenic contaminant in the freshwater aquatic environment and has been identified as a potential disrupter of endocrine function in aquatic animals. This study was conducted to investigate the relationship between the function of the neuroendocrine stress axis in fish and inorganic N loading along reaches of rivers receiving cumulative point source and diffuse chemical inputs. To accomplish this, the responsiveness of the stress axis, quantified as the rate of release of cortisol to water across the gills during exposure to a standardised stressor, was measured in three-spined sticklebacks (Gasterosteus aculeatus L.) resident at three sites on each of four rivers in north-west England. The magnitude of the stress response in fish captured at the sites furthest downstream on all rivers was more than twice that of fish captured at upstream sites. Site-specific variation in stress axis reactivity was better explained by between-site variation in concentrations of dissolved nitrate, nitrite, and ammonia than by the concentration of wastewater treatment works effluent. An increase in the magnitude of the stress response was seen among sticklebacks at sites where long-term averaged concentrations of NH3-N, NO3-N and NO2-N exceeded 0.6, 4.0 and 0.1 mg/L respectively. These data suggest that either (i) inorganic N is a better surrogate than wastewater effluent concentration for an unknown factor or factors affecting stress axis function in fish, or (ii) dissolved inorganic N directly exerts a disruptive influence on the function of the neuroendocrine stress axis in fish, supporting concerns that nitrate is an endocrine-modulating chemical. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Widespread endocrine disruption and reproductive impairment in an estuarine fish population exposed to seasonal hypoxia.

    Science.gov (United States)

    Thomas, Peter; Rahman, Md Saydur; Khan, Izhar A; Kummer, James A

    2007-11-07

    The long-term effects on marine fish populations of the recent increase worldwide in the incidence of coastal hypoxia are unknown. Here we show that chronic environmental exposure of Atlantic croaker (Micropogonias undulatus) to hypoxia in a Florida estuary caused marked suppression of ovarian and testicular growth which was accompanied by endocrine disruption. Laboratory hypoxia studies showed that the endocrine disruption was associated with impairment of reproductive neuroendocrine function and decreases in hypothalamic serotonin (5-HT) content and the activity of the 5-HT biosynthetic enzyme, tryptophan hydroxylase. Pharmacological restoration of hypothalamic 5-HT levels also restored neuroendocrine function, indicating that the stimulatory serotonergic neuroendocrine pathway is a major site of hypoxia-induced inhibition. Inhibition of tryptophan hydroxylase activity to downregulate reproductive activity could have evolved as an adaptive mechanism to survive periodic hypoxia, but in view of the recent increased incidence of coastal hypoxia could become maladaptive and potentially affect fish population abundance and threaten valuable fishery resources.

  6. Insights into the mechanisms underlying mercury-induced oxidative stress in gills of wild fish (Liza aurata) combining (1)H NMR metabolomics and conventional biochemical assays.

    Science.gov (United States)

    Cappello, Tiziana; Brandão, Fátima; Guilherme, Sofia; Santos, Maria Ana; Maisano, Maria; Mauceri, Angela; Canário, João; Pacheco, Mário; Pereira, Patrícia

    2016-04-01

    sensitive and effective towards a mechanistically based assessment of Hg toxicity in gills of wild fish, providing new insights into the toxicological pathways underlying the oxidative stress. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. The Impact of Marine Protected Areas on Reef-Wide Population Structure and Fishing-Induced Phenotypes in Coral-Reef Fishes

    Science.gov (United States)

    Fidler, Robert Young, III

    Overfishing and destructive fishing practices threaten the sustainability of fisheries worldwide. In addition to reducing population sizes, anthropogenic fishing effort is highly size-selective, preferentially removing the largest individuals from harvested stocks. Intensive, size-selective mortality induces widespread phenotypic shifts toward the predominance of smaller and earlier-maturing individuals. Fish that reach sexual maturity at smaller size and younger age produce fewer, smaller, and less viable larvae, severely reducing the reproductive capacity of exploited populations. These directional phenotypic alterations, collectively known as "fisheries-induced evolution" (FIE) are among the primary causes of the loss of harvestable fish biomass. Marine protected areas (MPAs) are one of the most widely utilized components of fisheries management programs around the world, and have been proposed as a potential mechanism by which the impacts of FIE may be mitigated. The ability of MPAs to buffer exploited populations against fishing pressure, however, remains debated due to inconsistent results across studies. Additionally, empirical evidence of phenotypic shifts in fishes within MPAs is lacking. This investigation addresses both of these issues by: (1) using a categorical meta-analysis of MPAs to standardize and quantify the magnitude of MPA impacts across studies; and (2) conducting a direct comparison of life-history phenotypes known to be influenced by FIE in six reef-fish species inside and outside of MPAs. The Philippines was used as a model system for analyses due to the country's significance in global marine biodiversity and reliance on MPAs as a fishery management tool. The quantitative impact of Philippine MPAs was assessed using a "reef-wide" meta-analysis. This analysis used pooled visual census data from 39 matched pairs of MPAs and fished reefs surveyed twice over a mean period of 3 years. In 17 of these MPAs, two additional surveys were conducted

  8. Serum apolipoproteins in relation to intakes of fish in population of Arkhangelsk County

    Directory of Open Access Journals (Sweden)

    Petrenya Natalia

    2012-06-01

    Full Text Available Abstract Background Diets rich in omega-3 fatty acids and low in saturated fat were found beneficially associated with blood lipids and cardio-vascular health. Lean reindeer meet and local cold water white-fish species high in omega-3 are among the main sources of nutrients in the rural area of the Nenets Autonomous Okrug (NAO in Russia and are not normally consumed by the urban population from the same region. The aims of the study were firstly, to compare serum lipid profiles of residents of urban (Arkhangelsk city and rural (NAO regions of Arkhangelsk County, and secondly, to investigate the effects of fish consumption on the predictor of cardiovascular events apolipoprotein (Apo B/ApoA-I ratio in these populations. Methods A cross-sectional study conducted in Arkhangelsk County, Russia. Sample size of 249 adults: 132 subjects from Arkhangelsk city, aged 21–70 and 117 subject (87% Ethnic Nenets from NAO, aged 18–69. Results We observed more favorable lipid levels in NAO compared to Arkhangelsk participants. Age-adjusted geometric means of ApoB/ApoA-I ratio were 1.02 and 0.98 in men and women from Arkhangelsk; 0.84 and 0.91 in men and women from NAO respectively. Age and consumption of animal fat were positively associated with ApoB/ApoA-I ratio in women (pooled samples from Arkhangelsk and NAO. Body mass index and low levels of physical activity were positively associated with ApoB/ApoA-I ratio in men (pooled samples from Arkhangelsk and NAO. Reported oily fish consumption was not significantly correlated with ApoB/ApoA-I ratio. Conclusion The population sample from rural NAO, consisting largely of the indigenous Arctic population Nenets with healthier dietary sources, had a relatively less atherogenic lipid profile compared to the urban Arkhangelsk group. Fish consumption had no effect on apolipoproteins profile.

  9. Genetic differentiation, effective population size and gene flow in marine fishes : implications for stock management

    OpenAIRE

    Jose M., CANO; Takahito, Shikano; Anna, KUPARINEN; Juha, MERILA; Ecological Genetics Research Unit, Department of Bio- and Environmental Sciences

    2008-01-01

    Many commercially exploited marine fish and mollusc species exhibit no or a low degree of genetic differentiation in neutral marker genes. This lack of genetic differentiation, typically attributed to high degree of gene flow in marine environments, has sometimes supported the thinking that genetically indistinguishable stocks can be managed as being one panmictic population. Recent comparative studies of neutral marker gene and quantitative trait differentiation in a wide variety of taxa - i...

  10. Long telomeres are associated with clonality in wild populations of the fissiparous starfish Coscinasterias tenuispina

    OpenAIRE

    García-Cisneros, Álex; Pérez-Portela, R.; Almroth, B. C.; Degerman, S; Palacín, Carlos; Sköld, H Nilsson

    2015-01-01

    Telomeres usually shorten during an organism’s lifespan and have thus been used as an aging and health marker. When telomeres become sufficiently short, senescence is induced. The most common method of restoring telomere length is via telomerase reverse transcriptase activity, highly expressed during embryogenesis. However, although asexual reproduction from adult tissues has an important role in the life cycles of certain species, its effect on the aging and fitness of wild populati...

  11. Environmental heterogeneity and the evolution of plant-virus interactions: Viruses in wild pepper populations.

    Science.gov (United States)

    Fraile, Aurora; McLeish, Michael J; Pagán, Israel; González-Jara, Pablo; Piñero, Daniel; García-Arenal, Fernando

    2017-09-15

    Understanding host-pathogen interactions requires analyses to address the multiplicity of scales in heterogeneous landscapes. Anthropogenic influence on plant communities, especially cultivation, is a major cause of environmental heterogeneity. We have approached the analysis of how environmental heterogeneity determines plant-virus interactions by studying virus infection in a wild plant currently undergoing incipient domestication, the wild pepper or chiltepin, across its geographical range in Mexico. We have shown previously that anthropogenic disturbance is associated with higher infection and disease risk, and with disrupted patterns of host and virus genetic spatial structure. We now show that anthropogenic factors, species richness, host genetic diversity and density in communities supporting chiltepin differentially affect infection risk according to the virus analysed. We also show that in addition to these factors, a broad range of abiotic and biotic variables meaningful to continental scales, have an important role on the risk of infection depending on the virus. Last, we show that natural virus infection of chiltepin plants in wild communities results in decreased survival and fecundity, hence negatively affecting fitness. This important finding paves the way for future studies on plant-virus co-evolution. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Connectivity of microbial populations in coral reef environments: microbiomes of sediment, fish and water

    Science.gov (United States)

    Biddle, J.; Leon, Z. R.; McCargar, M.; Drew, J.

    2016-12-01

    The benthic environments of coral reefs are heavily shaped by physiochemical factors, but also the ecological interactions of the animals and plants in the reef ecosystem. Microbial populations may be shared between the ecosystem of sediments, seagrasses and reef fish, however it is unknown to what degree. We investigated the potential connections between the microbiomes of sediments, seagrass blades and roots (Syringodium isoetifolium), Surgeonfish (A. nigricauda, Acanthurinae sp. unknown, C. striatus) and Parrotfish (C. spinidens) guts in reef areas of Fiji. We contrasted these with sediment samples from the Florida Keys and ocean water microbiomes from the Atlantic, Pacific and Indian Oceans. In general, we see a higher diversity of sediment microbial communities in Fiji compared to the Florida Keys. However, many of the same taxa are shared in these chemically similar environments, whereas the ocean water environments are completely distinct with few overlapping groups. We were able to show connectivity of a core microbiome between seagrass, fish and sediments in Fiji, including identifying a potential environmental reservoir of a surgeonfish symbiont, Epulopiscum. Finally, we show that fish guts have different microbial populations from crop to hindgut, and that microbial populations differ based on food source. The connection of these ecosystems suggest that the total microbiome of these environments may vary as their animal inhabitants shift in a changing ocean.

