Impacts of species introductions on the health of fish communities receiving chronic radionuclide exposures

International Nuclear Information System (INIS)

Yankovich, T.L.; Casselman, J.M.; Cornett, R.J.J.

2006-01-01

A study was conducted to evaluate the potential impacts of a northern pike introduction on the health of a fish community receiving chronic radionuclide exposure, primarily from 90 Sr. Overall, although significant changes occurred in the community composition and the health of fish populations following the pike introduction, these were not linked to radionuclide dose to fishes. This finding was further supported by assessing the health of forage fishes, which did not significantly change in the pre-versus post-pike fish communities and were comparable in condition to forage fishes inhabiting lakes with background radionuclide levels. Application of such resilient species as 'baseline organisms' can provide a useful tool in the routine monitoring of ecosystems affected by multiple stressors. (author)

Effect of forage quality in faeces from different ruminant species fed high and low quality forage

DEFF Research Database (Denmark)

Jalali, A R; Nørgaard, P; Nielsen, M O

2010-01-01

Effect of forage quality in faeces from different ruminant species fed high and low quality forage......Effect of forage quality in faeces from different ruminant species fed high and low quality forage...

Variations of thiaminase I activity pH dependencies among typical Great Lakes forage fish and Paenibacillus thiaminolyticus.

Science.gov (United States)

Zajicek, J.L.; Brown, L.; Brown, S.B.; Honeyfield, D.C.; Fitzsimons, J.D.; Tillitt, D.E.

2009-01-01

The source of thiaminase in the Great Lakes food web remains unknown. Biochemical characterization of the thiaminase I activities observed in forage fish was undertaken to provide insights into potential thiaminase sources and to optimize catalytic assay conditions. We measured the thiaminase I activities of crude extracts from five forage fish species and one strain of Paenibacillus thiaminolyticus over a range of pH values. The clupeids, alewife Alosa pseudoharengus and gizzard shad Dorosoma cepedianum, had very similar thiaminase I pH dependencies, with optimal activity ranges (> or = 90% of maximum activity) between pH 4.6 and 5.5. Rainbow smelt Osmerus mordax and spottail shiner Notropis hudsonius had optimal activity ranges between pH 5.5-6.6. The thiaminase I activity pH dependence profile of P. thiaminolyticus had an optimal activity range between pH 5.4 and 6.3, which was similar to the optimal range for rainbow smelt and spottail shiners. Incubation of P. thiaminolyticus extracts with extracts from bloater Coregonus hoyi (normally, bloaters have little or no detectable thiaminase I activity) did not significantly alter the pH dependence profile of P. thiaminolyticus-derived thiaminase I, such that it continued to resemble that of the rainbow smelt and spottail shiner, with an apparent optimal activity range between pH 5.7 and 6.6. These data are consistent with the hypothesis of a bacterial source for thiaminase I in the nonclupeid species of forage fish; however, the data also suggest different sources of thiaminase I enzymes in the clupeid species.

Turtle cleaners: reef fishes foraging on epibionts of sea turtles in the tropical Southwestern Atlantic, with a summary of this association type

Directory of Open Access Journals (Sweden)

Cristina Sazima

Full Text Available In the present study we record several instances of reef fish species foraging on epibionts of sea turtles (cleaning symbiosis at the oceanic islands of Fernando de Noronha Archipelago and near a shipwreck, both off the coast of Pernambuco State, northeast Brazil. Nine reef fish species and three turtle species involved in cleaning are herein recorded. Besides our records, a summary of the literature on this association type is presented. Postures adopted by turtles during the interaction are related to the habits of associated fishes. Feeding associations between fishes and turtles seem a localized, albeit common, phenomenon.

Habitat Requirements and Foraging Ecology of the Madagascar Fish-Eagle

OpenAIRE

Berkelman, James

1997-01-01

With a population estimate of 99 pairs, the Madagascar fish-eagle (Haliaeetus vociferoides) is one of the rarest birds of prey in the world. I investigated the ecological requirements of the Madagascar fish-eagle in 1994 and 1995 to help determine management action to prevent its extinction. I investigated fish-eagle foraging ecology in 1996 to determine its prey preference and whether fish abundance and availabi...

Positive Interactions among Foraging Seabirds, Marine Mammals and Fishes and Implications for Their Conservation

Directory of Open Access Journals (Sweden)

Richard R. Veit

2017-10-01

Full Text Available There is increasing recognition of the importance of “positive interactions” among species in structuring communities. For seabirds, an important kind of positive interaction is the use of birds of the same species, birds of other species, and other marine predators such as cetaceans, seals and fishes as cues to the presence of prey. The process by which a single bird uses, say, a feeding flock of birds as a cue to the presence of prey is called “local enhancement” or “facilitation.” There are subtly different uses of each of these terms, but the issue we address here is the ubiquity of positive interactions between seabirds and other marine predators when foraging at sea, and whether as a result of their associations the feeding success, and therefore presumably the fitness, of individual seabirds is increased. If this contention is true, then it implies that conservation of any one species of seabird must take into consideration the status and possible conservation of those species that the focal species uses as a cue while foraging. For example, conservation of great shearwaters (Ardenna gravis, which often feed over tuna (e.g., Thunnus schools, should take in to consideration conservation of tuna. Ecosystem management depends on understanding the importance of such processes; the loss of biodiversity, and the consequent threat to foraging success, may be a substantial threat to the stability of marine ecosystems.

Terrestrial and Marine Foraging Strategies of an Opportunistic Seabird Species Breeding in the Wadden Sea.

Directory of Open Access Journals (Sweden)

Stefan Garthe

Full Text Available Lesser black-backed gulls Larus fuscus are considered to be mainly pelagic. We assessed the importance of different landscape elements (open sea, tidal flats and inland by comparing marine and terrestrial foraging behaviours in lesser black-backed gulls breeding along the coast of the southern North Sea. We attached GPS data loggers to eight incubating birds and collected information on diet and habitat use. The loggers recorded data for 10-19 days to allow flight-path reconstruction. Lesser black-backed gulls foraged in both offshore and inland areas, but rarely on tidal flats. Targets and directions were similar among all eight individuals. Foraging trips (n = 108 lasted 0.5-26.4 h (mean 8.7 h, and ranges varied from 3.0-79.9 km (mean 30.9 km. The total distance travelled per foraging trip ranged from 7.5-333.6 km (mean 97.9 km. Trips out to sea were significantly more variable in all parameters than inland trips. Presence in inland areas was closely associated with daylight, whereas trips to sea occurred at day and night, but mostly at night. The most common items in pellets were grass (48%, insects (38%, fish (28%, litter (26% and earthworms (20%. There was a significant relationship between the carbon and nitrogen isotope signals in blood and the proportional time each individual spent foraging at sea/land. On land, gulls preferentially foraged on bare ground, with significantly higher use of potato fields and significantly less use of grassland. The flight patterns of lesser black-backed gulls at sea overlapped with fishing-vessel distribution, including small beam trawlers fishing for shrimps in coastal waters close to the colony and large beam-trawlers fishing for flatfish at greater distances. Our data show that individuals made intensive use of the anthropogenic landscape and seascape, indicating that lesser black-backed gulls are not a predominantly marine species during the incubation period.

Foraging in corallivorous butterflyfish varies with wave exposure

Science.gov (United States)

Noble, Mae M.; Pratchett, Morgan S.; Coker, Darren J.; Cvitanovic, Christopher; Fulton, Christopher J.

2014-06-01

Understanding the foraging patterns of reef fishes is crucial for determining patterns of resource use and the sensitivity of species to environmental change. While changes in prey availability and interspecific competition have been linked to patterns of prey selection, body condition, and survival in coral reef fishes, rarely has the influence of abiotic environmental conditions on foraging been considered. We used underwater digital video to explore how prey availability and wave exposure influence the behavioural time budgets and prey selectivity of four species of obligate coral-feeding butterflyfishes. All four species displayed high selectivity towards live hard corals, both in terms of time invested and frequency of searching and feeding events. However, our novel analysis revealed that such selectivity was sensitive to wave exposure in some species, despite there being no significant differences in the availability of each prey category across exposures. In most cases, these obligate corallivores increased their selectivity towards their most favoured prey types at sites of high wave exposure. This suggests there are costs to foraging under different wave environments that can shape the foraging patterns of butterflyfishes in concert with other conditions such as prey availability, interspecific competition, and territoriality. Given that energy acquisition is crucial to the survival and fitness of fishes, we highlight how such environmental forcing of foraging behaviour may influence the ecological response of species to the ubiquitous and highly variable wave climates of shallow coral reefs.

The global susceptibility of coastal forage fish to competition by large jellyfish

DEFF Research Database (Denmark)

Schnedler-Meyer, Nicolas Azaña; Mariani, Patrizio; Kiørboe, Thomas

2016-01-01

dominance at low primary production, and a shift towards jellyfish with increasing productivity, turbidity and fishing. We present an index of global ecosystem susceptibility to shifts in fish–jellyfish dominance that compares well with data on jellyfish distributions and trends. The results are a step......Competition between large jellyfish and forage fish for zooplankton prey is both a possible cause of jellyfish increases and a concern for the management of marine ecosystems and fisheries. Identifying principal factors affecting this competition is therefore important for marine management......, but the lack of both good quality data and a robust theoretical framework have prevented general global analyses. Here, we present a general mechanistic food web model that considers fundamental differences in feeding modes and predation pressure between fish and jellyfish. The model predicts forage fish...

Impacts of species introductions on the health of fish communities receiving chronic radionuclide inputs

International Nuclear Information System (INIS)

Yankovich, T.L.; Casselman, J.M.; Cornett, R.J.J.

2004-01-01

There is widespread interest in gaining further understanding of the relative influences of multiple stressors on aquatic ecosystem structure and function. To address this, work has been done to evaluate the effects of the introduction of an efficient predator (northern pike) on a fish community in a small lake (Perch Lake, Chalk River, Ontario) receiving chronic inputs of radionuclides over a 50-year period. In general, large changes in fish community structure, with corresponding changes in fish health, occurred following the pike introduction. For example, several forage fish species were extirpated from the lake and densities of the past top predator, yellow perch, became greatly reduced, likely due to predation by northern pike and/or other species in the lake. The reduced perch numbers appeared to alleviate an ecological bottleneck, which resulted in significant increases in brown bullhead densities to levels that were much higher than observed in other water bodies under typical conditions. Corresponding changes in the health of the Perch Lake fish community could also be detected, and included decreased fish diversity, shifts in fish community size structure to smaller body sizes, significant reductions in fish condition factors, reduced hepato-somatic indices, depletion of fish internal fat reserves, hardening of the gastrointestinal tract, resorption of gonadal material, degradation of muscle tissue, emaciation and ultimately, mortality of northern pike and brown bullheads. Evaluation of data indicated that female fishes responded more quickly than did males in terms of condition loss, likely due to their higher energetic requirements. In addition, although pike and bullheads were detrimentally affected by the pike introduction, health of forage fish species, such as pumpkinseeds, did not appear to be greatly influenced. No clear relationships existed between fish community health and exposure to radionuclides in the lake. (author)

Has eutrophication promoted forage fish production in the Baltic Sea?

DEFF Research Database (Denmark)

Eero, Margit; Andersson, Helén C; Almroth-Rosell, Elin

2016-01-01

Reducing anthropogenic nutrient inputs is a major policy goal for restoring good environmental status of coastal marine ecosystems. However, it is unclear to what extent reducing nutrients would also lower fish production and fisheries yields. Empirical examples of changes in nutrient loads...... and concurrent fish production can provide useful insights to this question. In this paper, we investigate to what extent a multi-fold increase in nutrient loads from the 1950s to 1980s enhanced forage fish production in the Baltic Sea. We use monitoring data on fish stock dynamics covering the period...

Mercury effects on predator avoidance behavior of a forage fish, golden shiner (Notemigonus crysoleucas)

Science.gov (United States)

Webber, H.M.; Haines, T.A.

2003-01-01

Mercury contamination of fish is widespread in North America and has resulted in the establishment of fish consumption advisories to protect human health, However, the effects of mercury exposure to fish have seldom been investigated. We examined the effects of dietary mercury exposure at environmental levels in a common forage species, golden shiner (Notemigonus crysoleucas). Fish were fed either an unaltered diet (12 ng/g wet wt methylmercury [MeHg] as Hg), a low-Hg diet (455 ng/g Hg), or a high-Hg diet (959 ng/g Hg). After 90 d mean fish whole-body total Hg concentrations were 41, 230, and 518 ng/g wet wt, respectively, which were within the range of concentrations found in this species in northern U.S. lakes. There were no mortalities or differences in growth rate among groups. Groups of fish from each treatment were exposed to a model avian predator and their behavioral response videotaped for analysis. Brain acetylcholinesterase (AChE) activity was determined in fish after behavioral testing. Fish fed the high-Hg diet had significantly greater shoal vertical dispersal following predator exposure, took longer to return to pre-exposure activity level, and had greater shoal area after return to pre-exposure activity than did the other treatments, all of which would increase vulnerability of the fish to predation. There were no differences in brain AChE among treatments. We conclude that mercury exposure at levels currently occurring in northern United States lakes alters fish predator-avoidance behavior in a manner that may increase vulnerability to predation. This finding has significant implications for food chain transfer of Hg and Hg exposure of fish predators.

Evaluation of nutritional value some forage species available in Iran ...

African Journals Online (AJOL)

Novin

2012-07-17

Jul 17, 2012 ... and chemical composition of forage species was estimated. MATERIALS AND METHODS ... head per day at 8.00 a.m. and 6.00 p.m. Forage samples (2 g DM with 2 mm screen ) were weighed into nylon bags ..... methods to study the kinetics of degradation of forage species, instead of the in situ technique, ...

Oceanographic conditions structure forage fishes into lipid-rich and lipid-poor communities in lower Cook Inlet, Alaska, USA

Science.gov (United States)

Abookire, Alisa A.; Piatt, John F.

2005-01-01

Forage fishes were sampled with a mid-water trawl in lower Cook Inlet, Alaska, USA, from late July to early August 1996 to 1999. We sampled 3 oceanographically distinct areas of lower Cook Inlet: waters adjacent to Chisik Island, in Kachemak Bay, and near the Barren Islands. In 163 tows using a mid-water trawl, 229 437 fishes with fork length lipid-poor gadids (walleye pollock and Pacific cod), and significantly increased in lipid-rich species such as Pacific sand lance, Pacific herring, and capelin. ?? Inter-Research 2005.

Optimal Foraging for Multiple Resources in Several Food Species

NARCIS (Netherlands)

Hengeveld, G.M.; Langevelde, van F.; Groen, T.A.; Knegt, de H.J.

2009-01-01

The concentrations of resources in forage are not perfectly balanced to the needs of an animal, and food species differ in these concentrations. Under many circumstances, animals should thus forage on multiple food species to attain the maximum and most balanced intake of several resources. In this

Optimal foraging for multiple resources in several food species

NARCIS (Netherlands)

Hengeveld, G.M.; van Langevelde, F.; Groen, T.A.; de Knegt, H.J.

2009-01-01

The concentrations of resources in forage are not perfectly balanced to the needs of an animal, and food species differ in these concentrations. Under many circumstances, animals should thus forage on multiple food species to attain the maximum and most balanced intake of several resources. In this

Morphology and Efficiency of a Specialized Foraging Behavior, Sediment Sifting, in Neotropical Cichlid Fishes

Science.gov (United States)

Willis, Stuart; Watkins, Crystal; Honeycutt, Rodney L.; Winemiller, Kirk O.

2014-01-01

Understanding of relationships between morphology and ecological performance can help to reveal how natural selection drives biological diversification. We investigate relationships between feeding behavior, foraging performance and morphology within a diverse group of teleost fishes, and examine the extent to which associations can be explained by evolutionary relatedness. Morphological adaptation associated with sediment sifting was examined using a phylogenetic linear discriminant analysis on a set of ecomorphological traits from 27 species of Neotropical cichlids. For most sifting taxa, feeding behavior could be effectively predicted by a linear discriminant function of ecomorphology across multiple clades of sediment sifters, and this pattern could not be explained by shared evolutionary history alone. Additionally, we tested foraging efficiency in seven Neotropical cichlid species, five of which are specialized benthic feeders with differing head morphology. Efficiency was evaluated based on the degree to which invertebrate prey could be retrieved at different depths of sediment. Feeding performance was compared both with respect to feeding mode and species using a phylogenetic ANCOVA, with substrate depth as a covariate. Benthic foraging performance was constant across sediment depths in non-sifters but declined with depth in sifters. The non-sifting Hypsophrys used sweeping motions of the body and fins to excavate large pits to uncover prey; this tactic was more efficient for consuming deeply buried invertebrates than observed among sediment sifters. Findings indicate that similar feeding performance among sediment-sifting cichlids extracting invertebrate prey from shallow sediment layers reflects constraints associated with functional morphology and, to a lesser extent, phylogeny. PMID:24603485

Morphology and efficiency of a specialized foraging behavior, sediment sifting, in neotropical cichlid fishes.

Directory of Open Access Journals (Sweden)

Hernán López-Fernández

Full Text Available Understanding of relationships between morphology and ecological performance can help to reveal how natural selection drives biological diversification. We investigate relationships between feeding behavior, foraging performance and morphology within a diverse group of teleost fishes, and examine the extent to which associations can be explained by evolutionary relatedness. Morphological adaptation associated with sediment sifting was examined using a phylogenetic linear discriminant analysis on a set of ecomorphological traits from 27 species of Neotropical cichlids. For most sifting taxa, feeding behavior could be effectively predicted by a linear discriminant function of ecomorphology across multiple clades of sediment sifters, and this pattern could not be explained by shared evolutionary history alone. Additionally, we tested foraging efficiency in seven Neotropical cichlid species, five of which are specialized benthic feeders with differing head morphology. Efficiency was evaluated based on the degree to which invertebrate prey could be retrieved at different depths of sediment. Feeding performance was compared both with respect to feeding mode and species using a phylogenetic ANCOVA, with substrate depth as a covariate. Benthic foraging performance was constant across sediment depths in non-sifters but declined with depth in sifters. The non-sifting Hypsophrys used sweeping motions of the body and fins to excavate large pits to uncover prey; this tactic was more efficient for consuming deeply buried invertebrates than observed among sediment sifters. Findings indicate that similar feeding performance among sediment-sifting cichlids extracting invertebrate prey from shallow sediment layers reflects constraints associated with functional morphology and, to a lesser extent, phylogeny.

Morphology and efficiency of a specialized foraging behavior, sediment sifting, in neotropical cichlid fishes.

Science.gov (United States)

López-Fernández, Hernán; Arbour, Jessica; Willis, Stuart; Watkins, Crystal; Honeycutt, Rodney L; Winemiller, Kirk O

2014-01-01

Understanding of relationships between morphology and ecological performance can help to reveal how natural selection drives biological diversification. We investigate relationships between feeding behavior, foraging performance and morphology within a diverse group of teleost fishes, and examine the extent to which associations can be explained by evolutionary relatedness. Morphological adaptation associated with sediment sifting was examined using a phylogenetic linear discriminant analysis on a set of ecomorphological traits from 27 species of Neotropical cichlids. For most sifting taxa, feeding behavior could be effectively predicted by a linear discriminant function of ecomorphology across multiple clades of sediment sifters, and this pattern could not be explained by shared evolutionary history alone. Additionally, we tested foraging efficiency in seven Neotropical cichlid species, five of which are specialized benthic feeders with differing head morphology. Efficiency was evaluated based on the degree to which invertebrate prey could be retrieved at different depths of sediment. Feeding performance was compared both with respect to feeding mode and species using a phylogenetic ANCOVA, with substrate depth as a covariate. Benthic foraging performance was constant across sediment depths in non-sifters but declined with depth in sifters. The non-sifting Hypsophrys used sweeping motions of the body and fins to excavate large pits to uncover prey; this tactic was more efficient for consuming deeply buried invertebrates than observed among sediment sifters. Findings indicate that similar feeding performance among sediment-sifting cichlids extracting invertebrate prey from shallow sediment layers reflects constraints associated with functional morphology and, to a lesser extent, phylogeny.

A stochastic differential equation model for the foraging behavior of fish schools.

Science.gov (United States)

Tạ, Tôn Việt; Nguyen, Linh Thi Hoai

2018-03-15

Constructing models of living organisms locating food sources has important implications for understanding animal behavior and for the development of distribution technologies. This paper presents a novel simple model of stochastic differential equations for the foraging behavior of fish schools in a space including obstacles. The model is studied numerically. Three configurations of space with various food locations are considered. In the first configuration, fish swim in free but limited space. All individuals can find food with large probability while keeping their school structure. In the second and third configurations, they move in limited space with one and two obstacles, respectively. Our results reveal that the probability of foraging success is highest in the first configuration, and smallest in the third one. Furthermore, when school size increases up to an optimal value, the probability of foraging success tends to increase. When it exceeds an optimal value, the probability tends to decrease. The results agree with experimental observations.

A stochastic differential equation model for the foraging behavior of fish schools

Science.gov (United States)

Tạ, Tôn ệt, Vi; Hoai Nguyen, Linh Thi

2018-05-01

Constructing models of living organisms locating food sources has important implications for understanding animal behavior and for the development of distribution technologies. This paper presents a novel simple model of stochastic differential equations for the foraging behavior of fish schools in a space including obstacles. The model is studied numerically. Three configurations of space with various food locations are considered. In the first configuration, fish swim in free but limited space. All individuals can find food with large probability while keeping their school structure. In the second and third configurations, they move in limited space with one and two obstacles, respectively. Our results reveal that the probability of foraging success is highest in the first configuration, and smallest in the third one. Furthermore, when school size increases up to an optimal value, the probability of foraging success tends to increase. When it exceeds an optimal value, the probability tends to decrease. The results agree with experimental observations.

A foraging cost of migration for a partially migratory cyprinid fish

DEFF Research Database (Denmark)

Chapman, Ben B; Eriksen, Anders; Baktoft, Henrik

2013-01-01

Rutilus rutilus, which migrates from shallow lakes to streams during winter. By sampling fish from stream and lake habitats in the autumn and spring and measuring their stomach fullness and diet composition, we tested if migrating roach pay a cost of reduced foraging when migrating. Resident fish had...... fuller stomachs containing more high quality prey items than migrant fish. Hence, we document a feeding cost to migration in roach, which adds additional support for the validity of the p/g model of migration in freshwater systems....

Evaluating the role of large jellyfish and forage fishes as energy pathways, and their interplay with fisheries, in the Northern Humboldt Current System

Science.gov (United States)

Chiaverano, Luciano M.; Robinson, Kelly L.; Tam, Jorge; Ruzicka, James J.; Quiñones, Javier; Aleksa, Katrina T.; Hernandez, Frank J.; Brodeur, Richard D.; Leaf, Robert; Uye, Shin-ichi; Decker, Mary Beth; Acha, Marcelo; Mianzan, Hermes W.; Graham, William M.

2018-05-01

Large jellyfish are important consumers of plankton, fish eggs and fish larvae in heavily fished ecosystems worldwide; yet they are seldom included in fisheries production models. Here we developed a trophic network model with 41 functional groups using ECOPATH re-expressed in a donor-driven, end-to-end format to directly evaluate the efficiency of large jellyfish and forage fish at transferring energy to higher trophic levels, as well as the ecosystem-wide effects of varying jellyfish and forage fish consumption rates and fishing rates, in the Northern Humboldt Current system (NHCS) off of Peru. Large jellyfish were an energy-loss pathway for high trophic-level consumers, while forage fish channelized the production of lower trophic levels directly into production of top-level consumers. A simulated jellyfish bloom resulted in a decline in productivity of all functional groups, including forage fish (12%), with the exception of sea turtles. A modeled increase in forage fish consumption rate by 50% resulted in a decrease in large jellyfish productivity (29%). A simulated increase of 40% in forage fish harvest enhanced jellyfish productivity (24%), while closure of all fisheries caused a decline in large jellyfish productivity (26%) and productivity increases in upper level consumers. These outcomes not only suggest that jellyfish blooms and fisheries have important effects on the structure of the NHCS, but they also support the hypothesis that forage fishing provides a competitive release for large jellyfish. We recommend including jellyfish as a functional group in future ecosystem modeling efforts, including ecosystem-based approaches to fishery management of coastal ecosystems worldwide.

A new approach to study of seabird-fishery overlap: Connecting chick feeding with parental foraging and overlap with fishing vessels

Directory of Open Access Journals (Sweden)

Junichi Sugishita

2015-07-01

Full Text Available Incidental fisheries bycatch is recognised as a major threat to albatross populations worldwide. However, fishery discards and offal produced in large quantities might benefit some scavenging seabirds. Here, we demonstrate an integrated approach to better understand the ecological ramifications of fine-scale overlap between seabirds and fisheries. As a case study, we examined whether foraging in association with a fishing vessel is advantageous for chick provisioning in terms of quantity of food delivered to chicks, in northern royal albatross (Diomedea sanfordi at Taiaroa Head, New Zealand. Fine-scale overlap between albatrosses and vessels was quantified by integrating GPS tracking and Vessel Monitoring Systems (VMS. Meal size delivered to chicks was measured using custom-designed nest balances, and monitoring of attendance of adults fitted with radio transmitters was used in conjunction with time-lapse photography at the nest allowed us to allocate each feeding event to a specific parent. The combination of these techniques enabled comparison of meal sizes delivered to chicks with parental foraging trip durations with or without fishing vessels association. A total of 45 foraging trips and associated chick feeding events were monitored during the chick-rearing period in 2012. Differences in the meal size and foraging trip duration relative to foraging overlap with fisheries were examined using a linear mixed-effect model, adjusted for chick age. Our results, based on three birds, suggest that foraging in association with vessels does not confer an advantage for chick feeding for this population that demonstrated low rates of overlap while foraging. The integrated research design presented can be applied to other seabird species that are susceptible to bycatch, and offers a valuable approach to evaluate habitat quality by linking habitat use and foraging success in terms of total amount of food delivered to offspring.

Investigating functional redundancy versus complementarity in Hawaiian herbivorous coral reef fishes.

Science.gov (United States)

Kelly, Emily L A; Eynaud, Yoan; Clements, Samantha M; Gleason, Molly; Sparks, Russell T; Williams, Ivor D; Smith, Jennifer E

2016-12-01

Patterns of species resource use provide insight into the functional roles of species and thus their ecological significance within a community. The functional role of herbivorous fishes on coral reefs has been defined through a variety of methods, but from a grazing perspective, less is known about the species-specific preferences of herbivores on different groups of reef algae and the extent of dietary overlap across an herbivore community. Here, we quantified patterns of redundancy and complementarity in a highly diverse community of herbivores at a reef on Maui, Hawaii, USA. First, we tracked fish foraging behavior in situ to record bite rate and type of substrate bitten. Second, we examined gut contents of select herbivorous fishes to determine consumption at a finer scale. Finally, we placed foraging behavior in the context of resource availability to determine how fish selected substrate type. All species predominantly (73-100 %) foraged on turf algae, though there were differences among the types of macroalgae and other substrates bitten. Increased resolution via gut content analysis showed the composition of turf algae consumed by fishes differed across herbivore species. Consideration of foraging behavior by substrate availability revealed 50 % of herbivores selected for turf as opposed to other substrate types, but overall, there were variable foraging portfolios across all species. Through these three methods of investigation, we found higher complementarity among herbivorous fishes than would be revealed using a single metric. These results suggest differences across species in the herbivore "rain of bites" that graze and shape benthic community composition.

Ecosystem-based management objectives for the North Sea: riding the forage fish rollercoaster

DEFF Research Database (Denmark)

Dickey-Collas, Mark; Engelhard, Georg H.; Rindorf, Anna

2014-01-01

The North Sea provides a useful model for considering forage fish (FF) within ecosystem-based management as it has a complex assemblage of FF species. This paper is designed to encourage further debate and dialogue between stakeholders about management objectives. Changing the management...... whether maintaining the reserves of prey biomass or a more integral approach of monitoring mortality rates across the trophic system is more robust under the ecosystem approach. In terms of trophic energy transfer, stability, and resilience of the ecosystem, FF should be considered as both a sized-based...... pool of biomass and as species components of the system by managers and modellers. Policy developers should not consider the knowledge base robust enough to embark on major projects of ecosystem engineering. Management plans appear able to maintain sustainable exploitation in the short term. Changes...

Shifts in North Sea forage fish productivity and potential fisheries yield

NARCIS (Netherlands)

Clausen, Lotte W.; Rindorf, Anna; Deurs, van Mikael; Dickey-Collas, Mark; Hintzen, Niels T.

2018-01-01

1. Forage fish populations support large scale fisheries and are key components of marine ecosystems across the world, linking secondary production to higher trophic levels. While climate-induced changes in the North Sea zooplankton community are described and documented in literature, the

Turbidity interferes with foraging success of visual but not chemosensory predators.

Science.gov (United States)

Lunt, Jessica; Smee, Delbert L

2015-01-01

Predation can significantly affect prey populations and communities, but predator effects can be attenuated when abiotic conditions interfere with foraging activities. In estuarine communities, turbidity can affect species richness and abundance and is changing in many areas because of coastal development. Many fish species are less efficient foragers in turbid waters, and previous research revealed that in elevated turbidity, fish are less abundant whereas crabs and shrimp are more abundant. We hypothesized that turbidity altered predatory interactions in estuaries by interfering with visually-foraging predators and prey but not with organisms relying on chemoreception. We measured the effects of turbidity on the predation rates of two model predators: a visual predator (pinfish, Lagodon rhomboides) and a chemosensory predator (blue crabs, Callinectes sapidus) in clear and turbid water (0 and ∼100 nephelometric turbidity units). Feeding assays were conducted with two prey items, mud crabs (Panopeus spp.) that rely heavily on chemoreception to detect predators, and brown shrimp (Farfantepenaus aztecus) that use both chemical and visual cues for predator detection. Because turbidity reduced pinfish foraging on both mud crabs and shrimp, the changes in predation rates are likely driven by turbidity attenuating fish foraging ability and not by affecting prey vulnerability to fish consumers. Blue crab foraging was unaffected by turbidity, and blue crabs were able to successfully consume nearly all mud crab and shrimp prey. Turbidity can influence predator-prey interactions by reducing the feeding efficiency of visual predators, providing a competitive advantage to chemosensory predators, and altering top-down control in food webs.

An indicator for ecosystem externalities in fishing

DEFF Research Database (Denmark)

Ravn-Jonsen, Lars; Andersen, Ken Haste; Vestergaard, Niels

2016-01-01

Ecosystem externalities arise when one use of an ecosystem affects its other uses through the production functions of the ecosystem. We use simulations with a size-spectrum ecosystem model to investigate the ecosystem externality created by fishing of multiple species. The model is based upon...... general ecological principles and is calibrated to the North Sea. Two fleets are considered: a "forage fish" fleet targeting species that mature at small sizes and a "large fish" fleet targeting large piscivorous species. Based on the marginal analysis of the present value of the rent, we develop...... a benefit indicator that explicitly divides the consequences of fishing into internal and external benefits. This analysis demonstrates that the forage fish fleet has a notable economic impact on the large fish fleet, but the reverse is not true. The impact can be either negative or positive, which entails...

A day in the life of fish larvae: modeling foraging and growth using quirks.

Directory of Open Access Journals (Sweden)

Klaus B Huebert

Full Text Available This article introduces "Quirks," a generic, individual-based model synthesizing over 40 years of empirical and theoretical insights into the foraging behavior and growth physiology of marine fish larvae. In Quirks, different types of larvae are defined by a short list of their biological traits, and all foraging and growth processes (including the effects of key environmental factors are modeled following one unified set of mechanistic rules. This approach facilitates ecologically meaningful comparisons between different species and environments. We applied Quirks to model young exogenously feeding larvae of four species: 5.5-mm European anchovy (Engraulis encrasicolus, 7-mm Atlantic cod (Gadus morhua, 13-mm Atlantic herring (Clupea harengus, and 7-mm European sprat (Sprattus sprattus. Modeled growth estimates explained the majority of variability among 53 published empirical growth estimates, and displayed very little bias: 0.65% ± 1.2% d(-1 (mean ± standard error. Prey organisms of ∼ 67% the maximum ingestible prey length were optimal for all larval types, in terms of the expected ingestion per encounter. Nevertheless, the foraging rate integrated over all favorable prey sizes was highest when smaller organisms made up >95% of the prey biomass under the assumption of constant normalized size spectrum slopes. The overall effect of turbulence was consistently negative, because its detrimental influence on prey pursuit success exceeded its beneficial influence on prey encounter rate. Model sensitivity to endogenous traits and exogenous environmental factors was measured and is discussed in depth. Quirks is free software and open source code is provided.

Invasive clonal plant species have a greater root-foraging plasticity than non-invasive ones.

Science.gov (United States)

Keser, Lidewij H; Dawson, Wayne; Song, Yao-Bin; Yu, Fei-Hai; Fischer, Markus; Dong, Ming; van Kleunen, Mark

2014-03-01

Clonality is frequently positively correlated with plant invasiveness, but which aspects of clonality make some clonal species more invasive than others is not known. Due to their spreading growth form, clonal plants are likely to experience spatial heterogeneity in nutrient availability. Plasticity in allocation of biomass to clonal growth organs and roots may allow these plants to forage for high-nutrient patches. We investigated whether this foraging response is stronger in species that have become invasive than in species that have not. We used six confamilial pairs of native European clonal plant species differing in invasion success in the USA. We grew all species in large pots under homogeneous or heterogeneous nutrient conditions in a greenhouse, and compared their nutrient-foraging response and performance. Neither invasive nor non-invasive species showed significant foraging responses to heterogeneity in clonal growth organ biomass or in aboveground biomass of clonal offspring. Invasive species had, however, a greater positive foraging response in terms of root and belowground biomass than non-invasive species. Invasive species also produced more total biomass. Our results suggest that the ability for strong root foraging is among the characteristics promoting invasiveness in clonal plants.

Foraging intention affects whether willow tits call to attract members of mixed-species flocks.