  13. Biomarkers in natural fish populations indicate adverse biological effects of offshore oil production.

    Directory of Open Access Journals (Sweden)

    Lennart Balk

    Full Text Available Despite the growing awareness of the necessity of a sustainable development, the global economy continues to depend largely on the consumption of non-renewable energy resources. One such energy resource is fossil oil extracted from the seabed at offshore oil platforms. This type of oil production causes continuous environmental pollution from drilling waste, discharge of large amounts of produced water, and accidental spills.Samples from natural populations of haddock (Melanogrammus aeglefinus and Atlantic cod (Gadus morhua in two North Sea areas with extensive oil production were investigated. Exposure to and uptake of polycyclic aromatic hydrocarbons (PAHs were demonstrated, and biomarker analyses revealed adverse biological effects, including induction of biotransformation enzymes, oxidative stress, altered fatty acid composition, and genotoxicity. Genotoxicity was reflected by a hepatic DNA adduct pattern typical for exposure to a mixture of PAHs. Control material was collected from a North Sea area without oil production and from remote Icelandic waters. The difference between the two control areas indicates significant background pollution in the North Sea.It is most remarkable to obtain biomarker responses in natural fish populations in the open sea that are similar to the biomarker responses in fish from highly polluted areas close to a point source. Risk assessment of various threats to the marine fish populations in the North Sea, such as overfishing, global warming, and eutrophication, should also take into account the ecologically relevant impact of offshore oil production.

  14. Epidermal Growth Factor Receptor (EGFR gene copy number (GCN correlates with clinical activity of irinotecan-cetuximab in K-RAS wild-type colorectal cancer: a fluorescence in situ (FISH and chromogenic in situ hybridization (CISH analysis

    Directory of Open Access Journals (Sweden)

    Scartozzi Mario

    2009-08-01

    Full Text Available Abstract Background K-RAS wild type colorectal tumors show an improved response rate to anti-EGFR monoclonal antibodies. Nevertheless 70% to 40% of these patients still does not seem to benefit from this therapeutic approach. FISH EGFR GCN has been previously demonstrated to correlate with clinical outcome of colorectal cancer treated with anti-EGFR monoclonal antibodies. CISH also seemed able to provide accurate EGFR GCN information with the advantage of a simpler and reproducible technique involving immunohistochemistry and light microscopy. Based on these findings we investigated the correlation between both FISH and CISH EGFR GCN and clinical outcome in K-RAS wild-type colorectal cancer treated with irinotecan-cetuximab. Methods Patients with advanced K-RAS wild-type, colorectal cancer receiving irinotecan-cetuximab after failure of irinotecan-based chemotherapy were eligible. A cut-off value for EGFR GCN of 2.6 and 2.12 for FISH and CISH respectively was derived from ROC curve analysis. Results Forty-four patients were available for analysis. We observed a partial remission in 9 (60% and 2 (9% cases with a FISH EGFR GCN ≥ 2.6 and Conclusion FISH and CISH EGFR GCN may both represent effective tools for a further patients selection in K-RAS wild-type colorectal cancer treated with cetuximab.

  15. Genetic diversity and structure of wild populations of Carica papaya in Northern Mesoamerica inferred by nuclear microsatellites and chloroplast markers.

    Science.gov (United States)

    Chávez-Pesqueira, Mariana; Núñez-Farfán, Juan

    2016-12-01

    Few studies have evaluated the genetic structure and evolutionary history of wild varieties of important crop species. The wild papaya (Carica papaya) is a key element of early successional tropical and sub-tropical forests in Mexico, and constitutes the genetic reservoir for evolutionary potential of the species. In this study we aimed to determine how diverse and structured is the genetic variability of wild populations of C. papaya in Northern Mesoamerica. Moreover, we assessed if genetic structure and evolutionary history coincide with hypothetized (1) pre-Pleistocene events (Isthmus of Tehuantepec sinking), (2) Pleistocene refugia or (3) recent patterns. We used six nuclear and two chloroplast (cp) DNA markers to assess the genetic diversity and phylogeographical structure of 19 wild populations of C. papaya in its natural distribution in Northern Mesoamerica. We found high genetic diversity (H o = 0·681 for nuclear markers, and h = 0·701 for cpDNA markers) and gene flow between populations of C. papaya (migration r up to 420 km). A lack of phylogeographical structure was found with the cpDNA markers (NST papaya. Because of its life history characteristics and lack of an ancient phylogeographical structure found with the cpDNA markers, we suggest that C. papaya was dispersed throughout the lowland rain forests of Mexico (along the coastal plains and foothills of Sierras). This scenario supports the hypothesis that tropical forests in Northern Mesoamerica did not experience important climate fluctuations during the Pleistocene, and that the life history of C. papaya could have promoted long-distance dispersal and rapid colonization of lowland rainforests. Moreover, the results obtained with the nuclear markers suggest recent human disturbances. The fragmentation of tropical habitats in Northern Mesoamerica appears to be the main driver of genetic structuring, and the major threat to the dispersion and survival of the species in the wild. © The Author 2016

  16. Marine protected areas facilitate parasite populations among four fished host species of central Chile.

    Science.gov (United States)

    Wood, Chelsea L; Micheli, Fiorenza; Fernández, Miriam; Gelcich, Stefan; Castilla, Juan Carlos; Carvajal, Juan

    2013-11-01

    1. Parasites comprise a substantial proportion of global biodiversity and exert important ecological influences on hosts, communities and ecosystems, but our knowledge of how parasite populations respond to human impacts is in its infancy. 2. Here, we present the results of a natural experiment in which we used a system of highly successful marine protected areas and matched open-access areas in central Chile to assess the influence of fishing-driven biodiversity loss on parasites of exploited fish and invertebrate hosts. We measured the burden of gill parasites for two reef fishes (Cheilodactylus variegatus and Aplodactylus punctatus), trematode parasites for a keyhole limpet (Fissurella latimarginata), and pinnotherid pea crab parasites for a sea urchin (Loxechinus albus). We also measured host density for all four hosts. 3. We found that nearly all parasite species exhibited substantially greater density (# parasites m(-2)) in protected than in open-access areas, but only one parasite species (a gill monogenean of C. variegatus) was more abundant within hosts collected from protected relative to open-access areas. 4. These data indicate that fishing can drive declines in parasite abundance at the parasite population level by reducing the availability of habitat and resources for parasites, but less commonly affects the abundance of parasites at the infrapopulation level (within individual hosts). 5. Considering the substantial ecological role that many parasites play in marine communities, fishing and other human impacts could exert cryptic but important effects on marine community structure and ecosystem functioning via reductions in parasite abundance. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.

  17. Parasite community structure within and across host populations of a marine pelagic fish: how repeatable is it?

    Science.gov (United States)

    Timi, Juan T; Poulin, Robert

    2003-10-01

    The geographical variation in parasite community structure among populations of the same host species remains one of the least understood aspects of parasite community ecology. Why are parasite communities clearly structured in some host populations, and randomly assembled in others? Here, we address this fundamental question using data on the metazoan parasite communities of different host size-classes of four distinct populations of a small pelagic fish, the Argentine anchovy, Engraulis anchoita, from the South West Atlantic. Within each fish sample, fish length was correlated with both the total intensity of parasites and species richness among infracommunities. More importantly, average fish length correlated with mean infracommunity richness and mean total intensity across the fish samples, indicating that the characteristics of parasite assemblages in a fish population are strongly influenced by the size of its fish in relation to those in other populations. Nested subset patterns were observed in about half of the fish samples. This means that the presence or absence of parasite species among fish individuals is often not random; however, no repeatability of nestedness among component communities was observed. Average fish length did not influence directly the likelihood that a parasite assemblage was significantly nested. However, variables influenced by average fish length, namely mean infracommunity richness and mean total intensity, determine the probability that a nested hierarchy will be observed; host size may thus indirectly affect parasite community structure either itself or via its influence on host movement and feeding patterns. To some extent, this apparent link may be due to the sensitivity of nestedness analyses to the proportion of presence in a presence/absence matrix; this in itself is a biological feature of the parasite community, however, which is associated with mean host length.

  18. Estimation of age structure of fish populations from length-frequency data

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, K.D.; Adams, S.M.

    1977-01-01

    A probability model is presented to determine the age structure of a fish population from length-frequency data. It is shown that when the age-length key is available, maximum-likelihood estimates of the age structure can be obtained. When the key is not available, approximate estimates of the age structure can be obtained. The model is used for determination of the age structure of populations of channel catfish and white crappie. Practical applications of the model to impact assessment are discussed.

  19. Monitoring of wild fish health at selected sites in the Great Lakes Basin: methods and preliminary results

    Science.gov (United States)

    Blazer, Vicki; Mazik, Patricia M.; Iwanowicz, Luke R.; Braham, Ryan; Hahn, Cassidy; Walsh, Heather L.; Sperry, Adam

    2014-01-01

    During fall 2010 and spring 2011, a total of 119 brown bullhead (Ameiurus nebulosus), 136 white sucker (Catostomus commersoni), 73 smallmouth bass (Micropterus dolomieu), and 59 largemouth bass (M. salmoides) were collected from seven Great Lakes Basin Areas of Concern and one Reference Site. Comprehensive fish health assessments were conducted in order to document potential adverse affects from exposure to complex chemical mixtures. Fish were necropsied on site, blood samples obtained, pieces of liver, spleen, kidney, gill and any abnormalities placed in fixative for histopathology. Liver samples were saved for gene expression analysis and otoliths were removed for aging. A suite of fish health indicators was developed and implemented for site comparisons and to document seasonal effects and species differences in response to environmental conditions. Organism level (grossly visible lesions, condition factor), tissue level (microscopic pathology, organosomatic indices, micronuclei, and other nuclear abnormalities), plasma factors (reproductive steroid hormones, vitellogenin), and molecular (gene expression) indicators were included. This report describes the methods and preliminary results.

  20. Epizootic and epidemiological situation of Trichinella sp. infection in Poland in 2006–2015 in view of wild boar population dynamics

    Directory of Open Access Journals (Sweden)

    Flis Marian

    2017-06-01

    Full Text Available Introduction: The objective was to evaluate the epizootic and epidemiological situation of Trichinella sp. infection in Poland between 2006 and 2015 against the dynamics of the wild boar population and its primary reservoir host.

  1. Inflammation in response to phytohemagglutinin injection in the Talas tuco-tuco (Ctenomys talarum): implications for the estimation of immunocompetence in natural populations of wild rodents

    National Research Council Canada - National Science Library

    Merlo, J.L; Cutrera, A.P; Zenuto, R.R

    2014-01-01

    The immunological variation in wild populations and its relation to life-history traits has recently become a central topic in the field of evolutionary biology, considering the critical contribution...