Science.gov (United States)

Suzuki, Toshitaka N; Kutsukake, Nobuyuki

2017-06-01

Understanding how individual behaviour influences the spatial and temporal distribution of other species is necessary to resolve the complex structure of species assemblages. Mixed-species bird flocks provide an ideal opportunity to investigate this issue, because members of the flocks are involved in a variety of behavioural interactions between species. Willow tits ( Poecile montanus ) often produce loud calls when visiting a new foraging patch to recruit other members of mixed-species flocks. The costs and benefits of flocking would differ with individual foraging behaviours (i.e. immediate consumption or caching); thus, willow tits may adjust the production of loud calls according to their foraging intention. In this study, we investigated the link between foraging decisions and calling behaviour in willow tits and tested its influence on the temporal cohesion with members of mixed-species flocks. Observations at experimental foraging patches showed that willow tits produced more calls when they consumed food items compared with when they cached them. Playback experiments revealed that these calls attracted flock members and helped to maintain their presence at foraging patches. Thus, willow tits adjusted calling behaviour according to their foraging intention, thereby coordinating the associations with members of mixed-species flocks. Our findings demonstrate the influence of individual decision-making on temporal cohesion with other species and highlight the importance of interspecific communication in mixed-species flocking dynamics.

Study the Seasonal Variability of Plankton and Forage Fish in the Gulf of Khambhat Using Npzfd Model

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Kumar, V.; Kumar, S.

2016-02-01

Numerical modelling of marine ecology exploits several assumptions and it is indeed quite challenging to include marine ecological phenomena into a mathematical framework with too many unknown parameters. The governing ordinary differential equations represent the interaction of the biological and chemical processes in a marine environment. The key concern in the development of a numerical models are parameterizations based on output, viz., mathematical modelling of ecological system mainly depends on parameters and its variations. Almost, all constituents of each trophic level of marine food web are depended on phytoplankton, which are mostly influenced by initial slope of P-I curve and nutrient stock in the study domain. Whereas, the earlier plankton dynamic models rarely include a compartment of small fish and as an agent in zooplankton mortality, which is most important for the modelling of higher trophic level of marine species. A compartment of forage fish in the modelling of plankton dynamics has been given more realistic mortality rates of plankton, viz., they feed upon phytoplankton and zooplankton. The inclusion of an additional compartment increases complexity of earlier plankton dynamics model as it introduces additional unknown parameters, which has been specified for performing the numerical simulations.As a case study we applied our analysis to explain the aquatic ecology of Gulf of Khambhat (19o 48' N - 22o20' N, 65o E - 72o40' E), west coast of India, which has rich bio-diversity and a high productive area in the form of plankton and forage fish. It has elevated turbidity and varying geography location, viz., one of the regions among world's ocean with high biological productivity.The model presented in this study is able to bring out the essential features of the observed data; that includes the bimodal oscillations in the observed data, monthly mean chlorophyll-a in the SeaWiFs/MODIS Aqua data and in-situ data of plankton. The additional

Simulating mechanisms for dispersal, production and stranding of small forage fish in temporary wetland habitats

Science.gov (United States)

Yurek, Simeon; DeAngelis, Donald L.; Trexler, Joel C.; Jopp, Fred; Donalson, Douglas D.

2013-01-01

Movement strategies of small forage fish (wetland habitats affect their overall population growth and biomass concentrations, i.e., availability to predators. These fish are often the key energy link between primary producers and top predators, such as wading birds, which require high concentrations of stranded fish in accessible depths. Expansion and contraction of seasonal wetlands induce a sequential alternation between rapid biomass growth and concentration, creating the conditions for local stranding of small fish as they move in response to varying water levels. To better understand how landscape topography, hydrology, and fish behavior interact to create high densities of stranded fish, we first simulated population dynamics of small fish, within a dynamic food web, with different traits for movement strategy and growth rate, across an artificial, spatially explicit, heterogeneous, two-dimensional marsh slough landscape, using hydrologic variability as the driver for movement. Model output showed that fish with the highest tendency to invade newly flooded marsh areas built up the largest populations over long time periods with stable hydrologic patterns. A higher probability to become stranded had negative effects on long-term population size, and offset the contribution of that species to stranded biomass. The model was next applied to the topography of a 10 km × 10 km area of Everglades landscape. The details of the topography were highly important in channeling fish movements and creating spatiotemporal patterns of fish movement and stranding. This output provides data that can be compared in the future with observed locations of fish biomass concentrations, or such surrogates as phosphorus ‘hotspots’ in the marsh.

Quality of the forage apparently consumed by beef calves in natural grassland under fertilization and oversown with cool season forage species

Directory of Open Access Journals (Sweden)

Denise Adelaide Gomes Elejalde

2012-06-01

Full Text Available The objective of this study was to evaluate the chemical composition of the forage apparently consumed by steers in a natural grassland on region of Campanha, in Rio Grande do Sul, Brazil, subjected or not to different inputs: NP - natural pasture without inputs; FNP - fertilized natural pasture and INP - improved natural grassland with fertilization and over-seeded with cultivated winter species. Three Angus steers testers and a variable number of regulator animals per experimental unit were utilized in order to maintain 13 kg of DM/100 kg of live weight (LW as forage allowance. One time at each season, hand plucking samples were performed along the daily grazing time simulating forage harvested by the animals. The collected samples after drying and grind were submitted to chemical analysis to determine the forage quality. Except in winter and spring, the values of neutral detergent fiber were higher than the critical value of 550 g/kg of DM, which could limit forage intake, demonstrating that the values of forage on offer provided (15.6; 13.7; 13.5; 15.8 kg of DM/100 kg of LW/day in summer, autumn, winter and spring, respectively were not restrictive to intake. The oversowing of winter cultivated species or fertilization positively alter the degradable fiber content. The seasons had marked influence on the chemical composition of forage apparently consumed; positively increasing some fractions of forage chemical composition in the seasons in which native or cultivated winter species increased their participation. The forage chemical composition is the determining factor in animal performance in natural pasture.

Fishing down the largest coral reef fish species.

Science.gov (United States)

Fenner, Douglas

2014-07-15

Studies on remote, uninhabited, near-pristine reefs have revealed surprisingly large populations of large reef fish. Locations such as the northwestern Hawaiian Islands, northern Marianas Islands, Line Islands, U.S. remote Pacific Islands, Cocos-Keeling Atoll and Chagos archipelago have much higher reef fish biomass than islands and reefs near people. Much of the high biomass of most remote reef fish communities lies in the largest species, such as sharks, bumphead parrots, giant trevally, and humphead wrasse. Some, such as sharks and giant trevally, are apex predators, but others such as bumphead parrots and humphead wrasse, are not. At many locations, decreases in large reef fish species have been attributed to fishing. Fishing is well known to remove the largest fish first, and a quantitative measure of vulnerability to fishing indicates that large reef fish species are much more vulnerable to fishing than small fish. The removal of large reef fish by fishing parallels the extinction of terrestrial megafauna by early humans. However large reef fish have great value for various ecological roles and for reef tourism. Copyright © 2014 Elsevier Ltd. All rights reserved.

Prey fish returned to Forster's tern colonies suggest spatial and temporal differences in fish composition and availability.

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Peterson, Sarah H; Ackerman, Joshua T; Eagles-Smith, Collin A; Herzog, Mark P; Hartman, C Alex

2018-01-01

Predators sample the available prey community when foraging; thus, changes in the environment may be reflected by changes in predator diet and foraging preferences. We examined Forster's tern (Sterna forsteri) prey species over an 11-year period by sampling approximately 10,000 prey fish returned to 17 breeding colonies in south San Francisco Bay, California. We compared the species composition among repeatedly-sampled colonies (≥ 4 years), using both relative species abundance and the composition of total dry mass by species. Overall, the relative abundances of prey species at seven repeatedly-sampled tern colonies were more different than would be expected by chance, with the most notable differences in relative abundance observed between geographically distant colonies. In general, Mississippi silverside (Menidia audens) and topsmelt silverside (Atherinops affinis) comprised 42% of individuals and 40% of dry fish mass over the study period. Three-spined stickleback (Gasterosteus aculeatus) comprised the next largest proportion of prey species by individuals (19%) but not by dry mass (6%). Five additional species each contributed ≥ 4% of total individuals collected over the study period: yellowfin goby (Acanthogobius flavimanus; 10%), longjaw mudsucker (Gillichthys mirabilis; 8%), Pacific herring (Clupea pallasii; 6%), northern anchovy (Engraulis mordax; 4%), and staghorn sculpin (Leptocottus armatus; 4%). At some colonies, the relative abundance and biomass of specific prey species changed over time. In general, the abundance and dry mass of silversides increased, whereas the abundance and dry mass of three-spined stickleback and longjaw mudsucker decreased. As central place foragers, Forster's terns are limited in the distance they forage; thus, changes in the prey species returned to Forster's tern colonies suggest that the relative availability of some fish species in the environment has changed, possibly in response to alteration of the available habitat.

Fish with red fluorescent eyes forage more efficiently under dim, blue-green light conditions.

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Harant, Ulrike Katharina; Michiels, Nicolaas Karel

2017-04-20

Natural red fluorescence is particularly conspicuous in the eyes of some small, benthic, predatory fishes. Fluorescence also increases in relative efficiency with increasing depth, which has generated speculation about its possible function as a "light organ" to detect cryptic organisms under bluish light. Here we investigate whether foraging success is improved under ambient conditions that make red fluorescence stand out more, using the triplefin Tripterygion delaisi as a model system. We repeatedly presented 10 copepods to individual fish (n = 40) kept under a narrow blue-green spectrum and compared their performance with that under a broad spectrum with the same overall brightness. The experiment was repeated for two levels of brightness, a shaded one representing 0.4% of the light present at the surface and a heavily shaded one with about 0.01% of the surface brightness. Fish were 7% more successful at catching copepods under the narrow, fluorescence-friendly spectrum than under the broad spectrum. However, this effect was significant under the heavily shaded light treatment only. This outcome corroborates previous predictions that fluorescence may be an adaptation to blue-green, heavily shaded environments, which coincides with the opportunistic biology of this species that lives in the transition zone between exposed and heavily shaded microhabitats.

Fatty acid composition of forage herb species

DEFF Research Database (Denmark)

Warner, D.; Jensen, Søren Krogh; Cone, J.W.

2010-01-01

The use of alternative forage species in grasslands for intensive livestock production is receiving renewed attention. Data on fatty acid composition of herbs are scarce, so four herbs (Plantago lanceolata, Achillea millefolium, Cichorium intybus, Pastinaca sativa) and one grass species (timothy......, Phleum pratense) were sown in a cutting trial. The chemical composition and concentration of fatty acids (FA) of individual species were determined during the growing season. Concentrations of crude protein and FA were generally higher in the herbs than in timothy. C. intybus had the highest nutritive...

The foraging behaviour of herons and egrets on the Magela Creek flood plain, Northern Territory

International Nuclear Information System (INIS)

Recher, H.F.; Holmes, R.T.

1982-03-01

Five species of diurnal herons are common on the Magela Creek flood plain and forage along the edges of natural and artifical waterbodies both inside and outside the Ranger Uranium Project Area. The species of heron differ in the kinds and sizes of prey they take, their foraging location, degree of sociality and foraging behaviour. Because it takes relatively large fish, the Great Egret, E. alba, is most likely to be affected by any contamination of the aquatic environment by heavy metals or radionuclides. The Nankeen Night Heron, Nycticorax caledonicus is also abundant on the flood plain and probably feeds on large fish and frogs. The other herons take smaller or immature prey or hunt mostly in terrestrial habitats and are therefore less likely to be affected by contamination of the aquatic environment

Prey fish returned to Forster’s tern colonies suggest spatial and temporal differences in fish composition and availability

Science.gov (United States)

Peterson, Sarah; Ackerman, Joshua T.; Eagles-Smith, Collin A.; Herzog, Mark; Hartman, C. Alex

2018-01-01

Predators sample the available prey community when foraging; thus, changes in the environment may be reflected by changes in predator diet and foraging preferences. We examined Forster’s tern (Sterna forsteri) prey species over an 11-year period by sampling approximately 10,000 prey fish returned to 17 breeding colonies in south San Francisco Bay, California. We compared the species composition among repeatedly-sampled colonies (≥ 4 years), using both relative species abundance and the composition of total dry mass by species. Overall, the relative abundances of prey species at seven repeatedly-sampled tern colonies were more different than would be expected by chance, with the most notable differences in relative abundance observed between geographically distant colonies. In general, Mississippi silverside (Menidia audens) and topsmelt silverside (Atherinops affinis) comprised 42% of individuals and 40% of dry fish mass over the study period. Three-spined stickleback (Gasterosteus aculeatus) comprised the next largest proportion of prey species by individuals (19%) but not by dry mass (6%). Five additional species each contributed ≥ 4% of total individuals collected over the study period: yellowfin goby (Acanthogobius flavimanus; 10%), longjaw mudsucker (Gillichthys mirabilis; 8%), Pacific herring (Clupea pallasii; 6%), northern anchovy (Engraulis mordax; 4%), and staghorn sculpin (Leptocottus armatus; 4%). At some colonies, the relative abundance and biomass of specific prey species changed over time. In general, the abundance and dry mass of silversides increased, whereas the abundance and dry mass of three-spined stickleback and longjaw mudsucker decreased. As central place foragers, Forster’s terns are limited in the distance they forage; thus, changes in the prey species returned to Forster’s tern colonies suggest that the relative availability of some fish species in the environment has changed, possibly in response to alteration of the available

Effects of habitat composition and landscape structure on worker foraging distances of five bumble bee species.

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Redhead, John W; Dreier, Stephanie; Bourke, Andrew F G; Heard, Matthew S; Jordan, William C; Sumner, Seirian; Wang, Jinliang; Carvell, Claire

2016-04-01

Bumble bees (Bombus spp.) are important pollinators of both crops and wildflowers. Their contribution to this essential ecosystem service has been threatened over recent decades by changes in land use, which have led to declines in their populations. In order to design effective conservation measures, it is important to understand the effects of variation in landscape composition and structure on the foraging activities of worker bumble bees. This is because the viability of individual colonies is likely to be affected by the trade-off between the energetic costs of foraging over greater distances and the potential gains from access to additional resources. We used field surveys, molecular genetics, and fine resolution remote sensing to estimate the locations of wild bumble bee nests and to infer foraging distances across a 20-km² agricultural landscape in southern England, UK. We investigated five species, including the rare B. ruderatus and ecologically similar but widespread B. hortorum. We compared worker foraging distances between species and examined how variation in landscape composition and structure affected foraging distances at the colony level. Mean worker foraging distances differed significantly between species. Bombus terrestris, B. lapidarius, and B. ruderatus exhibited significantly greater mean foraging distances (551, 536, and 501 m, respectively) than B. hortorum and B. pascuorum (336 and 272 m, respectively). There was wide variation in worker foraging distances between colonies of the same species, which was in turn strongly influenced by the amount and spatial configuration of available foraging habitats. Shorter foraging distances were found for colonies where the local landscape had high coverage and low fragmentation of semi-natural vegetation, including managed agri-environmental field margins. The strength of relationships between different landscape variables and foraging distance varied between species, for example the strongest

Mercury bioaccumulation and risk to three waterbird foraging guilds is influenced by foraging ecology and breeding stage

International Nuclear Information System (INIS)

Eagles-Smith, Collin A.; Ackerman, Joshua T.; De La Cruz, Susan E.W.; Takekawa, John Y.

2009-01-01

We evaluated mercury (Hg) in five waterbird species representing three foraging guilds in San Francisco Bay, CA. Fish-eating birds (Forster's and Caspian terns) had the highest Hg concentrations in thier tissues, but concentrations in an invertebrate-foraging shorebird (black-necked stilt) were also elevated. Foraging habitat was important for Hg exposure as illustrated by within-guild differences, where species more associated with marshes and salt ponds had higher concentrations than those more associated with open-bay and tidal mudflats. Importantly, Hg concentrations increased with time spent in the estuary. Surf scoter concentrations tripled over six months, whereas Forster's terns showed an up to 5-fold increase between estuary arrival and breeding. Breeding waterbirds were at elevated risk of Hg-induced reproductive impairment, particularly Forster's terns, in which 48% of breeding birds were at high risk due to their Hg levels. Our results highlight the importance of habitat and exposure timing, in addition to trophic position, on waterbird Hg bioaccumulation and risk. - The influence of foraging habitat, trophic position, and exposure timing on mercury bioaccumulation and risk to reproduction is evaluated in three waterbird guilds.

Social learning of an associative foraging task in zebrafish

Science.gov (United States)

Zala, Sarah M.; Määttänen, Ilmari

2013-05-01

The zebrafish ( Danio rerio) is increasingly becoming an important model species for studies on the genetic and neural mechanisms controlling behaviour and cognition. Here, we utilized a conditioned place preference (CPP) paradigm to study social learning in zebrafish. We tested whether social interactions with conditioned demonstrators enhance the ability of focal naïve individuals to learn an associative foraging task. We found that the presence of conditioned demonstrators improved focal fish foraging behaviour through the process of social transmission, whereas the presence of inexperienced demonstrators interfered with the learning of the control focal fish. Our results indicate that zebrafish use social learning for finding food and that this CPP paradigm is an efficient assay to study social learning and memory in zebrafish.

Exploring the nature of ecological specialization in a coral reef fish community: morphology, diet and foraging microhabitat use.

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Brandl, Simon J; Robbins, William D; Bellwood, David R

2015-09-22

Patterns of ecological specialization offer invaluable information about ecosystems. Yet, specialization is rarely quantified across several ecological niche axes and variables beyond the link between morphological and dietary specialization have received little attention. Here, we provide a quantitative evaluation of ecological specialization in a coral reef fish assemblage (f. Acanthuridae) along one fundamental and two realized niche axes. Specifically, we examined ecological specialization in 10 surgeonfish species with regards to morphology and two realized niche axes associated with diet and foraging microhabitat utilization using a recently developed multidimensional framework. We then investigated the potential relationships between morphological and behavioural specialization. These relationships differed markedly from the traditional ecomorphological paradigm. While morphological specialization showed no relationship with dietary specialization, it exhibited a strong relationship with foraging microhabitat specialization. However, this relationship was inverted: species with specialized morphologies were microhabitat generalists, whereas generalized morphotypes were microhabitat specialists. Interestingly, this mirrors relationships found in plant-pollinator communities and may also be applicable to other ecosystems, highlighting the potential importance of including niche axes beyond dietary specialization into ecomorphological frameworks. On coral reefs, it appears that morphotypes commonly perceived as most generalized may, in fact, be specialized in exploiting flat and easily accessible microhabitats. © 2015 The Author(s).

Habitat-specific foraging strategies in Australasian gannets

Directory of Open Access Journals (Sweden)

Melanie R. Wells

2016-07-01

Full Text Available Knowledge of top predator foraging adaptability is imperative for predicting their biological response to environmental variability. While seabirds have developed highly specialised techniques to locate prey, little is known about intraspecific variation in foraging strategies with many studies deriving information from uniform oceanic environments. Australasian gannets (Morus serrator typically forage in continental shelf regions on small schooling prey. The present study used GPS and video data loggers to compare habitat-specific foraging strategies at two sites of contrasting oceanographic regimes (deep water near the continental shelf edge, n=23; shallow inshore embayment, n=26, in south-eastern Australia. Individuals from the continental shelf site exhibited pelagic foraging behaviours typical of gannet species, using local enhancement to locate and feed on small schooling fish; in contrast only 50% of the individuals from the inshore site foraged offshore, displaying the typical pelagic foraging strategy. The remainder adopted a strategy of searching sand banks in shallow inshore waters in the absence of conspecifics and other predators for large, single prey items. Furthermore, of the individuals foraging inshore, 93% were male, indicating that the inshore strategy may be sex-specific. Large inter-colony differences in Australasian gannets suggest strong plasticity in foraging behaviours, essential for adapting to environmental change.

Foraging ecology of least terns and piping plovers nesting on Central Platte River sandpits and sandbars

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Sherfy, Mark H.; Anteau, Michael J.; Shaffer, Terry L.; Sovada, Marsha A.; Stucker, Jennifer H.

2012-01-01

Federally listed least terns (Sternula antillarum) and piping plovers (Charadrius melodus) nest on riverine sandbars on many major midcontinent river systems. On the Central Platte River, availability of sandbar habitat is limited, and both species nest on excavated sandpits in the river's floodplain. However, the extent to which sandpit-nesting birds use riverine habitats for foraging is unknown. We evaluated use of foraging habitats by least terns and piping plovers by collecting data on movements, behavior, foraging habitat, and productivity. We radiomarked 16 piping plovers and 23 least terns in 2009-2010 and monitored their movements using a network of fixed telemetry dataloggers. Piping plovers were detected primarily by the datalogger located in their nesting sandpit, whereas least terns were more frequently detected on dataloggers outside of the nesting sandpit. Telemetry data and behavioral observations showed that least terns tended to concentrate at the Kearney Canal Diversion Gates, where forage fish were apparently readily available. Fish sampling data suggested that forage fish were more abundant in riverine than in sandpit habitats, and behavioral observations showed that least terns foraged more frequently in riverine than in sandpit habitats. Piping plovers tended to forage in wet substrates along sandpit shorelines, but also used dry substrates and sandpit interior habitats. The greater mobility of least terns makes a wider range of potential foraging habitats available during brood rearing, making them able to exploit concentrations of fish outside the nesting colony. Thus, our data suggest that different spatial scales should be considered in managing nesting and foraging habitat complexes for piping plovers and least terns.

Effects of forage species or concentrate finishing on animal performance, carcass and meat quality.

Science.gov (United States)

Duckett, S K; Neel, J P S; Lewis, R M; Fontenot, J P; Clapham, W M

2013-03-01

Angus-cross steers (n = 128; initial BW = 270 ± 3.8 kg) were used in a 3-yr study to assess effects of forage species grazed before slaughter versus concentrate finishing on carcass and meat quality. At the completion of the stockering phase, steers were randomly allotted to mixed pasture (MP; n = 36/yr) or corn-silage concentrate (CON; n = 12/yr) finishing treatments. At 40 d before harvest, MP steers were randomly divided into 3 forage species treatments: alfalfa (AL), pearl millet (PM), or mixed pasture (MP). Average daily BW gain was greater (P = 0.001) for CON than for forage-finished (FOR) steers during the early and overall finishing phase. During the late finishing phase when FOR steers were grazing difference forage species, ADG was greater (P = 0.03) for PM than MP or AL. Harvest weight and HCW were greater (P animal performance. Total fat percentage of the 9th to 11th rib section was 46% less(P = 0.028) for FOR than CON due to reductions (P 0.78) between CON and FOR and were not altered (P > 0.40) by forage species. Trained sensory panel juiciness, initial tenderness, and overall tenderness scores did not differ (P > 0.17) by finishing treatment or forage species. Beef flavor intensity was greater (P 0.05) total lipid content of the LM. Oleic acid concentration and total MUFA of the LM were 21% and 22% less (P = 0.001) for FOR than CON. Concentrations of all individual [linolenic acid, eicosapentaenoic (EPA), docosapentaenoic (DPA), and docosadexaenoic (DHA) acids] and total n-3 fatty acids were greater (P carcass weight with same time endpoints and accelerates deposition of MUFA in comparison with FOR, which reduces carcass weight and fat deposition but maintains high concentrations of n-3 and CLA fatty acids. Finishing system or forage species grazed 40 d before slaughter did not alter beef tenderness but FOR had greater off-flavors according to both trained and descriptive sensory panelists.

Composition and foraging behaviour of mixed-species flocks in two ...

African Journals Online (AJOL)

Enlarged flock size resulted from a general increase in flocking tendency of all species. At the species level, the Long-billed Crombec Sylvietta rufescens and the Chinspot Batis Batis molitor showed clear feeding benefits within flocks, whereas tits obtained no feeding benefit. Crombecs and batises also changed foraging ...

Spatial management of marine resources can enhance the recovery of predators and avoid local depletion of forage fish

DEFF Research Database (Denmark)

Eero, Margit; Vinther, Morten; Haslob, Holger

2012-01-01

fish, i.e., sprat and herring, is historic low in this area, which in combination with increasing cod stock results in locally high predation mortality of forage fish and cannibalism of cod. In line with low prey availability, body weight and nutritional condition of cod drastically declined...... management to enhance the recovery of predator stocks...

Avian predator buffers against variability in marine habitats with flexible foraging behavior

Science.gov (United States)

Schoen, Sarah K.; Piatt, John F.; Arimitsu, Mayumi L.; Heflin, Brielle; Madison, Erica N.; Drew, Gary S.; Renner, Martin; Rojek, Nora A.; Douglas, David C.; DeGange, Anthony R.

2018-01-01

How well seabirds compensate for variability in prey abundance and composition near their breeding colonies influences their distribution and reproductive success. We used tufted puffins (Fratercula cirrhata) as forage fish samplers to study marine food webs from the western Aleutian Islands (53°N, 173°E) to Kodiak Island (57°N, 153°W), Alaska, during August 2012–2014. Around each colony we obtained data on: environmental characteristics (sea surface temperature and salinity, seafloor depth and slope, tidal range, and chlorophyll-a), relative forage fish biomass (hydroacoustic backscatter), and seabird community composition and density at-sea. On colonies, we collected puffin chick-meals to characterize forage communities and determine meal energy density, and measured chicks to obtain a body condition index. There were distinct environmental gradients from west to east, and environmental variables differed by ecoregions: the (1) Western-Central Aleutians, (2) Eastern Aleutians, and, (3) Alaska Peninsula. Forage fish biomass, species richness, and community composition all differed markedly between ecoregions. Forage biomass was strongly correlated with environmental gradients, and environmental gradients and forage biomass accounted for ~ 50% of the variability in at-sea density of tufted puffins and all seabird taxa combined. Despite the local and regional variability in marine environments and forage, the mean biomass of prey delivered to puffin chicks did not differ significantly between ecoregions, nor did chick condition or puffin density at-sea. We conclude that puffins can adjust their foraging behavior to produce healthy chicks across a wide range of environmental conditions. This extraordinary flexibility enables their overall success and wide distribution across the North Pacific Ocean.

Turtle cleaners: reef fishes foraging on epibionts of sea turtles in the tropical Southwestern Atlantic, with a summary of this association type

Directory of Open Access Journals (Sweden)

Cristina Sazima

2010-03-01

Full Text Available In the present study we record several instances of reef fish species foraging on epibionts of sea turtles (cleaning symbiosis at the oceanic islands of Fernando de Noronha Archipelago and near a shipwreck, both off the coast of Pernambuco State, northeast Brazil. Nine reef fish species and three turtle species involved in cleaning are herein recorded. Besides our records, a summary of the literature on this association type is presented. Postures adopted by turtles during the interaction are related to the habits of associated fishes. Feeding associations between fishes and turtles seem a localized, albeit common, phenomenon.No presente estudo registramos diversos episódios de peixes recifais alimentando-se de epibiontes sobre o corpo de tartarugas marinhas (simbiose de limpeza nas ilhas oceânicas do arquipélago de Fernando de Noronha e próximo a um naufrágio na costa de Pernambuco, nordeste do Brasil. Nove espécies de peixes recifais e três espécies de tartarugas envolvidas nas associações são aqui registradas. Além de nossos registros, apresentamos também um resumo da literatura sobre o tema. As posturas adotadas pelas tartarugas durante as interações estão relacionadas com os hábitos dos peixes associados. Associações alimentares entre peixes e tartarugas podem ser consideradas como um fenômeno local, embora comum.

The Effects of Zebra Mussels (Dreissena polymorpha) on the Foraging Success of Eurasian Perch (Perca fluviatilis) and Ruffe (Gymnocephalus cernuus)

Science.gov (United States)

Dieterich, Axel; Mörtl, Martin; Eckmann, Reiner

2004-07-01

Complex habitat structures can influence the foraging success of fish. Competition for food between fish species can therefore depend on the competitors' abilities to cope with structural complexity. In laboratory experiments, we comparatively assessed effects of zebra mussels (Dreissena polymorpha Pall.) on the foraging success of Eurasian perch (Perca fluviatilis L.) and ruffe (Gymnocephalus cernuus (L.)). In single-species and mixed-species experiments, the fish were fed caddisfly larvae (Tinodes waeneri (L.)) over complex (mussel-covered stones) and less-complex (bare stones) substrates. With intraspecific competition, food consumption by perch and ruffe decreased significantly when the complex substrate was used. With interspecific competition, food consumption by perch and ruffe did not change with substrate complexity, but perch clearly out-competed ruffe on both substrates. Zebra mussel beds provide a refuge for macrozoobenthos against predation by ruffe and probably also by perch. (

Emergence and seedling growth of five forage legume species at ...

African Journals Online (AJOL)

Jane

2011-08-17

Aug 17, 2011 ... A field study compared the seedling emergence and structure of five forage legumes .... mean seed mass (without seed coat) per species was used for W1 ...... Of light and length: regulation of hypocotyl growth in Arabidopsis.

Comparative analysis of diet composition and its relation to morphological characteristics in juvenile fish of three lutjanid species in a Mexican Pacific coastal lagoon

Directory of Open Access Journals (Sweden)

Consuelo M. Aguilar-Betancourt

2017-12-01

Full Text Available ABSTRACT The main goal of this research was to investigate the differences in diet composition among three species of the genus Lutjanus inhabiting a coastal lagoon as juveniles. The working hypothesis was that these species feed on a common base of food resources and therefore, some niche overlap is present in terms of general diet composition. However, changes in the trophic niche with size and differences in some morphological traits among species explain observed differences in diet. Fish were collected during 42 sampling trips conducted regularly from February 2011 to January 2012 using several types of fishing gear. Total number of analyzed stomachs was 288 for Lutjanus argentiventris from 2.3 to 19.9 cm total length (TL; 178 for Lutjanus colorado ranging from 2.4 to 30.1 cm TL; and 183 for Lutjanus novemfasciatus with 1.2 to 20.0 cm TL. Results indicate that juveniles of all three lutjanid species share a general diet based on decapods and fishes. However, L. novemfasciatus has a more piscivorous habit, which can be explained by a more slender body shape and larger teeth, characteristics, which increase fish catching performance. Larger fish of all three species eat larger prey, which is consistent with the optimum foraging theory.

Three-dimensional foraging habitat use and niche partitioning in two sympatric seabird species, Phalacrocorax auritus and P. penicillatus

Science.gov (United States)

Peck-Richardson, Adam G.; Lyons, Donald E.; Roby, Daniel D.; Cushing, Daniel A.; Lerczak, James A.

2018-01-01

Ecological theory predicts that co-existing, morphologically similar species will partition prey resources when faced with resource limitations. We investigated local movements, foraging dive behavior, and foraging habitat selection by breeding adults of 2 closely related cormorant species, double-crested cormorants Phalacrocorax auritus and Brandt’s cormorants P. penicillatus. These species nest sympatrically at East Sand Island in the Columbia River estuary at the border of Oregon and Washington states, USA. Breeding individuals of each species were tracked using GPS tags with integrated temperature and depth data-loggers. The overall foraging areas and core foraging areas (defined as the 95% and 50% kernel density estimates of dive locations, respectively) of double-crested cormorants were much larger and covered a broader range of riverine, mixed-estuarine, and nearshore marine habitats. Brandt’s cormorant foraging areas were less expansive, were exclusively marine, and mostly overlapped with double-crested cormorant foraging areas. Within these areas of overlap, Brandt’s cormorants tended to dive deeper (median depth = 6.48 m) than double-crested cormorants (median depth = 2.67 m), and selected dive locations where the water was deeper. Brandt’s cormorants also utilized a deeper, more benthic portion of the water column than did double-crested cormorants. Nevertheless, the substantial overlap in foraging habitat between the 2 cormorant species in the Columbia River estuary, particularly for Brandt’s cormorants, suggests that superabundant prey resources allow these 2 large and productive cormorant colonies to coexist on a single island near the mouth of the Columbia River.

Foragers of sympatric Asian honey bee species intercept competitor signals by avoiding benzyl acetate from Apis cerana alarm pheromone.

Science.gov (United States)

Wen, Ping; Cheng, Yanan; Qu, Yufeng; Zhang, Hongxia; Li, Jianjun; Bell, Heather; Tan, Ken; Nieh, James

2017-07-27

While foraging, animals can form inter- and intraspecific social signalling networks to avoid similar predators. We report here that foragers of different native Asian honey bee species can detect and use a specialized alarm pheromone component, benzyl acetate (BA), to avoid danger. We analysed the volatile alarm pheromone produced by attacked workers of the most abundant native Asian honey bee, Apis cerana and tested the responses of other bee species to these alarm signals. As compared to nest guards, A. cerana foragers produced 3.38 fold higher levels of BA. In foragers, BA and (E)-dec-2-en-1-yl acetate (DA) generated the strongest antennal electrophysiological responses. BA was also the only compound that alerted flying foragers and inhibited A. cerana foraging. BA thereby decreased A. cerana foraging for risky sites. Interestingly, although BA occurs only in trace amounts and is nearly absent in sympatric honeybee species (respectively only 0.07% and 0.44% as much in A. dorsata and A. florea), these floral generalists detected and avoided BA as strongly as they did to their own alarm pheromone on natural inflorescences. These results demonstrate that competing pollinators can take advantage of alarm signal information provided by other species.

Fisheries oceanography of northern pelagic fish species

DEFF Research Database (Denmark)

Tsoukali, Stavroula

for marine organisms. One of the impacts will be the time that species start to spawn, and there is already evidence for earlier spawning in some North Sea fish species. A change like that may likely have a chain reaction, affecting larval stages and whether they will live in environments with high food...... of the species they consume now and increased availability of new species. In addition, there will likely be economic impacts on the local fishing communities. How species respond to climate change is a field of research that receives great attention because the responses will affect the management of fisheries......People are familiar with marine fish species and the great variety of different species that are available in the market, such as herring, cod and sole. What may not be well known is that every individual fish goes through a long, risky journey during its life before reaching maturity. Most...

Ultra-High Foraging Rates of Harbor Porpoises Make Them Vulnerable to Anthropogenic Disturbance.

Science.gov (United States)

Wisniewska, Danuta Maria; Johnson, Mark; Teilmann, Jonas; Rojano-Doñate, Laia; Shearer, Jeanne; Sveegaard, Signe; Miller, Lee A; Siebert, Ursula; Madsen, Peter Teglberg

2016-06-06

The question of how individuals acquire and allocate resources to maximize fitness is central in evolutionary ecology. Basic information on prey selection, search effort, and capture rates are critical for understanding a predator's role in its ecosystem and for predicting its response to natural and anthropogenic disturbance. Yet, for most marine species, foraging interactions cannot be observed directly. The high costs of thermoregulation in water require that small marine mammals have elevated energy intakes compared to similar-sized terrestrial mammals [1]. The combination of high food requirements and their position at the apex of most marine food webs may make small marine mammals particularly vulnerable to changes within the ecosystem [2-4], but the lack of detailed information about their foraging behavior often precludes an informed conservation effort. Here, we use high-resolution movement and prey echo recording tags on five wild harbor porpoises to examine foraging interactions in one of the most metabolically challenged cetacean species. We report that porpoises forage nearly continuously day and night, attempting to capture up to 550 small (3-10 cm) fish prey per hour with a remarkable prey capture success rate of >90%. Porpoises therefore target fish that are smaller than those of commercial interest, but must forage almost continually to meet their metabolic demands with such small prey, leaving little margin for compensation. Thus, for these "aquatic shrews," even a moderate level of anthropogenic disturbance in the busy shallow waters they share with humans may have severe fitness consequences at individual and population levels. Copyright © 2016 Elsevier Ltd. All rights reserved.

DEVELOPMENT OF TECHNOLOGY FOR FISH CANNED PATE'S COD-FISH SPECIES

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A. A. Efremova

2014-01-01

Full Text Available Summary. Fish and seafood play an important role in a balanced diet. The most reliable method of preservation is the production of canned fish. Cod fishery considered traditional objects of the North Basin, which catches in recent years stored at a consistently high level. They are represented, mainly cod, haddock, pollack, whiting. Lately there has been a tendency to increase yield loaves (polar bib. The aim of this work - the development of technology - canned pate's cod fish species with the addition of plant materials. We used the adopted research microbiological, chemical and physical methods. The weight proportion of water, lipids, protein, mineral raw determined according to State standard 7636-85. Developed a technology - canned pate's cod fish species with the addition of plant materials. Optimized formulation is set to sterilization. Experimentally determined parameters of quality canned and given comprehensive assessment nutritional value of new products, organoleptic, physico-chemical, biochemical and microbiological tests showed that canned pates of Gadidae species of fish with vegetables, meet all safety requirements and are characterized, along with excellent consumer properties, high nutritional value. Based on the results of the research complex developed technical documentation for production of canned vegetables, pates of Gadidae species.

More Than Just a Spawning Location: Examining Fine Scale Space Use of Two Estuarine Fish Species at a Spawning Aggregation Site

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Ross E. Boucek

2017-11-01

Full Text Available Many species that provide productive marine fisheries form spawning aggregations. Aggregations are predictable both in time and space and constitute nearly all of the reproductive activity for these species. For species that spend weeks to months on spawning aggregation sites, individuals may need to rely on a forage base at or near the spawning site to balance the high energetic cost associated with reproduction. Here, we ask: do spawning fish with protracted spawning seasons use spawning aggregation sites more or less than adjacent foraging habitats? To answer our research question, we tracked 30 Snook (Centropomus undecimalis and 29 Spotted Seatrout (Cynoscion nebulosus at a spawning site during the 2007 spawning season in Tampa Bay (FL, U.S. using acoustic telemetry. We quantified the amount of time both males and females of both species spent in various habitats with network analyses. Surprisingly, results from network analyses revealed that receivers with the highest edge densities for Snook and Seatrout occurred within the seagrass habitat, not the location of spawning. Likewise, we found that both Snook and Seatrout during the spawning season were using the seagrass habitat near the spawning site as much, or more than the location where spawning occurs. Our results show that if protected areas are formed based on only where spawning occurs, the reproductive stock will not be protected from fishing. Further, our results suggest that spawning aggregation sites and areas surrounding used by fishes, may have multiple ecological functions (i.e., larval dispersal and energy provisioning that may need to be considered in conservation actions. Our case study further supports hypotheses put forth in previous work that suggest we must consider more than just spawning sites in protected area development and ecological conservation.

A non-digging zoobenthivorous fish attracts two opportunistic predatory fish associates

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Cristina Sazima

Full Text Available Following behaviour among reef fishes involves mostly a digging nuclear species while foraging, which attracts opportunistic followers preying on the exposed organisms. The flying gurnard Dactylopterus volitans preys on benthic animals, mostly crustaceans and small fishes, scratching and probing the bottom with the inner rays of its pectoral fins. We recorded the flying gurnard being followed by two opportunistic predators, the yellow jack Caranx bartholomaei and the coney Cephalopholis fulva at Fernando de Noronha, off northeast Brazil. Albeit not actually digging the substrate, the flying gurnard acts as a nuclear species by exploring algae tufts and by its wandering near the boulders and ledges, disturbing and flushing out hidden animals which thus become available to predation.

Variations in protein and fat contents and their fractions in milk from two species fed different forages.

Science.gov (United States)

Kholif, S M; El-Shewy, A A; Morsy, T A; Abd El-Rahman, H H

2015-02-01

This study aimed at determining the variations in milk constituents which could be varied by feed and animal species. To achieve this goal, two groups of homoparity Baladi cows and Egyptian buffaloes (n = 20 per species) were used. Each group was divided into two subgroups (n = 10): subgroup I received legume forage (Egyptian clover) and subgroup II received grass forage (sorghum forage). All experimental animals were fed the diet consisting of concentrate, forage and rice straw as 50, 25 and 25% of dry matter intake respectively. Milk samples were taken for analysis. The trial lasted until the 3rd month of parturition. The main results indicated that lactating cattle fed legume forage significantly (p ≤ 0.01) had more content of casein nitrogen (513 mg/100 ml milk), lower content of glutamic acid (23.56 g/100 g milk protein) and more content of cis-9, trans-11 18:2 conjugated linoleic acid (CLA) (0.77 g/100 g milk fat) compared with 433, 26.67 and 0.53, respectively, for cattle fed grass forage. With regard to the species effect, results showed that buffalo milk appeared to contain significantly higher (p ≤ 0.01) contents of casein nitrogen, phenylalanine, glutamic and arachidonic acid compared with cow's milk. However, the latter was significantly (p ≤ 0.01) more in the cis-9, trans-11CLA (0.59 g/100 g milk fat) than that in buffalo milk (0.47 g/100 g milk fat). The results revealed that not only forage type played a critical role in determining the variations of milk nitrogen distribution, milk amino acids and fatty acids but also animal species had a significant effect on these parameters. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

76 FR 27017 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2011-05-10

... FURTHER INFORMATION CONTACT: Garth Griffin, Portland, OR, ph.: 503- 231-2005, Fax: 503-230-5441, e-mail... Snohomish River estuary, and Shilshole Bay, Washington. The goal of these projects is to understand changes....g., trophic web effects, plant and animal community dynamics, and forage fish population...

Female social response to male sexual harassment in poeciliid fish: a comparison of six species

Science.gov (United States)

Dadda, Marco

2015-01-01

Sexual harassment is common among poeciliid fish. In some fishes, males show a high frequency of sneak copulation; such sexual activity is costly to the females in terms of foraging efficiency. In mosquitofish (Gambusia holbrooki), when males are present, the distance between females tends to decrease, and this behavior has been interpreted as an adaptive strategy to dilute the costs of male sexual activity. In this study, the tendency to reduce distance in the presence of a male has been investigated in females of six poeciliid species (Girardinus metallicus, Girardinus falcatus, G. holbrooki, Poecilia reticulata, Xiphophorus hellerii, and Xiphophorus mayae) that exhibit different male mating strategies and different levels of sexual activity. Results revealed large interspecific differences in the pattern of female aggregation. Females of species with a high frequency of sneak copulations tended to reduce their social distance in the presence of a male. By contrast, species that rely mainly on courtship showed little or no variation in social distance. The proportion of sneak copulations predicts the degree of variation in female social response, but the amount of total sexual activity does not, suggesting that the change in females' social distance when a male is present may indeed serve to reduce the costs of male sexual harassment. PMID:26483719

Female social response to male sexual harassment in poeciliid fish: A comparison of six species

Directory of Open Access Journals (Sweden)

Marco eDadda

2015-09-01

Full Text Available Sexual harassment is common among poeciliid fish. In some fishes, males show a high frequency of sneak copulation; such sexual activity is costly to the females in terms of foraging efficiency. In mosquitofish (Gambusia holbrooki, when males are present, the distance between females tends to decrease, and this behavior has been interpreted as an adaptive strategy to dilute the costs of male sexual activity. In this study, the tendency to reduce distance in the presence of a male has been investigated in females of 6 poeciliid species (Girardinus metallicus, Girardinus falcatus, Gambusia holbrooki, Poecilia reticulata, Xiphophorus hellerii and Xiphophorus mayae that exhibit different male mating strategies and different levels of sexual activity. Results revealed large interspecific differences in the pattern of female aggregation. Females of species with a high frequency of sneak copulations tended to reduce their social distance in the presence of a male. By contrast, species that rely mainly on courtship showed little or no variation in social distance. The proportion of sneak copulations predicts the degree of variation in female social response, but the amount of total sexual activity does not, suggesting that the change in females’ social distance when a male is present may indeed serve to reduce the costs of male sexual harassment.

Female social response to male sexual harassment in poeciliid fish: a comparison of six species.

Science.gov (United States)

Dadda, Marco

2015-01-01

Sexual harassment is common among poeciliid fish. In some fishes, males show a high frequency of sneak copulation; such sexual activity is costly to the females in terms of foraging efficiency. In mosquitofish (Gambusia holbrooki), when males are present, the distance between females tends to decrease, and this behavior has been interpreted as an adaptive strategy to dilute the costs of male sexual activity. In this study, the tendency to reduce distance in the presence of a male has been investigated in females of six poeciliid species (Girardinus metallicus, Girardinus falcatus, G. holbrooki, Poecilia reticulata, Xiphophorus hellerii, and Xiphophorus mayae) that exhibit different male mating strategies and different levels of sexual activity. Results revealed large interspecific differences in the pattern of female aggregation. Females of species with a high frequency of sneak copulations tended to reduce their social distance in the presence of a male. By contrast, species that rely mainly on courtship showed little or no variation in social distance. The proportion of sneak copulations predicts the degree of variation in female social response, but the amount of total sexual activity does not, suggesting that the change in females' social distance when a male is present may indeed serve to reduce the costs of male sexual harassment.

Forage yield and nutritive value of Elephant grass, Italian ryegrass and spontaneous growing species mixed with forage peanut or red clover

Directory of Open Access Journals (Sweden)

Michelle Schalemberg Diehl

2014-10-01

Full Text Available The objective of this research was to evaluate of three grazing systems (GS with elephant grass (EG, Italian ryegrass (IR + spontaneous growing species (SGS; EG + IR + SGS + forage peanut (FP; and EG + IR + SGS + red clover (RC, during the winter and summer periods in rotational grazing with dairy cattle. Experimental design was completely randomized with three treatments, two replicates with repeated measures. Lactating Holstein cows receiving 1% BW-daily feed supplement with concentrate were used in the evaluation. Eight grazing cycles were performed during the experimental period. The values of pre forage mass and stocking rate were 2.52, 2.60 and 2.99 t ha-1 and 2.64, 2.77 and 3.14 animal unit ha-1, respectively for GS. Samples of forage were collected by hand-plucking technique to analyze the crude protein (CP, neutral detergent fiber (NDF, in situ dry matter digestibility (ISDMD, in situ organic matter digestibility (ISOMD of forage present between rows of elephant grass, in the rows of elephant grass and the legumes. Higher value of CP, ISOMD and lower of NDF were observed for the grazing systems mixed with legumes forage.

Analysis of the potentiality haying of native forage species in semiarid region

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Enoque de Sousa Leão

2017-10-01

Full Text Available The objective of this study was to evaluate the potential hay production from Spiny Amaranth (Amaranthus spinosus, Hairy Woodrose (Merremia aegyptia, Malva (Sida galheirensis, Mucuna (Mucuna pruriens and Ervanço (Froelichia humboldtiana, native forage species of the semiarid region of Brazil by observing morphological components of the plant, such as the dehydration curve, crude protein loss (CPL curve, chemical composition of plant and hay and hay degradability in situ. There were differences (P < 0.05 among species on leaf, stem and inflorescence quantification with Ervanço, Hairy Woodrose, and Mucuna having a greater number of leaves. There was a linearly increasing response for the dehydration curve of the five forage plants species. Mucuna forage had the greatest hay point at 800 g kg-1 dried matter (DM after 11.8 hours and Woodrose had a lower dehydration efficiency, which required 25 hours of sun exposure. There was no difference in CPL. Mucuna had the lowest crude protein (CP, neutral detergent fiber (NDF and acid detergent fiber (ADF content, 8.4, 67.7 and 73.8 g kg DM-1 in hay in relation to the plant, respectively. Ervanço, Spiny Amaranth, Hairy Woodrose and Malva hay had more of soluble fraction “a” of DM of 31.0, 26.2, 22.1 and 9.7 g kg-1 DM than Mucuna, respectively. Spiny Amaranth and Malva hay had values of 335.4 and 193.2 g kg-1 DM of fraction “b” more than Ervanço hay, respectively. For fraction “a’’ of CP, Spiny Amaranth and Hairy Woodrose hay obtained 312.6 and 227.4 g kg-1 CP more than that observed for Malva, respectively. Mucuna had better hay potential among the forage studied in the semiarid region of Brazil.

DNA barcode-based molecular identification system for fish species.

Science.gov (United States)

Kim, Sungmin; Eo, Hae-Seok; Koo, Hyeyoung; Choi, Jun-Kil; Kim, Won

2010-12-01

In this study, we applied DNA barcoding to identify species using short DNA sequence analysis. We examined the utility of DNA barcoding by identifying 53 Korean freshwater fish species, 233 other freshwater fish species, and 1339 saltwater fish species. We successfully developed a web-based molecular identification system for fish (MISF) using a profile hidden Markov model. MISF facilitates efficient and reliable species identification, overcoming the limitations of conventional taxonomic approaches. MISF is freely accessible at http://bioinfosys.snu.ac.kr:8080/MISF/misf.jsp .

Complementarity in nutrient foraging strategies of absorptive fine roots and arbuscular mycorrhizal fungi across 14 coexisting subtropical tree species.

Science.gov (United States)

Liu, Bitao; Li, Hongbo; Zhu, Biao; Koide, Roger T; Eissenstat, David M; Guo, Dali

2015-10-01

In most cases, both roots and mycorrhizal fungi are needed for plant nutrient foraging. Frequently, the colonization of roots by arbuscular mycorrhizal (AM) fungi seems to be greater in species with thick and sparsely branched roots than in species with thin and densely branched roots. Yet, whether a complementarity exists between roots and mycorrhizal fungi across these two types of root system remains unclear. We measured traits related to nutrient foraging (root morphology, architecture and proliferation, AM colonization and extramatrical hyphal length) across 14 coexisting AM subtropical tree species following root pruning and nutrient addition treatments. After root pruning, species with thinner roots showed more root growth, but lower mycorrhizal colonization, than species with thicker roots. Under multi-nutrient (NPK) addition, root growth increased, but mycorrhizal colonization decreased significantly, whereas no significant changes were found under nitrogen or phosphate additions. Moreover, root length proliferation was mainly achieved by altering root architecture, but not root morphology. Thin-root species seem to forage nutrients mainly via roots, whereas thick-root species rely more on mycorrhizal fungi. In addition, the reliance on mycorrhizal fungi was reduced by nutrient additions across all species. These findings highlight complementary strategies for nutrient foraging across coexisting species with contrasting root traits. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Satellite lakes as reservoirs of fish species diversity

OpenAIRE

Nkalubo, W.; Wandera, S.B.; Namulemo, G.

2010-01-01

Satellite lakes and rivers in the Victoria and Kyoga basins provide a sanctuary for endangered native fish species. The structural heterogeneity of macrophyte covering these lakes has made it possible for most of the biodiversity to be kept intact. The Kyoga minor lakes have the highest fish species diversity especially of the haplochromines. Most fish communities of these satellite lakes are composed of native species.

Chemokines in teleost fish species.

Science.gov (United States)

Alejo, Alí; Tafalla, Carolina

2011-12-01

Chemokines are chemoattractant cytokines defined by the presence of four conserved cysteine residues which in mammals can be divided into four subfamilies depending on the arrangement of the first two conserved cysteines in their sequence: CXC (α), CC (β), C and CX(3)C classes. Evolutionarily, fish can be considered as an intermediate step between species which possess only innate immunity (invertebrates) and species with a fully developed acquired immune network such as mammals. Therefore, the functionality of their different immune cell types and molecules is sometimes also intermediate between innate and acquired responses. The first chemokine gene identified in a teleost was a rainbow trout (Oncorhynchus mykiss) chemokine designated as CK1 in 1998. Since then, many different chemokine genes have been identified in several fish species, but their role in homeostasis and immune response remains largely unknown. Extensive genomic duplication events and the fact that chemokines evolve more quickly than other immune genes, make it very difficult to establish true orthologues between fish and mammalian chemokines that would help us with the ascription of immune roles. In this review, we describe the current state of knowledge of chemokine biology in teleost fish, focusing mainly on which genes have been identified so far and highlighting the most important aspects of their expression regulation, due to the great lack of functional information available for them. As the number of chemokine genes begins to close down for some teleost species, there is an important need for functional assays that may elucidate the role of each of these molecules within the fish immune response. Copyright © 2011 Elsevier Ltd. All rights reserved.

Linking mesopelagic prey abundance and distribution to the foraging behavior of a deep-diving predator, the northern elephant seal

Science.gov (United States)

Saijo, Daisuke; Mitani, Yoko; Abe, Takuzo; Sasaki, Hiroko; Goetsch, Chandra; Costa, Daniel P.; Miyashita, Kazushi

2017-06-01

The Transition Zone in the eastern North Pacific is important foraging habitat for many marine predators. Further, the mesopelagic depths (200-1000 m) host an abundant prey resource known as the deep scattering layer that supports deep diving predators, such as northern elephant seals, beaked whales, and sperm whales. Female northern elephant seals (Mirounga angustirostris) undertake biannual foraging migrations to this region where they feed on mesopelagic fish and squid; however, in situ measurements of prey distribution and abundance, as well as the subsurface oceanographic features in the mesopelagic Transition Zone are limited. While concurrently tracking female elephant seals during their post-molt migration, we conducted a ship-based oceanographic and hydroacoustic survey and used mesopelagic mid-water trawls to sample the deep scattering layer. We found that the abundance of mesopelagic fish at 400-600 m depth zone was the highest in the 43 °N zone, the primary foraging area of female seals. We identified twenty-nine families of fishes from the mid-water trawls, with energy-rich myctophid fishes dominating by species number, individual number, and wet weight. Biomass of mesopelagic fishes is positively correlated to annual net primary productivity; however, at the temporal and spatial scale of our study, we found no relationship between satellite derived surface primary production and prey density. Instead, we found that the subsurface chlorophyll maximum correlated with the primary elephant seal foraging regions, indicating a stronger linkage between mesopelagic ecosystem dynamics and subsurface features rather than the surface features measured with satellites. Our study not only provides insights on prey distribution in a little-studied deep ocean ecosystem, but shows that northern elephant seals are targeting the dense, species-diverse mesopelagic ecosystem at the gyre-gyre boundary that was previously inferred from their diving behavior.

Shearwater foraging in the Southern Ocean: the roles of prey availability and winds.

Directory of Open Access Journals (Sweden)

Ben Raymond

Full Text Available BACKGROUND: Sooty (Puffinus griseus and short-tailed (P. tenuirostris shearwaters are abundant seabirds that range widely across global oceans. Understanding the foraging ecology of these species in the Southern Ocean is important for monitoring and ecosystem conservation and management. METHODOLOGY/PRINCIPAL FINDINGS: Tracking data from sooty and short-tailed shearwaters from three regions of New Zealand and Australia were combined with at-sea observations of shearwaters in the Southern Ocean, physical oceanography, near-surface copepod distributions, pelagic trawl data, and synoptic near-surface winds. Shearwaters from all three regions foraged in the Polar Front zone, and showed particular overlap in the region around 140 degrees E. Short-tailed shearwaters from South Australia also foraged in Antarctic waters south of the Polar Front. The spatial distribution of shearwater foraging effort in the Polar Front zone was matched by patterns in large-scale upwelling, primary production, and abundances of copepods and myctophid fish. Oceanic winds were found to be broad determinants of foraging distribution, and of the flight paths taken by the birds on long foraging trips to Antarctic waters. CONCLUSIONS/SIGNIFICANCE: The shearwaters displayed foraging site fidelity and overlap of foraging habitat between species and populations that may enhance their utility as indicators of Southern Ocean ecosystems. The results highlight the importance of upwellings due to interactions of the Antarctic Circumpolar Current with large-scale bottom topography, and the corresponding localised increases in the productivity of the Polar Front ecosystem.

Trophic interactions between native and introduced fish species in a littoral fish community.

Science.gov (United States)

Monroy, M; Maceda-Veiga, A; Caiola, N; De Sostoa, A

2014-11-01

The trophic interactions between 15 native and two introduced fish species, silverside Odontesthes bonariensis and rainbow trout Oncorhynchus mykiss, collected in a major fishery area at Lake Titicaca were explored by integrating traditional ecological knowledge and stable-isotope analyses (SIA). SIA suggested the existence of six trophic groups in this fish community based on δ(13)C and δ(15)N signatures. This was supported by ecological evidence illustrating marked spatial segregation between groups, but a similar trophic level for most of the native groups. Based on Bayesian ellipse analyses, niche overlap appeared to occur between small O. bonariensis (<90 mm) and benthopelagic native species (31.6%), and between the native pelagic killifish Orestias ispi and large O. bonariensis (39%) or O. mykiss (19.7%). In addition, Bayesian mixing models suggested that O. ispi and epipelagic species are likely to be the main prey items for the two introduced fish species. This study reveals a trophic link between native and introduced fish species, and demonstrates the utility of combining both SIA and traditional ecological knowledge to understand trophic relationships between fish species with similar feeding habits. © 2014 The Fisheries Society of the British Isles.

Context-dependent planktivory: interacting effects of turbidity and predation risk on adaptive foraging

Science.gov (United States)

Pangle, Kevin L.; Malinich, Timothy D.; Bunnell, David B.; DeVries, Dennis R.; Ludsin, Stuart A.

2012-01-01

By shaping species interactions, adaptive phenotypic plasticity can profoundly influence ecosystems. Predicting such outcomes has proven difficult, however, owing in part to the dependence of plasticity on the environmental context. Of particular relevance are environmental factors that affect sensory performance in organisms in ways that alter the tradeoffs associated with adaptive phenotypic responses. We explored the influence of turbidity, which simultaneously and differentially affects the sensory performance of consumers at multiple trophic levels, on the indirect effect of a top predator (piscivorous fish) on a basal prey resource (zooplankton) that is mediated through changes in the plastic foraging behavior of an intermediate consumer (zooplanktivorous fish). We first generated theoretical predictions of the adaptive foraging response of a zooplanktivore across wide gradients of turbidity and predation risk by a piscivore. Our model predicted that predation risk can change the negative relationship between intermediate consumer foraging and turbidity into a humped-shaped (unimodal) one in which foraging is low in both clear and highly turbid conditions due to foraging-related risk and visual constraints, respectively. Consequently, the positive trait-mediated indirect effect (TMIE) of the top predator on the basal resource is predicted to peak at low turbidity and decline thereafter until it reaches an asymptote of zero at intermediate turbidity levels (when foraging equals that which is predicted when the top predator is absent). We used field observations and a laboratory experiment to test our model predictions. In support, we found humped-shaped relationships between planktivory and turbidity for several zooplanktivorous fishes from diverse freshwater ecosystems with predation risk. Further, our experiment demonstrated that predation risk reduced zooplanktivory by yellow perch (Perca flavescens) at a low turbidity, but had no effect on consumption at

Differing foraging strategies influence mercury (Hg) exposure in an Antarctic penguin community.

Science.gov (United States)

Polito, Michael J; Brasso, Rebecka L; Trivelpiece, Wayne Z; Karnovsky, Nina; Patterson, William P; Emslie, Steven D

2016-11-01

Seabirds are ideal model organisms to track mercury (Hg) through marine food webs as they are long-lived, broadly distributed, and are susceptible to biomagnification due to foraging at relatively high trophic levels. However, using these species as biomonitors requires a solid understanding of the degree of species, sexual and age-specific variation in foraging behaviors which act to mediate their dietary exposure to Hg. We combined stomach content analysis along with Hg and stable isotope analyses of blood, feathers and common prey items to help explain inter and intra-specific patterns of dietary Hg exposure across three sympatric Pygoscelis penguin species commonly used as biomonitors of Hg availability in the Antarctic marine ecosystem. We found that penguin tissue Hg concentrations differed across species, between adults and juveniles, but not between sexes. While all three penguins species diets were dominated by Antarctic krill (Euphausia superba) and to a lesser extent fish, stable isotope based proxies of relative trophic level and krill consumption could not by itself sufficiently explain the observed patterns of inter and intra-specific variation in Hg. However, integrating isotopic approaches with stomach content analysis allowed us to identify the relatively higher risk of Hg exposure for penguins foraging on mesopelagic prey relative to congeners targeting epipelagic or benthic prey species. When possible, future seabird biomonitoring studies should seek to combine isotopic approaches with other, independent measures of foraging behavior to better account for the confounding effects of inter and intra-specific variation on dietary Hg exposure. Copyright © 2016 Elsevier Ltd. All rights reserved.

Primary versus secondary drivers of foraging activity in sandeel schools (Ammodytes tobianus)

DEFF Research Database (Denmark)

Deurs, Mikael van; Behrens, Jane; Warnar, Thomas

2011-01-01

to fishery biologists and has consequences for a wide range of predators ranging from birds and mammals to commercially important species. However, experimental studies that shed light on the primary drivers of foraging activity in fish are rare. In the present study, whole schools of sandeel (A. tobianus......The commercially and ecologically valuable sandeel (Ammodytes ssp.) make distinct vertical shifts between an inactive stage, during which they seek refuge in the sand, and a pelagic schooling stage, during which they forage. This characteristic discontinuous foraging pattern constitutes a challenge......) were caught in August in east Denmark (65A degrees 02'30N; 12A degrees 37'00E) and kept in large tanks in the laboratory. It was found that the amount of food ingested and memory of past days feeding history are primary drivers of foraging activity at the level of the entire school, whereas external...

Earning their stripes: The potential of tiger trout and other salmonids as biological controls of forage fishes in a western reservoir

Science.gov (United States)

Winters, Lisa K.; Budy, Phaedra; Thiede, Gary P.

2017-01-01

Maintaining a balance between predator and prey populations can be an ongoing challenge for fisheries managers, especially in managing artificial ecosystems such as reservoirs. In a high-elevation Utah reservoir, the unintentional introduction of the Utah Chub Gila atraria and its subsequent population expansion prompted managers to experimentally shift from exclusively stocking Rainbow Trout Oncorhynchus mykiss to also stocking tiger trout (female Brown Trout Salmo trutta × male Brook Trout Salvelinus fontinalis) and Bonneville Cutthroat Trout O. clarkii utah (hereafter, Cutthroat Trout) as potential biological control agents. We measured a combination of diet, growth, temperature, and abundance and used bioenergetic simulations to quantify predator demand versus prey supply. Utah Chub were the predominant prey type for tiger trout, contributing up to 80% of the diet depending on the season. Utah Chub represented up to 70% of the total diet consumed by Cutthroat Trout. Although Utah Chub dominated the fish biomass in the reservoir, we still estimated abundances of 238,000 tiger trout, 214,000 Cutthroat Trout, and 55,000 Rainbow Trout. Consequently, when expanded to the population level of each predator, tiger trout and Cutthroat Trout consumed large quantities of Utah Chub on an annual basis: tiger trout consumed 508,000 kg (2,660 g/predator) of the standing prey population, and Cutthroat Trout consumed an estimated 322,000 kg (1,820 g/predator). The estimated combined consumption by Cutthroat Trout and tiger trout exceeded the estimate of Utah Chub annual production. As such, our results suggest that the high rates of piscivory exhibited by Cutthroat Trout and tiger trout in artificial lentic ecosystems are likely sufficient to effectively reduce the overall abundance of forage fishes and to prevent forage fishes from dominating fish assemblages. Collectively, this research provides the first documented findings on tiger trout ecology and performance

Nesting season food habits of 4 species of Herons and Egrets at Lake Okeechobee, Florida

Science.gov (United States)

Smith, J.P.

1997-01-01

Based on the composition of nestling regurgitations collected during 3 breeding seasons, fish were the most important prey group for Great Egrets (Ardea alba: N = 200 nest-day samples; aggregate percent biomass [APB] = 73.4%), Snowy Egrets (Egretta thula: N = 115; APB = 91.4%), and Tricolored Herons (E. tricolor. N = 68; APB = 97.3%). For Little Blue Herons (E. caerulerr. N = 57), grass shrimp (Palaemoneles paludosus; APB = 39.7%) ranked higher in overall importance than all fishes combined (APB = 36.5%). Dietary overlap, as measured by Schoener's Similarity Index, was greatest between Snowy Egrets and Tricolored Herons (77%) and lowest between Tricolored Herons and Little Blue Herons (30%). Diet diversity, as measured by Shannon's Index, was highest for Great Egrets (2.04), intermediate for Snowy Egrets (1.71) and Tricolored Herons (1.68), and lowest for Little Blue Herons (1.60). Great Egrets ate a wider variety of fish species and sizes, especially larger fishes, and more crayfish than the other species. Little Blue Herons ate fewer fish and more grass shrimp and insects, and ate smaller forage fishes than Tricolored Herons but similar-sized fish as Snowy Egrets. The coarse-scale trophic composition of Snowy Egret and Tricolored Heron diets did not differ significantly, but Tricolored Herons ate larger forage fishes than Snowy Egrets. Pronounced interannual and intercolony variation in diet composition suggested that Great Egrets and Little Blue Herons switched prey types as hydrologic conditions and habitat availability changed. Conversely, lack of such variation suggested that Snowy Egrets and Tricolored Herons adjusted their foraging tactics to ensure contin-ued encounters with preferred prey despite changing habitat conditions. These results are generally consistent with other published data, help confirm some generalizations about foraging strategies and patterns of niche differentiation among these ecologically similar species, and have implications for

Foraging ecology as related to the distribution of planktivorous auklets in the Bering Sea

Science.gov (United States)

Hunt, George L.; Harrison, Nancy M.; Piatt, John F.

1993-01-01

We review recent accounts of the foraging ecologies of  five species of small auklets found in the Bering Sea. These birds eat a wide variety of zooplankton and micronekton. Least Auklets Aethia pusilla and Whiskered Auklets A. pygmaea, as far as is known, primarily eat copepods, whereas Created Auklets A. cristatella appear to specialize on euphausiids, at least during the breeding season. The diet of Parakeet Auklets Cyclorrhynchus psittacula is much broader than that of most other Aethia species, and includes many gelatinous species and their commensals. Little is known of the diet of Cassin's Auklet Ptychoramphus aleuticus in the Bering Sea, although elsewhere they take large copepods, euphausiids, and larval fish.There are considerable differences in the at-sea distributions and foraging behaviors of these five species of auklet. Least Auklets in the norhtern Bering Sea concentrate their foraging activities over strongly stratified water and near fronts where pycnoclines may approach the surface. In the Aleutian Islands, Least Auklets forage where oceanic and tidal currents strike the shelf between the islands and rise toward the surface carrying plankton. Least Auklets and Crested Auklets are often found in large flocks, whereas Parakeet Auklets are rarely found in groups of more than three birds and are usually widely dispersed. The few at-sea observations of Whiskered Auklets have been of small flocks in turbulent waters of island passes. We relate prey types taken, foraging dispersion, and the use of hydrographic features by these auklet species.

Assessing diet compositions of Lake Ontario predators using fatty acid profiles of prey fishes

Science.gov (United States)

Happell, Austin; Pattridge, Robert; Rinchard, Jacques; Walsh, Maureen

2017-01-01

Fatty acid profiles are used in food web studies to assess trophic interactions between predator and prey. The present study provides the first comprehensive fatty acid dataset for important prey and predator species in Lake Ontario. Three major prey fish (alewife, rainbow smelt, and round goby) were collected at three sites along the southern shore of Lake Ontario during the spring and fall of 2013, and predator species were collected in similar locations during the summer of 2013. Fatty acid compositions were compared among all prey species, all predator species, and information from both predator and prey was used to infer foraging differences among predators. Seasonal differences in fatty acids were found within each prey species studied. Differences among prey species were greater than any spatio-temporal differences detected within species. Fatty acids of predators revealed species-specific differences that matched known foraging habits. Chinook and Coho salmon, which are known to select alewife as their dominant prey item, had relatively little variation in fatty acid profiles. Conversely, brown trout, lake trout, yellow perch and esocids had highly variable fatty acid profiles and likely highly variable diet compositions. In general, our data suggested three dominant foraging patterns: 1) diet composed of nearly exclusively alewife for Chinook and Coho Salmon; 2) a mixed diet of alewife and round goby for brown and lake trout, and both rock and smallmouth bass; 3) a diet that is likely comprised of forage fishes other than those included in our study for northern pike and chain pickerel.

Parasites of forage fishes in the vicinity of Steller sea lion (Eumetopias jubatus) habitat in Alaska.