  2. Molecular analysis of utility of a retrotransposon, p-SINE1-r2 in the Asian wild rice and weedy rice populations.

    Science.gov (United States)

    Prathepha, Preecha

    2009-02-01

    The distribution of a retrotransposon, p-SINE1-r2 located at the waxy locus was analyzed by the PCR assay in the perennial wild rice (Oryza rufipogon) which inhabited in four isolated and six disturbed populations and in the weedy rice population. The level of clonality of the wild rice species was determined in populations subject to level of water supply and another disturbance. The results showed that all four isolated populations carried the genotype (-/-) and (-/+), while three genotypes (-/-), (-/+) and (+/+) was found on the six populations which grown near by rice fields. This finding was strongly supported the idea that the original wild rice populations of O. rufipogon exhibited prominent genotype (-/-) and (-/+) and mainly propagated by vegetative reproduction and the allele (+) which found in the wild rice plant with the genotype (+/+) may originated from gene flow from cultivated rice to wild rice. Weedy rice accessions used in this study showed the three genotypes based on this DNA locus. The distribution of this DNA locus in wild rice and weedy rice populations were deviated from the Hardy-Weinberg equilibrium. The perennial wild rice populations were annually under season drought (March to May of the year in Thailand, Laos and Cambodia), they tended to have small size clones with relatively high clonal diversity (i.e., number of genotypes), except for the population from Cambodia, which carried only the genotype (-/+). Although DNA maker used to detect genetic variation at population levels is too small, but this locus is very sensitive enough to be a useful indicator for genetic variation at the population level.

  3. Functional diversity of the lateral line system among populations of a native Australian freshwater fish.

    Science.gov (United States)

    Spiller, Lindsey; Grierson, Pauline F; Davies, Peter M; Hemmi, Jan; Collin, Shaun P; Kelley, Jennifer L

    2017-06-15

    Fishes use their mechanoreceptive lateral line system to sense nearby objects by detecting slight fluctuations in hydrodynamic motion within their immediate environment. Species of fish from different habitats often display specialisations of the lateral line system, in particular the distribution and abundance of neuromasts, but the lateral line can also exhibit considerable diversity within a species. Here, we provide the first investigation of the lateral line system of the Australian western rainbowfish ( Melanotaenia australis ), a species that occupies a diversity of freshwater habitats across semi-arid northwest Australia. We collected 155 individuals from eight populations and surveyed each habitat for environmental factors that may contribute to lateral line specialisation, including water flow, predation risk, habitat structure and prey availability. Scanning electron microscopy and fluorescent dye labelling were used to describe the lateral line system in M. australis , and to examine whether the abundance and arrangement of superficial neuromasts (SNs) varied within and among populations. We found that the SNs of M. australis were present in distinct body regions rather than lines. The abundance of SNs within each body region was highly variable, and also differed among populations and individuals. Variation in SN abundance among populations was best explained by habitat structure and the availability of invertebrate prey. Our finding that specific environmental factors explain among-population variation in a key sensory system suggests that the ability to acquire sensory information is specialised for the particular behavioural needs of the animal. © 2017. Published by The Company of Biologists Ltd.

  4. Efficacy of RAPD, ISSR and DAMD markers in assessment of genetic variability and population structure of wild Musa acuminata colla.

    Science.gov (United States)

    Lamare, Animos; Rao, Satyawada Rama

    2015-07-01

    North east India is considered as one of the major biodiversity hotspots worldwide and centre of origin of several plant species including Musa. Musa acuminata Colla is known to be one of the wild progenitors of cultivated bananas and plantains. Three single primer based DNA marker techniques viz., random amplified polymorphic DNA (RAPD), inter simple sequence repeat (ISSR) and directed amplification of minisatellites DNA (DAMD) were used for diversity diagnostics among 25 genotypes of wild M. acuminata collected from Meghalaya province of north east India. A total of 58 primers (26-RAPD, 21-ISSR, and11-DAMD) yielded 451 DNA fragments, of which 395 (87.58 %) were found to be polymorphic in nature. The polymorphic information content (PIC) values were almost identical for each marker system. The resolving power of the marker system was found to be highest in RAPD (3.96) whereas ISSR resolved highest marker index (16.39) in the study. Selected amplicon data obtained through single primer amplification reactions were utilized for determination of diversity within and among the populations of M. acuminata. Nei's genetic differentiation (Gst) value (0.451) indicated higher proportion of the genetic variation within the populations which is supported by the AMOVA analysis (88 %). The study provides insight into the efficacy of RAPD, ISSR and DAMD to analyse the genetic variation existing in the wild Musa germplasm, which can further be exploited for quality trait improvement and domestication of such important horticultural crops. The genetic diversity based population structure may shed light on the genetic basis of speciation and evolution of various species within the genus Musa.

  5. Association mapping of insecticide resistance in wild Anopheles gambiae populations: major variants identified in a low-linkage disequilbrium genome.

    Directory of Open Access Journals (Sweden)

    David Weetman

    2010-10-01

    Full Text Available Association studies are a promising way to uncover the genetic basis of complex traits in wild populations. Data on population stratification, linkage disequilibrium and distribution of variant effect-sizes for different trait-types are required to predict study success but are lacking for most taxa. We quantified and investigated the impacts of these key variables in a large-scale association study of a strongly selected trait of medical importance: pyrethroid resistance in the African malaria vector Anopheles gambiae.We genotyped ≈1500 resistance-phenotyped wild mosquitoes from Ghana and Cameroon using a 1536-SNP array enriched for candidate insecticide resistance gene SNPs. Three factors greatly impacted study power. (1 Population stratification, which was attributable to co-occurrence of molecular forms (M and S, and cryptic within-form stratification necessitating both a partitioned analysis and genomic control. (2 All SNPs of substantial effect (odds ratio, OR>2 were rare (minor allele frequency, MAF<0.05. (3 Linkage disequilibrium (LD was very low throughout most of the genome. Nevertheless, locally high LD, consistent with a recent selective sweep, and uniformly high ORs in each subsample facilitated significant direct and indirect detection of the known insecticide target site mutation kdr L1014F (OR≈6; P<10(-6, but with resistance level modified by local haplotypic background.Primarily as a result of very low LD in wild A. Gambiae, LD-based association mapping is challenging, but is feasible at least for major effect variants, especially where LD is enhanced by selective sweeps. Such variants will be of greatest importance for predictive diagnostic screening.

  6. Systematic review of management strategies to control chronic wasting disease in wild deer populations in North America.

    Science.gov (United States)

    Uehlinger, F D; Johnston, A C; Bollinger, T K; Waldner, C L

    2016-08-22

    Chronic wasting disease (CWD) is a contagious, fatal prion disease affecting cervids in a growing number of regions across North America. Projected deer population declines and concern about potential spread of CWD to other species warrant strategies to manage this disease. Control efforts to date have been largely unsuccessful, resulting in continuing spread and increasing prevalence. This systematic review summarizes peer-reviewed published reports describing field-applicable CWD control strategies in wild deer populations in North America using systematic review methods. Ten databases were searched for peer-reviewed literature. Following deduplication, relevance screening, full-text appraisal, subject matter expert review and qualitative data extraction, nine references were included describing four distinct management strategies. Six of the nine studies used predictive modeling to evaluate control strategies. All six demonstrated one or more interventions to be effective but results were dependant on parameters and assumptions used in the model. Three found preferential removal of CWD infected deer to be effective in reducing CWD prevalence; one model evaluated a test and slaughter strategy, the other selective removal of infected deer by predators and the third evaluated increased harvest of the sex with highest prevalence (males). Three models evaluated non-selective harvest of deer. There were only three reports that examined primary data collected as part of observational studies. Two of these studies supported the effectiveness of intensive non-selective culling; the third study did not find a difference between areas that were subjected to culling and those that were not. Seven of the nine studies were conducted in the United States. This review highlights the paucity of evaluated, field-applicable control strategies for CWD in wild deer populations. Knowledge gaps in the complex epidemiology of CWD and the intricacies inherent to prion diseases currently

  7. Identification, genealogical structure and population genetics of S-alleles in Malus sieversii, the wild ancestor of domesticated apple.

    Science.gov (United States)

    Ma, X; Cai, Z; Liu, W; Ge, S; Tang, L

    2017-09-01

    The self-incompatibility (SI) gene that is specifically expressed in pistils encodes the SI-associated ribonuclease (S-RNase), functioning as the female-specificity determinant of a gametophytic SI system. Despite extensive surveys in Malus domestica, the S-alleles have not been fully investigated for Malus sieversii, the primary wild ancestor of the domesticated apple. Here we screened the M. sieversii S-alleles via PCR amplification and sequencing, and identified 14 distinct alleles in this species. By contrast, nearly 40 are present in its close wild relative, Malus sylvestris. We further sequenced 8 nuclear genes to provide a neutral reference, and investigated the evolution of S-alleles via genealogical and population genetic analyses. Both shared ancestral polymorphism and an excess of non-synonymous substitution were detected in the S-RNases of the tribe Maleae in Rosaceae, indicating the action of long-term balancing selection. Approximate Bayesian Computations based on the reference neutral loci revealed a severe bottleneck in four of the six studied M. sieversii populations, suggesting that the low number of S-alleles found in this species is mainly the result of diversity loss due to a drastic population contraction. Such a bottleneck may lead to ambiguous footprints of ongoing balancing selection detected at the S-locus. This study not only elucidates the constituents and number of S-alleles in M. sieversii but also illustrates the potential utility of S-allele number shifts in demographic inference for self-incompatible plant species.

  8. A review of methods to assess connectivity and dispersal between fish populations in the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Antonio Calò

    2013-11-01

    Full Text Available Fish populations are linked to each other via dispersal of individuals as eggs, larvae, juveniles or adults. The understanding of this process, known as connectivity, has a pivotal role for the management of overexploited fish stocks and the development of accurate conservation strategies. Knowledge on connectivity and fish movements is considered fundamental toward the correct design of marine protected area (MPA networks for the achievement of the benefits of protection. Connectivity patterns are still largely unknown worldwide. A general lack of knowledge is particularly evident for the Mediterranean Sea where few studies dealing with this topic have been carried out and some methods, currently available for assessing connectivity, have not been used yet. In this review we present the methods used for studying connectivity patterns and fish movements at different life history stages and the main results achieved until now in the Mediterranean Sea. We encompass the pros and cons of each method, and conclude with future perspectives on the use of these methodologies in the Mediterranean context.

  9. Development of fish populations in seismostrsss conditions of the south of Russia

    Directory of Open Access Journals (Sweden)

    P. V. Lyushvin

    2009-01-01

    Full Text Available The last decades communications between reproduction of many food fishes and traditionally considered factors are lost, is unpredictable time recessions food are observed. The purpose of thepresent work to show, that in the seismo-seas of the south of Russia where there is a unloading litosheric fluids, seismo factors often are defining in reproduction fishes. Earthquakes lead to shortterm unloadings on breaks of an earth's crust through the made active volcanos and griffins of hundreds tons litosheric waters and km³ gases (metane, hydrogen, hydrogen sulphide, radon, etc.. Presence of some of these fluids even in midget concentration (less than 0.1-1 ml/½ causes destruction young fishes, infringement of reproductive functions due to what the food base crabs grows, and after their reproduction and extraction. Landslide reductions of fish populations in current decade it is caused by passage of a maximum of century cyclicity of earthquakes.