Science.gov (United States)

Moles, A; Heintz, R A

2007-07-01

Fish serve as intermediate hosts for a number of larval parasites that have the potential of maturing in marine mammals such as Steller sea lions (Eumetopias jubatus). We examined the prevalence of parasites from 229 fish collected between March and July 2002 near two islands used by Steller sea lions in Southeast Alaska and island habitats in the Aleutian Islands. Sea lion populations have remained steady in Southeast Alaska but have been declining over the last 30 yr in the Aleutian Islands. Even though the fish samples near the Southeast Alaska haul-outs were composed of numerous small species of fish and the Aleutian Islands catch was dominated by juveniles of commercially harvested species, the parasite fauna was similar at all locations. Eleven of the 20 parasite taxa identified were in their larval stage in the fish hosts, several of which have been described from mammalian final hosts. Four species of parasite were more prevalent in Southeast Alaska fish samples, and seven parasite species, including several larval forms capable of infecting marine mammals, were more prevalent in fish from the Aleutian Islands. Nevertheless, parasites available to Steller sea lions from common fish prey are not likely to be a major factor in the decline of this marine mammal species.

CAGE BREEDING OF WARM WATER FRESHWATER FISH SPECIES

Directory of Open Access Journals (Sweden)

Roman Safner

2008-10-01

Full Text Available In the 1970s, Croatia became actively involved in the contemporary trend of breeding fish in floating cages. In addition to various species of marine fishes, breeding was attempted with trout, carp, catfish, cisco and salmon. Of the above freshwater fish species, specific standards were established only for the cage breeding of rainbow trout. Cage breeding of the remaining species remained at the level of occasional attempts, with more of an experimental than a commercial character. The regular attempts to master this technique for cage breeding of warm water freshwater fish species were aimed at achieving the known benefits of such breeding, such as simplicity of implementing technological measures, easier establishment of the breeding system, simpler manipulation, the possibility of denser colonies per unit volume with a high level of production, easier adaptations to market conditions and fewer initial structural investments. Despite the many advantages, the main reasons for the lack of greater implementation of the cage breeding technology for warm water species of freshwater fish include problems in obtaining the appropriate category and quantity of healthy fry, the specificity and applicability of physical and chemical properties of the recipients and human error. In evaluating the advantages and disadvantages, the final decision on the justification of cage breeding for individual warm water freshwater species must be based on both biological and economic factors. Based on the knowledge of cage breeding acquired to date, the rule for virtually all intensive breeding systems is that it is only recommended for those species with high market demand and a high market price. The technology that demands nutrition with highly concentrated feed and other production expenditures is costly, and is therefore not profitable with less expensive fish species. Furthermore, production must be market oriented, i.e. the appropriate market research measures

Apparent foraging success reflects habitat quality in an irruptive species, the Black-backed Woodpecker

Science.gov (United States)

Christopher T. Rota; Mark A. Rumble; Chad P. Lehman; Dylan C. Kesler; Joshua J. Millspaugh

2015-01-01

Dramatic fluctuations in food resources are a key feature of many habitats, and many species have evolved a movement strategy to exploit food resources that are unpredictable in space and time. The availability of food resources may be a particularly strong determinant of habitat quality for irruptive bird species. We studied the apparent foraging success of Black-...

Otolith Length-Fish Length Relationships of Eleven US Arctic Fish Species and Their Application to Ice Seal Diet Studies

Science.gov (United States)

Walker, K. L.; Norcross, B.

2016-02-01

The Arctic ecosystem has moved into the spotlight of scientific research in recent years due to increased climate change and oil and gas exploration. Arctic fishes and Arctic marine mammals represent key parts of this ecosystem, with fish being a common part of ice seal diets in the Arctic. Determining sizes of fish consumed by ice seals is difficult because otoliths are often the only part left of the fish after digestion. Otolith length is known to be positively related to fish length. By developing species-specific otolith-body morphometric relationships for Arctic marine fishes, fish length can be determined for fish prey found in seal stomachs. Fish were collected during ice free months in the Beaufort and Chukchi seas 2009 - 2014, and the most prevalent species captured were chosen for analysis. Otoliths from eleven fish species from seven families were measured. All species had strong linear relationships between otolith length and fish total length. Nine species had coefficient of determination values over 0.75, indicating that most of the variability in the otolith to fish length relationship was explained by the linear regression. These relationships will be applied to otoliths found in stomachs of three species of ice seals (spotted Phoca largha, ringed Pusa hispida, and bearded Erignathus barbatus) and used to estimate fish total length at time of consumption. Fish lengths can in turn be used to calculate fish weight, enabling further investigation into ice seal energetic demands. This application will aid in understanding how ice seals interact with fish communities in the US Arctic and directly contribute to diet comparisons among and within ice seal species. A better understanding of predator-prey interactions in the US Arctic will aid in predicting how ice seal and fish species will adapt to a changing Arctic.

Intra-seasonal variation in foraging behavior among Adélie penguins (Pygocelis adeliae) breeding at Cape Hallett, Ross Sea, Antarctica

Science.gov (United States)

Lyver, P.O.B.; MacLeod, C.J.; Ballard, G.; Karl, B.J.; Barton, K.J.; Adams, J.; Ainley, D.G.; Wilson, P.R.

2011-01-01

We investigated intra-seasonal variation in foraging behavior of chick-rearing Adélie penguins, Pygoscelis adeliae, during two consecutive summers at Cape Hallett, northwestern Ross Sea. Although foraging behavior of this species has been extensively studied throughout the broad continental shelf region of the Ross Sea, this is the first study to report foraging behaviors and habitat affiliations among birds occupying continental slope waters. Continental slope habitat supports the greatest abundances of this species throughout its range, but we lack information about how intra-specific competition for prey might affect foraging and at-sea distribution and how these attributes compare with previous Ross Sea studies. Foraging trips increased in both distance and duration as breeding advanced from guard to crèche stage, but foraging dive depth, dive rates, and vertical dive distances travelled per hour decreased. Consistent with previous studies within slope habitats elsewhere in Antarctic waters, Antarctic krill (Euphausia superba) dominated chick meal composition, but fish increased four-fold from guard to crèche stages. Foraging-, focal-, and core areas all doubled during the crèche stage as individuals shifted distribution in a southeasterly direction away from the coast while simultaneously becoming more widely dispersed (i.e., less spatial overlap among individuals). Intra-specific competition for prey among Adélie penguins appears to influence foraging behavior of this species, even in food webs dominated by Antarctic krill.

Forage fish quality: seasonal lipid dynamics of herring (Clupea harengus L.) and sprat (Sprattus sprattus L.) in the Baltic Sea

DEFF Research Database (Denmark)

Røjbek, Maria; Tomkiewicz, Jonna; Jacobsen, Charlotte

2013-01-01

seasonally with high levelstowards the end of the annual zooplankton production cycle, succeeded by a decline. Lipid content and fatty acid composition differed significantly between sprat and herring. Sprat lipid content was higher than herring, increasing with fish size and characterized by large......This study investigates lipid content and fatty acid composition of two important forage fish, sprat (Sprattus sprattus) and herring (Clupea harengus) in the Baltic Sea ecosystem. Seasonal variation in lipids was studied during three periods following the annual reproductive cycle considering...... potential differences relating to fish size, sex, and reproductive status. The isopod Saduria entomon, being at times an important prey for predatory fish, was included for comparison. In both sprat and herring, lipid content and absolute contents of essential polyunsaturated fatty acids (PUFAs) varied...

Alien fish species in reservoir systems in Turkey: a review

OpenAIRE

Deniz Innal

2012-01-01

Turkey’s natural river systems have been anthropogenically altered in the past century. Native fish communities of river systems have comeunder increasing pressure from water engineering projects, pollution, overfishing and the movements of alien fish species. Introduction ofalien fishes is one of the main threats to the survival and genetic integrity of native fishes around the world. In Turkey, alien freshwater fish are continuing to increase in number of species, abundance, and distributio...

Targeting Abundant Fish Stocks while Avoiding Overfished Species: Video and Fishing Surveys to Inform Management after Long-Term Fishery Closures

Science.gov (United States)

2016-01-01

Historically, it has been difficult to balance conservation goals and yield objectives when managing multispecies fisheries that include stocks with various vulnerabilities to fishing. As managers try to maximize yield in mixed-stock fisheries, exploitation rates can lead to less productive stocks becoming overfished. In the late 1990s, population declines of several U.S. West Coast groundfish species caused the U.S. Pacific Fishery Management Council to create coast-wide fishery closures, known as Rockfish Conservation Areas, to rebuild overfished species. The fishery closures and other management measures successfully reduced fishing mortality of these species, but constrained fishing opportunities on abundant stocks. Restrictive regulations also caused the unintended consequence of reducing fishery-dependent data available to assess population status of fished species. As stocks rebuild, managers are faced with the challenge of increasing fishing opportunities while minimizing fishing mortality on rebuilding species. We designed a camera system to evaluate fishes in coastal habitats and used experimental gear and fishing techniques paired with video surveys to determine if abundant species could be caught in rocky habitats with minimal catches of co-occurring rebuilding species. We fished a total of 58 days and completed 741 sets with vertical hook-and-line fishing gear. We also conducted 299 video surveys in the same locations where fishing occurred. Comparison of fishing and stereo-video surveys indicated that fishermen could fish with modified hook-and-line gear to catch abundant species while limiting bycatch of rebuilding species. As populations of overfished species continue to recover along the U.S. West Coast, it is important to improve data collection, and video and fishing surveys may be key to assessing species that occur in rocky habitats. PMID:28002499

Neotropical fish-fruit interactions: eco-evolutionary dynamics and conservation.

Science.gov (United States)

Correa, Sandra Bibiana; Costa-Pereira, Raul; Fleming, Theodore; Goulding, Michael; Anderson, Jill T

2015-11-01

Frugivorous fish play a prominent role in seed dispersal and reproductive dynamics of plant communities in riparian and floodplain habitats of tropical regions worldwide. In Neotropical wetlands, many plant species have fleshy fruits and synchronize their fruiting with the flood season, when fruit-eating fish forage in forest and savannahs for periods of up to 7 months. We conducted a comprehensive analysis to examine the evolutionary origin of fish-fruit interactions, describe fruit traits associated with seed dispersal and seed predation, and assess the influence of fish size on the effectiveness of seed dispersal by fish (ichthyochory). To date, 62 studies have documented 566 species of fruits and seeds from 82 plant families in the diets of 69 Neotropical fish species. Fish interactions with flowering plants are likely to be as old as 70 million years in the Neotropics, pre-dating most modern bird-fruit and mammal-fruit interactions, and contributing to long-distance seed dispersal and possibly the radiation of early angiosperms. Ichthyochory occurs across the angiosperm phylogeny, and is more frequent among advanced eudicots. Numerous fish species are capable of dispersing small seeds, but only a limited number of species can disperse large seeds. The size of dispersed seeds and the probability of seed dispersal both increase with fish size. Large-bodied species are the most effective seed dispersal agents and remain the primary target of fishing activities in the Neotropics. Thus, conservation efforts should focus on these species to ensure continuity of plant recruitment dynamics and maintenance of plant diversity in riparian and floodplain ecosystems. © 2015 Cambridge Philosophical Society.

Alien fish species in reservoir systems in Turkey: a review

Directory of Open Access Journals (Sweden)

Deniz Innal

2012-12-01

Full Text Available Turkey’s natural river systems have been anthropogenically altered in the past century. Native fish communities of river systems have comeunder increasing pressure from water engineering projects, pollution, overfishing and the movements of alien fish species. Introduction ofalien fishes is one of the main threats to the survival and genetic integrity of native fishes around the world. In Turkey, alien freshwater fish are continuing to increase in number of species, abundance, and distribution. The present paper reviews fish stocking studies in Turkey’s reservoirs.

76 FR 2663 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2011-01-14

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... and steelhead, and natural juvenile green sturgeon while carrying out a study measuring fish response... species, taking of length measurements), tissue sampling, release of moribund fish or fish carcasses back...

Do low-mercury terrestrial resources subsidize low-mercury growth of stream fish? Differences between species along a productivity gradient.

Directory of Open Access Journals (Sweden)

Darren M Ward

Full Text Available Low productivity in aquatic ecosystems is associated with reduced individual growth of fish and increased concentrations of methylmercury (MeHg in fish and their prey. However, many stream-dwelling fish species can use terrestrially-derived food resources, potentially subsidizing growth at low-productivity sites, and, because terrestrial resources have lower MeHg concentrations than aquatic resources, preventing an increase in diet-borne MeHg accumulation. We used a large-scale field study to evaluate relationships among terrestrial subsidy use, growth, and MeHg concentrations in two stream-dwelling fish species across an in-stream productivity gradient. We sampled young-of-the-year brook trout (Salvelinus fontinalis and Atlantic salmon (Salmo salar, potential competitors with similar foraging habits, from 20 study sites in streams in New Hampshire and Massachusetts that encompassed a wide range of aquatic prey biomass. Stable isotope analysis showed that brook trout used more terrestrial resources than Atlantic salmon. Over their first growing season, Atlantic salmon tended to grow larger than brook trout at sites with high aquatic prey biomass, but brook grew two-fold larger than Atlantic salmon at sites with low aquatic prey biomass. The MeHg concentrations of brook trout and Atlantic salmon were similar at sites with high aquatic prey biomass and the MeHg concentrations of both species increased at sites with low prey biomass and high MeHg in aquatic prey. However, brook trout had three-fold lower MeHg concentrations than Atlantic salmon at low-productivity, high-MeHg sites. These results suggest that differential use of terrestrial resource subsidies reversed the growth asymmetry between potential competitors across a productivity gradient and, for one species, moderated the effect of low in-stream productivity on MeHg accumulation.

Fish species diversity and conservation in Beijing and adjacent areas

OpenAIRE

Chunguang Zhang; Yahui Zhao; Yingchun Xing; Ruilu Guo; Qing Zhang; Yun Feng; Enyuan Fan

2011-01-01

Based on field surveys between 2002 and 2010, and fish collections in the National Zoological Museum, Institute of Zoology, Chinese Academy of Sciences, a total of 93 wild fish species including 12 in-troduced species had been recorded in Beijing and adjacent areas. Eighty five of these species, including some migratory and estuarine fishes, are native to the region. Only 43 native wild species were collected in our field work from 2002 to 2010. Compared with the historical records, nearly 50...

The Relationships between Morphological Characteristics and Foraging Behavior in Four Selected Species of Shorebirds and Water Birds Utilizing Tropical Mudflats

Directory of Open Access Journals (Sweden)

Nor Atiqah Norazlimi

2015-01-01

Full Text Available A study was conducted to investigate the relationship between the physical morphology of shorebirds and water birds (i.e., Lesser adjutant (Leptoptilos javanicus, Common redshank (Tringa totanus, Whimbrel (Numenius phaeopus, and Little heron (Butorides striata and their foraging behavior in the mudflats area of Selangor, Peninsular Malaysia, from August 2013 to July 2014 by using direct observation techniques (using binoculars and a video recorder. The actively foraging bird species were watched, and their foraging activities were recorded for at least 30 seconds for up to a maximum of five minutes. A Spearman Rank Correlation highlighted a significant relationship between bill size and foraging time (R=0.443, p<0.05, bill size and prey size (R=-0.052, p<0.05, bill size and probing depth (R=0.42, p=0.003, and leg length and water/mud depth (R=0.706, p<0.005. A Kruskal-Wallis Analysis showed a significant difference between average estimates of real probing depth of the birds (mm and species (H=15.96, p=0.0012. Three foraging techniques were recorded: pause-travel, visual-feeding, and tactile-hunting. Thus, morphological characteristics of bird do influence their foraging behavior and strategies used when foraging.

Diet composition of age-0 fishes in created habitats of the Lower Missouri River

Science.gov (United States)

Starks, Trevor A.; Long, James M.

2017-01-01

Channelization of the Missouri River has greatly reduced the availability of shallow water habitats used by many larval and juvenile fishes and contributed to imperilment of floodplain-dependent biota. Creation of small side channels, or chutes, is being used to restore shallow water habitat and reverse negative environmental effects associated with channelization. In the summer of 2012, the U.S. Army Corps of Engineers collected early life stages of fishes from constructed chutes and nearby unrestored shallow habitats at six sites on the Missouri River between Rulo, Nebraska and St. Louis, Missouri. We compared the diets of two abundant species of fishes to test the hypothesis that created shallow chutes provided better foraging habitat for early life stages than nearby unrestored shallow habitats. Graphical analysis of feeding patterns of freshwater drum indicated specialization on chironomid larvae, which were consumed in greater numbers in unrestored mainstem reaches compared to chutes. Hiodon spp. were more generalist feeders with no differences in prey use between habitat types. Significantly greater numbers of individuals with empty stomachs were observed in chute shallow-water habitats, indicating poor foraging habitat. For these two species, constructed chute shallow-water habitat does not appear to provide the hypothesized benefits of higher quality foraging habitat.

75 FR 2106 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2010-01-14

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... NMFS regulations (50 CFR parts 222-226) governing listed fish and wildlife permits. Species Covered in... steelhead not to exceed 2 percent of the total number of fish captured for each life stage and species...

Genetic calibration of species diversity among North America's freshwater fishes.

Science.gov (United States)

April, Julien; Mayden, Richard L; Hanner, Robert H; Bernatchez, Louis

2011-06-28

Freshwater ecosystems are being heavily exploited and degraded by human activities all over the world, including in North America, where fishes and fisheries are strongly affected. Despite centuries of taxonomic inquiry, problems inherent to species identification continue to hamper the conservation of North American freshwater fishes. Indeed, nearly 10% of species diversity is thought to remain undescribed. To provide an independent calibration of taxonomic uncertainty and to establish a more accessible molecular identification key for its application, we generated a standard reference library of mtDNA sequences (DNA barcodes) derived from expert-identified museum specimens for 752 North American freshwater fish species. This study demonstrates that 90% of known species can be delineated using barcodes. Moreover, it reveals numerous genetic discontinuities indicative of independently evolving lineages within described species, which points to the presence of morphologically cryptic diversity. From the 752 species analyzed, our survey flagged 138 named species that represent as many as 347 candidate species, which suggests a 28% increase in species diversity. In contrast, several species of parasitic and nonparasitic lampreys lack such discontinuity and may represent alternative life history strategies within single species. Therefore, it appears that the current North American freshwater fish taxonomy at the species level significantly conceals diversity in some groups, although artificially creating diversity in others. In addition to providing an easily accessible digital identification system, this study identifies 151 fish species for which taxonomic revision is required.

Ontogenetic foraging activity and feeding selectivity of the Brazilian endemic parrotfish Scarus zelindae

OpenAIRE

Pereira, Pedro H.C.; Santos, Marcus; Lippi, Daniel L.; Silva, Pedro

2016-01-01

Parrotfish are fundamental species in controlling algal phase-shifts and ensuring the resilience of coral reefs. Nevertheless, little is known on their ecological role in the south-western Atlantic Ocean. The present study analysed the ontogenetic foraging activity and feeding selectivity of the Brazilian endemic parrotfish Scarus zelindae using behavioural observation and benthic composition analyses. We found a significant negative relationship between fish size and feeding rates for S. zel...

Agency interaction at the Savannah River Plant under the Endangered Species Act

International Nuclear Information System (INIS)

Mackey, H.E. Jr.

1985-01-01

The 300 square mile Savannah River Plant (SRP) offers a variety of protected habitats for endangered species including the alligator (resident), red-cockaded woodpecker (resident), short-nose sturgeon (migratory), and wood stork (fish-forager). The most recent of these four species to be listed by the US Fish and Wildlife Service (US FWS) is the wood stork. It had been observed prior to 1983 as an infrequent forager in the SRP Savannah River Swamp which adjoins SRP on the south and southwest. In anticipation of its listing as an endangered species, DOE-SR requested in the spring of 1983 that the Savannah River Ecology Laboratory, University of Georgia, conduct field surveys and studies of the nearest colony of wood storks to SRP (the Birdsville colony in north-central Georgia). The objective of these studies was to determine potential effects of the flooding of the Steel Creek swamp area with cooling water from L-Reactor. L-Reactor, which is proposed for restart, has not been operated since 1968. The survey found that wood storks forage in the Steel Creek delta swamp area of the Savannah River at SRP. Based on the numbers of storks at various foraging locations, sites at SRP ranked higher than non-SRP sites during the pre-fledging phase of the colony. Cold flow testing of L-Reactor also demonstrated that foraging sites in the Steel Creek delta would be unavailable during L-Reactor operation because of increased water levels

Phytoplankton IF-FISH: Species-specific labeling of cellular proteins by immunofluorescence (IF) with simultaneous species identification by fluorescence immunohybridization (FISH).

Science.gov (United States)

Meek, Megan E; Van Dolah, Frances M

2016-05-01

Phytoplankton rarely occur as unialgal populations. Therefore, to study species-specific protein expression, indicative of physiological status in natural populations, methods are needed that will both assay for a protein of interest and identify the species expressing it. Here we describe a protocol for IF-FISH, a dual labeling procedure using immunofluorescence (IF) labeling of a protein of interest followed by fluorescence in situ hybridization (FISH) to identify the species expressing that protein. The protocol was developed to monitor expression of the cell cycle marker proliferating cell nuclear antigen (PCNA) in the red tide dinoflagellate, Karenia brevis, using a large subunit (LSU) rRNA probe to identify K. brevis in a mixed population of morphologically similar Karenia species. We present this protocol as proof of concept that IF-FISH can be successfully applied to phytoplankton cells. This method is widely applicable for the analysis of single-cell protein expression of any protein of interest within phytoplankton communities. Copyright © 2016 Elsevier B.V. All rights reserved.

CHEMICAL COMPOSITION OF CAATINGA POTENTIAL FORAGES SPECIES

Directory of Open Access Journals (Sweden)

Dynara Layza de Souza da Silva

2015-12-01

Full Text Available Chemical composition of some potential forages species, natives from Caatinga region, were evaluated. Samples of Macroptilium heterophyllum, Stylosanthes humilis, Rhynchosia mínima, Desmodium tortuosum Sw. Dc, Merremia aegyptia, Mimosa tenuiflora Wild, Bauhinia cheilantha and as well Macroptilium lathyroides, Caesalpinia pyramidalis and Mimosa tenuiflora hays were collected in Rio Grande do Norte Stated, during 2011 rainy season. The analyses: dry matter (DM, crude protein (CP mineral matter (MM ether extract  (EE neutral detergent fiber (NDF, acid detergent fiber (ADF, lignin (LIG, insoluble neutral detergent nitrogen, (INDN insoluble acid detergent nitrogen, (ADIN, total phenol (TF and total tannin (TT were done at Embrapa Caprinos e Ovinos in Ceará State. Plants analyzed, as expected, for tropical species, exhibited high level of cell wall constituents, high lignifications rate and revealed substantial presence of anti nutritional compounds. However, regardless of this data, the main problem, for grazing animals, is due to its xerophytes characteristics. Most of the shrubs and trees are deciduous, losing its leaves during the dry season. In addition, herbaceous presents a very rapid lifetime cycle, germinating and senescing during the brief wet season.

Sensory quality criteria for five fish species

DEFF Research Database (Denmark)

Warm, Karin; Nielsen, Jette; Hyldig, Grethe

2000-01-01

Sensory profiling has been used to develop one sensory vocabulary for five fish species: cod (Gadus morhua), saithe (Pollachius virens), rainbow trout (Salmo gardineri), herring (Clupea harengus) and flounder (Platichthys flessus). A nine- member trained panel assessed 18 samples with variation i...... variation and by presenting references, panel discussions and interpreting plots from multivariate data analysis. The developed profile can be used as a sensory wheel for these species, and with minor changes it may be adapted to similar species......Sensory profiling has been used to develop one sensory vocabulary for five fish species: cod (Gadus morhua), saithe (Pollachius virens), rainbow trout (Salmo gardineri), herring (Clupea harengus) and flounder (Platichthys flessus). A nine- member trained panel assessed 18 samples with variation...

Specific IgE to fish extracts does not predict allergy to specific species within an adult fish allergic population.

Science.gov (United States)

Schulkes, Karlijn Jg; Klemans, Rob Jb; Knigge, Lidy; de Bruin-Weller, Marjolein; Bruijnzeel-Koomen, Carla Afm; Marknell deWitt, Asa; Lidholm, Jonas; Knulst, André C

2014-01-01

Fish is an important cause of food allergy. Studies on fish allergy are scarce and in most cases limited to serological evaluation. Our objective was to study patterns of self-reported allergy and tolerance to different commonly consumed fish species and its correlation to IgE sensitization to the same species. Thirty-eight adult fish allergic patients completed a questionnaire regarding atopy, age of onset and symptoms to 13 commonly consumed fish species in the Netherlands (pangasius, cod, herring, eel, hake, pollock, mackerel, tilapia, salmon, sardine, tuna, plaice and swordfish). Specific IgE to these fish extracts were analyzed by ImmunoCAP. Median age of onset of fish allergy was 8.5 years. Severe reactions were reported by the majority of patients (n = 20 (53%) respiratory and of these 20 patients, 6 also had cardiovascular symptoms). After diagnosis, 66% of the patients had eliminated all fish from their diet. Allergy to all species ever tried was reported by 59%. In relation to species ever tried, cod (84%) and herring (79%) were the most frequently reported culprit species while hake (57%) and swordfish (55%) were the least frequent. A positive sIgE (value ≥ 0.35 kUA/L) to the culprit species ranged between 50% (swordfish) and 100% (hake). In tolerant patients, a negative sIgE (value allergy or tolerance was 82% and 25%, respectively. Sensitization to cod parvalbumin (Gad c 1) was present in 77% of all patients. Serological cross-reactivity between fish species is frequent, but in a significant proportion of patients, clinical relevance appears to be limited to only certain species. A well-taken history or food challenge is required for discrimination between allergy to the different fish species.

Total mercury levels in commercial fish species from Italian fishery and aquaculture.

Science.gov (United States)

Di Lena, Gabriella; Casini, Irene; Caproni, Roberto; Fusari, Andrea; Orban, Elena

2017-06-01

Total mercury levels were measured in 42 commercial fish species caught off the Central Adriatic and Tyrrhenian coasts of Italy and in 6 aquaculture species. The study on wild fish covered species differing in living habitat and trophic level. The study on farmed fish covered marine and freshwater species from intensive and extensive aquaculture and their feed. Mercury levels were analysed by thermal decomposition-amalgamation-atomic absorption spectrophotometry. Total mercury concentrations in the muscle of wild fish showed a high variability among species (0.025-2.20 mg kg -1 wet weight). The lowest levels were detected in low trophic-level demersal and pelagic-neritic fish and in young individuals of high trophic-level species. Levels exceeding the European Commission limits were found in large-size specimens of high trophic-level pelagic and demersal species. Fish from intensive farming showed low levels of total mercury (0.008-0.251 mg kg -1 ). Fish from extensive rearing showed variable contamination levels, depending on the area of provenience. An estimation of the human intake of mercury associated to the consumption of the studied fish and its comparison with the tolerable weekly intake is provided.

Preliminary list of endangered fish species (Pisces, Elasmobranchii , Actinopterygii) in Brazil

OpenAIRE

Rosa, Ricardo S; Menezes, Naércio A

1996-01-01

The Brazilian fish fauna is still poorly known with respect to its diversity and conservation status, particularly of freshwater species. Human activities and population growth are rapidly impacting this fauna to an unchecked extent, so that many fish species are presently threatened. Also, some areas have been so critically altered that their fish fauna can no longer be properly inventoried. There is an urgent need to evaluate the conservation status of Brazilian fish species, since none are...

Endangered Fish Species in Kansas: Historic vs Contemporary Distribution

Science.gov (United States)

Background/Question/Methods Kansas state has more freshwater fish species than other states in the west and northern US. Based on recent count, more than 140 fishes have been documented in Kansas rivers. And at least five are categorized as endangered species in Kansas (and thre...

Investigation of biological condition of fish species in lower Ogun ...

African Journals Online (AJOL)

The study was carried out to investigate the biological condition of fish species in lower Ogun River wetlands. A total of 175 individual fish belonging to 10 species were collected from artisanal fishermen using different types of fishing gears. Two biological indices; condition factor “K” and growth exponent “b” obtained from ...

Forage fish interactions: A symposium on creating the tools for ecosystem-based management of marine resources

DEFF Research Database (Denmark)

Peck, M.A.; Neuenfeldt, Stefan; Essington, V.M.

2014-01-01

Forage fish (FF) have a unique position within marine foodwebs and the development of sustainable harvest strategies for FF will be a critical step in advancing and implementing the broader, ecosystem-based management of marine systems. In all, 70 scientists from 16 nations gathered for a symposium...... on 12–14 November 2012 that was designed to address three key questions regarding the effective management of FF and their ecosystems: (i) how do environmental factors and predator–prey interactions drive the productivity and distribution of FF stocks across ecosystems worldwide, (ii) what...

76 FR 14923 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2011-03-18

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... knowledge of species listed under the Endangered Species Act (ESA) and help guide management and... harvested groundfish species. The survey would collect data on 90+ fish species in the ocean to fulfill the...

California Least Tern Foraging Ecology in Southern California: A Review of Foraging Behavior Relative to Proposed Dredging Locations

Science.gov (United States)

2016-05-01

additional data are necessary to understand the relationship among turbidity plumes, behavior of CLT prey fish , and CLT foraging behavior. KBC...activities. Fish actively seek out or avoid turbid waters for a number of reasons, including predator avoidance and food resources, and this...Birds 14:57-72. Atwood, J. L., and P. R. Kelly. 1984. Fish dropped on breeding colonies as indicators of Least Tern food habits. Wilson Bulletin 96: 34

Agronomic and forage characteristics of Guazuma ulmifolia Lam.

OpenAIRE

Manríquez-Mendoza, Leonor Yalid; López-Ortíz, Silvia; Pérez-Hernández, Ponciano; Ortega- Jiménez, Eusebio; López-Tecpoyotl, Zenón Gerardo; Villarruel-Fuentes, Manuel

2011-01-01

Native trees are an important source of forage for livestock, particularly in regions having prolonged dry periods. Some tree species have fast growth rates, good nutritional quality, and the ability to produce forage during dry periods when the need for forage is greater. Guazuma ulmifolia Lam. is a tree native to tropical America that has a high forage potential. This species is mentioned in a number of studies assessing the forage potential of trees in a diverse array of environments and v...

forage systems mixed with forage legumes grazed by lactating cows

Directory of Open Access Journals (Sweden)

Clair Jorge Olivo

2017-02-01

Full Text Available Current research evaluates productivity, stocking and nutritional rates of three forage systems with Elephant Grass (EG + Italian Ryegrass (IR + Spontaneous Growth Species (SGS, without forage legumes; EG + IR + SGS + Forage Peanut (FP, mixed with FP; and EG + IR + SGS + Red Clover (RC, mixed with RC, in rotational grazing method by lactating cows. IR developed between rows of EG. FP was maintained, whilst RC was sow to respective forage systems. The experimental design was completely randomized, with three treatments and two replication, subdivided into parcels over time. Mean rate for forage yield and average stocking rate were 10.6, 11.6 and 14.4 t ha-1; 3.0, 2.8 and 3.1 animal unit ha-1 day-1, for the respective systems. Levels of crude protein and total digestible nutrients were 17.8, 18.7 and 17.5%; 66.5, 66.8 and 64.8%, for the respective forage systems. The presence of RC results in better and higher forage yield in the mixture, whilst FP results in greater control of SGS. The inclusion of forage legumes in pasture systems provides better nutritional rates.

Individual diet variation in a marine fish assemblage: Optimal Foraging Theory, Niche Variation Hypothesis and functional identity

Science.gov (United States)

Cachera, M.; Ernande, B.; Villanueva, M. C.; Lefebvre, S.

2017-02-01

Individual diet variation (i.e. diet variation among individuals) impacts intra- and inter-specific interactions. Investigating its sources and relationship with species trophic niche organization is important for understanding community structure and dynamics. Individual diet variation may increase with intra-specific phenotypic (or "individual state") variation and habitat variability, according to Optimal Foraging Theory (OFT), and with species trophic niche width, according to the Niche Variation Hypothesis (NVH). OFT proposes "proximate sources" of individual diet variation such as variations in habitat or size whereas NVH relies on "ultimate sources" related to the competitive balance between intra- and inter-specific competitions. The latter implies as a corollary that species trophic niche overlap, taken as inter-specific competition measure, decreases as species niche width and individual niche variation increase. We tested the complementary predictions of OFT and NVH in a marine fish assemblage using stomach content data and associated trophic niche metrics. The NVH predictions were tested between species of the assemblage and decomposed into a between- and a within-functional group component to assess the potential influence of species' ecological function. For most species, individual diet variation and niche overlap were consistently larger than expected. Individual diet variation increased with intra-specific variability in individual state and habitat, as expected from OFT. It also increased with species niche width but in compliance with the null expectation, thus not supporting the NVH. In contrast, species niche overlap increased significantly less than null expectation with both species niche width and individual diet variation, supporting NVH corollary. The between- and within-functional group components of the NVH relationships were consistent with those between species at the assemblage level. Changing the number of prey categories used to

Indigenous fish species in the modern ichthyofauna of the Balkhash basin

Directory of Open Access Journals (Sweden)

Nadir Shamilevich Mamilov

2015-11-01

Full Text Available Indigenous fish fauna of the Balkhash basin was mostly formed in the postglacial period and consists of 10 species from Cyprinidae family, 5 from Balitoridae, and 1 from Percidae. More than 20 alien fish species were introduced here during XXth century that led to eradication of indigenous fishes from the Balkhash Lake and the Ili River. Our investigations of the fish fauna during last 25 years revealed permanent shortage of living area of indigenous fishes. Nowadays fish communities from only indigenous fish species exist in some remote and isolated water bodies. Areas of all indigenous fish species are become disconnected. Reduction of habitats goes relatively slow for naked osman Gymnodiptychus dybowskii (Kessler, 1874, spotted thicklip loach Triplophysa strauchii (Kessler, 1874, and gray loach Triplophysa dorsalis (Kessler, 1872. Drastic reductions of areas were revealed for Ili marinka Schizothorax pseudoaksaiensis Herzenstein 1889, Balkhash marinka Schizothorax argentatus Kessler 1874, Severtsov’s loach Triplophysa sewerzowii (G.Nikolskii, 1938, Seven River’s minnow Phoxinus brachyurus Berg 1912, Balkhsh minnow Rhynchocypris poljakowii Kessler 1879, and Balkhash perch Perca schrenkii Kessler 1874. Marinkas, osmans and perch often become victims of overfishing and poaching of local people. In that region water resources usually are used by wasteful way and loaded with pollutants. Many indigenous fish species are able to bear relatively high level of environment pollution. Hence, the main threats for indigenous fishes are introductions of trout and sander, habitats lose and unstable hydrological regimen.