  10. Scalable population estimates using spatial-stream-network (SSN) models, fish density surveys, and national geospatial database frameworks for streams

    Science.gov (United States)

    Daniel J. Isaak; Jay M. Ver Hoef; Erin E. Peterson; Dona L. Horan; David E. Nagel

    2017-01-01

    Population size estimates for stream fishes are important for conservation and management, but sampling costs limit the extent of most estimates to small portions of river networks that encompass 100s–10 000s of linear kilometres. However, the advent of large fish density data sets, spatial-stream-network (SSN) models that benefit from nonindependence among samples,...

  11. Gnathostoma spinigerum in live Asian swamp eels (Monopterus spp.) from food markets and wild populations, United States

    Science.gov (United States)

    Cole, Rebecca A.; Choudhury, Anindo; Nico, Leo G.; Griffin, Kathryn M.

    2014-01-01

    In Southeast Asia, swamp eels (Synbranchidae: Monopterus spp.) are a common source of human gnathostomiasis, a foodborne zoonosis caused by advanced third-stage larvae (AL3) of Gnathostoma spp. nematodes. Live Asian swamp eels are imported to US ethnic food markets, and wild populations exist in several states. To determine whether these eels are infected, we examined 47 eels from markets and 67 wild-caught specimens. Nematodes were identified by morphologic features and ribosomal intergenic transcribed spacer–2 gene sequencing. Thirteen (27.7%) M. cuchia eels from markets were infected with 36 live G. spinigerum AL3: 21 (58.3%) in liver; 7 (19.4%) in muscle; 5 (13.8%) in gastrointestinal tract, and 3 (8.3%) in kidneys. Three (4.5%) wild-caught M. albus eels were infected with 5 G. turgidum AL3 in muscle, and 1 G. lamothei AL3 was found in a kidney (both North American spp.). Imported live eels are a potential source of human gnathostomiasis in the United States.

  12. Population-genetic analysis of HvABCG31 promoter sequence in wild barley (Hordeum vulgare ssp. spontaneum

    Directory of Open Access Journals (Sweden)

    Ma Xiaoying

    2012-09-01

    Full Text Available Abstract Background The cuticle is an important adaptive structure whose origin played a crucial role in the transition of plants from aqueous to terrestrial conditions. HvABCG31/Eibi1 is an ABCG transporter gene, involved in cuticle formation that was recently identified in wild barley (Hordeum vulgare ssp. spontaneum. To study the genetic variation of HvABCG31 in different habitats, its 2 kb promoter region was sequenced from 112 wild barley accessions collected from five natural populations from southern and northern Israel. The sites included three mesic and two xeric habitats, and differed in annual rainfall, soil type, and soil water capacity. Results Phylogenetic analysis of the aligned HvABCG31 promoter sequences clustered the majority of accessions (69 out of 71 from the three northern mesic populations into one cluster, while all 21 accessions from the Dead Sea area, a xeric southern population, and two isolated accessions (one from a xeric population at Mitzpe Ramon and one from the xeric ‘African Slope’ of “Evolution Canyon” formed the second cluster. The southern arid populations included six haplotypes, but they differed from the consensus sequence at a large number of positions, while the northern mesic populations included 15 haplotypes that were, on average, more similar to the consensus sequence. Most of the haplotypes (20 of 22 were unique to a population. Interestingly, higher genetic variation occurred within populations (54.2% than among populations (45.8%. Analysis of the promoter region detected a large number of transcription factor binding sites: 121–128 and 121–134 sites in the two southern arid populations, and 123–128,125–128, and 123–125 sites in the three northern mesic populations. Three types of TFBSs were significantly enriched: those related to GA (gibberellin, Dof (DNA binding with one finger, and light. Conclusions Drought stress and adaptive natural selection may have been important

  13. New Cultivars Derived from Crosses between Commercial Cultivar and a Wild Population of Papaya Rescued at Its Center of Origin

    OpenAIRE

    Mariela Vázquez Calderón; Manuel Jesús Zavala León; Fernando Amilcar Contreras Martín; Francisco Espadas y Gil; Abelardo Navarrete Yabur; Lorenzo Felipe Sánchez Teyer; Jorge M. Santamaría

    2014-01-01

    In order to generate new varieties, this study focused on the rescue and use of landraces and wild Carica papaya L. populations located at southern Yucatan, Mexico, to cross them with a commercial papaya cultivar (Maradol). In the cross L7 × M22, The native parent line L7 was used as the receiver parent while the commercial Maradol (M22) was used as the donor parent, seeking to generate genotypes with improved productivity and reduced plant height. Cluster analysis and principal components an...

  14. Detection of dwarf gourami iridovirus (Infectious spleen and kidney necrosis virus) in populations of ornamental fish prior to and after importation into Australia, with the first evidence of infection in domestically farmed Platy (Xiphophorus maculatus).

    Science.gov (United States)

    Rimmer, Anneke E; Becker, Joy A; Tweedie, Alison; Lintermans, Mark; Landos, Matthew; Stephens, Fran; Whittington, Richard J

    2015-11-01

    The movement of ornamental fish through international trade is a major factor for the transboundary spread of pathogens. In Australia, ornamental fish which may carry dwarf gourami iridovirus (DGIV), a strain of Infectious spleen and kidney necrosis virus (ISKNV), have been identified as a biosecurity risk despite relatively stringent import quarantine measures being applied. In order to gain knowledge of the potential for DGIV to enter Australia, imported ornamental fish were sampled prior to entering quarantine, during quarantine, and post quarantine from wholesalers and aquatic retail outlets in Australia. Samples were tested by quantitative polymerase chain reaction (qPCR) for the presence of megalocytivirus. Farmed and wild ornamental fish were also tested. Megalocytivirus was detected in ten of fourteen species or varieties of ornamental fish. Out of the 2086 imported gourami tested prior to entering quarantine, megalocytivirus was detected in 18.7% of fish and out of the 51 moribund/dead ornamental fish tested during the quarantine period, 68.6% were positive for megalocytivirus. Of fish from Australian wholesalers and aquatic retail outlets 14.5% and 21.9%, respectively, were positive. Out of 365 farmed ornamental fish, ISKNV-like megalocytivirus was detected in 1.1%; these were Platy (Xiphophorus maculatus). Megalocytivirus was not detected in free-living breeding populations of Blue gourami (Trichopodus trichopterus) caught in Queensland. This study showed that imported ornamental fish are vectors for DGIV and it was used to support an import risk analysis completed by the Australian Department of Agriculture. Subsequently, the national biosecurity policy was revised and from 1 March 2016, a health certification is required for susceptible families of fish to be free of this virus prior to importation. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

  15. The scaling of population persistence with carrying capacity does not asymptote in populations of a fish experiencing extreme climate variability.

    Science.gov (United States)

    White, Richard S A; Wintle, Brendan A; McHugh, Peter A; Booker, Douglas J; McIntosh, Angus R

    2017-06-14

    Despite growing concerns regarding increasing frequency of extreme climate events and declining population sizes, the influence of environmental stochasticity on the relationship between population carrying capacity and time-to-extinction has received little empirical attention. While time-to-extinction increases exponentially with carrying capacity in constant environments, theoretical models suggest increasing environmental stochasticity causes asymptotic scaling, thus making minimum viable carrying capacity vastly uncertain in variable environments. Using empirical estimates of environmental stochasticity in fish metapopulations, we showed that increasing environmental stochasticity resulting from extreme droughts was insufficient to create asymptotic scaling of time-to-extinction with carrying capacity in local populations as predicted by theory. Local time-to-extinction increased with carrying capacity due to declining sensitivity to demographic stochasticity, and the slope of this relationship declined significantly as environmental stochasticity increased. However, recent 1 in 25 yr extreme droughts were insufficient to extirpate populations with large carrying capacity. Consequently, large populations may be more resilient to environmental stochasticity than previously thought. The lack of carrying capacity-related asymptotes in persistence under extreme climate variability reveals how small populations affected by habitat loss or overharvesting, may be disproportionately threatened by increases in extreme climate events with global warming. © 2017 The Author(s).

  16. Comparison of genetic diversity between wild-caught broodstock and hatchery-produced offspring populations of the vulnerable Korean kelp grouper (Epinephelus bruneus) by microsatellites.

    Science.gov (United States)

    An, H S; Yang, S G; Moon, T S; Park, J Y; Hong, C G; Hwang, H K; Myeong, J I; An, C M

    2014-11-14

    The kelp grouper Epinephelus bruneus (Perciformes: Haemulidae), is one of the most economically important fishery resources in Korea. This fish is regarded as a target for prospective aquaculture diversification; therefore, maintenance of stock quality is important. To investigate the effects of current artificial reproduction in a hatchery facility, genetic variation in wild-caught broodstock and hatchery-produced offspring of kelp grouper was analyzed using eight polymorphic nuclear microsatellite DNA loci; 77 alleles were identified. Allelic variability ranged from 2 to 22 in the broodstock and from 1 to 10 in the offspring. The average observed and expected heterozygosities were 0.620 and 0.623 in the broodstock and 0.600 and 0.513 in the offspring, respectively. The possibility of a recent genetic bottleneck was suggested in both populations of E. bruneus. The minor, but significant, genetic differentiation (FST = 0.047, P hatchery procedures. Therefore, genetic variation between broodstock and offspring in a hatchery should be monitored in both breeding and release programs as a routine hatchery operation, and inbreeding should ideally be controlled to improve kelp grouper hatchery management. Our data provide a useful genetic basis for future planning of sustainable culture and management of E. bruneus in fisheries.

  17. Genetic structure of wild bonobo populations: diversity of mitochondrial DNA and geographical distribution.

    Directory of Open Access Journals (Sweden)

    Yoshi Kawamoto

    Full Text Available Bonobos (Pan paniscus inhabit regions south of the Congo River including all areas between its southerly tributaries. To investigate the genetic diversity and evolutionary relationship among bonobo populations, we sequenced mitochondrial DNA from 376 fecal samples collected in seven study populations located within the eastern and western limits of the species' range. In 136 effective samples from different individuals (range: 7-37 per population, we distinguished 54 haplotypes in six clades (A1, A2, B1, B2, C, D, which included a newly identified clade (D. MtDNA haplotypes were regionally clustered; 83 percent of haplotypes were locality-specific. The distribution of haplotypes across populations and the genetic diversity within populations thus showed highly geographical patterns. Using population distance measures, seven populations were categorized in three clusters: the east, central, and west cohorts. Although further elucidation of historical changes in the geological setting is required, the geographical patterns of genetic diversity seem to be shaped by paleoenvironmental changes during the Pleistocene. The present day riverine barriers appeared to have a weak effect on gene flow among populations, except for the Lomami River, which separates the TL2 population from the others. The central cohort preserves a high genetic diversity, and two unique clades of haplotypes were found in the Wamba/Iyondji populations in the central cohort and in the TL2 population in the eastern cohort respectively. This knowledge may contribute to the planning of bonobo conservation.

  18. DISPLACE: a dynamic, individual-based model for spatial fishing planning and effort displacement: Integrating underlying fish population models

    DEFF Research Database (Denmark)

    Bastardie, Francois; Nielsen, J. Rasmus; Miethe, Tanja

    We previously developed a spatially explicit, individual-based model (IBM) evaluating the bio-economic efficiency of fishing vessel movements between regions according to the catching and targeting of different species based on the most recent high resolution spatial fishery data. The main purpose...... was to test the effects of alternative fishing effort allocation scenarios related to fuel consumption, energy efficiency (value per litre of fuel), sustainable fish stock harvesting, and profitability of the fisheries. The assumption here was constant underlying resource availability. Now, an advanced...... by vessels on the fish stocks, with resulting fishing mortality, and the vessels’ economic consequences are evaluated on high spatial and seasonal disaggregation levels by simulating different individual choices of vessel speed, fishing grounds and ports. All tested scenarios led to increased overall energy...

  19. Evaluating genetic traceability methods for captive-bred marine fish and their applications in fisheries management and wildlife forensics

    NARCIS (Netherlands)

    Bylemans, Jonas; Maes, Gregory E.; Diopere, Eveline; Cariani, Alessia; Senn, Helen; Taylor, Martin I.; Helyar, Sarah; Bargelloni, Luca; Bonaldo, Alessio; Carvalho, Gary; Guarniero, Ilaria; Komen, Hans; Martinsohn, Jann T.; Nielsen, Einar E.; Tinti, Fausto; Volckaert, Filip A.M.; Ogden, Rob

    2016-01-01

    Growing demands for marine fish products is leading to increased pressure on already depleted wild populations and a rise in aquaculture production. Consequently, more captive-bred fish are released into the wild through accidental escape or deliberate releases. The increased mixing of

  20. Genetic diversity and differentiation of yellowwood [Cladrastis kentukea (Dum.Cours.) Rudd] growing in the wild and in planted populations outside the natural range

    Science.gov (United States)

    Nicholas LaBonte; Jadelys Tonos; Colleen Hartel; Keith E. Woeste

    2017-01-01

    Yellowwood (Cladrastis kentukea) grows in small, widely scattered populations in the wild, but is also a popular ornamental tree that thrives when planted in urban areas outside its natural range. Since the small native populations of yellowwood in several states are considered at risk of extirpation, the cultivated population could serve as an ex...

  1. Chromosome segment detection for seed size and shape traits using an improved population of wild soybean chromosome segment substitution lines.

    Science.gov (United States)

    Yang, Hongyan; Wang, Wubin; He, Qingyuan; Xiang, Shihua; Tian, Dong; Zhao, Tuanjie; Gai, Junyi

    2017-10-01

    Size and shape of soybean seeds are closely related to seed yield and market value. Annual wild soybeans have the potential to improve cultivated soybeans, but their inferior seed characteristics should be excluded. To detect quantitative trait loci (QTLs)/segments of seed size and shape traits in annual wild soybean, its chromosome segment substitution lines (CSSLs) derived from NN1138-2 (recurrent parent, Glycine max) and N24852 (donor parent, Glycine soja) and then modified 2 iterations (coded SojaCSSLP3) were improved further to contain more lines (diagonal segments) and less heterozygous and missing portions. The new population (SojaCSSLP4) composed of 195 CSSLs was evaluated under four environments, and 11, 13, 7, 15 and 14 QTLs/segments were detected for seed length (SL), seed width (SW), seed roundness (SR), seed perimeter (SP) and seed cross section area (SA), respectively, with all 60 wild allele effects negative. Among them, 16 QTLs/segments were shared by 2-5 traits, respectively, but 0-3 segments for each of the 5 traits were independent. The non-shared Satt274 and shared Satt305, Satt540 and Satt239 were major segments, along with other segments composed of two different but related sets of genetic systems for SR and the other 4 traits, respectively. Compared with the literature, 7 SL, 5 SW and 2 SR QTLs/segments were also detected in cultivated soybeans; allele distinction took place between cultivated and wild soybeans, and also among cultivated parents. The present mapping is understood as macro-segment mapping, the segments may be further dissected into smaller segments as well as corresponding QTLs/genes.

  2. Effects of stocking hatchery fish on the phenotype of indigenous populations in the amago salmon Oncorhynchus masou ishikawae in Japan.

    Science.gov (United States)

    Kawamura, K; Furukawa, M; Kubota, M; Harada, Y

    2012-07-01

    The expression of colour marks (parr marks, red and black spots) of the amago salmon Oncorhynchus masou ishikawae was compared with microsatellite information, to see the effects of stocking hatchery fish on the phenotype of indigenous populations, which face extinction through extensive stocking. A Bayesian-based assignment test suggested introgression of two exotic clusters into one indigenous cluster in the stocked area and its vicinity. The number of parr marks was significantly higher in one hatchery-origin population, which exclusively comprised one exotic cluster. An increased number of red spots in stocked hatchery fish was probably a consequence of hatchery feeding conditions. The number of black spots was correlated with body size in many populations, except for hatchery and heavily introgressed populations. Coefficients of correlation and regression of black spots with body size, which were largest in indigenous populations, decreased with an increase of introgression by hatchery fish. As indigenous populations have low genetic diversity with high relatedness, it was inferred that the height of correlation and regression coefficients in black spots is caused by high genetic homogeneity and fixation of alleles in loci related to the increase of black spots, both of which might have collapsed with introgression by hatchery fish. These results suggest the possibility that introgression by stocked fish causes a change of phenotype in indigenous populations. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  3. Mapping long-term spatial trends of the Taimyr wild reindeer population

    Directory of Open Access Journals (Sweden)

    Andrey N. Petrov

    2013-03-01

    Full Text Available This report presents preliminary results of mapping and analyzing wild reindeer spatial dynamics in Taimyr, Russia. We collected, spatially referenced, and systematized comprehensive aerial and land survey information spanning from 1969 to 2003, which is the most complete long-term data available about a wild reindeer herd in Eurasia. The report introduces some of the mapping products and presents a summary of our observations on spatiotemporal changes in reindeer distribution and migration. Using these data and new digital products in the GIS (Geographic Information Systems environment, we were able to observe the long-term shift of the Taimyr Reindeer Herd's summer, winter, and calving areas to the east and south with a simultaneous expansion of the habitat. We identified and confirmed locations of large reindeer concentrations (herds seasonally formed throughout the study period. Using the most recent summer survey data (2009 we also were able to confirm the existence of two major migration flows in the fall: eastern (most reindeer and western.

  4. Insecticide Susceptibility Status of Wild-Caught Sand Fly Populations Collected from Two Leishmaniasis Endemic Areas in Western Turkey

    Directory of Open Access Journals (Sweden)

    Mehmet Karakus

    2017-04-01

    Full Text Available Background: In Turkey, vector control programs are mainly based on indoor residual spraying with pyre­throids against mosquitoes. No special control program is available for sand flies. Most insecticide susceptibil­ity tests were done for mosquitoes but not for sand flies. We therefore aimed to determine the insecticide susceptibility against two commonly used insecticides; deltamethrin and permethrin, on wild-caught sand fly populations collected in two geographically separated leishmaniasis endemic areas.Methods: Insecticide susceptibility of wild-caught sand flies to deltamethrin (0.05% and permethrin (0.75% using ready-to use impregnated insecticide papers of WHO was investigated in 2010 based on knock­down time using standard WHO tube-test kit and procedures. Sand flies used in this study were col­lected from villages of Aydin (Bascayır and Mugla (Tepecik.Results: The resistance and early resistance were detected on the sand fly population from Mugla province against deltamethrin and permethrin, respectively. However, populations from Aydin Province were sensitive to both insecticides.Conclusion: The resistance against deltamethrin and permethrin was detected on sand fly population in Mugla Province where both insecticides have been applied for long time while no resistance was found in the insecticide free area, Aydin Province. These findings can be an indicator for showing the ability for develop­ing the insecticide resistance in sand flies. Because of the presence and dominancy of vector sand fly species of Leishmania infantum (Phlebotomus neglectus, P. tobbi in both study areas, the systematic monitoring for resistance of sand fly populations and more attention are needed by the authorities involved in control pro­grams for sand fly-borne diseases.

  5. Insecticide Susceptibility Status of Wild-Caught Sand Fly Populations Collected from Two Leishmaniasis Endemic Areas in Western Turkey.

    Science.gov (United States)

    Karakus, Mehmet; Gocmen, Bayram; Özbel, Yusuf

    2017-03-01

    In Turkey, vector control programs are mainly based on indoor residual spraying with pyrethroids against mosquitoes. No special control program is available for sand flies. Most insecticide susceptibility tests were done for mosquitoes but not for sand flies. We therefore aimed to determine the insecticide susceptibility against two commonly used insecticides; deltamethrin and permethrin, on wild-caught sand fly populations collected in two geographically separated leishmaniasis endemic areas. Insecticide susceptibility of wild-caught sand flies to deltamethrin (0.05%) and permethrin (0.75%) using ready-to use impregnated insecticide papers of WHO was investigated in 2010 based on knockdown time using standard WHO tube-test kit and procedures. Sand flies used in this study were collected from villages of Aydin (Bascayır) and Mugla (Tepecik). The resistance and early resistance were detected on the sand fly population from Mugla province against deltamethrin and permethrin, respectively. However, populations from Aydin Province were sensitive to both insecticides. The resistance against deltamethrin and permethrin was detected on sand fly population in Mugla Province where both insecticides have been applied for long time while no resistance was found in the insecticide free area, Aydin Province. These findings can be an indicator for showing the ability for developing the insecticide resistance in sand flies. Because of the presence and dominancy of vector sand fly species of Leishmania infantum ( Phlebotomus neglectus , P. tobbi ) in both study areas, the systematic monitoring for resistance of sand fly populations and more attention are needed by the authorities involved in control programs for sand fly-borne diseases.

  6. Inter-population differences in salinity tolerance and osmoregulation of juvenile wild and hatchery-born Sacramento splittail

    Science.gov (United States)

    Verhille, Christine E.; Dabruzzi, Theresa F.; Cocherell, Dennis E.; Mahardja, Brian; Feyrer, Frederick V.; Foin, Theodore C.; Baerwald, Melinda R.; Fangue, Nann A.