Genetic Analysis of Seed Yield Components and its Association with Forage Production in Wild and Cultivated Species of Sainfoin

Directory of Open Access Journals (Sweden)

A. Najafipoor

2017-02-01

Full Text Available Little is known about genetic variation of seed related traits and their association with forage characters in sainfoin. In order to investigate the variation and relationship among seed yield and its components, 93 genotypes from 21 wild and cultivated species of genus Onobrychis were evaluated using a randomized complete block design with four replications at Isfahan University of Technology Research Farm, Isfahan, Iran. Analysis of variance showed that there was significant difference among genotypes, indicating existence of considerable genetic variation in this germplasm. Panicle fertility and panicle length had the most variation in cultivated and the wild genotypes, respectively. Results of correlation analysis showed that seed yield was positively correlated with number of stems per plant and number of seeds per panicle and negatively correlated with panicle length and days to 50% flowering. Seed yield had positive correlation with forage yield in wild species while this correlation was not significant in cultivated one. Cluster analysis classified the genotypes into three groups which separate wild and cultivated species. Based on principal component analysis the first component was related to seed yield and the second one was related to components of forage yield which can be used for selection of high forage and seed yielding genotypes.

Metazoan parasite species richness in Neotropical fishes: hotspots and the geography of biodiversity.

Science.gov (United States)

Luque, J L; Poulin, R

2007-06-01

Although research on parasite biodiversity has intensified recently, there are signs that parasites remain an underestimated component of total biodiversity in many regions of the planet. To identify geographical hotspots of parasite diversity, we performed qualitative and quantitative analyses of the parasite-host associations in fishes from Latin America and the Caribbean, a region that includes known hotspots of plant and animal biodiversity. The database included 10,904 metazoan parasite-host associations involving 1660 fish species. The number of host species with at least 1 parasite record was less than 10% of the total known fish species in the majority of countries. Associations involving adult endoparasites in actinopterygian fish hosts dominated the database. Across the whole region, no significant difference in parasite species richness was detected between marine and freshwater fishes. As a rule, host body size and study effort (number of studies per fish species) were good predictors of parasite species richness. Some interesting patterns emerged when we included only the regions with highest fish species biodiversity and study effort (Brazil, Mexico and the Caribbean Islands). Independently of differences in study effort or host body sizes, Mexico stands out as a hotspot of parasite diversity for freshwater fishes, as does Brasil for marine fishes. However, among 57 marine fish species common to all 3 regions, populations from the Caribbean consistently harboured more parasite species. These differences may reflect true biological patterns, or regional discrepancies in study effort and local priorities for fish parasitology research.

76 FR 27016 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2011-05-10

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... increase knowledge of species listed under the Endangered Species Act (ESA) and help guide management and... during the species' upstream migration. Captured fish would be transported in a tanker truck and released...

Species specific anaesthetics for fish anaesthesia and euthanasia.

Science.gov (United States)

Readman, Gareth D; Owen, Stewart F; Knowles, Toby G; Murrell, Joanna C

2017-08-02

There is a need to ensure that the care and welfare for fish maintained in the laboratory are to the highest standards. This extends to the use of anaesthetics for both scientific study, humane killing and euthanasia at end of life. An anaesthetic should not induce negative behaviours and fish should not seek to avoid the anaesthetic. Surprisingly little information is available to facilitate a humane choice of anaesthetic agent for fish despite over 100 years of use and the millions of fish currently held in thousands of laboratories worldwide. Using a chemotaxic choice chamber we found different species specific behavioural responses among four closely related fish species commonly held in the laboratory, exposed to three widely used anaesthetic agents. As previously found for zebrafish (Danio rerio), the use of MS-222 and benzocaine also appears to induce avoidance behaviours in medaka (Oryzias latipes); but etomidate could provide an alternative choice. Carp (Cyprinus carpio), although closely related to zebrafish showed avoidance behaviours to etomidate, but not benzocaine or MS-222; and rainbow trout (Oncorhynchus mykiss) showed no avoidance to the three agents tested. We were unable to ascertain avoidance responses in fathead minnows (Pimephales promelas) and suggest different test paradigms are required for that species.

Fish spawning in a large temperate floodplain: the role of flooding and temperature

NARCIS (Netherlands)

Górski, K.; Winter, H.V.; Leeuw, de J.J.; Minin, A.E.; Nagelkerke, L.A.J.

2010-01-01

1. Floodplains are a key habitat for foraging, spawning and as a nursery for many riverine fish species. The lower Volga floodplains (Russian Federation) are still relatively undisturbed, while in Europe and North America, about 90% of floodplains have effectively been lost. 2. We examined

78 FR 28806 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2013-05-16

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... Resources (CDWR), Permit 17428 to the United States Fish and Wildlife Service (USFWS), and Permit 17777 to... NMFS regulations (50 CFR parts 222-226) governing listed fish and wildlife permits. Species Covered in...

Liquid chromatographic determination of oxytetracycline in edible fish fillets from six species of fish

Science.gov (United States)

Meinertz, J.R.; Stehly, G.R.; Gingerich, W.H.

1998-01-01

The approved use of oxytetracycline (OTC) in U.S. Aquaculture is limited to specific diseases in salmonids and channel catfish. OTC may also be effective in controlling diseases in other fish species important to public aquaculture, but before approved use of OTC can be augmented, an analytical method for determining OTC in fillet tissue from multiple species of fish will be required to support residue depletion studies. The objective of this study was to develop and validate a liquid chromatographic (LC) method that is accurate, precise, and sensitive for OTC in edible fillets from multiple species of fish. Homogenized fillet tissues from walleye, Atlantic salmon, striped bass, white sturgeon, rainbow trout, and channel catfish were fortified with OTC at nominal concentrations of 10, 20, 100, 1000, and 5000 ng/g. In tissues fortified with OTC at 100, 1000, and 5000 ng/g, mean recoveries ranged from 83 to 90%, and relative standard deviations (RSDs) ranged from 0.9 to 5.8%. In all other tissues, mean recoveries ranged from 59 to 98%, and RSDs ranged from 3.3 to 20%. Method quantitation limits ranged from 6 to 22 ng/g for the 6 species. The LC parameters produced easily integratable OTC peaks without coelution of endogenous compounds. The method is accurate, precise, and sensitive for OTC in fillet tissue from 6 species of fish from 5 phylogenetically diverse groups.

Phylogeny of Fish-Infecting Calyptospora species (Apicomplexa: Eimeriorina)

Science.gov (United States)

There are numerous species of apicomplexans that infect poikilothermic vertebrates such as fishes, and possess unique morphological features that provide insight into the evolution of this important phylum of parasites. Here the relationship of the fish-infecting Calyptospora spe...

Movement patterns for a critically endangered species, the leatherback turtle (Dermochelys coriacea), linked to foraging success and population status.

Science.gov (United States)

Bailey, Helen; Fossette, Sabrina; Bograd, Steven J; Shillinger, George L; Swithenbank, Alan M; Georges, Jean-Yves; Gaspar, Philippe; Strömberg, K H Patrik; Paladino, Frank V; Spotila, James R; Block, Barbara A; Hays, Graeme C

2012-01-01

Foraging success for pelagic vertebrates may be revealed by horizontal and vertical movement patterns. We show markedly different patterns for leatherback turtles in the North Atlantic versus Eastern Pacific, which feed on gelatinous zooplankton that are only occasionally found in high densities. In the Atlantic, travel speed was characterized by two modes, indicative of high foraging success at low speeds (turtles. The most parsimonious explanation for these findings is that Eastern Pacific turtles rarely achieve high foraging success. This is the first support for foraging behaviour differences between populations of this critically endangered species and suggests that longer periods searching for prey may be hindering population recovery in the Pacific while aiding population maintenance in the Atlantic.

75 FR 16738 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2010-04-02

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... River fall Chinook salmon under the Endangered Species Act (ESA). The FMEP specifies the future... fish, sturgeon, carp, and other species.'' The FMEP describes the management of recreational fisheries...

76 FR 15946 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2011-03-22

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... research permit application request relating to salmonids listed under the Endangered Species Act (ESA... research activities. The purpose of the research program is to collect warmwater fish species to analyze...

Foraging niche segregation in Malaysian babblers (Family: Timaliidae.

Directory of Open Access Journals (Sweden)

Mohammad Saiful Mansor

Full Text Available Tropical rainforests are considered as hotspots for bird diversity, yet little is known about the system that upholds the coexistence of species. Differences in body size that are associated with foraging strategies and spatial distribution are believed to promote the coexistence of closely related species by reducing competition. However, the fact that many babbler species do not differ significantly in their morphology has challenged this view. We studied the foraging ecology of nine sympatric babbler species (i.e., Pellorneum capistratum, P. bicolor, P. malaccense, Malacopteron cinereum, M. magnum, Stachyris nigriceps, S. nigricollis, S. maculata, and Cyanoderma erythropterum in the Krau Wildlife Reserve in Peninsular Malaysia. We investigated; i how these babblers forage in the wild and use vegetation to obtain food, and ii how these trophically similar species differ in spatial distribution and foraging tactics. Results indicated that most babblers foraged predominantly on aerial leaf litter and used gleaning manoeuvre in intermediate-density foliage but exhibited wide ranges of vertical strata usage, thus reducing interspecific competition. The principal component analysis indicated that two components, i.e., foraging height and substrate are important as mechanisms to allow the coexistence of sympatric babblers. The present findings revealed that these bird species have unique foraging niches that are distinct from each other, and this may apply to other insectivorous birds inhabiting tropical forests. This suggests that niche separation does occur among coexisting birds, thus following Gause' law of competitive exclusion, which states two species occupying the same niche will not stably coexist.

Foraging niche segregation in Malaysian babblers (Family: Timaliidae).

Science.gov (United States)

Mansor, Mohammad Saiful; Ramli, Rosli

2017-01-01

Tropical rainforests are considered as hotspots for bird diversity, yet little is known about the system that upholds the coexistence of species. Differences in body size that are associated with foraging strategies and spatial distribution are believed to promote the coexistence of closely related species by reducing competition. However, the fact that many babbler species do not differ significantly in their morphology has challenged this view. We studied the foraging ecology of nine sympatric babbler species (i.e., Pellorneum capistratum, P. bicolor, P. malaccense, Malacopteron cinereum, M. magnum, Stachyris nigriceps, S. nigricollis, S. maculata, and Cyanoderma erythropterum) in the Krau Wildlife Reserve in Peninsular Malaysia. We investigated; i) how these babblers forage in the wild and use vegetation to obtain food, and ii) how these trophically similar species differ in spatial distribution and foraging tactics. Results indicated that most babblers foraged predominantly on aerial leaf litter and used gleaning manoeuvre in intermediate-density foliage but exhibited wide ranges of vertical strata usage, thus reducing interspecific competition. The principal component analysis indicated that two components, i.e., foraging height and substrate are important as mechanisms to allow the coexistence of sympatric babblers. The present findings revealed that these bird species have unique foraging niches that are distinct from each other, and this may apply to other insectivorous birds inhabiting tropical forests. This suggests that niche separation does occur among coexisting birds, thus following Gause' law of competitive exclusion, which states two species occupying the same niche will not stably coexist.

Foraging niche segregation in Malaysian babblers (Family: Timaliidae)

Science.gov (United States)

Mansor, Mohammad Saiful; Ramli, Rosli

2017-01-01

Tropical rainforests are considered as hotspots for bird diversity, yet little is known about the system that upholds the coexistence of species. Differences in body size that are associated with foraging strategies and spatial distribution are believed to promote the coexistence of closely related species by reducing competition. However, the fact that many babbler species do not differ significantly in their morphology has challenged this view. We studied the foraging ecology of nine sympatric babbler species (i.e., Pellorneum capistratum, P. bicolor, P. malaccense, Malacopteron cinereum, M. magnum, Stachyris nigriceps, S. nigricollis, S. maculata, and Cyanoderma erythropterum) in the Krau Wildlife Reserve in Peninsular Malaysia. We investigated; i) how these babblers forage in the wild and use vegetation to obtain food, and ii) how these trophically similar species differ in spatial distribution and foraging tactics. Results indicated that most babblers foraged predominantly on aerial leaf litter and used gleaning manoeuvre in intermediate-density foliage but exhibited wide ranges of vertical strata usage, thus reducing interspecific competition. The principal component analysis indicated that two components, i.e., foraging height and substrate are important as mechanisms to allow the coexistence of sympatric babblers. The present findings revealed that these bird species have unique foraging niches that are distinct from each other, and this may apply to other insectivorous birds inhabiting tropical forests. This suggests that niche separation does occur among coexisting birds, thus following Gause’ law of competitive exclusion, which states two species occupying the same niche will not stably coexist. PMID:28253284

77 FR 27186 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2012-05-09

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... Endangered Species Act (ESA) and to help guide management and conservation efforts. The applications may be... salmon, and LCR steelhead. The purpose of this research is to determine fish species presence and...

76 FR 57717 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2011-09-16

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS..., importing, and exporting of endangered and threatened species (50 CFR parts 222-226). Permits Permit 15926... will be captured by fyke net, identified to species, enumerated and measured. Dead or moribund fish...

77 FR 51763 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2012-08-27

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... INFORMATION: Authority The issuance of permits and permit modifications, as required by the Endangered Species... (50 CFR parts 222-226) governing listed fish and wildlife permits. Species Covered in This Notice This...

Development of Solar Drying Model for Selected Cambodian Fish Species

Science.gov (United States)

Hubackova, Anna; Kucerova, Iva; Chrun, Rithy; Chaloupkova, Petra; Banout, Jan

2014-01-01

A solar drying was investigated as one of perspective techniques for fish processing in Cambodia. The solar drying was compared to conventional drying in electric oven. Five typical Cambodian fish species were selected for this study. Mean solar drying temperature and drying air relative humidity were 55.6°C and 19.9%, respectively. The overall solar dryer efficiency was 12.37%, which is typical for natural convection solar dryers. An average evaporative capacity of solar dryer was 0.049 kg·h−1. Based on coefficient of determination (R 2), chi-square (χ 2) test, and root-mean-square error (RMSE), the most suitable models describing natural convection solar drying kinetics were Logarithmic model, Diffusion approximate model, and Two-term model for climbing perch and Nile tilapia, swamp eel and walking catfish and Channa fish, respectively. In case of electric oven drying, the Modified Page 1 model shows the best results for all investigated fish species except Channa fish where the two-term model is the best one. Sensory evaluation shows that most preferable fish is climbing perch, followed by Nile tilapia and walking catfish. This study brings new knowledge about drying kinetics of fresh water fish species in Cambodia and confirms the solar drying as acceptable technology for fish processing. PMID:25250381

Legumes and forage species sole or intercropped with corn in soybean-corn succession in midwestern Brazil

Directory of Open Access Journals (Sweden)

Gessí Ceccon

2013-02-01

Full Text Available The feasibility of no-tillage in the Cerrado (Savanna-like vegetation of Brazil depends on the production of sufficient above-ground crop residue, which can be increased by corn-forage intercropping. This study evaluated how above-ground crop residue production and yields of soybean and late-season corn in a soybean-corn rotation were influenced by the following crops in the year before soybean: corn (Zea mays L. intercropped with Brachiaria (Urochloa brizantha cv. Marandu, B. decumbens cv. Basilisk, B. ruziziensis, cv. comum., Panicummaximum cv. Tanzânia, sunn hemp (Crotalaria juncea L., pigeon pea [Cajanus cajan (L. Millsp]; sole corn, forage sorghum [Sorghum bicolor (L. Moench (cv. Santa Elisa], and ruzi grass. In March 2005, corn and forage species were planted in alternate rows spaced 0.90 m apart, and sole forage species were planted in rows spaced 0.45 m apart. In October 2005, the forages were killed with glyphosate and soybean was planted. After the soybean harvest in March 2006, sole late-season corn was planted in the entire experimental area. Corn grain and stover yields were unaffected by intercropping. Above-ground crop residue was greater when corn was intercropped with Tanzania grass (10.7 Mg ha-1, Marandu (10.1 Mg ha-1, and Ruzi Grass (9.8 Mg ha-1 than when corn was not intercropped (4.0 Mg ha-1. The intercropped treatments increased the percentage of soil surface covered with crop residue. Soybean and corn grain yields were higher after sole ruzi grass and intercropped ruzi grass than after other crops. The intercropping corn with Brachiaria spp. and corn with Panicum spp. increases above-ground crop residue production and maintains nutrients in the soil without reducing late-season corn yield and the viability of no-till in the midwestern region of Brazil.

75 FR 78226 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2010-12-15

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... permits and permit modifications, as required by the Endangered Species Act of 1973 (16 U.S.C. 1531-1543... electrofisher and dipnet; sample fish for species identification, tags, marks and finclips, lengths and weights...

Jointness through fishing days input in a multi-species fishery

DEFF Research Database (Denmark)

Hansen, Lars Gårn; Jensen, Carsten Lynge

.g. translog, normalized quadratic). In this paper we argue that jointness in the latter, essentially separable fishery is caused by allocation of fishing days input among harvested species. We developed a structural model of a multi-species fishery where the allocation of fishing days input causes production...

Total mercury concentration in common fish species of Lake Victoria ...

African Journals Online (AJOL)

Total mercury (THg) concentration was analysed in muscles of common fish species of Lake Victoria in the eastern and southern parts of the lake using cold vapour Atomic Absorption Spectrophotometric technique. Mercury concentration in all fish species was generally lower than the WHO maximum allowable ...

The distribution, composition and abundance of fish species in two ...

African Journals Online (AJOL)

Fish composition and abundance of two Gold mine reservoir were investigated between May, 2008 and May, 2009. Seven fish families comprising of twelve species of fish were caught during the period of study. The families of fish caught included Anabantidae, Channidae, Clariidae, Cichlidae, Melanopluridae, Mormyridae ...

[Species composition and geographical distribution of threatened fishes in Yunnan Province of Southwest China].

Science.gov (United States)

Zhang, Qian; Zhong, Jin-Xin

2013-05-01

Based on the related published papers, and by using Geographic Information System (ArcGIS 9.3), this paper analyzed the species composition and geographical distribution of threatened fishes in Yunnan Province of Southwest China. There were 83 threatened species living in the Province, belonging to 5 orders, 13 families, and 47 genera. Cypriniformes was absolutely dominant, with 64 species, followed by Siluriformes, with 16 species. Cyprinidae fishes had 51 species, accounting for 79.7% of Cypriniformes. The most species of Cyprinid fishes were of Barbinae (14 species), Cyprininae (10 species), and Cultrinae (10 species). The threatened fishes could be divided into two zoogeographical regions, i. e., Tibetan Plateau region and Oriental region, and their species composition and geographical distribution were resulted from the historical evolution adapted to the related environments. Whatever in rivers and in lakes, the Cyprinid fishes were both absolutely dominant, occupying 36.1% and 31.3% of the total, respectively. The Cyprinid fishes in rivers were mostly of endangered species, while those in lakes were mostly of vulnerable species. The factors affecting the threatened fishes in the Province were discussed from the two aspects of geodynamic evolution and present situation.

Fish species composition, density-distribution patterns, and impingement during upwelling

International Nuclear Information System (INIS)

Spigarelli, S.A.; Sharma, R.K.

1975-01-01

The effects of cooling system intakes and discharges on Lake Michigan fishes are highly dependent on inshore species composition and spatial distribution which, in turn, are affected by natural hydrological conditions. Significant (5 to 10 C) short-term decreases in water temperature (due to upwelling) could cause cold shock in fish equilibrated to either ambient or plume temperatures; substantial changes in distribution due to avoidance or attraction responses; and resultant changes in susceptibility to impingement. The objectives of this study are to characterize the changes in fish species composition, density, and thermal distribution as a result of natural upwellings, and to relate these factors to intake and discharge effects. Day and night sampling was conducted in ambient (reference) and thermal plume waters near the Zion Nuclear Plant on four occasions between 17 July and 11 September 1975. Density-distribution patterns and species composition of fish were determined by means of gill nets, bottom trawls, seines, and a sonic fish locater

Oral vaccination of fish: Lessons from humans and veterinary species.

Science.gov (United States)

Embregts, Carmen W E; Forlenza, Maria

2016-11-01

The limited number of oral vaccines currently approved for use in humans and veterinary species clearly illustrates that development of efficacious and safe oral vaccines has been a challenge not only for fish immunologists. The insufficient efficacy of oral vaccines is partly due to antigen breakdown in the harsh gastric environment, but also to the high tolerogenic gut environment and to inadequate vaccine design. In this review we discuss current approaches used to develop oral vaccines for mass vaccination of farmed fish species. Furthermore, using various examples from the human and veterinary vaccine development, we propose additional approaches to fish vaccine design also considering recent advances in fish mucosal immunology and novel molecular tools. Finally, we discuss the pros and cons of using the zebrafish as a pre-screening animal model to potentially speed up vaccine design and testing for aquaculture fish species. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Forage production in mixed grazing systems of elephant grass with arrowleaf clover or forage peanut

Directory of Open Access Journals (Sweden)

Daiane Cristine Seibt

Full Text Available ABSTRACT Most dairy production systems are pasture-based, usually consisting of sole grass species. This system facilitates pasture management, but results in high production costs, mainly because of nitrogen fertilizers. An alternative to making forage systems more sustainable is to introduce legumes into the pasture. Mixed pastures allow better forage distribution over time and reduce fertilization costs. Thus, the objective of this study was to evaluate, throughout the year, three forage systems (FS: FS1 (control - elephant grass (EG, ryegrass (RG, and spontaneous species (SS; FS2 - EG + RG + SS + arrowleaf clover; and FS3 - EG + RG + SS + forage peanut. Elephant grass was planted in rows spaced 4 m apart. Ryegrass was sown between the EG lines, in the winter. Arrowleaf clover was sown according to the respective treatments and forage peanut was preserved. Evaluation was carried out using Holstein cows. The experiment was arranged in a completely randomized design, with three treatments (FS, and three repetitions (paddocks with repeated measurements (grazing cycles. Forage mass achieved 3.46, 3.80, and 3.91 t ha-1 for the treatments FS1, FS2 and FS3, respectively. The forage systems intercropped with legumes produced the best results.

76 FR 51352 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2011-08-18

... Department of Fish and Wildlife (WDFW), for a direct take permit pursuant to the Endangered Species Act of... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... Section 9 of the ESA and Federal regulations prohibit the ``taking'' of a species listed as endangered or...

Proteolytic activities in fillets of selected underutilized Australian fish species.

Science.gov (United States)

Ahmed, Z; Donkor, O; Street, W A; Vasiljevic, T

2013-09-01

The hydrolytic activity of major endogenous proteases, responsible for proteolysis of myofibrillar proteins during post-mortem storage, may be an indicator of the textural quality of fish which influences consumer purchasing behaviour and thus market value of the final product. Furthermore, it may also influence the type and bioactive properties of the peptides released during post-mortem proteolysis of myofibrillar proteins. This study compared the activities of cathepsins B, B+L, D, H and calpain-like enzymes in crude muscle extracted from 16 Australian underutilized fish species. Fish species had a significant effect on the activity of these enzymes with barracouta showing the highest cathepsins B, B+L, D and H activities. Activities of cathepsins B and B+L were higher than cathepsin H for all studied species. The more commercially important rock ling and tiger flathead demonstrated higher cathepsin B+L activity, whereas gemfish and eastern school whiting showed higher activity towards cathepsin B. Underutilized fish species showing higher endogenous protease activities may be suitable for fish sauce production, whereas those with lower protease activities for surimi processing. Copyright © 2013 Elsevier Ltd. All rights reserved.

Mercury and stable isotope signatures in caged marine fish and fish feeds

Energy Technology Data Exchange (ETDEWEB)

Onsanit, Sarayut; Chen, Min; Ke, Caihuan [State Key Laboratory for Marine Environmental Science, College of Oceanography and Environmental Science, Xiamen University, Xiamen 361005 (China); Wang, Wen-Xiong [State Key Laboratory for Marine Environmental Science, College of Oceanography and Environmental Science, Xiamen University, Xiamen 361005 (China)

2012-02-15

Highlights: Black-Right-Pointing-Pointer Mercury concentrations in caged fish were closely related to Hg concentrations in fish feeds. Black-Right-Pointing-Pointer The trophic transfer factor of methylmercury was dependent on fish feeds, and was the highest for fish fed on pellet feeds. Black-Right-Pointing-Pointer Fish farming may be a good way of reducing the human exposure to Hg because Hg levels can be carefully controlled. - Abstract: Total mercury (THg) and methylmercury (MeHg) concentrations were determined in four species of marine caged carnivorous fish, one species of herbivorous fish and three types of fish feeds (dried pellet feed, forage fish and fish viscera), collected from five cage sites in the rural areas along Fujian coastline, China. For the carnivorous fish, the concentrations of THg and MeHg ranged from 0.03 to 0.31 {mu}g/g and from 0.02 to 0.30 {mu}g/g on wet weight basis, respectively. The concentrations were lower for the herbivorous fish with both within the range of 0.01-0.03 {mu}g/g. Out of the three tested fish feeds, tuna viscera contained the highest level of mercury (0.20 {mu}g/g THg and 0.13 {mu}g/g MeHg), with pellet feed containing the lowest level (0.05 {mu}g/g THg and 0.01 {mu}g/g MeHg). The calculated trophic transfer factor of MeHg was the highest (12-64) for fish fed on pellet feeds, and was the lowest for fish fed on tuna viscera. A significant relationship was found between Hg concentrations in caged fish and in fish feeds, thus Hg was primarily accumulated from the diet. Furthermore, the stable isotope {delta}{sup 15}N was positively correlated with the Hg concentration in two caged sites, indicating that {delta}{sup 15}N may be a suitable tool for tracking mercury in caged fish. We conclude that fish farming may be a good way of reducing the human exposure to Hg because mercury levels can be carefully controlled in such farming systems.

Mercury and stable isotope signatures in caged marine fish and fish feeds

International Nuclear Information System (INIS)

Onsanit, Sarayut; Chen, Min; Ke, Caihuan; Wang, Wen-Xiong

2012-01-01

Highlights: ► Mercury concentrations in caged fish were closely related to Hg concentrations in fish feeds. ► The trophic transfer factor of methylmercury was dependent on fish feeds, and was the highest for fish fed on pellet feeds. ► Fish farming may be a good way of reducing the human exposure to Hg because Hg levels can be carefully controlled. - Abstract: Total mercury (THg) and methylmercury (MeHg) concentrations were determined in four species of marine caged carnivorous fish, one species of herbivorous fish and three types of fish feeds (dried pellet feed, forage fish and fish viscera), collected from five cage sites in the rural areas along Fujian coastline, China. For the carnivorous fish, the concentrations of THg and MeHg ranged from 0.03 to 0.31 μg/g and from 0.02 to 0.30 μg/g on wet weight basis, respectively. The concentrations were lower for the herbivorous fish with both within the range of 0.01–0.03 μg/g. Out of the three tested fish feeds, tuna viscera contained the highest level of mercury (0.20 μg/g THg and 0.13 μg/g MeHg), with pellet feed containing the lowest level (0.05 μg/g THg and 0.01 μg/g MeHg). The calculated trophic transfer factor of MeHg was the highest (12–64) for fish fed on pellet feeds, and was the lowest for fish fed on tuna viscera. A significant relationship was found between Hg concentrations in caged fish and in fish feeds, thus Hg was primarily accumulated from the diet. Furthermore, the stable isotope δ 15 N was positively correlated with the Hg concentration in two caged sites, indicating that δ 15 N may be a suitable tool for tracking mercury in caged fish. We conclude that fish farming may be a good way of reducing the human exposure to Hg because mercury levels can be carefully controlled in such farming systems.

75 FR 14134 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2010-03-24

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... modifications, as required by the Endangered Species Act of 1973 (16 U.S.C. 1531 1543) (ESA), is based on a... trap and beach seine, anesthesize and sample fish for species identification, tags, marks and fin clips...

75 FR 33243 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2010-06-11

... and Threatened Species; Take of Anadromous Fish AGENCY: NOAA's National Marine Fisheries Service (NMFS... Endangered Species Act of 1973 (16 U.S.C. 1531-1543) (ESA), is based on a finding that such permits... NMFS regulations (50 CFR parts 222-226) governing listed fish and wildlife permits. Species Covered in...

Yield and soil carbon sequestration in grazed pastures sown with two or five forage species

Science.gov (United States)

Increasing plant species richness is often associated with an increase in productivity and associated ecosystem services such as soil C sequestration. In this paper we report on a nine-year experiment to evaluate the relative forage production and C sequestration potential of grazed pastures sown to...

Humans are one of several users of forage fish re- sources. Others ...

African Journals Online (AJOL)

and Dyer 1995), fish species that also contribute the bulk of the ... layed sexual maturity, that act to buffer their popula- .... The Act took cognizance of several international ..... seals displace endangered, endemic seabirds off Namibia. Biol.

Development of Solar Drying Model for Selected Cambodian Fish Species

Directory of Open Access Journals (Sweden)

Anna Hubackova

2014-01-01

Full Text Available A solar drying was investigated as one of perspective techniques for fish processing in Cambodia. The solar drying was compared to conventional drying in electric oven. Five typical Cambodian fish species were selected for this study. Mean solar drying temperature and drying air relative humidity were 55.6°C and 19.9%, respectively. The overall solar dryer efficiency was 12.37%, which is typical for natural convection solar dryers. An average evaporative capacity of solar dryer was 0.049 kg·h−1. Based on coefficient of determination (R2, chi-square (χ2 test, and root-mean-square error (RMSE, the most suitable models describing natural convection solar drying kinetics were Logarithmic model, Diffusion approximate model, and Two-term model for climbing perch and Nile tilapia, swamp eel and walking catfish and Channa fish, respectively. In case of electric oven drying, the Modified Page 1 model shows the best results for all investigated fish species except Channa fish where the two-term model is the best one. Sensory evaluation shows that most preferable fish is climbing perch, followed by Nile tilapia and walking catfish. This study brings new knowledge about drying kinetics of fresh water fish species in Cambodia and confirms the solar drying as acceptable technology for fish processing.

Accounting for Incomplete Species Detection in Fish Community Monitoring

Energy Technology Data Exchange (ETDEWEB)

McManamay, Ryan A [ORNL; Orth, Dr. Donald J [Virginia Polytechnic Institute and State University; Jager, Yetta [ORNL

2013-01-01

Riverine fish assemblages are heterogeneous and very difficult to characterize with a one-size-fits-all approach to sampling. Furthermore, detecting changes in fish assemblages over time requires accounting for variation in sampling designs. We present a modeling approach that permits heterogeneous sampling by accounting for site and sampling covariates (including method) in a model-based framework for estimation (versus a sampling-based framework). We snorkeled during three surveys and electrofished during a single survey in suite of delineated habitats stratified by reach types. We developed single-species occupancy models to determine covariates influencing patch occupancy and species detection probabilities whereas community occupancy models estimated species richness in light of incomplete detections. For most species, information-theoretic criteria showed higher support for models that included patch size and reach as covariates of occupancy. In addition, models including patch size and sampling method as covariates of detection probabilities also had higher support. Detection probability estimates for snorkeling surveys were higher for larger non-benthic species whereas electrofishing was more effective at detecting smaller benthic species. The number of sites and sampling occasions required to accurately estimate occupancy varied among fish species. For rare benthic species, our results suggested that higher number of occasions, and especially the addition of electrofishing, may be required to improve detection probabilities and obtain accurate occupancy estimates. Community models suggested that richness was 41% higher than the number of species actually observed and the addition of an electrofishing survey increased estimated richness by 13%. These results can be useful to future fish assemblage monitoring efforts by informing sampling designs, such as site selection (e.g. stratifying based on patch size) and determining effort required (e.g. number of

Functional feeding traits as predictors of invasive success of alien freshwater fish species using a food-fish model.

Directory of Open Access Journals (Sweden)

Leopold A J Nagelkerke

Full Text Available Invasions of Ponto-Caspian fish species into north-western European river basins accelerated since the opening of the Rhine-Main-Danube Canal in 1992. Since 2002, at least five Ponto-Caspian alien fish species have arrived in The Netherlands. Four species belong to the Gobiidae family (Neogobius fluviatilis, Neogobius melanostomus, Ponticola kessleri, and Proterorhinus semilunaris and one to the Cyprinidae family (Romanogobio belingi. These species are expected to be potentially deleterious for the populations of four native benthic fish species: Gobio gobio (Cyprinidae, Barbatula barbatula (Nemacheilidae, Cottus perifretum, and C. rhenanus (Cottidae. Invasion success may be dependent on competitive trophic interactions with native species, which are enabled and/or constrained by feeding-related morphological traits. Twenty-two functional feeding traits were measured in nine species (in total 90 specimens. These traits were quantitatively linked to the mechanical, chemical and behavioral properties of a range of aquatic resource categories, using a previously developed food-fish model (FFM. The FFM was used to predict the trophic profile (TP of each fish: the combined capacities to feed on each of the resource types. The most extreme TPs belonged to three alien species, indicating that they were most specialized among the studied species. Of these three, only P. kessleri overlapped with the two native Cottus species, indicating potential trophic competition. N. fluviatilis and R. belingi did not show any overlap, indicating that there is low trophic competition. The two remaining alien goby species (N. melanostomus and P. semilunaris had average TPs and could be considered generalist feeders. They overlapped with each other and with G. gobio and B. barbatula, indicating potential trophic competition. This study suggests that both generalist and specialist species can be successful invaders. Since the FFM predicts potential interactions between

Functional feeding traits as predictors of invasive success of alien freshwater fish species using a food-fish model.