    2016-01-01

    The Sacramento splittail (Pogonichthys macrolepidotus) is a minnow endemic to the highly modified San Francisco Estuary of California, USA and its associated rivers and tributaries. This species is composed of two genetically distinct populations, which, according to field observations and otolith strontium signatures, show largely allopatric distribution patterns as recently hatched juveniles. Juvenile Central Valley splittail are found primarily in the nearly fresh waters of the Sacramento and San Joaquin rivers and their tributaries, whereas San Pablo juveniles are found in the typically higher-salinity waters (i.e. up to 10‰) of the Napa and Petaluma Rivers. As the large salinity differences between young-of-year habitats may indicate population-specific differences in salinity tolerance, we hypothesized that juvenile San Pablo and Central Valley splittail populations differ in their response to salinity. In hatchery-born and wild-caught juvenile San Pablo splittail, we found upper salinity tolerances, where mortalities occurred within 336 h of exposure to 16‰ or higher, which was higher than the upper salinity tolerance of 14‰ for wild-caught juvenile Central Valley splittail. This, in conjunction with slower recovery of plasma osmolality, but not ion levels, muscle moisture or gill Na+,K+-ATPase activity, in Central Valley relative to San Pablo splittail during osmoregulatory disturbance provides some support for our hypothesis of inter-population variation in salinity tolerance and osmoregulation. The modestly improved salinity tolerance of San Pablo splittail is consistent with its use of higher-salinity habitats. Although confirmation of the putative adaptive difference through further studies is recommended, this may highlight the need for population-specific management considerations.

  7. Inter-population differences in salinity tolerance and osmoregulation of juvenile wild and hatchery-born Sacramento splittail.

    Science.gov (United States)

    Verhille, Christine E; Dabruzzi, Theresa F; Cocherell, Dennis E; Mahardja, Brian; Feyrer, Frederick; Foin, Theodore C; Baerwald, Melinda R; Fangue, Nann A

    2016-01-01

    The Sacramento splittail (Pogonichthys macrolepidotus) is a minnow endemic to the highly modified San Francisco Estuary of California, USA and its associated rivers and tributaries. This species is composed of two genetically distinct populations, which, according to field observations and otolith strontium signatures, show largely allopatric distribution patterns as recently hatched juveniles. Juvenile Central Valley splittail are found primarily in the nearly fresh waters of the Sacramento and San Joaquin rivers and their tributaries, whereas San Pablo juveniles are found in the typically higher-salinity waters (i.e. up to 10‰) of the Napa and Petaluma Rivers. As the large salinity differences between young-of-year habitats may indicate population-specific differences in salinity tolerance, we hypothesized that juvenile San Pablo and Central Valley splittail populations differ in their response to salinity. In hatchery-born and wild-caught juvenile San Pablo splittail, we found upper salinity tolerances, where mortalities occurred within 336 h of exposure to 16‰ or higher, which was higher than the upper salinity tolerance of 14‰ for wild-caught juvenile Central Valley splittail. This, in conjunction with slower recovery of plasma osmolality, but not ion levels, muscle moisture or gill Na(+),K(+)-ATPase activity, in Central Valley relative to San Pablo splittail during osmoregulatory disturbance provides some support for our hypothesis of inter-population variation in salinity tolerance and osmoregulation. The modestly improved salinity tolerance of San Pablo splittail is consistent with its use of higher-salinity habitats. Although confirmation of the putative adaptive difference through further studies is recommended, this may highlight the need for population-specific management considerations.

  8. STORED RETINOIDS IN POPULATIONS OF AN ESTUARINE FISH, FUNDULUS HETERCLITUS, INDIGENOUS TO PCB-CONTAMINATED AND REFERENCE SITES

    Science.gov (United States)

    Concentrations of retinoids, derivatives of vitamin A, were measured in populations of the nonmigratory estuarine fish Fundulus heteroclitus, indigenous to a reference site and a site highly contaminated with polychlorinated biphenyls (PCBs) to address the hypothesis that contami...

  9. Genomic resources for wild populations of the house mouse, Mus musculus and its close relative Mus spretus.

    Science.gov (United States)

    Harr, Bettina; Karakoc, Emre; Neme, Rafik; Teschke, Meike; Pfeifle, Christine; Pezer, Željka; Babiker, Hiba; Linnenbrink, Miriam; Montero, Inka; Scavetta, Rick; Abai, Mohammad Reza; Molins, Marta Puente; Schlegel, Mathias; Ulrich, Rainer G; Altmüller, Janine; Franitza, Marek; Büntge, Anna; Künzel, Sven; Tautz, Diethard

    2016-09-13

    Wild populations of the house mouse (Mus musculus) represent the raw genetic material for the classical inbred strains in biomedical research and are a major model system for evolutionary biology. We provide whole genome sequencing data of individuals representing natural populations of M. m. domesticus (24 individuals from 3 populations), M. m. helgolandicus (3 individuals), M. m. musculus (22 individuals from 3 populations) and M. spretus (8 individuals from one population). We use a single pipeline to map and call variants for these individuals and also include 10 additional individuals of M. m. castaneus for which genomic data are publically available. In addition, RNAseq data were obtained from 10 tissues of up to eight adult individuals from each of the three M. m. domesticus populations for which genomic data were collected. Data and analyses are presented via tracks viewable in the UCSC or IGV genome browsers. We also provide information on available outbred stocks and instructions on how to keep them in the laboratory.

  10. Comparing climate change and species invasions as drivers of coldwater fish population extirpations.

    Directory of Open Access Journals (Sweden)

    Sapna Sharma

    Full Text Available Species are influenced by multiple environmental stressors acting simultaneously. Our objective was to compare the expected effects of climate change and invasion of non-indigenous rainbow smelt (Osmerus mordax on cisco (Coregonus artedii population extirpations at a regional level. We assembled a database of over 13,000 lakes in Wisconsin, USA, summarising fish occurrence, lake morphology, water chemistry, and climate. We used A1, A2, and B1 scenarios from the Intergovernmental Panel on Climate Change (IPCC of future temperature conditions for 15 general circulation models in 2046-2065 and 2081-2100 totalling 78 projections. Logistic regression indicated that cisco tended to occur in cooler, larger, and deeper lakes. Depending upon the amount of warming, 25-70% of cisco populations are predicted to be extirpated by 2100. In addition, cisco are influenced by the invasion of rainbow smelt, which prey on young cisco. Projecting current estimates of rainbow smelt spread and impact into the future will result in the extirpation of about 1% of cisco populations by 2100 in Wisconsin. Overall, the effect of climate change is expected to overshadow that of species invasion as a driver of coldwater fish population extirpations. Our results highlight the potentially dominant role of climate change as a driver of biotic change.

  11. RAPD markers indicate the occurrence of structured populations in a migratory freshwater fish species

    Directory of Open Access Journals (Sweden)

    Hatanaka Terumi

    2003-01-01

    Full Text Available Many factors have contributed to the destruction of fish habitats. Hydroelectric dams, water pollution and other environmental changes have resulted in the eradication of natural stocks. The aim of this study was to detect the genetic variation in Prochilodus marggravii from three collection sites in the area of influence of the Três Marias dam (MG on the São Francisco river (Brazil, using the RAPD technique. The results obtained revealed that the fish in the downstream region nearest the dam have a higher similarity coefficient than those from the other sampling sites that may be related to differences in environmental characteristics in these regions. Additionaly, significant differences in the band frequencies were observed from one collection site to another. These both findings suggest the occurrence of a structured population and have important implications for the conservation of the genetic variability of distinct natural P. marggravii stocks.

  12. Assortative mating among Lake Malawi cichlid fish populations is not simply predictable from male nuptial colour

    Directory of Open Access Journals (Sweden)

    Taylor Martin I

    2009-03-01

    Full Text Available Abstract Background Research on the evolution of reproductive isolation in African cichlid fishes has largely focussed on the role of male colours and female mate choice. Here, we tested predictions from the hypothesis that allopatric divergence in male colour is associated with corresponding divergence in preference. Methods We studied four populations of the Lake Malawi Pseudotropheus zebra complex. We predicted that more distantly-related populations that independently evolved similar colours would interbreed freely while more closely-related populations with different colours mate assortatively. We used microsatellite genotypes or mesh false-floors to assign paternity. Fisher's exact tests as well as Binomial and Wilcoxon tests were used to detect if mating departed from random expectations. Results Surprisingly, laboratory mate choice experiments revealed significant assortative mating not only between population pairs with differently coloured males, but between population pairs with similarly-coloured males too. This suggested that assortative mating could be based on non-visual cues, so we further examined the sensory basis of assortative mating between two populations with different male colour. Conducting trials under monochromatic (orange light, intended to mask the distinctive male dorsal fin hues (blue v orange of these populations, did not significantly affect the assortative mating by female P. emmiltos observed under control conditions. By contrast, assortative mating broke down when direct contact between female and male was prevented. Conclusion We suggest that non-visual cues, such as olfactory signals, may play an important role in mate choice and behavioural isolation in these and perhaps other African cichlid fish. Future speciation models aimed at explaining African cichlid radiations may therefore consider incorporating such mating cues in mate choice scenarios.

  13. Population structure, fluctuating asymmetry and genetic variability in an endemic and highly isolated Astyanax fish population (Characidae

    Directory of Open Access Journals (Sweden)

    Maria Claudia Gross

    2004-01-01

    Full Text Available Morphological and chromosomal markers were used to infer the structure and genetic variability of a population of fish of the genus Astyanax, geographically isolated at sinkhole 2 of Vila Velha State Park, Paraná, Brazil. Two morphotypes types were observed, the standard phenotype I and phenotype II which showed an anatomical alteration probably due to an inbreeding process. Fluctuating asymmetry (FA analysis of different characters showed low levels of morphological variation among the population from sinkhole 2 and in another population from the Tibagi river (Paraná, Brazil. The Astyanax karyotype was characterized in terms of chromosomal morphology, constitutive heterochromatin and nucleolar organizer regions. Males and females presented similar karyotypes (2n=48, 6M+18SM+14ST+10A with no evidence of a sex chromosome system. One female from sinkhole 2 was a natural triploid with 2n=3x=72 chromosomes (9M+27SM+21ST+15A. The data are discussed regarding the maintenance of population structure and their evolutionary importance, our data suggesting that Astyanax from the Vila Velha State Park sinkhole 2 is a recently isolated population.

  14. Evolutionary mechanisms shaping the genetic population structure of coastal fish: insight from populations of Coilia nasus in Northwestern Pacific.

    Science.gov (United States)

    Gao, Tianxiang; Wan, Zhenzhen; Song, Na; Zhang, Xiumei; Han, Zhiqiang

    2014-12-01

    A number of evolutionary mechanisms have been suggested for generating significant genetic structuring among marine fish populations in Northwestern Pacific. We used mtDNA control region to assess the factors in shaping the genetic structure of Japanese grenadier anchovy, Coilia nasus, an anadromous and estuarine coastal species, in Northwestern Pacific. Sixty seven individuals from four locations in Northwestern Pacific were sequenced for mitochondrial control region, detecting 61 haplotypes. The length of amplified control region varied from 677 to 754 bp. This length variability was due to the presence of varying numbers of a 38-bp tandemly repeated sequence. Two distinct lineages were detected, which might have diverged during Pleistocene low sea levels. There were strong differences in the geographical distribution of the two lineages. Analyses of molecular variance and the population statistic ΦST revealed significant genetic structure between China and Ariake Bay populations. Based on the frequency distribution of tandem repeat units, significant genetic differentiation was also detected between China and Ariake Bay populations. Isolation by distance seems to be the main factor driving present genetic structuring of C. nasus populations, indicating coastal dispersal pattern in this coastal species. Such an evolutionary process agrees well with some of the biological features characterizing this species.