Science.gov (United States)

Nagelkerke, Leopold A J; van Onselen, Eline; van Kessel, Nils; Leuven, Rob S E W

2018-01-01

Invasions of Ponto-Caspian fish species into north-western European river basins accelerated since the opening of the Rhine-Main-Danube Canal in 1992. Since 2002, at least five Ponto-Caspian alien fish species have arrived in The Netherlands. Four species belong to the Gobiidae family (Neogobius fluviatilis, Neogobius melanostomus, Ponticola kessleri, and Proterorhinus semilunaris) and one to the Cyprinidae family (Romanogobio belingi). These species are expected to be potentially deleterious for the populations of four native benthic fish species: Gobio gobio (Cyprinidae), Barbatula barbatula (Nemacheilidae), Cottus perifretum, and C. rhenanus (Cottidae). Invasion success may be dependent on competitive trophic interactions with native species, which are enabled and/or constrained by feeding-related morphological traits. Twenty-two functional feeding traits were measured in nine species (in total 90 specimens). These traits were quantitatively linked to the mechanical, chemical and behavioral properties of a range of aquatic resource categories, using a previously developed food-fish model (FFM). The FFM was used to predict the trophic profile (TP) of each fish: the combined capacities to feed on each of the resource types. The most extreme TPs belonged to three alien species, indicating that they were most specialized among the studied species. Of these three, only P. kessleri overlapped with the two native Cottus species, indicating potential trophic competition. N. fluviatilis and R. belingi did not show any overlap, indicating that there is low trophic competition. The two remaining alien goby species (N. melanostomus and P. semilunaris) had average TPs and could be considered generalist feeders. They overlapped with each other and with G. gobio and B. barbatula, indicating potential trophic competition. This study suggests that both generalist and specialist species can be successful invaders. Since the FFM predicts potential interactions between species, it

Salinity ranges of some southern African fish species occurring in ...

African Journals Online (AJOL)

The recorded salinity ranges of 96 fish species occurring in southern African estuaries are documented. Factors influen- cing the tolerance of fishes to low and high salinity regimes are discussed, with most species tolerant of low rather than high salinity conditions. This is important since most systems are subject to periodic ...

Ecomorphological patterns of the fishes inhabiting the tide pools of the Amazonian Coastal Zone, Brazil

Directory of Open Access Journals (Sweden)

Bruno Eleres Soares

Full Text Available The present study was based on the identification of the ecomorphological patterns that characterize the fish species found in tide pools in the Amazonian Coastal Zone (ACZ in the Pará State, Brazil. Representatives of 19 species were collected during two field campaigns in 2011. The dominance, residence status, and trophic guild of each species were established, and morphometric data were obtained for up to 10 specimens of each species. A total of 23 ecomorphological attributes related to locomotion, position in the water column, and foraging behavior were calculated for the analysis of ecomorphological distance. Principal Component Analysis (PCA was utilized for the evaluation of ecomorphological attributes that explained the variation among species. Mantel Test was used to correlate the taxonomic distance with species' morphological patterns and a partial Mantel Test to analyze the correlation among trophic guilds and ecomorphological patterns, controlling the effects of taxonomic distance among species. The analyses revealed two principal axes of the variation related to locomotion, correlated with the width of the caudal peduncle and the shape of the anal fin, as well as the influence of taxonomic distance on the ecomorphological characteristics of the different species. The dominant and resident species both presented a reduced capacity for continuous swimming. The two principal axes identified in relation to the position of the fish in the water column were correlated with the position of the eyes, the area of the pelvic fin, and body shape, with evidence of the influence of taxonomic distance on the morphology of the species. PCA grouped species with pelagic habits with benthonic ones. In the case of foraging behavior, the two principal axes formed by the analysis correlated with the size of the mouth, eye size, and the length of the digestive tract. Species of different guilds were grouped together, indicating a weak relationship

Fish impingement at Lake Michigan power plants

International Nuclear Information System (INIS)

Sharma, R.K.; Freeman, R.F.; Spigarelli, S.A.

1976-01-01

A study was initiated in 1974 to survey the magnitude and to evaluate the impact of fish impingement at 20 power plants on the Great Lakes. Data on impingement rates, site characteristics, intake designs and operational features have been collected and analyzed. Interpretive analyses of these data are in progress. The objectives of this study were: to summarize fish impingement data for Lake Michigan (16/20 plants surveyed are on Lake Michigan); to assess the significance of total and source-related mortalities on populations of forage and predator species; and to expand the assessment of power plant impingement to include all water intakes on Lake Michigan. Data are tabulated

Fish allergy in patients with parvalbumin-specific immunoglobulin E depends on parvalbumin content rather than molecular differences in the protein among fish species.

Science.gov (United States)

Kobayashi, Ayako; Kobayashi, Yukihiro; Shiomi, Kazuo

2016-10-01

Allergenic characteristics of purified parvalbumins from different fish species have not been thoroughly investigated. We revealed that purified parvalbumins from nine different fish species have identical IgE-reactivities and high cross-reactivities. We also showed that fish allergenicity is associated with the parvalbumin content of the fish species, rather than species-specific differences in the molecular characteristics of the individual parvalbumin proteins.

Mercury and selenium levels in 19 species of saltwater fish from New Jersey as a function of species, size, and season

Science.gov (United States)

Burger, Joanna; Gochfeld, Michael

2014-01-01

There are few data on risks to biota and humans from mercury levels in saltwater fish. This paper examines mercury and selenium levels in muscle of 19 species of fish caught by recreational fisherfolk off the New Jersey shore, as a function of species of fish, size, and season, and risk of mercury to consumers. Average mercury levels ranged from 0.01 ppm (wet weight) (Menhaden Brevoortia tyrannus) to 1.83 ppm (Mako Shark Isurus oxyrinchus). There were four categories of mercury levels: very high (only Mako), high (averaging 0.3–0.5 ppm, 3 species), medium (0.14–0.20 ppm, 10 species), and low (below 0.13 ppm, 5 species). Average selenium levels for the fish species ranged from 0.18 ppm to 0.58 ppm, and had lower variability than mercury (coefficient of variation=38.3 vs 69.1%), consistent with homeostatic regulation of this essential element. The correlation between mercury and selenium was significantly positive for five and negative for two species. Mercury levels showed significant positive correlations with fish size for ten species. Size was the best predictor of mercury levels. Selenium showed no consistent relationship to fish length. Over half of the fish species had some individual fish with mercury levels over 0.3 ppm, and a third had fish with levels over 0.5 ppm, levels that pose a human health risk for high end consumers. Conversely several fish species had no individuals above 0.5 ppm, and few above 0.3 ppm, suggesting that people who eat fish frequently, can reduce their risk from mercury by selecting which species (and which size) to consume. Overall, with the exception of shark, Bluefin Tuna (Thunnus thynnus), Bluefish (Pomatomus saltatrix) and Striped Bass (Morone saxatilis), the species sampled are generally medium to low in mercury concentration. Selenium:mercury molar ratios were generally above 1:1, except for the Mako shark. PMID:21292311

Warming impacts on fish species composition in the Kattegat-Belt Sea

DEFF Research Database (Denmark)

Bryndum, Karoline Minna; MacKenzie, Brian

Sea temperatures have been rising in the waters near Denmark during the past 1-2 decades and are expected to affect marine populations, species, communities and foodwebs. Here we investigate whether and how the species richness and composition of the marine fish community in the Kattegat and Belt...... of the southern range limits of all species captured in the surveys shows that the mean southern latitudinal limit of the fish community has been decreasing and is also corrrelated with bottom temperatures; these patterns are consistent with immigration of fish from southerly zoogeographic regions. Warm...

Foraging strategies of the ant Ectatomma vizottoi (Hymenoptera, Formicidae

Directory of Open Access Journals (Sweden)

Luan D. Lima

2013-12-01

Full Text Available Foraging strategies of the ant Ectatomma vizottoi (Hymenoptera, Formicidae. Foraging activity may be limited by temperature, humidity, radiation, wind, and other abiotic factors, all of which can affect energy costs during foraging. Ectatomma vizottoi's biology has only recently been studied, and no detailed information is available on its foraging patterns or diet in the field. For this reason, and because foraging activity is an important part of the ecological success of social insects, the present study aimed to investigate E. vizottoi's foraging strategies and dietary habits. First, we determined how abiotic factors constrained E. vizottoi's foraging patterns in the field by monitoring the foraging activity of 16 colonies on eight different days across two seasons. Second, we characterized E. vizottoi's diet by monitoring another set of 26 colonies during peak foraging activity. Our results show that E. vizottoi has foraging strategies that are similar to those of congeneric species. In spite of having a low efficiency index, colonies adopted strategies that allowed them to successfully obtain food resources while avoiding adverse conditions. These strategies included preying on other ant species, a foraging tactic that could arise if a wide variety of food items are not available in the environment or if E. vizottoi simply prefers, regardless of resource availability, to prey on other invertebrates and especially on other ant species.

DNA barcoding for species assignment: the case of Mediterranean marine fishes.

Directory of Open Access Journals (Sweden)

Monica Landi

Full Text Available DNA barcoding enhances the prospects for species-level identifications globally using a standardized and authenticated DNA-based approach. Reference libraries comprising validated DNA barcodes (COI constitute robust datasets for testing query sequences, providing considerable utility to identify marine fish and other organisms. Here we test the feasibility of using DNA barcoding to assign species to tissue samples from fish collected in the central Mediterranean Sea, a major contributor to the European marine ichthyofaunal diversity.A dataset of 1278 DNA barcodes, representing 218 marine fish species, was used to test the utility of DNA barcodes to assign species from query sequences. We tested query sequences against 1 a reference library of ranked DNA barcodes from the neighbouring North East Atlantic, and 2 the public databases BOLD and GenBank. In the first case, a reference library comprising DNA barcodes with reliability grades for 146 fish species was used as diagnostic dataset to screen 486 query DNA sequences from fish specimens collected in the central basin of the Mediterranean Sea. Of all query sequences suitable for comparisons 98% were unambiguously confirmed through complete match with reference DNA barcodes. In the second case, it was possible to assign species to 83% (BOLD-IDS and 72% (GenBank of the sequences from the Mediterranean. Relatively high intraspecific genetic distances were found in 7 species (2.2%-18.74%, most of them of high commercial relevance, suggesting possible cryptic species.We emphasize the discriminatory power of COI barcodes and their application to cases requiring species level resolution starting from query sequences. Results highlight the value of public reference libraries of reliability grade-annotated DNA barcodes, to identify species from different geographical origins. The ability to assign species with high precision from DNA samples of disparate quality and origin has major utility in several

Characterization of the Cultivable Gut Microflora in Wild-Caught 
Mediterranean Fish Species.

Science.gov (United States)

Jammal, Ahmad; Bariche, Michel; Zu Dohna, Heinrich; Kambris, Zakaria

2017-05-01

Microflora of the gastrointestinal tract plays important roles in food digestion, nutrient absorption and in host defense against ingested pathogens. Several studies have focused on the microflora of farmed fishes, but the gut flora of wild fishes remains poorly characterized. The aim of this work was to provide an overview of the bacteria colonizing the gut of wild-caught fishes and to determine whether some bacterial species can be pathogenic. We isolated cultivable bacteria from fifteen wild-caught Mediterranean fish species corresponding to different habitat, diet and origin. Bacterial species identity was determined by 16s rRNA gene sequencing for the 61 isolates. The potential pathogenicity of isolated bacteria was investigated using fruit fly (Drosophila melanogaster) and zebrafish (Danio rerio) as model organisms. Two bacterial strains (Serratia sp. and Aeromonas salmonicida) were lethal when microinjected to Drosophila, while zebrafish did not develop any disease when exposed to any of 34 isolated bacterial strains. However, it was interesting to note that two bacterial strains (Shewanella and Arthrobacter) isolated from marine fishes were able to colonize the guts of freshwater zebrafish. The results of this study give an overview of the bacterial species found in the guts of wild fishes living off Beirut seashore. It shows that some parameters believed to be limiting factors to host-gut colonization by bacteria can be overcome by some species. This pilot study could be extended by sampling a larger number of fish species with several specimens per fish species, and by identifying uncultivable bacteria that reside in the fish guts. Our results may have implications for the utilization of certain bacterial species in fish farming or their use as bio-indicators for water and/or food quality.

Life history strategies of fish species and biodiversity in eastern USA streams

Science.gov (United States)

Meador, Michael R.; Brown, Larry M.

2015-01-01

Predictive models have been used to determine fish species that occur less frequently than expected (decreasers) and those that occur more frequently than expected (increasers) in streams in the eastern U.S. Coupling life history traits with 51 decreaser and 38 increaser fish species provided the opportunity to examine potential mechanisms associated with predicted changes in fish species distributions in eastern streams. We assigned six life history traits – fecundity, longevity, maturation age, maximum total length, parental care, and spawning season duration – to each fish species. Decreaser species were significantly smaller in size and shorter-lived with reduced fecundity and shorter spawning seasons compared to increaser species. Cluster analysis of traits revealed correspondence with a life history model defining equilibrium (low fecundity, high parental care), opportunistic (early maturation, low parental care), and periodic (late maturation, high fecundity, low parental care) end-point strategies. Nearly 50 % of decreaser species were associated with an intermediate opportunistic-periodic strategy, suggesting that abiotic factors such as habitat specialization and streamflow alteration may serve as important influences on life history traits and strategies of decreaser species. In contrast, the percent of increaser species among life history strategy groups ranged from 21 to 32 %, suggesting that life history strategies of increaser species were more diverse than those of decreaser species. This study highlights the utility of linking life history theory to biodiversity to better understand mechanisms that contribute to fish species distributions in the eastern U.S.

Development of forage cryo minced fish technology

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Titova S. A.

2017-11-01

Full Text Available The technology of grinding the frozen fish raw material using the useful model of a piston-type extrusion plant with cold working bodies for fodder minced fish (cryo minced fish feed by the method of cryoextrusion has been developed. The possibility of replacing the standard manufacturing operations (defrosting and subsequent grinding of raw materials to the one (cryoextrusion has been substantiated. The optimal shape of holes of the die for forcing the raw material has been determined in the form of "hourglass", the hole diameter is 7 mm, the length of the process of pushing is 40 s. It has been established that the finished product (cryo minced fish feed has a homogeneous grinding, juicy, crumbly texture, the temperature in the thickness of the product is equal to the temperature of the raw material before processing (–18 °C. The technological scheme of producing the minced fish feed by the method of cryoextrusion has been developed. Researching the chemical composition of fish and feed of mince produced by the traditional and developed methods it has been established that protein content in the cryo minced fish feed remains unchanged. The amino acid composition of cryo minced fish feed has been determined, the amount of essential amino acids is 365.6 mg/g of protein. In the proteins of the cryo minced fish feed methionine has been contained in the minimum quantity (10.0 mg/g protein and in the maximum – serine (155.3 mg/g protein. In the protein of the cryo minced fish feed the only limiting amino acid is methionine. The coefficient of rationality of the cryo minced fish feed whiting is equal to 0.33. The product is not toxic, is not subject to contamination with dangerous microorganisms, has high biological value, contains necessary in animal nutrition mineral elements, the energy value per 100 g of the product is 87 kcal. The combination of the processes of cryoextrusion and lyophilization allows to obtain a new food product with high

Underappreciated species in ecology: "ugly fish" in the northwest Atlantic Ocean.

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Link, Jason S

2007-10-01

Species shifts and replacements are common in ecological studies. Observations thereof serve as the impetus for many ecological endeavors. Many of the species now known to dominate ecosystem functioning were largely ignored until studies of those underappreciated species elucidated their critical roles. Recognizing the potential importance of underappreciated species has implications for functional redundancies in ecosystems and should alter our approach to long-term monitoring. One example of an applied ecological system containing species shifts, underappreciated species, and potential changes in functional redundancies is the topic of fisheries. The demersal component of many fish communities usually consists of high-profile and commercially valuable species that are targets of fisheries, plus a diverse group of lesser known species that have minimal commercial value and focus. Yet ecologically these traditionally nontargeted species are often a major biomass sink in marine ecosystems and can also be critical in the functioning of bentho-demersal food webs. I examined the biomass trajectories of several species of skates, cottids, lophiids, anarhichadids, zooarcids, and similar species in the northeast U.S. Atlantic ecosystem to determine whether their relative abundance has changed across the past four decades. Distribution and stomach contents of these species were also evaluated over time to further elucidate the relative importance of these species. Landings of these underappreciated bentho-demersal fish were also examined in comparison to those species that historically have been commercially targeted. Of particular emphasis was the evaluation of evidence for sequential stock depletion and the ramifications for functional redundancy for this ecosystem. Results indicate that some of these fish species are now the dominant piscivores, benthivores, and scavengers in this ecosystem. These formerly under-studied species generally have either maintained a

Functional diversity measures revealed impacts of non-native species and habitat degradation on species-poor freshwater fish assemblages.

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Colin, Nicole; Villéger, Sébastien; Wilkes, Martin; de Sostoa, Adolfo; Maceda-Veiga, Alberto

2018-06-01

Trait-based ecology has been developed for decades to infer ecosystem responses to stressors based on the functional structure of communities, yet its value in species-poor systems is largely unknown. Here, we used an extensive dataset in a Spanish region highly prone to non-native fish invasions (15 catchments, N=389 sites) to assess for the first time how species-poor communities respond to large-scale environmental gradients using a taxonomic and functional trait-based approach in riverine fish. We examined total species richness and three functional trait-based indices available when many sites have ≤3 species (specialization, FSpe; originality, FOri and entropy, FEnt). We assessed the responses of these taxonomic and functional indices along gradients of altitude, water pollution, physical habitat degradation and non-native fish biomass. Whilst species richness was relatively sensitive to spatial effects, functional diversity indices were responsive across natural and anthropogenic gradients. All four diversity measures declined with altitude but this decline was modulated by physical habitat degradation (richness, FSpe and FEnt) and the non-native:total fish biomass ratio (FSpe and FOri) in ways that varied between indices. Furthermore, FSpe and FOri were significantly correlated with Total Nitrogen. Non-native fish were a major component of the taxonomic and functional structure of fish communities, raising concerns about potential misdiagnosis between invaded and environmentally-degraded river reaches. Such misdiagnosis was evident in a regional fish index widely used in official monitoring programs. We recommend the application of FSpe and FOri to extensive datasets from monitoring programs in order to generate valuable cross-system information about the impacts of non-native species and habitat degradation, even in species-poor systems. Scoring non-native species apart from habitat degradation in the indices used to determine ecosystem health is

Food limitation of sea lion pups and the decline of forage off central and southern California

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McClatchie, Sam; Field, John; Thompson, Andrew R.; Gerrodette, Tim; Lowry, Mark; Fiedler, Paul C.; Watson, William; Nieto, Karen M.; Vetter, Russell D.

2016-01-01

California sea lions increased from approximately 50 000 to 340 000 animals in the last 40 years, and their pups are starving and stranding on beaches in southern California, raising questions about the adequacy of their food supply. We investigated whether the declining sea lion pup weight at San Miguel rookery was associated with changes in abundance and quality of sardine, anchovy, rockfish and market squid forage. In the last decade off central California, where breeding female sea lions from San Miguel rookery feed, sardine and anchovy greatly decreased in biomass, whereas market squid and rockfish abundance increased. Pup weights fell as forage food quality declined associated with changes in the relative abundances of forage species. A model explained 67% of the variance in pup weights using forage from central and southern California and 81% of the variance in pup weights using forage from the female sea lion foraging range. A shift from high to poor quality forage for breeding females results in food limitation of the pups, ultimately flooding animal rescue centres with starving sea lion pups. Our study is unusual in using a long-term, fishery-independent dataset to directly address an important consequence of forage decline on the productivity of a large marine predator. Whether forage declines are environmentally driven, are due to a combination of environmental drivers and fishing removals, or are due to density-dependent interactions between forage and sea lions is uncertain. However, declining forage abundance and quality was coherent over a large area (32.5–38° N) for a decade, suggesting that trends in forage are environmentally driven. PMID:27069651

78 FR 23222 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2013-04-18

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XC630 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: NOAA's National Marine Fisheries Service (NMFS... CFR parts 222-226) governing listed fish and wildlife permits. Species Covered in This Notice This...

Foraging behavior and virulence of some entomopathogenic nematodes

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Manana A. Lortkipanidze

2016-06-01

Full Text Available At present the biological control as a pest control technology is becoming more desirable. Biological formulations on basis of entomopathogenic nematodes are one of the effective means for the protection of agricultural and forest plants from harmful insects. Nowadays, the use of entomopathogenic nematodes as biological control agents is a key component in IPM system. The foraging strategies of entomopathogenic nematodes (EPNs vary between species. This variation is consistent with use of different foraging strategies between ambush, cruise and intermediate to find their host insects. In order to ambush prey, some species of EPNs nictate, or raise their bodies of the soil surface so they are better poised to attach passing insects, other species adopt a cruising strategy and rarely nictate. Some species adopt an intermediate strategy between ambush and cruise. We compared in laboratory the foraging strategies of the entomopathogenic nematode species: Steinernema carpocapsae, Heterorhabditis bacteriophora and the recently described species Steinernema tbilisiensis and assessed their virulence against mealworm beetle, Tenebrio molitor L. (Coleoptera: Tenebrionidae. The tests showed that S. tbilisiensis adopts both foraging strategies.

Patch dynamics of a foraging assemblage of bees.

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Wright, David Hamilton

1985-03-01

The composition and dynamics of foraging assemblages of bees were examined from the standpoint of species-level arrival and departure processes in patches of flowers. Experiments with bees visiting 4 different species of flowers in subalpine meadows in Colorado gave the following results: 1) In enriched patches the rates of departure of bees were reduced, resulting in increases in both the number of bees per species and the average number of species present. 2) The reduction in bee departure rates from enriched patches was due to mechanical factors-increased flower handling time, and to behavioral factors-an increase in the number of flowers visited per inflorescence and in the number of inflorescences visited per patch. Bees foraging in enriched patches could collect nectar 30-45% faster than those foraging in control patches. 3) The quantitative changes in foraging assemblages due to enrichment, in terms of means and variances of species population sizes, fraction of time a species was present in a patch, and in mean and variance of the number of species present, were in reasonable agreement with predictions drawn from queuing theory and studies in island biogeography. 4) Experiments performed with 2 species of flowers with different corolla tube lengths demonstrated that manipulation of resources of differing availability had unequal effects on particular subsets of the larger foraging community. The arrival-departure process of bees on flowers and the immigration-extinction process of species on islands are contrasted, and the value of the stochastic, species-level approach to community composition is briefly discussed.

Niche partitioning among frugivorous fishes in response to fluctuating resources in the Amazonian floodplain forest.

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Correa, Sandra Bibiana; Winemiller, Kirk O

2014-01-01

In response to temporal changes in the quality and availability of food resources, consumers should adjust their foraging behavior in a manner that maximizes energy and nutrient intake and, when resources are limiting, minimizes dietary overlap with other consumers. Floodplains of the Amazon and its lowland tributaries are characterized by strong, yet predictable, hydrological seasonality, seasonal availability of fruits, seeds, and other food resources of terrestrial origin, and diverse assemblages of frugivorous fishes, including morphologically similar species of several characiform families. Here, we investigated how diets of frugivorous fishes in the Amazon change in response to fluctuations in food availability, and how this influences patterns of interspecific dietary overlap. We tested predictions from classical theories of foraging and resource competition by estimating changes in diet breadth and overlap across seasons. We monitored fruiting phenology to assess food availability, and surveyed local fish populations during three hydrological seasons in an oligotrophic river and an adjacent oxbow lake in the Colombian Amazon. We analyzed stomach contents and stable isotope data to evaluate temporal and interspecific relationships for dietary composition, breadth, and overlap. Diets of six species of characiform fishes representing three genera changed according to seasonal fluctuations in food availability, and patterns of diet breadth and interspecific overlap during the peak flood pulse were consistent with predictions of optimal foraging theory. During times of high fruit abundance, fishes consumed items to which their functional morphological traits seemed best adapted, potentially enhancing net energy and nutritional gains. As the annual flood pulse subsided and availability of forest food resources in aquatic habitats changed, there was not a consistent pattern of diet breadth expansion or compression. Nonetheless, shifts in both diet composition and

Endangered fish species of Kenya's inland waters with emphasis on Labeo spp

OpenAIRE

Kibaara, D.

1986-01-01

The importance of water masses, natural or otherwise, in supporting fisheries, and the importance of fish as human food, cannot be overemphasized. The inland waters of Kenya act as habitats for fish, harbouring many different fish species. It has been observed with interest that certain fish species have decreased in numbers over the years within the inland waters. The decline has been at a rate which, if left unchecked, will eventually cause total di...

Shape and Texture Based Classification of Fish Species

DEFF Research Database (Denmark)

Larsen, Rasmus; Ólafsdóttir, Hildur; Ersbøll, Bjarne Kjær

2009-01-01

In this paper we conduct a case study of ¯sh species classi- fication based on shape and texture. We consider three fish species: cod, haddock, and whiting. We derive shape and texture features from an appearance model of a set of training data. The fish in the training images were manual outlined......, and a few features including the eye and backbone contour were also annotated. From these annotations an optimal MDL curve correspondence and a subsequent image registration were derived. We have analyzed a series of shape and texture and combined shape and texture modes of variation for their ability...

Foraging behavior and success of a mesopelagic predator in the northeast Pacific Ocean: insights from a data-rich species, the northern elephant seal.

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Patrick W Robinson

Full Text Available The mesopelagic zone of the northeast Pacific Ocean is an important foraging habitat for many predators, yet few studies have addressed the factors driving basin-scale predator distributions or inter-annual variability in foraging and breeding success. Understanding these processes is critical to reveal how conditions at sea cascade to population-level effects. To begin addressing these challenging questions, we collected diving, tracking, foraging success, and natality data for 297 adult female northern elephant seal migrations from 2004 to 2010. During the longer post-molting migration, individual energy gain rates were significant predictors of pregnancy. At sea, seals focused their foraging effort along a narrow band corresponding to the boundary between the sub-arctic and sub-tropical gyres. In contrast to shallow-diving predators, elephant seals target the gyre-gyre boundary throughout the year rather than follow the southward winter migration of surface features, such as the Transition Zone Chlorophyll Front. We also assessed the impact of added transit costs by studying seals at a colony near the southern extent of the species' range, 1,150 km to the south. A much larger proportion of seals foraged locally, implying plasticity in foraging strategies and possibly prey type. While these findings are derived from a single species, the results may provide insight to the foraging patterns of many other meso-pelagic predators in the northeast Pacific Ocean.

Fishing elevates variability in the abundance of exploited species.

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Hsieh, Chih-Hao; Reiss, Christian S; Hunter, John R; Beddington, John R; May, Robert M; Sugihara, George

2006-10-19

The separation of the effects of environmental variability from the impacts of fishing has been elusive, but is essential for sound fisheries management. We distinguish environmental effects from fishing effects by comparing the temporal variability of exploited versus unexploited fish stocks living in the same environments. Using the unique suite of 50-year-long larval fish surveys from the California Cooperative Oceanic Fisheries Investigations we analyse fishing as a treatment effect in a long-term ecological experiment. Here we present evidence from the marine environment that exploited species exhibit higher temporal variability in abundance than unexploited species. This remains true after accounting for life-history effects, abundance, ecological traits and phylogeny. The increased variability of exploited populations is probably caused by fishery-induced truncation of the age structure, which reduces the capacity of populations to buffer environmental events. Therefore, to avoid collapse, fisheries must be managed not only to sustain the total viable biomass but also to prevent the significant truncation of age structure. The double jeopardy of fishing to potentially deplete stock sizes and, more immediately, to amplify the peaks and valleys of population variability, calls for a precautionary management approach.

78 FR 74116 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2013-12-10

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... plans and request for comment. SUMMARY: Notice is hereby given that the Oregon Department of Fish and... River and Columbia River basins by providing hatchery fish to support fishing opportunities while...

BIOMETRY AND COMPOSITION OF FISH SPECIES IN OWENA RESERVOIR, ONDO STATE, NIGERIA

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FAPOHUNDA Olawumi Oluwafunmilola

2007-11-01

Full Text Available A survey of fish species present in Owena reservoir was conducted between October 2004 and March 2005. Fish samples were taken from the catch of the fishermen operating in the reservoir. The results of the survey showed that 14 fish species belonging to seven families were recorded. Two families namely Characidae and Clariidae constituted the dominant fish families in the reservoir. Among the Characidae, Brycinus nurse (23.1% and among the Clariidae family, Clarias gariepinus (22.8% were dominant. Other fish species with significant abundance were Sarotherodon galilaeus (9.3%, Parachanna obscura (8.0%, Clarias anguillaris (7.7% and Oreochromis niloticus (6.4%. The meristic features of the two most abundant fish species caught are as follows: Brycinus nurse had two dorsal spines with eight dorsal fins, two anal spines with eleven anal fins, 25 caudal fins, one pectoral spine and 13 pectoral fins and two ventral spines with seven ventral fins. Clarias gariepinus had 75 dorsal fins, 31 anal fins, 10 caudal fins, six pectoral fins and five ventral fins. The morphometric features of the two most abundant fish species are: Brycinus nurse: total length: 312mm, standard length: 255mm, head length: 60mm, body length: 90mm and body girth: 190mm. Clarias gariepinus: total length: 265mm, standard length: 240mm, head length: 62mm, body length: 62mm and body girth: 130mm.

A New Perspective on the Foraging Ecology of Apex Predators in the California Current: Results from a Fully Coupled Ecosystem Model

Science.gov (United States)

Fiechter, J.; Huckstadt, L. A.; Rose, K.; Costa, D. P.; Curchitser, E. N.; Hedstrom, K.; Edwards, C. A.; Moore, A. M.

2016-02-01

Results from a fully coupled end-to-end ecosystem model for the California Current Large Marine Ecosystem are used to describe the impact of environmental variability on the foraging ecology of its most abundant apex predator, California sea lions (Zalophus californianus). The ecosystem model consists of a biogeochemical submodel embedded in a regional ocean circulation submodel, and both coupled with a multi-species individual-based submodel for forage fish (sardine and anchovy) and California sea lions. For sea lions, bioenergetics and behavioral attributes are specified using available TOPP (Tagging Of Pacific Predators) data on their foraging patterns and diet in the California Current. Sardine and anchovy are explicitly included in the model as they represent important prey sources for California sea lions and exhibit significant interannual and decadal variability in population abundances. Output from a 20-year run (1989-2008) of the model demonstrates how different physical and biological processes control habitat utilization and foraging success of California sea lions on interannual time scales. A principal component analysis of sea lion foraging patterns indicates that the first mode of variability is alongshore and tied to sardine availability, while the second mode is cross-shore and associated with coastal upwelling intensity (a behavior consistent with male sea lion tracking data collected in 2004 vs. 2005). The results also illustrate how variability in environmental conditions and forage fish distribution affects sea lions feeding success. While specifically focusing on the foraging ecology of sea lions, our modeling framework has the ability to provide new and unique perspectives on trophic interactions in the California Current, or other regions where similar end-to-end ecosystem models may be implemented.

Determining spatio-temporal distribution of bee forage species of Al-Baha region based on ground inventorying supported with GIS applications and Remote Sensed Satellite Image analysis

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Nuru Adgaba

2017-07-01

Full Text Available In arid zones, the shortage of bee forage is critical and usually compels beekeepers to move their colonies in search of better forages. Identifying and mapping the spatiotemporal distribution of the bee forages over given area is important for better management of bee colonies. In this study honey bee plants in the target areas were inventoried following, ground inventory work supported with GIS applications. The study was conducted on 85 large plots of 50 × 50 m each. At each plot, data on species name, height, base diameter, crown height, crown diameter has been taken for each plant with their respective geographical positions. The data were stored, and processed using Trimble GPS supported with ArcGIS10 software program. The data were used to estimate the relative frequency, density, abundance and species diversity, species important value index and apicultural value of the species. In addition, Remotely Sensed Satellite Image of the area was obtained and processed using Hopfield Artificial Neural Network techniques. During the study, 182 species from 49 plant families were identified as bee forages of the target area. From the total number of species; shrubs, herbs and trees were accounting for 61%, 27.67%, and 11.53% respectively. Of which Ziziphus spina-christi, Acacia tortilis, Acacia origina, Acacia asak, Lavandula dentata, and Hypoestes forskaolii were the major nectar source plants of the area in their degree of importance. The average vegetation cover values of the study areas were low (<30% with low Shannon’s species diversity indices (H′ of 0.5–1.52 for different sites. Based on the eco-climatological factors and the variations in their flowering period, these major bee forage species were found to form eight distinct spatiotemporal categories which allow beekeepers to migrate their colonies to exploit the resources at different seasons and place. The Remote Sensed Satellite Image analysis confirmed the spatial

Deep diving odontocetes foraging strategies and their prey field as determined by acoustic techniques

Science.gov (United States)

Giorli, Giacomo

Deep diving odontocetes, like sperm whales, beaked whales, Risso's dolphins, and pilot whales are known to forage at deep depths in the ocean on squid and fish. These marine mammal species are top predators and for this reason are very important for the ecosystems they live in, since they can affect prey populations and control food web dynamics through top-down effects. The studies presented in this thesis investigate deep diving odontocetes. foraging strategies, and the density and size of their potential prey in the deep ocean using passive and active acoustic techniques. Ecological Acoustic Recorders (EAR) were used to monitor the foraging activity of deep diving odontocetes at three locations around the world: the Josephine Seamount High Sea Marine Protected Area (JHSMPA), the Ligurian Sea, and along the Kona coast of the island of Hawaii. In the JHSMPA, sperm whales. and beaked whales. foraging rates do not differ between night-time and day-time. However, in the Ligurian Sea, sperm whales switch to night-time foraging as the winter approaches, while beaked whales alternate between hunting mainly at night, and both at night and at day. Spatial differences were found in deep diving odontocetes. foraging activity in Hawaii where they forage most in areas with higher chlorophyll concentrations. Pilot whales (and false killer whales, clustered together in the category "blackfishes") and Risso's dolphins forage mainly at night at all locations. These two species adjust their foraging activity with the length of the night. The density and size of animals living in deep sea scattering layers was studied using a DIDSON imaging sonar at multiple stations along the Kona coast of Hawaii. The density of animals was affected by location, depth, month, and the time of day. The size of animals was influenced by station and month. The DIDSON proved to be a successful, non-invasive technique to study density and size of animals in the deep sea. Densities were found to be an

Boa constrictor (Boa constrictor): foraging behavior

Science.gov (United States)

Sorrell, G.G.; Boback, M.S.; Reed, R.N.; Green, S.; Montgomery, Chad E.; DeSouza, L.S.; Chiaraviglio, M.