  15. Shape variation in the skull and lower carnassial in a wild population of raccoon dog (Nyctereutes procyonoides).

    Science.gov (United States)

    Asahara, Masakazu

    2013-03-01

    Individual variations in skull and lower carnassial morphology within a wild population of raccoon dog were examined using geometric morphometric techniques. We compared individual morphological variations by using relative warp analysis, and then tested morphological integration between the skull and carnassial by using partial least square (PLS) analysis. The most marked variation in skull shape was the dorsoventral flexion; i.e., deformation from klinorhynchy to airorhynchy. Two remarkable variations were observed, including tilting between the trigonid (or carnassial blade) and the talonid in the lower carnassial, and the relative sizes of the trigonid and the talonid. This observed variation in skull shape was similar to previous reports of variations among dog breeds that correlate with a polymorphism of the Runx2 gene. This polymorphism has also been reported to correlate with snout length, which is strongly related to carnivorous or omnivorous dietary adaptations, across the entire order Carnivora. Our results in the lower carnassial were also similar to previously reported patterns observed for carnivorous or omnivorous dietary adaptations among Carnivora. However, in our PLS analysis between skull and carnassial shapes, we only found a significant correlation in a lower dimension, suggesting a lower degree of integration. These results indicate that shape variations, which could be sources of natural selection in the skull and carnassial, were present in a wild population, suggesting high evolvability of these variations in the raccoon dog and the order Carnivora in general.

  16. Yield-related salinity tolerance traits identified in a nested association mapping (NAM) population of wild barley

    KAUST Repository

    Saade, Stephanie

    2016-09-02

    Producing sufficient food for nine billion people by 2050 will be constrained by soil salinity, especially in irrigated systems. To improve crop yield, greater understanding of the genetic control of traits contributing to salinity tolerance in the field is needed. Here, we exploit natural variation in exotic germplasm by taking a genome-wide association approach to a new nested association mapping population of barley called HEB-25. The large population (1,336 genotypes) allowed cross-validation of loci, which, along with two years of phenotypic data collected from plants irrigated with fresh and saline water, improved statistical power. We dissect the genetic architecture of flowering time under high salinity and we present genes putatively affecting this trait and salinity tolerance. In addition, we identify a locus on chromosome 2H where, under saline conditions, lines homozygous for the wild allele yielded 30% more than did lines homozygous for the Barke allele. Introgressing this wild allele into elite cultivars could markedly improve yield under saline conditions. © 2016 The Author(s).

  17. The power to detect trends in Missouri River fish populations within the Pallid Sturgeon Population Assessment Program

    Science.gov (United States)

    Bryan, Janice L.; Wildhaber, Mark L.; Gladish, Dan; Holan, Scott; Ellerseick, Mark

    2010-01-01

    As with all large rivers in the United States, the Missouri River has been altered, with approximately 32.5 percent of the main stem length impounded and 32.5 percent channelized. These physical alterations to the environment have had effects on the fisheries, but studies examining the effects of alterations have been localized and for short periods of time. In response to the U.S. Fish and Wildlife Service biological opinion, the U.S. Army Corps of Engineers initiated monitoring of the fish community of the Missouri River in 2003. The goal of the Pallid Sturgeon Population Assessment Program is to provide information to detect changes in populations and habitat preferences with time for pallid sturgeon (Scaphirhynchus albus) and native target species in the Missouri River Basin. To determine statistical power of the Pallid Sturgeon Population Assessment Program, a power analysis was conducted using a normal linear mixed model with variance component estimates based on the first 3 years of data (2003 to 2005). In cases where 3 years of data were unavailable, estimates were obtained using those data. It was determined that at least 20 years of data, sampling 12 bends with 8 subsamples per bend, would be required to detect a 5 percent annual decline in most of the target fish populations. Power varied between Zones. Zone 1 (upstream from Lake Sakakawea) did not have any species/gear type combinations with adequate power, whereas Zone 3 (downstream from Gavins Point Dam) had 19 species/gear type combinations with adequate power. With a slight increase in the sampling effort to 12 subsamples per bend, the Pallid Sturgeon Population Assessment Program has adequate power to detect declines in shovelnose sturgeon (S. platorynchus) throughout the entire Missouri River because of large catch rates. The lowest level of non-occurrence (in other words, zero catches) at the bend level for pallid sturgeon was 0.58 using otter trawls in Zone 1. Consequently, the power of the

  18. Ecotoxicology of polychlorinated biphenyls in fish--a critical review.

    Science.gov (United States)

    Henry, T B

    2015-01-01

    Polychlorinated biphenyls (PCBs) are widespread persistent anthropogenic contaminants that can accumulate in tissues of fish. The toxicity of PCBs and their transformation products has been investigated for nearly 50 years, but there is a lack of consensus regarding the effects of these environmental contaminants on wild fish populations. The objective of this review is to critically examine these investigations and evaluate publicly available databases for evidence of effects of PCBs in wild fish. Biological activity of PCBs is limited to a small proportion of PCB congeners [e.g., dioxin-like PCBs (DL-PCBs)] and occurs at concentrations that are typically orders of magnitude higher than PCB levels detected in wild fish. Induction of biomarkers consistent with PCB exposure (e.g., induction of cytochrome P450 monooxygenase system) has been evaluated frequently and shown to be induced in fish from some environments, but there does not appear to be consistent reports of damage (i.e., biomarkers of effect) to biomolecules (i.e., oxidative injury) in these fish. Numerous investigations of endocrine system dysfunction or effects on other organ systems have been conducted in wild fish, but collectively there is no consistent evidence of PCB effects on these systems in wild fish. Early life stage toxicity of DL-PCBs does not appear to occur at concentrations reported in wild fish embryos, and results do not support an association between PCBs and decreased survival of early life stages of wild fish. Overall, there appears to be little evidence that PCBs have had any widespread effect on the health or survival of wild fish.

  19. Ecto- and endoparasites in remaining population of wild rabbit Oryctolagus cuniculus (L., 1758 in east Bohemia

    Directory of Open Access Journals (Sweden)

    Vladimír Bádr

    2005-01-01

    Full Text Available An investigation of ecto- and endoparasites of wild rabbit Oryctolagus cuniculus (L., 1758 was made during February and March 2004. Together five species of ectoparasites and seven species of endopara- sites was found in five specimens of host. Ectoparasites: acarids Leporacarus gibbus (Pagenstecher, 1862, Psoroptes cuniculi (Delafond, 1859, and Cheyletiella parasitivorax (Mégnin, 1878, flea Spilopsyllus cuniculi (Dale, 1878, and louse Haemodipsus ventricosus (Denny, 1842. Except of petechial haemorrhagies inside both earlobes of one rabbit neither hyperkeratosis nor scale with any degrees of hairlessness were detected. Higher incidence of flea Spilopsyllus cuniculi could be important for spreading of myxomatosis. In one rabbit abnormal damage of incisivi was found, which caused the highest documented incidence of acarids Cheyletiella parasitivorax (485 ex., fleas Spilopsyllus cuniculi (65 ex., and especially enormous amount of louse Haemodipsus ventricosus (1840 ex. This finding establish close relation between prevalence and counts of ectoparasites with health of host, because popu- lation of ectoparasites from different taxonomic groups are principally affected by effective hostęs cleanup. Handicapped hosts are not able to make clarify as effective as the healthy ones. Endoparasites: tapeworm Taenia pisiformis (Bloch, 1780 – larvae, nematods Passalurus ambiguus (Rudolphi, 1819 Rudolphi, 1845; Graphidium strigosum (Dujardin, 1845 Railliet and Henry, 1909, Trichostrongylus retortaeformis (Zeder, 1800 Loos, 1905 and protozoa Eimeria piriformis Kotlan & Pospesch, 1934; E. media Kessel, 1929, and E. perforans (Leuckart, 1879 Sluiter & Swellengrebel, 1912. All endoparasites were found in very low or middle intensity, which does not seem to be main cause of decreasing number of wild rabbits in monitored areas.

  20. The early bird gets the shrimp: Confronting assumptions of isotopic equilibrium and homogeneity in a wild bird population

    Science.gov (United States)

    Wunder, Michael B.; Jehl, Joseph R.; Stricker, Craig A.

    2012-01-01

    1. Because stable isotope distributions in organic material vary systematically across energy gradients that exist in ecosystems, community and population structures, and in individual physiological systems, isotope values in animal tissues have helped address a broad range of questions in animal ecology. It follows that every tissue sample provides an isotopic profile that can be used to study dietary or movement histories of individual animals. Interpretations of these profiles depend on the assumption that metabolic pools are isotopically well mixed and in equilibrium with dietary resources prior to tissue synthesis, and they extend to the population level by assuming isotope profiles are identically distributed for animals using the same proximal dietary resource. As these assumptions are never fully met, studying structure in the variance of tissue isotope values from wild populations is informative. 2. We studied variation in δ13C, δ15N, δ2H and δ18O data for feathers from a population of eared grebes (Podiceps nigricollis) that migrate to Great Salt Lake each fall to moult feathers. During this time, they cannot fly and feed almost exclusively on superabundant brine shrimp (Artemia franciscana). The ecological simplicity of this situation minimized the usual spatial and trophic complexities often present in natural studies of feather isotope values. 3. Ranges and variances of isotope values for the feathers were larger than those from previously published studies that report feather isotopic variance, but they were bimodally distributed in all isotope dimensions. Isotope values for proximal dietary resources and local surface water show that some of the feathers we assumed to have been grown locally must have been grown before birds reached isotopic equilibrium with local diet or immediately prior to arrival at Great Salt Lake. 4. Our study provides novel insights about resource use strategies in eared grebes during migration. More generally, it

  1. Chimerism in wild adult populations of the broadcast spawning coral Acropora millepora on the Great Barrier Reef.

    Directory of Open Access Journals (Sweden)

    Eneour Puill-Stephan

    Full Text Available BACKGROUND: Chimeras are organisms containing tissues or cells of two or more genetically distinct individuals, and are known to exist in at least nine phyla of protists, plants, and animals. Although widespread and common in marine invertebrates, the extent of chimerism in wild populations of reef corals is unknown. METHODOLOGY/PRINCIPAL FINDINGS: The extent of chimerism was explored within two populations of a common coral, Acropora millepora, on the Great Barrier Reef, Australia, by using up to 12 polymorphic DNA microsatellite loci. At least 2% and 5% of Magnetic Island and Pelorus Island populations of A. millepora, respectively, were found to be chimeras (3% overall, based on conservative estimates. A slightly less conservative estimate indicated that 5% of colonies in each population were chimeras. These values are likely to be vast underestimates of the true extent of chimerism, as our sampling protocol was restricted to a maximum of eight branches per colony, while most colonies consist of hundreds of branches. Genotypes within chimeric corals showed high relatedness, indicating that genetic similarity is a prerequisite for long-term acceptance of non-self genotypes within coral colonies. CONCLUSIONS/SIGNIFICANCE: While some brooding corals have been shown to form genetic chimeras in their early life history stages under experimental conditions, this study provides the first genetic evidence of the occurrence of coral chimeras in the wild and of chimerism in a broadcast spawning species. We hypothesize that chimerism is more widespread in corals than previously thought, and suggest that this has important implications for their resilience, potentially enhancing their capacity to compete for space and respond to stressors such as pathogen infection.