2011-01-01

Boa constrictor is often referred to as a sit-and-wait or ambush forager that chooses locations to maximize the likelihood of prey encounters (Greene 1983. In Janzen [ed.], Costa Rica Natural History, pp. 380-382. Univ. Chicago Press, Illinois). However, as more is learned about the natural history of snakes in general, the dichotomy between active versus ambush foraging is becoming blurred. Herein, we describe an instance of diurnal active foraging by a B. constrictor, illustrating that this species exhibits a range of foraging behaviors.

The nuclear question: rethinking species importance in multi-species animal groups.

Science.gov (United States)

Srinivasan, Umesh; Raza, Rashid Hasnain; Quader, Suhel

2010-09-01

1. Animals group for various benefits, and may form either simple single-species groups, or more complex multi-species associations. Multi-species groups are thought to provide anti-predator and foraging benefits to participant individuals. 2. Despite detailed studies on multi-species animal groups, the importance of species in group initiation and maintenance is still rated qualitatively as 'nuclear' (maintaining groups) or 'attendant' (species following nuclear species) based on species-specific traits. This overly simplifies and limits understanding of inherently complex associations, and is biologically unrealistic, because species roles in multi-species groups are: (i) likely to be context-specific and not simply a fixed species property, and (ii) much more variable than this dichotomy indicates. 3. We propose a new view of species importance (measured as number of inter-species associations), along a continuum from 'most nuclear' to 'least nuclear'. Using mixed-species bird flocks from a tropical rainforest in India as an example, we derive inter-species association measures from randomizations on bird species abundance data (which takes into account species 'availability') and data on 86 mixed-species flocks from two different flock types. Our results show that the number and average strength of inter-species associations covary positively, and we argue that species with many, strong associations are the most nuclear. 4. From our data, group size and foraging method are ecological and behavioural traits of species that best explain nuclearity in mixed-species bird flocks. Parallels have been observed in multi-species fish shoals, in which group size and foraging method, as well as diet, have been shown to correlate with nuclearity. Further, the context in which multi-species groups occur, in conjunction with species-specific traits, influences the role played by a species in a multi-species group, and this highlights the importance of extrinsic factors in

Fearful foragers: honey bees tune colony and individual foraging to multi-predator presence and food quality.

Directory of Open Access Journals (Sweden)

Ken Tan

Full Text Available Fear can have strong ecosystem effects by giving predators a role disproportionate to their actual kill rates. In bees, fear is shown through foragers avoiding dangerous food sites, thereby reducing the fitness of pollinated plants. However, it remains unclear how fear affects pollinators in a complex natural scenario involving multiple predator species and different patch qualities. We studied hornets, Vespa velutina (smaller and V. tropica (bigger preying upon the Asian honey bee, Apis cerana in China. Hornets hunted bees on flowers and were attacked by bee colonies. Bees treated the bigger hornet species (which is 4 fold more massive as more dangerous. It received 4.5 fold more attackers than the smaller hornet species. We tested bee responses to a three-feeder array with different hornet species and varying resource qualities. When all feeders offered 30% sucrose solution (w/w, colony foraging allocation, individual visits, and individual patch residence times were reduced according to the degree of danger. Predator presence reduced foraging visits by 55-79% and residence times by 17-33%. When feeders offered different reward levels (15%, 30%, or 45% sucrose, colony and individual foraging favored higher sugar concentrations. However, when balancing food quality against multiple threats (sweeter food corresponding to higher danger, colonies exhibited greater fear than individuals. Colonies decreased foraging at low and high danger patches. Individuals exhibited less fear and only decreased visits to the high danger patch. Contrasting individual with emergent colony-level effects of fear can thus illuminate how predators shape pollination by social bees.

Individual differences in foraging strategies of parasitic sabre-tooth blennies.

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Andrea Bshary

Full Text Available Originally, evolutionary game theory typically predicted that optimal behaviour in a given situation is uniform or bimodal. However, the growing evidence that animals behave more variably while individuals may differ consistently in their behaviour, has led to the development of models that predict a distribution of strategies. Here we support the importance of such models in a study on a coral reef fish host-parasite system. Parasitic blennies (Plagiotremus sp. regularly attack other fishes to bite off scales and mucus. Individuals of some victim species react to being bitten with punishing the parasite through aggressive chasing. Our field observations and laboratory experiments show that individual blennies differ markedly in how they incorporate being punished into their foraging decisions. We discuss how these differences may affect the payoff structure and hence the net effect of punishment on punishers and on the appearance of a public good for look-alikes.

Aerobic capacity influences the spatial position of individuals within fish schools

DEFF Research Database (Denmark)

Killen, Shaun S.; Marras, Stefano; Steffensen, John Fleng

2012-01-01

the rear of schools. These trailing fish required fewer tail beats to swim at the same speed as individuals at the front of schools, indicating that posterior positions provide hydrodynamic benefits that reduce swimming costs. Conversely, fish with high aerobic capacity can withstand increased drag......The schooling behaviour of fish is of great biological importance, playing a crucial role in the foraging and predator avoidance of numerous species. The extent to which physiological performance traits affect the spatial positioning of individual fish within schools is completely unknown. Schools...... of juvenile mullet Liza aurata were filmed at three swim speeds in a swim tunnel, with one focal fish from each school then also measured for standard metabolic rate (SMR), maximal metabolic rate (MMR), aerobic scope (AS) and maximum aerobic swim speed. At faster speeds, fish with lower MMR and AS swam near...

With the noose around the neck: Marine debris entangling otariid species.

Science.gov (United States)

Franco-Trecu, Valentina; Drago, Massimiliano; Katz, Helena; Machín, Emanuel; Marín, Yamandú

2017-01-01

Plastic debris in marine environments and its impact on wildlife species is becoming a problem of increasing concern. In pinnipeds, entanglements commonly consist of loops around the neck of non-biodegradable materials from fishing gear or commercial packaging, known as "neck collars". These entanglements can cause injuries, death by suffocation and starvation, and therefore they may add to the overall decrease in population. Our objective was to describe the entanglement of two species of otariids (Arctocephalus australis and Otaria flavescens) in the South West Atlantic Ocean. These two species have widely different population sizes and contrasting trends, being the O. flavescens population one order of magnitude lower in abundance with a negative population trend. A total number of 47 entangled individuals and the ingestion of a fishing sinker were recorded (A. australis: n = 26; O. flavescens: n = 22). For A. australis about 40% of the objects came from industrial fishing with which this species overlap their foraging areas, although also its lost or discarded gear can travel long distances. In O. flavescens 48% of observed injuries were very severe, which might indicate that they had been entangled for a long time. More than 60% of the objects came from artisanal and recreational fishing that operates within 5 nautical miles off the coast, which is probably related to coastal foraging habits of this species. Due to the frequent interaction between artisanal fisheries and O. flavescens, it is possible that entangled nets could be active gears. An important contribution to mitigate entanglements can be the development of education programs setting the scenario for effective communication, and exchange with involved fishermen to collect and recycle old fishing nets. Returning to natural fibers or replacement of the current materials used in fishing gear for biodegradable materials can also be a recommended mitigation measure. Copyright © 2016

Trophic levels of fish species of commercial importance in the Colombian Caribbean

Directory of Open Access Journals (Sweden)

Camilo B García

2011-09-01

Full Text Available Ecological studies on commercial important fish species are of great value to support resource management issues. This study calculated trophic levels of those Colombian Caribbean fish species whose diet has been locally described. Usable diet data of 119 species resulted in 164 trophic level estimates. An ordinary regression model relating trophic level and fish size was formulated. The regression slope was positive and significantly different from zero (p<0.05 suggesting a scaling of trophic level with fish size. Both the list of trophic levels and the regression model should be of help in the formulation of trophic indicators and models of neotropical ecosystems. Rev. Biol. Trop. 59 (3: 1195-1203. Epub 2011 September 01.

GPS tracking devices reveal foraging strategies of black-legged kittiwakes

Science.gov (United States)

Kotzerka, Jana; Garthe, Stefan; Hatch, Scott A.

2010-01-01

The Black-legged Kittiwake Rissa tridactyla is the most abundant gull species in the world, but some populations have declined in recent years, apparently due to food shortage. Kittiwakes are surface feeders and thus can compensate for low food availability only by increasing their foraging range and/or devoting more time to foraging. The species is widely studied in many respects, but long-distance foraging and the limitations of conventional radio telemetry have kept its foraging behavior largely out of view. The development of Global Positioning System (GPS) loggers is advancing rapidly. With devices as small as 8 g now available, it is possible to use this technology for tracking relatively small species of oceanic birds like kittiwakes. Here we present the first results of GPS telemetry applied to Black-legged Kittiwakes in 2007 in the North Pacific. All but one individual foraged in the neritic zone north of the island. Three birds performed foraging trips only close to the colony (within 13 km), while six birds had foraging ranges averaging about 40 km. The maximum foraging range was 59 km, and the maximum distance traveled was 165 km. Maximum trip duration was 17 h (mean 8 h). An apparently bimodal distribution of foraging ranges affords new insight on the variable foraging behaviour of Black-legged Kittiwakes. Our successful deployment of GPS loggers on kittiwakes holds much promise for telemetry studies on many other bird species of similar size and provides an incentive for applying this new approach in future studies.

[Selective feeding in fish: Effect of feeding and defensive motivations evoked by natural odors].

Science.gov (United States)

Kasumyan, A O; Marusov, E A

2015-01-01

The effect of feeding and defensive motivations evoked by natural olfactory signals (the food odor, the alarm pheromone) on choice and consumption of food items different in color and taste, and the manifestation of foraging behavior were examined in fish (koi Cyprinus carpio, roach Rutilus rutilus). The agar-agar pellets of red and green color having one of the amino acids (glycine, L-proline, L-alanine; all in concentration of 0.1 M) were simultaneously offered to single fishes in pure water, and in water extract of Chironomidae larvae or in water extract of fish skin. It was found out that odors used have different effects on fish foraging activity and on pellet selection for both pellet choice and consumption. On background of food odor, fish grasped pellets more often than in pure water. The equal choice of red and green pellets in pure water shifted to the preference of red ones in the presence of food odor. Despite the increase in the absolute number of pellets grasped, the relative consumption reduced and was replaced by selective consumption of pellets with glycine regardless of their color. Increasing demand for the food quality, due to the increased feeding motivation in response to food odor, is an important adaptation enhancing selection and consumption of food with more appropriate sensory qualities for fish. Defensive motivation caused by alarm pheromone suppressed predisposition. of fish to feed. Fish grasped pellets several times less often than in pure water and refused most of them. Any changes in the color or taste preferences were absent. Feeding behavior of fish of both species was characterized by repeated intraoral pellet testing, but in koi handling was less typical than in roach. In both species, handling activity was higher in those cases when the pellet was finally rejected. This activity was enhanced also on the background of food odor.

POPs and stable isotopes in bird and forage fish tissues - Persistent organic pollutant levels in juvenile salmonids, forage fish and their avian predators from Puget Sound and the outer WA coast

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This project is examining contaminant loads of fish prey species of a resident marine bird (Rhinoceros Auklet) breeding in inland waters (Puget Sound) and in the...

78 FR 59005 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2013-09-25

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... with Section 10(a)(1)(A) of the ESA of 1973 (16 U.S.C. 1531-1543) and regulations governing listed fish.... Applications Received Permit 1415 The U.S. Fish and Wildlife Services' (USFWS) Red Bluff Fish and Wildlife...

77 FR 51520 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2012-08-24

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... (16 U.S.C. 1531-1543) and regulations governing listed fish and wildlife permits (50 CFR parts 222-226... expect to kill any listed fish but a small number, up to 20 percent (equivalent to one fish), may die as...

Sperm quality and cryopreservation of Brazilian freshwater fish species: a review.

Science.gov (United States)

Viveiros, A T M; Godinho, H P

2009-03-01

The Brazilian freshwater fish diversity is the richest in the world. Only 0.7% of all Brazilian species have had any aspect of their sperm biology addressed up to this date. The majority of the fish species described in this review migrate during the spawning season (a phenomenon known as piracema). Urbanization, pollution, hydroelectric dams and deforestation are some of the causes of stock depletion or even local extinction of some of these species. The knowledge concerning sperm quality and minimum sperm:egg ratio is important to maximize the use of males without reducing hatching rates. Furthermore, sperm cryopreservation and gene banking can guarantee the conservation of genetic diversity and development of adequate breeding programs of native fish species. In this review, we present and evaluate the existing information on Brazilian fish species that have been subject to sperm quality and cryopreservation studies. The following parameters were evaluated: volume of extractable sperm, sperm motility, sperm concentration, freezing media, freezing methods, and post-thaw sperm quality. Although the existing protocols yield relatively high post-thaw motility and fertilization rates, the use of cryopreserved sperm in routine hatchery production is still limited in Brazil.

Genetic calibration of species diversity among North America's freshwater fishes

OpenAIRE

April, Julien; Mayden, Richard L.; Hanner, Robert H.; Bernatchez, Louis

2011-01-01

Freshwater ecosystems are being heavily exploited and degraded by human activities all over the world, including in North America, where fishes and fisheries are strongly affected. Despite centuries of taxonomic inquiry, problems inherent to species identification continue to hamper the conservation of North American freshwater fishes. Indeed, nearly 10% of species diversity is thought to remain undescribed. To provide an independent calibration of taxonomic uncertainty and to establish a mor...

Effects of recreational fishing on three fish species from the Posidonia oceanica meadows off Minorca (Balearic archipelago, western Mediterranean

Directory of Open Access Journals (Sweden)

Luis Cardona

2007-12-01

Full Text Available Experimental fishing and visual censuses were conducted at nine Posidonia oceanica sites off Minorca exposed to different levels of fishing intensity to assess the effects of recreational fishing on the species that dominate the catch. Total catch per unit effort (CPUE was highly seasonal and a statistically significant interaction term existed between the season and the level of fishing intensity. CPUE decreased everywhere at the end of the fishing season (autumn, but such a reduction was more intense at those sites exposed to the highest level of fishing. Visual censuses confirmed that there was a lower abundance of vulnerable fish in autumn. Differences vanished in spring probably because fish reshuffled between the considered sites throughout the winter, when the level of fishing intensity was extremely low. Although the average total lengths of Serranus scriba and Diplodus annularis were unaffected by the level of fishing intensity, the average total length of Coris julis was smaller at the most heavily fished sites. In conclusion, recreational fishing has a relevant impact on most of the exploited species and some of the seasonality reported for the Posidonia oceanica fish assemblages might be caused by the seasonality of the fishery.

Comparative sucrose responsiveness in Apis mellifera and A. cerana foragers.

Science.gov (United States)

Yang, Wenchao; Kuang, Haiou; Wang, Shanshan; Wang, Jie; Liu, Wei; Wu, Zhenhong; Tian, Yuanyuan; Huang, Zachary Y; Miao, Xiaoqing

2013-01-01

In the European honey bee, Apis mellifera, pollen foragers have a higher sucrose responsiveness than nectar foragers when tested using a proboscis extension response (PER) assay. In addition, Africanized honey bees have a higher sucrose responsiveness than European honey bees. Based on the biology of the Eastern honey bee, A. cerana, we hypothesized that A. cerana should also have a higher responsiveness to sucrose than A. mellifera. To test this hypothesis, we compared the sucrose thresholds of pollen foragers and nectar foragers in both A. cerana and A. mellifera in Fujian Province, China. Pollen foragers were more responsive to sucrose than nectar foragers in both species, consistent with previous studies. However, contrary to our hypothesis, A. mellifera was more responsive than A. cerana. We also demonstrated that this higher sucrose responsiveness in A. mellifera was not due to differences in the colony environment by co-fostering two species of bees in the same mixed-species colonies. Because A. mellifera foragers were more responsive to sucrose, we predicted that their nectar foragers should bring in less concentrated nectar compared to that of A. cerana. However, we found no differences between the two species. We conclude that A. cerana shows a different pattern in sucrose responsiveness from that of Africanized bees. There may be other mechanisms that enable A. cerana to perform well in areas with sparse nectar resources.

Comparative sucrose responsiveness in Apis mellifera and A. cerana foragers.

Directory of Open Access Journals (Sweden)

Wenchao Yang

Full Text Available In the European honey bee, Apis mellifera, pollen foragers have a higher sucrose responsiveness than nectar foragers when tested using a proboscis extension response (PER assay. In addition, Africanized honey bees have a higher sucrose responsiveness than European honey bees. Based on the biology of the Eastern honey bee, A. cerana, we hypothesized that A. cerana should also have a higher responsiveness to sucrose than A. mellifera. To test this hypothesis, we compared the sucrose thresholds of pollen foragers and nectar foragers in both A. cerana and A. mellifera in Fujian Province, China. Pollen foragers were more responsive to sucrose than nectar foragers in both species, consistent with previous studies. However, contrary to our hypothesis, A. mellifera was more responsive than A. cerana. We also demonstrated that this higher sucrose responsiveness in A. mellifera was not due to differences in the colony environment by co-fostering two species of bees in the same mixed-species colonies. Because A. mellifera foragers were more responsive to sucrose, we predicted that their nectar foragers should bring in less concentrated nectar compared to that of A. cerana. However, we found no differences between the two species. We conclude that A. cerana shows a different pattern in sucrose responsiveness from that of Africanized bees. There may be other mechanisms that enable A. cerana to perform well in areas with sparse nectar resources.

Comparative Sucrose Responsiveness in Apis mellifera and A. cerana Foragers

Science.gov (United States)

Yang, Wenchao; Kuang, Haiou; Wang, Shanshan; Wang, Jie; Liu, Wei; Wu, Zhenhong; Tian, Yuanyuan; Huang, Zachary Y.; Miao, Xiaoqing

2013-01-01

In the European honey bee, Apis mellifera, pollen foragers have a higher sucrose responsiveness than nectar foragers when tested using a proboscis extension response (PER) assay. In addition, Africanized honey bees have a higher sucrose responsiveness than European honey bees. Based on the biology of the Eastern honey bee, A. cerana, we hypothesized that A. cerana should also have a higher responsiveness to sucrose than A. mellifera. To test this hypothesis, we compared the sucrose thresholds of pollen foragers and nectar foragers in both A. cerana and A. mellifera in Fujian Province, China. Pollen foragers were more responsive to sucrose than nectar foragers in both species, consistent with previous studies. However, contrary to our hypothesis, A. mellifera was more responsive than A. cerana. We also demonstrated that this higher sucrose responsiveness in A. mellifera was not due to differences in the colony environment by co-fostering two species of bees in the same mixed-species colonies. Because A. mellifera foragers were more responsive to sucrose, we predicted that their nectar foragers should bring in less concentrated nectar compared to that of A. cerana. However, we found no differences between the two species. We conclude that A. cerana shows a different pattern in sucrose responsiveness from that of Africanized bees. There may be other mechanisms that enable A. cerana to perform well in areas with sparse nectar resources. PMID:24194958

76 FR 2664 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2011-01-14

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS...) and 14092 (applicant: California Department of Fish and Game). In that notice, the permit application... American green sturgeon associated with conducting surveys measuring fish response to initial and...

Cyprinid fishes: systematics, biology, and exploitation

National Research Council Canada - National Science Library

Winfield, Ian J; Nelson, Joseph S

1991-01-01

.... As this family is extremely important as forage fish for other animals, as food fish for humans and are commonly used as models in experimental work, the book will be of great interest to all those with an interest in freshwater fish, fish ecology, fisheries biology and aquaculture systems.

possible stimuli for social behaviour in three species of freshwater fish

African Journals Online (AJOL)

Social behaviour in fish is manifested in many situations and one form. of this phenomenon is especially interesting. Some species of fish have .... Experi- mental methods of study of fish behaviour, in Techniques lor the Investigation 0/ Fish. Physiology, ed. Pavlovskii, E. N., Oldbourne. Press, London. R ep rod u ced b y Sa b.

77 FR 42278 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2012-07-18

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... regulations governing listed fish and wildlife permits (50 CFR parts 222-226). NMFS issues permits based on.... This project will examine predation by introduced fishes (striped bass, largemouth bass, smallmouth...

ABC transporters in fish species: a review

Directory of Open Access Journals (Sweden)

Marta eFerreira

2014-07-01

Full Text Available ATP-binding cassette (ABC proteins were first recognized for their role in multidrug resistance (MDR in chemotherapeutic treatments, which is a major impediment for the successful treatment of many forms of malignant tumors in humans. These proteins, highly conserved throughout vertebrate species, were later related to cellular detoxification and accounted as responsible for protecting aquatic organisms from xenobiotic insults in the so-called multixenobiotic resistance mechanism (MXR. In recent years, research on these proteins in aquatic species has highlighted their importance in the detoxification mechanisms in fish thus it is of extreme added value to continue these studies. Several transporters have been pointed out as relevant in the ecotoxicological context associated to the transport of xenobiotics, such as P-glycoproteins (Pgps, multidrug-resistance-associated proteins (MRPs 1-5 and breast resistance associated protein (BCRP. In mammals, several nuclear receptors have been identified as mediators of phase I and II metabolizing enzymes and ABC transporters. In aquatic species, knowledge on co-regulation of detoxification mechanism is scarce and needs to be addressed. The interaction of emergent contaminants, with chemosensitizer potential, with ABC transporters in aquatic organisms can compromise detoxification processes and have population effects and should be studied in more detail. This review intends to summarize the recent advances in research on MXR mechanisms in fish species, focusing in 1 regulation and functioning of ABC proteins; 2 cooperation with phase I and II biotransformation enzymes; and 3 ecotoxicological relevance and information on emergent pollutants with ability to modulate ABC transporters expression and activity. Several lines of evidence are clear suggesting the important role of these transporters in detoxification mechanisms and must be further investigated in fish.

Resource partitioning within major bottom fish species in a highly productive upwelling ecosystem

Science.gov (United States)

Abdellaoui, Souad; El Halouani, Hassan; Tai, Imane; Masski, Hicham

2017-09-01

The Saharan Bank (21-26°N) is a wide subtropical continental shelf and a highly productive upwelling ecosystem. The bottom communities are dominated by octopus and sparid fish, which are the main targets of bottom-trawl fishing fleets. To investigate resource partitioning within the bottom fish community, adult fish from 14 of the most abundant species were investigated for stomach content analysis. Samples were collected during two periods: October 2003 and May 2007. The diet of the analysed species showed more variation between periods than between size classes, suggesting that temporal or spatial variability in prey availability appears to play a significant role in their diet. Multivariate analysis and subsequent clustering led to a grouping of the species within five trophic guilds. Two species were fish feeders, and the others mainly fed on benthic invertebrates, where epibenthic crustaceans, lamellibranchs and fish were the most important groups in defining trophic guilds. We found that the studied species had a high rate of overlapping spatial distributions and overlapping trophic niches. In this highly productive upwelling ecosystem, where food resources may not be a limiting factor, inter-specific competition did not appear to be an important factor in structuring bottom fish communities. For the species that showed differences in the proportions of prey categories in comparison with other ecosystems, the rise of the proportion of epibenthic crustaceans in their diet was a common feature; a possible consequence of the benthic productivity of this highly productive upwelling ecosystem.

Comparative visual ecophysiology of mid-Atlantic temperate reef fishes

Directory of Open Access Journals (Sweden)

Andrij Z. Horodysky

2013-11-01

The absolute light sensitivities, temporal properties, and spectral sensitivities of the visual systems of three mid-Atlantic temperate reef fishes (Atlantic spadefish [Ephippidae: Chaetodipterus faber], tautog [Labridae: Tautoga onitis], and black sea bass [Serranidae: Centropristis striata] were studied via electroretinography (ERG. Pelagic Atlantic spadefish exhibited higher temporal resolution but a narrower dynamic range than the two more demersal foragers. The higher luminous sensitivities of tautog and black sea bass were similar to other benthic and demersal coastal mid-Atlantic fishes. Flicker fusion frequency experiments revealed significant interspecific differences at maximum intensities that correlated with lifestyle and habitat. Spectral responses of the three species spanned 400–610 nm, with high likelihood of cone dichromacy providing the basis for color and contrast discrimination. Significant day-night differences in spectral responses were evident in spadefish and black sea bass but not tautog, a labrid with characteristic structure-associated nocturnal torpor. Atlantic spadefish responded to a wider range of wavelengths than did deeper-dwelling tautog or black sea bass. Collectively, these results suggest that temperate reef-associated fishes are well-adapted to their gradient of brighter to dimmer photoclimates, representative of their unique ecologies and life histories. Continuing anthropogenic degradation of water quality in coastal environments, at a pace faster than the evolution of visual systems, may however impede visual foraging and reproductive signaling in temperate reef fishes.

Ontogenetic foraging activity and feeding selectivity of the Brazilian endemic parrotfish Scarus zelindae

Directory of Open Access Journals (Sweden)

Pedro H.C. Pereira

2016-10-01

Full Text Available Parrotfish are fundamental species in controlling algal phase-shifts and ensuring the resilience of coral reefs. Nevertheless, little is known on their ecological role in the south-western Atlantic Ocean. The present study analysed the ontogenetic foraging activity and feeding selectivity of the Brazilian endemic parrotfish Scarus zelindae using behavioural observation and benthic composition analyses. We found a significant negative relationship between fish size and feeding rates for S. zelindae individuals. Thus, terminal phase individuals forage with lower feeding rates compared to juveniles and initial phase individuals. The highest relative foraging frequency of S. zelindae was on epilithic algae matrix (EAM with similar values for juveniles (86.6%, initial phase (88.1% and terminal phase (88.6% individuals. The second preferred benthos for juveniles was sponge (11.6% compared with initial (4.5% and terminal life phases (1.3%. Different life phases of S. zelindae foraged on different benthos according to their availability. Based on Ivlev’s electivity index, juveniles selected EAM and sponge, while initial phase and terminal phase individuals only selected EAM. Our findings demonstrate that the foraging frequency of the endemic parrotfish S. zelindae is reduced according to body size and that there is a slight ontogenetic change in feeding selectivity. Therefore, ecological knowledge of ontogenetic variations on resource use is critical for the remaining parrotfish populations which have been dramatically reduced in the Southwestern Atlantic Ocean.

Distribution, behavior, and condition of herbivorous fishes on coral reefs track algal resources.

Science.gov (United States)

Tootell, Jesse S; Steele, Mark A

2016-05-01

Herbivore distribution can impact community structure and ecosystem function. On coral reefs, herbivores are thought to play an important role in promoting coral dominance, but how they are distributed relative to algae is not well known. Here, we evaluated whether the distribution, behavior, and condition of herbivorous fishes correlated with algal resource availability at six sites in the back reef environment of Moorea, French Polynesia. Specifically, we tested the hypotheses that increased algal turf availability would coincide with (1) increased biomass, (2) altered foraging behavior, and (3) increased energy reserves of herbivorous fishes. Fish biomass and algal cover were visually estimated along underwater transects; behavior of herbivorous fishes was quantified by observations of focal individuals; fish were collected to assess their condition; and algal turf production rates were measured on standardized tiles. The best predictor of herbivorous fish biomass was algal turf production, with fish biomass increasing with algal production. Biomass of herbivorous fishes was also negatively related to sea urchin density, suggesting competition for limited resources. Regression models including both algal turf production and urchin density explained 94 % of the variation in herbivorous fish biomass among sites spread over ~20 km. Behavioral observations of the parrotfish Chlorurus sordidus revealed that foraging area increased as algal turf cover decreased. Additionally, energy reserves increased with algal turf production, but declined with herbivorous fish density, implying that algal turf is a limited resource for this species. Our findings support the hypothesis that herbivorous fishes can spatially track algal resources on coral reefs.

78 FR 43858 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2013-07-22

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... number of predicted adults increase, the number of fish escaping to the spawning grounds will also... fish; and (3) application of a sliding scale approach to determine appropriate ESA take limits on...

78 FR 31518 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2013-05-24

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XC690 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... Department of Fish and Wildlife (ODFW), Washington Department of Fish and Wildlife (WDFW), and U.S. Bureau of...

78 FR 18963 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2013-03-28

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... governing listed fish and wildlife permits (50 CFR parts 222-226). NMFS issues permits based on findings... Administrator for Fisheries, NMFS. Applications Received Permit 17551 The California Department of Fish and...

As multiple fish species in large marine ecosystems are harvested ...

African Journals Online (AJOL)

CMPTMAC10

and of other top predators such as marine mammals. This concern ... whereas single-species fishing theory implies that fishing leads to surplus by removing larger, older, less-productive ...... pools (the “cod is not a tuna” problem, Longhurst.

Application of instrumental neutron activation analysis for the analysis of six fish species

Energy Technology Data Exchange (ETDEWEB)

Moon, J. H.; Oh, M.; Kim, S. H.; Chung, Y. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

According to the meeting report of the Food and Agriculture Organization (FAO), annual food fish supply per capita has increased from an average of 9.9 kg in the 1960s to 18.4 kg in 2009, and fish consumption was lowest in Africans (9.1 kg per capita), while Asians consumed 20.7 kg per capita. From the viewpoint of food safety, fish accumulates environmental contaminants and an analysis of hazardous chemical species including toxic heavy metals is important for human health. The aims of this study were to determine the inorganic elemental content in six popular fish species of Korea by NAA and to aid in the evaluation of dietary intake levels in terms of toxic and essential elements. An INAA for the six fish species that are popular in Korea was performed, and sixteen elemental contents were determined. Based on these analytical data and survey data in 2010, intake levels for 3 toxic heavy metals by each fish species are evaluated for Koreans. These dietary intake values for heavy metals can be used for an assessment of human health risk.

Analysis of Inter- and Intra-individual Variation in Foraging Habits of the Endangered Hawaiian Petrel Using Stables Isotopes

Science.gov (United States)

Morra, K. E.; Ostrom, P. H.; Wiley, A. E.; James, H. F.; Stricker, C. A.; Gandhi, H.

2014-12-01

Stable isotope analysis of the endangered Hawaiian petrel's (Pterodroma sandwichensis, HAPE) feathers provides otherwise intractable information regarding non-breeding season foraging habits. Adult HAPE spend 3.5-6 months at sea during the non-breeding season, at which time they sequentially molt their flight feathers. Because feathers are metabolically inert once synthesized, they capture isotopic signals while they are grown, providing an opportunity to study foraging habits over time. Here we use stable hydrogen (δD), carbon (δ13C) and nitrogen (δ15N) isotopes to assess variation in foraging habits within and between individuals, and among four breeding colonies. δD is an indicator of prevalence of fish vs. invertebrates in the diet. In one analysis, we observed large variation in feather δD (125‰), with adults from Maui and Kauai having significantly higher δD values than corresponding hatch-year birds, indicating significant dietary differences between age groups. In a second analysis, we utilized δ13C and δ15N of Hawaii, Maui and Lanai adults, values which vary with trophic level and also at the base of the food web across HAPE's foraging range, potentially revealing information about feeding location, as well as diet. Furthermore, because the sequence of molt is known, we are able to determine whether individual foraging specialization (continued use of the same foraging behavior over time) exists in this species. To do this, we analyzed two primary feathers, P1 and P6, which reflect the beginning and the middle of the non-breeding season, respectively. We did not find significant differences in δ13C or δ15N between P1 and P6, suggesting consistent foraging habits within individuals over time. This provides evidence that individual foraging specialization exists within these populations. Analysis of a secondary feather grown late in the molt sequence would further illuminate the extent of foraging specialization. Finally, δ15N differs

Forage mass and the nutritive value of pastures mixed with forage peanut and red clover

Directory of Open Access Journals (Sweden)

Ricardo Lima de Azevedo Junior

2012-04-01

Full Text Available The objective of this research was to estimate three pasture-based systems mixed with elephantgrass + spontaneous growth species, annual ryegrass, for pasture-based system 1; elephantgrass + spontaneous growth species + forage peanut, for pasture-based system 2; and elephantgrass + spontaneous growth species + annual ryegrass + red clover, for pasture-based system 3. Elephantgrass was planted in rows 4 m apart from each other. During the cool-season, annual ryegrass was sown in the alleys between the rows of elephantgrass; forage peanut and red clover were sown in the alleys between the elephantgrass according to the respective treatment. The experimental design was totally randomized in the three treatments (pasture-based systems, two replicates (paddocks in completely split-plot time (grazing cycles. Holstein cows receiving 5.5 kg-daily complementary concentrate feed were used in the evaluation. Pre-grazing forage mass, botanical composition and stocking rate were evaluated. Samples of simulated grazing were collected to analyze organic matter (OM, neutral detergent fiber (NDF, crude protein (CP and organic matter in situ digestibility (OMISD. Nine grazing cycles were performed during the experimental period (341 days. The average dry matter values for pre-grazing and stocking rate were 3.34; 3.46; 3.79 t/ha, and 3.28; 3.34; 3.60 AU/ha for each respective pasture-based system. Similar results were observed between the pasture-based systems for OM, NDF, CP and OMISD. Considering forage mass, stocking rate and nutritive value, the pasture-based system intercropped with forage legumes presented better performance.

Grey seal predation on forage fish in the Baltic Sea

DEFF Research Database (Denmark)

Eero, Aro; Neuenfeldt, Stefan; Aho, Teija

The mean annual growth rate of grey seal stock in the Baltic has been on average 7.5% annually during the last decade. In 2010, a total of approximately 23 100 grey seals were counted. The increase in stock size was highest in the northern areas and the predation pressure of grey seals on clupeoids...... has increased accordingly. The diet of grey seal in the Baltic consists of ca. 20 fish species. The most abundant prey items in the Baltic proper are Baltic herring, sprat, and cod, and in the Bothnian Sea and Bothnian Bay Baltic herring, Coregonus sp., Baltic salmon, and sea trout. An adult seal...... consumes on average round 4.5 kg fish per day, of which 55% are clupeoids in the Baltic Main basin and 70% in the Bothnian Sea and Bothnian Bay. According to acoustic estimates, predator– prey distribution patterns, migration patterns, and multispecies analysis (SMS), the predation effect of grey seals...