  2. Causes of morbidity in wild raptor populations admitted at a wildlife rehabilitation centre in Spain from 1995-2007: a long term retrospective study.

    Science.gov (United States)

    Molina-López, Rafael A; Casal, Jordi; Darwich, Laila

    2011-01-01

    Morbidity studies complement the understanding of hazards to raptors by identifying natural or anthropogenic factors. Descriptive epidemiological studies of wildlife have become an important source of information about hazards to wildlife populations. On the other hand, data referenced to the overall wild population could provide a more accurate assessment of the potential impact of the morbidity/mortality causes in populations of wild birds. The present study described the morbidity causes of hospitalized wild raptors and their incidence in the wild populations, through a long term retrospective study conducted at a wildlife rehabilitation centre of Catalonia (1995-2007). Importantly, Seasonal Cumulative Incidences (SCI) were calculated considering estimations of the wild population in the region and trend analyses were applied among the different years. A total of 7021 birds were analysed: 7 species of Strigiformes (n = 3521) and 23 of Falconiformes (n = 3500). The main causes of morbidity were trauma (49.5%), mostly in the Falconiformes, and orphaned/young birds (32.2%) mainly in the Strigiformes. During wintering periods, the largest morbidity incidence was observed in Accipiter gentillis due to gunshot wounds and in Tyto alba due to vehicle trauma. Within the breeding season, Falco tinnunculus (orphaned/young category) and Bubo bubo (electrocution and metabolic disorders) represented the most affected species. Cases due to orphaned/young, infectious/parasitic diseases, electrocution and unknown trauma tended to increase among years. By contrast, cases by undetermined cause, vehicle trauma and captivity decreased throughout the study period. Interestingly, gunshot injuries remained constant during the study period. Frequencies of morbidity causes calculated as the proportion of each cause referred to the total number of admitted cases, allowed a qualitative assessment of hazards for the studied populations. However, cumulative incidences based on

  3. Causes of morbidity in wild raptor populations admitted at a wildlife rehabilitation centre in Spain from 1995-2007: a long term retrospective study.

    Directory of Open Access Journals (Sweden)

    Rafael A Molina-López

    Full Text Available BACKGROUND: Morbidity studies complement the understanding of hazards to raptors by identifying natural or anthropogenic factors. Descriptive epidemiological studies of wildlife have become an important source of information about hazards to wildlife populations. On the other hand, data referenced to the overall wild population could provide a more accurate assessment of the potential impact of the morbidity/mortality causes in populations of wild birds. METHODOLOGY/PRINCIPAL FINDINGS: The present study described the morbidity causes of hospitalized wild raptors and their incidence in the wild populations, through a long term retrospective study conducted at a wildlife rehabilitation centre of Catalonia (1995-2007. Importantly, Seasonal Cumulative Incidences (SCI were calculated considering estimations of the wild population in the region and trend analyses were applied among the different years. A total of 7021 birds were analysed: 7 species of Strigiformes (n = 3521 and 23 of Falconiformes (n = 3500. The main causes of morbidity were trauma (49.5%, mostly in the Falconiformes, and orphaned/young birds (32.2% mainly in the Strigiformes. During wintering periods, the largest morbidity incidence was observed in Accipiter gentillis due to gunshot wounds and in Tyto alba due to vehicle trauma. Within the breeding season, Falco tinnunculus (orphaned/young category and Bubo bubo (electrocution and metabolic disorders represented the most affected species. Cases due to orphaned/young, infectious/parasitic diseases, electrocution and unknown trauma tended to increase among years. By contrast, cases by undetermined cause, vehicle trauma and captivity decreased throughout the study period. Interestingly, gunshot injuries remained constant during the study period. CONCLUSIONS/SIGNIFICANCE: Frequencies of morbidity causes calculated as the proportion of each cause referred to the total number of admitted cases, allowed a qualitative assessment of

  4. Genomic diversity and differentiation of a managed island wild boar population

    DEFF Research Database (Denmark)

    Iacolina, Laura; Scandura, Massimo; J. Goedbloed, Daniel

    2016-01-01

    .169). Such evidences were mostly unaffected by an uneven sample size, although clustering results in reference populations changed when the number of individuals was standardized. Runs of homozygosity (ROHs) pattern and distribution in Sardinian WB are consistent with a past expansion following a bottleneck (small...... ROHs) and recent population substructuring (highly homozygous individuals). The observed effect of a non-random selection of Sardinian individuals on diversity, FST and ROH estimates, stressed the importance of sampling design in the study of structured or introgressed populations. Our results support...

  5. Genetic and cytogenetic structure of wild lemon grass (Elionurus muticus populations

    Directory of Open Access Journals (Sweden)

    Thanise Nogueira Füller

    2015-12-01

    Full Text Available Elionurus muticus is a native aromatic grass from the Pampa biome that produces an essential oil that is rich in citral. Despite the importance of citral, few studies have examined this species. The aims of this work were to evaluate the genetic structure and to characterize cytogenetically natural populations collected from Brazil. Genetic characterization was performed using AFLP markers, and cytogenetics assessed the chromosome number, karyotype and meiosis. The studied populations had genetic variability, especially within populations, indicating the possibility of selecting plants with relevant characters. High variability also suggests the preferential occurrence of outcrossing in natural populations. Regular meiosis was observed in the cytogenetic analysis with chromosome number 2n=20. The karyotype of the species is presented for the first time, with the karyotype formula 3sm + 4a + 1saSAT.

  6. Scale-Dependent Seasonal Pool Habitat Use by Sympatric Wild Brook Trout and Brown Trout Populations

    National Research Council Canada - National Science Library

    Davis, Lori A; Wagner, Tyler

    2016-01-01

    .... Discrete-choice models were used to (1) evaluate fall and early winter daytime habitat use by sympatric Brook Trout and Brown Trout populations based on available residual pool habitat within a stream network and (2...

  7. Estimating population size of the red swamp crayfish (Procambarus clarkii in fish-ponds (Brenne, Central France

    Directory of Open Access Journals (Sweden)

    Coignet A.

    2012-07-01

    Full Text Available The red swamp crayfish, Procambarus clarkii, was discovered in 2007 in the “Parc naturel régional (PNR de la Brenne” (France. Ten colonized sites have been identified in the park to date, including two new sites discovered in 2011. The present study aims at establishing a protocol suitable for estimating the population size of P. clarkii by the use of a Capture-Mark-Recapture (CMR technique in a chain of five connected fish-ponds. Results show different cohorts of individuals among seasons and fish-ponds. However, trapping effort was not efficient enough to obtain an accurate estimate of the population size of this species in a fish-pond larger than 2 − 3 ha. On the other hand, the adopted protocol appeared useful to assess, in smaller fish-ponds, the effect of intensive trapping and other control methods on P. clarkii populations.

  8. Visual Basic, Excel-based fish population modeling tool - The pallid sturgeon example

    Science.gov (United States)

    Moran, Edward H.; Wildhaber, Mark L.; Green, Nicholas S.; Albers, Janice L.

    2016-02-10

    The model presented in this report is a spreadsheet-based model using Visual Basic for Applications within Microsoft Excel (http://dx.doi.org/10.5066/F7057D0Z) prepared in cooperation with the U.S. Army Corps of Engineers and U.S. Fish and Wildlife Service. It uses the same model structure and, initially, parameters as used by Wildhaber and others (2015) for pallid sturgeon. The difference between the model structure used for this report and that used by Wildhaber and others (2015) is that variance is not partitioned. For the model of this report, all variance is applied at the iteration and time-step levels of the model. Wildhaber and others (2015) partition variance into parameter variance (uncertainty about the value of a parameter itself) applied at the iteration level and temporal variance (uncertainty caused by random environmental fluctuations with time) applied at the time-step level. They included implicit individual variance (uncertainty caused by differences between individuals) within the time-step level.The interface developed for the model of this report is designed to allow the user the flexibility to change population model structure and parameter values and uncertainty separately for every component of the model. This flexibility makes the modeling tool potentially applicable to any fish species; however, the flexibility inherent in this modeling tool makes it possible for the user to obtain spurious outputs. The value and reliability of the model outputs are only as good as the model inputs. Using this modeling tool with improper or inaccurate parameter values, or for species for which the structure of the model is inappropriate, could lead to untenable management decisions. By facilitating fish population modeling, this modeling tool allows the user to evaluate a range of management options and implications. The goal of this modeling tool is to be a user-friendly modeling tool for developing fish population models useful to natural resource

  9. Essential oil variation in wild populations of Artemisia saharae (Asteraceae) from Tunisia: chemical composition, antibacterial and antioxidant properties.

    Science.gov (United States)

    Zouari, Sami; Ayadi, Imen; Fakhfakh, Nahed; Jdir, Hamida; Aloui, Latifa; Kossentini, Mohamed; Rebai, Ahmed; Zouari, Nacim

    2014-12-01

    Artemisia saharae Pomel is a new taxon of Artemisia herba-alba Asso (Asteraceae) which is endemic to Tunisia and Algeria. This shrub, commonly known as white wormwood or desert wormwood, is largely used in folk medicine and as a culinary herb. The bulks aromatic plants come from wild populations whose essential oils compositions as well as their biological properties are severely affected by several factors such as geographic conditions. Therefore, the aim of the present work is to provide more information about the influence of altitude variation on the essential oil composition, antimicrobial and antioxidant properties of Artemisia saharae growing wild in the same geographical area. Essential oils were extracted by hydrodistillation of leaves and flowers of the plant collected from seven different altitudes of the Baten Zamour region (southwest of Tunisia). The highest essential oil yields (2.70-2.80%) were obtained for populations of high altitudes. Seventy-five compounds, representing 92.78 to 96.95% of the total essential oils, were separated and identified. Essential oils were characterized by very high percentage of oxygenated monoterpenes (52.1-72.6%) which constituted the predominant class. From the analyzed populations, the major compounds (>7%) were α-thujone, β-thujone, chrysanthenone, camphor, chrysanthenyl acetate, and sabinyl acetate. Sabiny