SURROGATE SPECIES IN ASSESSING CONTAMINANT RISK FOR ENDANGERED FISHES

Science.gov (United States)

Rainbow trout, fathead minnows, and sheepshead minnows were tested as surrogate species to assess contaminant risk for 17 endangered fishes and one toad species. Acute toxicity tests were conducted with carbaryl, copper, 4-nonylphenol, pentachlorophenol, and permethrin in accord...

Nutritive values of some food plants, fresh and processed fish species

Directory of Open Access Journals (Sweden)

Ali Aberoumand

2015-12-01

Full Text Available The chemical composition of four edible plant foods species, three fish species and one prawn were analyzed in Food Chemistry Laboratory of Behbahan Khatam Alanbia University of Technology, Behbahan, Iran in 2014. The analysis of fatty acid and sugars composition were performed by gas liquid chromatography and high performance liquid chromatography, respectively. Protein and lipid content were founded higher in baked and fried in fish S. commersonnianus (74.29%, (20.20%, fish Sphyraena helleri (88.12% and (17.77%, respectively. Ash content in fish S. commersonnianus varies from 9.80% to 15.34%, and in fish S. helleri from 5.83% to 7.68%. Based on the proximate analysis, it can be calculated that an edible portion of 100 g of studied edible plant foods provides, on average, around 303.9±1.04 kcal. The plant Portulaca neglecta is suitable for high temperature food processes. The macronutrient profile in general revealed that the wild plant foods were with rich sources of protein and carbohydrates, and had low amounts of fat. The highest protein, the lowest fat and energy contents were found in boiled in both fish species; therefore, boiling can be recommended as the best cooking method for healthy diet.

Determining spatio-temporal distribution of bee forage species of Al-Baha region based on ground inventorying supported with GIS applications and Remote Sensed Satellite Image analysis.

Science.gov (United States)

Adgaba, Nuru; Alghamdi, Ahmed; Sammoud, Rachid; Shenkute, Awraris; Tadesse, Yilma; Ansari, Mahammad J; Sharma, Deepak; Hepburn, Colleen

2017-07-01

In arid zones, the shortage of bee forage is critical and usually compels beekeepers to move their colonies in search of better forages. Identifying and mapping the spatiotemporal distribution of the bee forages over given area is important for better management of bee colonies. In this study honey bee plants in the target areas were inventoried following, ground inventory work supported with GIS applications. The study was conducted on 85 large plots of 50 × 50 m each. At each plot, data on species name, height, base diameter, crown height, crown diameter has been taken for each plant with their respective geographical positions. The data were stored, and processed using Trimble GPS supported with ArcGIS10 software program. The data were used to estimate the relative frequency, density, abundance and species diversity, species important value index and apicultural value of the species. In addition, Remotely Sensed Satellite Image of the area was obtained and processed using Hopfield Artificial Neural Network techniques. During the study, 182 species from 49 plant families were identified as bee forages of the target area. From the total number of species; shrubs, herbs and trees were accounting for 61%, 27.67%, and 11.53% respectively. Of which Ziziphus spina-christi , Acacia tortilis , Acacia origina , Acacia asak , Lavandula dentata , and Hypoestes forskaolii were the major nectar source plants of the area in their degree of importance. The average vegetation cover values of the study areas were low (GIS and satellite image processing techniques could be an important tool for characterizing and mapping the available bee forage resources leading to their efficient and sustainable utilization.

78 FR 28805 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2013-05-16

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS..., NMFS received an application, including an HGMP, from the Idaho Department of Fish and Game, a section... the Snake River basin, rear juveniles, and release eggs, juveniles, and adult fish into upper Salmon...

78 FR 79674 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2013-12-31

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... the ESA (16 U.S.C. 1531 et seq.) and regulations governing listed fish and wildlife permits (50 CFR.... Fish and Wildlife Service (USFWS) submitted an application and supporting documents to NMFS for a...

78 FR 32378 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2013-05-30

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... application was provided by the Washington Department of Fish and Wildlife (WDFW) and the Public Utility... Department of Fish and Wildlife submitted an application for an ESA permit to operate the Nason Creek spring...

76 FR 8713 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2011-02-15

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... (16 U.S.C. 1531-1543) and regulations governing listed fish and wildlife permits (50 CFR parts 222-226... handling of fish is already covered under the Incidental Take Statement associated with the Biological...

77 FR 63294 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2012-10-16

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... Klallam Tribe and the Washington Department of Fish and Wildlife have submitted five Hatchery and Genetic... programs are currently operating, and all five hatchery programs raise fish native to the Elwha River basin...

78 FR 25954 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2013-05-03

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... 15, 2012, NMFS received an application, including an HGMP, from the Idaho Department of Fish and Game... salmon returning to the Snake River basin, rear juveniles, and release eggs, juveniles, and adult fish...

Detection of Listeria species in Gamma irradiated Fishes during Storage periods

International Nuclear Information System (INIS)

Mohamed, W.S.

2011-01-01

This investigation was carried out to detect the post irradiation recovery and growth of Listeria species encountered in frozen whole Tilapia fishes ,Tilapia fillet and frozen Hamour fillets fishes (-18 degree C) irradiated at 1, 2, 2.5 and 3 kGy. The pathogen was eliminated at a dose of 2.5 kGy of gamma radiation. The presence of the microorganism was monitored for sex months on appropriate selective media. The ability of recovery of the organism from irradiation damage was not influenced by the kind of fish. No increased counts of the organism in irradiated fishes at 2.5 kGy of gamma radiation was noticed during 6 months of freezing storage at -18 degree C. This study also aimed to evaluate the effect of different enrichment procedures on the detection of Listeria species in fishes

Reef fishes in biodiversity hotspots are at greatest risk from loss of coral species.

Science.gov (United States)

Holbrook, Sally J; Schmitt, Russell J; Messmer, Vanessa; Brooks, Andrew J; Srinivasan, Maya; Munday, Philip L; Jones, Geoffrey P

2015-01-01

Coral reef ecosystems are under a variety of threats from global change and anthropogenic disturbances that are reducing the number and type of coral species on reefs. Coral reefs support upwards of one third of all marine species of fish, so the loss of coral habitat may have substantial consequences to local fish diversity. We posit that the effects of habitat degradation will be most severe in coral regions with highest biodiversity of fishes due to greater specialization by fishes for particular coral habitats. Our novel approach to this important but untested hypothesis was to conduct the same field experiment at three geographic locations across the Indo-Pacific biodiversity gradient (Papua New Guinea; Great Barrier Reef, Australia; French Polynesia). Specifically, we experimentally explored whether the response of local fish communities to identical changes in diversity of habitat-providing corals was independent of the size of the regional species pool of fishes. We found that the proportional reduction (sensitivity) in fish biodiversity to loss of coral diversity was greater for regions with larger background species pools, reflecting variation in the degree of habitat specialization of fishes across the Indo-Pacific diversity gradient. This result implies that habitat-associated fish in diversity hotspots are at greater risk of local extinction to a given loss of habitat diversity compared to regions with lower species richness. This mechanism, related to the positive relationship between habitat specialization and regional biodiversity, and the elevated extinction risk this poses for biodiversity hotspots, may apply to species in other types of ecosystems.

Reef fishes in biodiversity hotspots are at greatest risk from loss of coral species.

Directory of Open Access Journals (Sweden)

Sally J Holbrook

Full Text Available Coral reef ecosystems are under a variety of threats from global change and anthropogenic disturbances that are reducing the number and type of coral species on reefs. Coral reefs support upwards of one third of all marine species of fish, so the loss of coral habitat may have substantial consequences to local fish diversity. We posit that the effects of habitat degradation will be most severe in coral regions with highest biodiversity of fishes due to greater specialization by fishes for particular coral habitats. Our novel approach to this important but untested hypothesis was to conduct the same field experiment at three geographic locations across the Indo-Pacific biodiversity gradient (Papua New Guinea; Great Barrier Reef, Australia; French Polynesia. Specifically, we experimentally explored whether the response of local fish communities to identical changes in diversity of habitat-providing corals was independent of the size of the regional species pool of fishes. We found that the proportional reduction (sensitivity in fish biodiversity to loss of coral diversity was greater for regions with larger background species pools, reflecting variation in the degree of habitat specialization of fishes across the Indo-Pacific diversity gradient. This result implies that habitat-associated fish in diversity hotspots are at greater risk of local extinction to a given loss of habitat diversity compared to regions with lower species richness. This mechanism, related to the positive relationship between habitat specialization and regional biodiversity, and the elevated extinction risk this poses for biodiversity hotspots, may apply to species in other types of ecosystems.

Foraging modality and plasticity in foraging traits determine the strength of competitive interactions among carnivorous plants, spiders and toads.

Science.gov (United States)

Jennings, David E; Krupa, James J; Rohr, Jason R

2016-07-01

Foraging modalities (e.g. passive, sit-and-wait, active) and traits are plastic in some species, but the extent to which this plasticity affects interspecific competition remains unclear. Using a long-term laboratory mesocosm experiment, we quantified competition strength and the plasticity of foraging traits in a guild of generalist predators of arthropods with a range of foraging modalities. Each mesocosm contained eight passively foraging pink sundews, and we employed an experimental design where treatments were the presence or absence of a sit-and-wait foraging spider and actively foraging toad crossed with five levels of prey abundance. We hypothesized that actively foraging toads would outcompete the other species at low prey abundance, but that spiders and sundews would exhibit plasticity in foraging traits to compensate for strong competition when prey were limited. Results generally supported our hypotheses. Toads had a greater effect on sundews at low prey abundances, and toad presence caused spiders to locate webs higher above the ground. Additionally, the closer large spider webs were to the ground, the greater the trichome densities produced by sundews. Also, spider webs were larger with than without toads and as sundew numbers increased, and these effects were more prominent as resources became limited. Finally, spiders negatively affected toad growth only at low prey abundance. These findings highlight the long-term importance of foraging modality and plasticity of foraging traits in determining the strength of competition within and across taxonomic kingdoms. Future research should assess whether plasticity in foraging traits helps to maintain coexistence within this guild and whether foraging modality can be used as a trait to reliably predict the strength of competitive interactions. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

78 FR 7755 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2013-02-04

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS...)(A) of the ESA of 1973 (16 U.S.C. 1531-1543) and regulations governing listed fish and wildlife.... In situations where the SWFSC are unable to rely on collaborators to capture fish through rotary...

77 FR 76001 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2012-12-26

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... regulations governing listed fish and wildlife permits(50 CFR parts 222-226). NMFS issues permits based on... described below, researchers do not expect to kill any listed fish but a small number may die as an...

Genetic assessment of ornamental fish species from North East India.

Science.gov (United States)

Dhar, Bishal; Ghosh, Sankar Kumar

2015-01-25

Ornamental fishes are traded with multiple names from various parts around the world, including North East India. Most are collected from the wild, due to lack of species-specific culture or breeding, and therefore, such unmanaged collection of the wild and endemic species could lead to severe threats to biodiversity. Despite many regulatory policies, trade of threatened species, including the IUCN listed species have been largely uncontrolled, due to species identification problems arising from the utilization of multiple trade names. So, the development of species-specific DNA marker is indispensable where DNA Barcoding is proved to be helpful in species identification. Here, we investigated, through DNA Barcoding and morphological assessment, the identification of 128 ornamental fish specimens exported from NE India from different exporters. The generated sequences were subjected to similarity match in BOLD-IDS as well as BLASTN, and analysed using MEGA5.2 for species identification through Neighbour-Joining (NJ) clustering, and K2P distance based approach. The analysis revealed straightforward identification of 84 specimens into 35 species, while 44 specimens were difficult to distinguish based on CO1 barcode alone. However, these cases were resolved through morphology, NJ and distanced based method and found to be belonging to 16 species. Among the 51 identified species, 14 species represented multiple trade names; 17 species belonged to threatened category. Species-level identification through DNA Barcoding along with traditional morphotaxonomy reflects its efficacy in regulating ornamental fish trade and therefore, appeals for their conservation in nature. The use of trade names rather than the zoological name created the passage for trafficking of the threatened species and demands immediate attention for sustaining wildlife conservation. Copyright © 2014 Elsevier B.V. All rights reserved.

The fish fauna of Anambra river basin, Nigeria: species abundance and morphometry

Directory of Open Access Journals (Sweden)

Gregory Ejikeme Odo

2009-06-01

Full Text Available The fish yields of most Nigeria inland waters are generally on the decline for causes that may range from inadequate management of the fisheries to degradation of the water bodies. Sustainable exploitation requires knowledge of the ichthyofaunal composition in the water bodies. We did a survey of fish species in Anambra river basin for 22 months. Fish samples were collected using four different gears -hook and line of size 13, caste nets, gill nets, and cages of mesh sizes of 50mm, 75mm, and 100mm each. We recorded 52 fish species belonging to 17 families: 171, 236, and 169 individuals at Ogurugu, Otuocha, and Nsugbe stations respectively. Two families, Characidae, 19.5 %, and Mochokidae, 11.8%, constituted the dominant fish families in the river. The dominant fish species were Citherinus citherius, 9.02%, and Alestes nurse, 7.1%. Other fish species with significant abundance were Synodontis clarias 6.9%, Macrolepidotus curvier 5.7%, Labeo coubie 5.4%, Distichodus rostrtus 4.9%, and Schilbe mystus 4.5%. The meristic features of the two most abundant fish species caught are as follows: Citharinus citharius dorsal fins 20, anal fins 30, caudal fins 21, pectoral fins, 9 and 8 ventral fins, and Alestes nurse 10 dorsal fins, 14 anal fins, 31 caudal fins, 7 pectoral fins and 6 ventral fins. The morphometric features of the two most abundant fish species are Citharinus citharius total length 300mm, standard length 231mm, head length 69mm, body length 101mm, body girth 176 mm, body weight 900mg. Alestes nurse total length 200, standard length 140mm, head length 60mm, body length 80mm, body girth120mm, body weight 400mg. The most abundant animal utilizing the basin was Ardea cinerea(D3 with 22.2% occurrence (D4 and this was followed by Caprini with 13.51%, and Varanus niloticus, 10.04%. The least abundant animals utilizing basin were Chephalophus rufilatus, and Erythrocebus patas, with 0.58% each of occurrence. Rev. Biol. Trop. 57 (1-2: 177-186. Epub

Individual-based analyses reveal limited functional overlap in a coral reef fish community.

Science.gov (United States)

Brandl, Simon J; Bellwood, David R

2014-05-01

Detailed knowledge of a species' functional niche is crucial for the study of ecological communities and processes. The extent of niche overlap, functional redundancy and functional complementarity is of particular importance if we are to understand ecosystem processes and their vulnerability to disturbances. Coral reefs are among the most threatened marine systems, and anthropogenic activity is changing the functional composition of reefs. The loss of herbivorous fishes is particularly concerning as the removal of algae is crucial for the growth and survival of corals. Yet, the foraging patterns of the various herbivorous fish species are poorly understood. Using a multidimensional framework, we present novel individual-based analyses of species' realized functional niches, which we apply to a herbivorous coral reef fish community. In calculating niche volumes for 21 species, based on their microhabitat utilization patterns during foraging, and computing functional overlaps, we provide a measurement of functional redundancy or complementarity. Complementarity is the inverse of redundancy and is defined as less than 50% overlap in niche volumes. The analyses reveal extensive complementarity with an average functional overlap of just 15.2%. Furthermore, the analyses divide herbivorous reef fishes into two broad groups. The first group (predominantly surgeonfishes and parrotfishes) comprises species feeding on exposed surfaces and predominantly open reef matrix or sandy substrata, resulting in small niche volumes and extensive complementarity. In contrast, the second group consists of species (predominantly rabbitfishes) that feed over a wider range of microhabitats, penetrating the reef matrix to exploit concealed surfaces of various substratum types. These species show high variation among individuals, leading to large niche volumes, more overlap and less complementarity. These results may have crucial consequences for our understanding of herbivorous processes on

Some peculiarities of fish abundance, species and sizes distribution, and spacing

International Nuclear Information System (INIS)

Astrauskas, A.; Bernotas, E.; Jovaisha, R.

1995-01-01

During the construction and exploitation process of Ignalina NPP the abundance of fishes has dropped, and especially stenothermic species (smelt and vendace). The general increase of fish abundance is observed in recent years (1992-1994). This is linked with changes of fish species and their adaptation to the new environmental conditions. Now the partial renovation of vendace abundance is observed, too. It is a result of free feeding recess coming out as the smelt dramatically decreased. Before now the ecosystem of the lake is greatly disbalanced due to antropogenetic impact of the NPP. It's partial stabilisation (but on the essentially high level) is possible only in some generations of fish living in the lake. (author). 18 refs., 1 tab., 11 figs

Chemical composition, mineral content and amino acid and lipid profiles in bones from various fish species.

Science.gov (United States)

Toppe, Jogeir; Albrektsen, Sissel; Hope, Britt; Aksnes, Anders

2007-03-01

The chemical composition, content of minerals and the profiles of amino acids and fatty acids were analyzed in fish bones from eight different species of fish. Fish bones varied significantly in chemical composition. The main difference was lipid content ranging from 23 g/kg in cod (Gadus morhua) to 509 g/kg in mackerel (Scomber scombrus). In general fatty fish species showed higher lipid levels in the bones compared to lean fish species. Similarly, lower levels of protein and ash were observed in bones from fatty fish species. Protein levels differed from 363 g/kg lipid free dry matter (dm) to 568 g/kg lipid free dm with a concomitant inverse difference in ash content. Ash to protein ratio differed from 0.78 to 1.71 with the lowest level in fish that naturally have highest swimming and physical activity. Saithe (Pollachius virens) and salmon (Salmo salar) were found to be significantly different in the levels of lipid, protein and ash, and ash/protein ratio in the bones. Only small differences were observed in the level of amino acids although species specific differences were observed. The levels of Ca and P in lipid free fish bones were about the same in all species analyzed. Fatty acid profile differed in relation to total lipid levels in the fish bones, but some minor differences between fish species were observed.

Length-weight relationships for 13 fish species from the Gulf of ...

African Journals Online (AJOL)

Length-weight relationships (LWR) were estimated for 13 fish species which are of economic relevance in the commercial fisheries of the Gulf of Gabes (southern Tunisia). A total of 2403 fish specimens were sampled with several fishing gears from October 2008 to September 2009. The sample size ranged from 65 ...

Temporal comparison and predictors of fish species abundance and richness on undisturbed coral reef patches

Directory of Open Access Journals (Sweden)

Elena L.E.S. Wagner

2015-12-01

Full Text Available Large disturbances can cause rapid degradation of coral reef communities, but what baseline changes in species assemblages occur on undisturbed reefs through time? We surveyed live coral cover, reef fish abundance and fish species richness in 1997 and again in 2007 on 47 fringing patch reefs of varying size and depth at Mersa Bareika, Ras Mohammed National Park, Egypt. No major human or natural disturbance event occurred between these two survey periods in this remote protected area. In the absence of large disturbances, we found that live coral cover, reef fish abundance and fish species richness did not differ in 1997 compared to 2007. Fish abundance and species richness on patches was largely related to the presence of shelters (caves and/or holes, live coral cover and patch size (volume. The presence of the ectoparasite-eating cleaner wrasse, Labroides dimidiatus, was also positively related to fish species richness. Our results underscore the importance of physical reef characteristics, such as patch size and shelter availability, in addition to biotic characteristics, such as live coral cover and cleaner wrasse abundance, in supporting reef fish species richness and abundance through time in a relatively undisturbed and understudied region.

[Seasonal changes of fish species composition and diversity in mudflat wetlands of Hangzhou Bay].

Science.gov (United States)

Jia, Xing-huan; Zhang, Heng; Jiang, Ke-yi; Wu, Ming

2010-12-01

In order to understand the spatiotemporal variation of fish species composition and biodiversity in the mudflat wetlands of Hangzhou Bay, thirty six surveys were conducted in the mudflat area, inning area, and aquaculture area in the south bank of the Bay in. March (early spring), May (spring), July (summer), and October (autumn), 2009. A total of 41 species belonging to 9 orders and 16 families were observed, among which, Cyprinid had the largest species number (14 species, 33.3% of the total), followed by Gobiidae (8 species, 19.1%). According to the lifestyle of fish, these 41 species could be divided into five ecological types, i.e., freshwater type (21 species), brackish-water type (16 species), inshore type (2 species), anadromous type (Coilia ectenes), and catadromios type (Anguilla japonica). The fish abundance was the highest (54. 5 fish per net) in summer, followed by in spring and autumn, and the lowest (17.7 fish per net) in early spring. In the three habitats, mudflat area and inning area had the similar seasonal change of fish abundance, i.e., the lowest in early spring, the highest in summer, and then decreased in autumn. Only two or three species were the dominant species in different seasons. In mudflat area, the dominant species were Mugil cephalus and Liza carinatus; while in inning and aquaculture areas, the dominant species were Carassius auratus, Hemiculter leucisculus, and Pseudorasbora parva. The values of Margalef's richness index (D), Pielou's evenness index (J), and Shannon index (H) were lower in March than in other months, but had no significant differences among May, July, and October (P > 0.05). The H value ranged in 0. 27-2. 13, being the lowest in March and higher in May and October (1.66 and 1.63, respectively). Overall, the fish abundance and biodiversity in the mudflat wetlands of Hangzhou Bay had apparent seasonal changes.

77 FR 3743 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2012-01-25

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... with section 10(a)(1)(A) of the ESA of 1973 (16 U.S.C. 1531-1543) and regulations governing listed fish... listed fish but a small number may die as an unintended result of the research activities. The objectives...

78 FR 17355 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2013-03-21

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... 10(a)(1)(A) of the ESA of 1973 (16 U.S.C. 1531-1543) and regulations governing listed fish and... expect to kill any listed fish but a small number may die as an unintended result of the research...

Forage quantity and quality

Science.gov (United States)

Jorgenson, Janet C.; Udevitz, Mark S.; Felix, Nancy A.; Douglas, David C.; Reynolds, Patricia E.; Rhode, E.B.

2002-01-01

The Porcupine caribou herd has traditionally used the coastal plain of the Arctic National Wildlife Refuge, Alaska, for calving. Availability of nutritious forage has been hypothesized as one of the reasons the Porcupine caribou herd migrates hundreds of kilometers to reach the coastal plain for calving (Kuropat and Bryant 1980, Russell et al. 1993).Forage quantity and quality and the chronology of snowmelt (which determines availability and phenological stages of forage) have been suggested as important habitat attributes that lead calving caribou to select one area over another (Lent 1980, White and Trudell 1980, Eastland et al. 1989). A major question when considering the impact of petroleum development is whether potential displacement of the caribou from the 1002 Area to alternate calving habitat will limit access to high quantity and quality forage.Our study had the following objectives: 1) quantify snowmelt patterns by area; 2) quantify relationships among phenology, biomass, and nutrient content of principal forage species by vegetation type; and 3) determine if traditional concentrated calving areas differ from adjacent areas with lower calving densities in terms of vegetation characteristics.

Effects of industrial processing on the immunogenicity of commonly ingested fish species.

Science.gov (United States)

Sletten, Gaynour; Van Do, Thien; Lindvik, Helene; Egaas, Eliann; Florvaag, Erik

2010-01-01

Food-processing techniques may induce changes in fish protein immunogenicity. Allergens from >100 fish species have been identified, but little is known on the effects of processing on fish protein immunogenicity. IgE binding of sera of patients allergic to fresh and processed (smoked, salted/sugar-cured, canned, lye-treated and fermented) cod, haddock, salmon, trout, tuna, mackerel and herring and of hydrolysates based on salmon and whiting was investigated using immunoblot and inhibition ELISA. Parvalbumin oligomers were identified using monoclonal and polyclonal antibodies. IgE binding was seen in most sera at 12-14 kDa (parvalbumin), and at 17-60 kDa for all fish except tuna. Changes in IgE binding appeared to reflect altered parvalbumin monomers and oligomers. Smoked haddock, salmon and mackerel had increased IgE binding and novel bands at 30 kDa. Chemically processed cod, salmon, trout and pickled herring had reduced or abolished IgE binding. The serum of 1 subject, however, had increased IgE binding to these products and also inhibition of binding by both fish hydrolysates to their constituent fish species. Process-induced changes in fish protein immunogenicity were more dependent on process rather than species, although individual responses varied. Changes in the allergenicity of a product may depend on the net effect of processing on parvalbumin oligomerization patterns, which may also vary in different species. Chemical processes generally caused loss in IgE-binding activity, though sensitization may occur to modified or degraded rather than intact peptides as shown by increased binding by chemically processed fish and hydrolysates in 1 subject. The clinical significance of these findings remains to be established.

Numerical abilities in fish: A methodological review.

Science.gov (United States)

Agrillo, Christian; Miletto Petrazzini, Maria Elena; Bisazza, Angelo

2017-08-01

The ability to utilize numerical information can be adaptive in a number of ecological contexts including foraging, mating, parental care, and anti-predator strategies. Numerical abilities of mammals and birds have been studied both in natural conditions and in controlled laboratory conditions using a variety of approaches. During the last decade this ability was also investigated in some fish species. Here we reviewed the main methods used to study this group, highlighting the strengths and weaknesses of each of the methods used. Fish have only been studied under laboratory conditions and among the methods used with other species, only two have been systematically used in fish-spontaneous choice tests and discrimination learning procedures. In the former case, the choice between two options is observed in a biologically relevant situation and the degree of preference for the larger/smaller group is taken as a measure of the capacity to discriminate the two quantities (e.g., two shoals differing in number). In discrimination learning tasks, fish are trained to select the larger or the smaller of two sets of abstract objects, typically two-dimensional geometric figures, using food or social companions as reward. Beyond methodological differences, what emerges from the literature is a substantial similarity of the numerical abilities of fish with those of other vertebrates studied. Copyright © 2017 Elsevier B.V. All rights reserved.

Grades of 43 Fish Species in Japan Based on IgE-binding Activity

Directory of Open Access Journals (Sweden)

Harumi Koyama

2006-01-01

Conclusions: A correlation was observed between IgE levels and expression of symptoms after fish ingestion. High consumption of salmon, tuna, scad (including saurel, skipper, yellowtail, sardine, bonita and mackerel in Japan might be the cause of the high IgE-binding activity of these species. The grades of fish species consumed widely in Japan are likely to be useful for nutritional instruction of fish-allergic patients.

By the Light of the Moon: North Pacific Dolphins Optimize Foraging with the Lunar Cycle

Science.gov (United States)

Simonis, Anne Elizabeth

The influence of the lunar cycle on dolphin foraging behavior was investigated in the productive, southern California Current Ecosystem and the oligotrophic Hawaiian Archipelago. Passive acoustic recordings from 2009 to 2015 were analyzed to document the presence of echolocation from four dolphin species that demonstrate distinct foraging preferences and diving abilities. Visual observations of dolphins, cloud coverage, commercial landings of market squid (Doryteuthis opalescens) and acoustic backscatter of fish were also considered in the Southern California Bight. The temporal variability of echolocation is described from daily to annual timescales, with emphasis on the lunar cycle as an established behavioral driver for potential dolphin prey. For dolphins that foraged at night, the presence of echolocation was reduced during nights of the full moon and during times of night that the moon was present in the night sky. In the Southern California Bight, echolocation activity was reduced for both shallow- diving common dolphins (Delphinus delphis) and deeper-diving Risso's dolphins (Grampus griseus) during times of increased illumination. Seasonal differences in acoustic behavior for both species suggest a geographic shift in dolphin populations, shoaling scattering layers or prey switching behavior during warm months, whereby dolphins target prey that do not vertically migrate. In the Hawaiian Archipelago, deep-diving short-finned pilot whales (Globicephala macrorhynchus) and shallow-diving false killer whales (Pseudorca crassidens) also showed reduced echolocation behavior during periods of increased lunar illumination. In contrast to nocturnal foraging in the northwestern Hawaiian Islands, false killer whales in the main Hawaiian Islands mainly foraged during the day and the lunar cycle showed little influence on their nocturnal acoustic behavior. Different temporal patterns in false killer whale acoustic behavior between the main and northwestern Hawaiian

Artificial marine habitats favour a single fish species on a long-term scale: the dominance of Boops boops around off-shore fish cages

Directory of Open Access Journals (Sweden)

Rodrigo Riera

2014-12-01

Full Text Available Off-shore fish cages are new artificial habitats that can affect pelagic fish assemblages and constitute an important food source for wild fish assemblages. This aggregation has noticeable ecological consequences in cage areas in impoverished ecosystems such as those in the Canary archipelago (NE Atlantic Ocean. However, this new habitat could be dominated by a single species, reducing its positive ecological effects. Wild fish assemblages associated with an off-shore fish lease on the northeastern coast of Tenerife (Canary Islands were sampled for six years. Fish assemblage structure beneath fish cages and at controls ( > 500 m from cages differed significantly between locations, with 13 times greater abundance at cage locations. These differences were mainly explained by the dominance of bogue (Boops boops around fish cages. This trend was consistent in the long-term throughout the study period (2004-2009, affecting local fisheries. The presence of fish cages significantly altered wild fish assemblages in the study area, enhancing mainly biomass and abundance of one species, bogue, and causing shifts in species composition.

[Dietary composition and food competition of six main fish species in rocky reef habitat off Gouqi Island].

Science.gov (United States)

Wang, Kai; Zhang, Shou-Yu; Wang, Zhen-Hua; Zhao, Jing; Xu, Min; Lin, Jun

2012-02-01

Based on the monthly investigation data of fish resources in the rocky reef habitat off Gouqi Island from March 2009 to February 2010, this paper studied the dietary composition of three native fish species (Sebasticus marmoratus, Hexagrammos otakii and Hexagrammos agrammus) and three non-native fish species (Lateolabrax japonica, Nibea albiflora and Larimichthys polyactis). The analysis of gut content indicated that the main prey items of these six dominant fish species were Caprellidae, Gammaridea, juvenile S. marmoratus, Engraulis japonicas and Acetes chinensis and the dietary composition of each of the 6 fish species had obvious seasonal variation. There was an intense food competition between native species H. otakii and H. agrammus in autumn, between non-native species N. albiflora and L. polyactis in summer, between non-native species N. albiflora and native species S. marmoratus in autumn, and between non-native species N. albiflora and native species H. otakii in winter. It was suggested the non-native species N. albiflora was the key species in the food competition among the six dominant fish species in this rocky reef habitat, and thus the feeding behaviors of these six fish species could have definite effects on the resource capacity of juvenile S. marmoratus.

Endangered fish species of the world - a review

OpenAIRE

Radu Hărşan; I. Valentin Petrescu-Mag

2008-01-01

The present paper summarizes a large part of the endangered and critically endangered fish species of the world. The list was constructed using the comprehensive IUCN Red List of Threatened Species (available in December 2008) and the well elaborated FISHBASE (available on the official website, in 2008) for taxonomy and accepted scientific names of the species. To these two important sources, many scientific papers and communications were added when recent and useful reports were found. Howev...

Differential regulation of the foraging gene associated with task behaviors in harvester ants

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Kleeman Lindsay

2011-08-01

Full Text Available Abstract Background The division of labor in social insect colonies involves transitions by workers from one task to another and is critical to the organization and ecological success of colonies. The differential regulation of genetic pathways is likely to be a key mechanism involved in plasticity of social insect task behavior. One of the few pathways implicated in social organization involves the cGMP-activated protein kinase gene, foraging, a gene associated with foraging behavior in social insect species. The association of the foraging gene with behavior is conserved across diverse species, but the observed expression patterns and proposed functions of this gene vary across taxa. We compared the protein sequence of foraging across social insects and explored whether the differential regulation of this gene is associated with task behaviors in the harvester ant, Pogonomyrmex occidentalis. Results Phylogenetic analysis of the coding region of the foraging gene reveals considerable conservation in protein sequence across insects, particularly among hymenopteran species. The absence of amino acid variation in key active and binding sites suggests that differences in behaviors associated with this gene among species may be the result of changes in gene expression rather than gene divergence. Using real time qPCR analyses with a harvester ant ortholog to foraging (Pofor, we found that the brains of harvester ant foragers have a daily fluctuation in expression of foraging with mRNA levels peaking at midday. In contrast, young workers inside the nest have low levels of Pofor mRNA with no evidence of daily fluctuations in expression. As a result, the association of foraging expression with task behavior within a species changes depending on the time of day the individuals are sampled. Conclusions The amino acid protein sequence of foraging is highly conserved across social insects. Differences in foraging behaviors associated with this gene among

Fish stomach contents in benthic macroinvertebrate assemblage assessments

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TH. Tupinambás

Full Text Available The choice of sampling gears to assess benthic macroinvertebrate communities depends on environmental characteristics, study objectives, and cost effectiveness. Because of the high foraging capacity and diverse habitats and behaviors of benthophagous fishes, their stomach contents may offer a useful sampling tool in studies of benthic macroinvertebrates, especially in large, deep, fast rivers that are difficult to sample with traditional sediment sampling gear. Our objective was to compare the benthic macroinvertebrate communities sampled from sediments with those sampled from fish stomachs. We collected benthic macroinvertebrates and fish from three different habitat types (backwater, beach, riffle in the wet season, drying season, and dry season along a single reach of the Grande River (Paraná River Basin, southeast Brazil. We sampled sediments through use of a Petersen dredge (total of 216 grabs and used gill nets to sample fish (total of 36 samples. We analyzed the stomach contents of three commonly occurring benthophagous fish species (Eigenmannia virescens, Iheringichthys labrosus, Leporinus amblyrhynchus. Chironomids dominated in both sampling methods. Macroinvertebrate taxonomic composition and abundances from fish stomachs differed from those from sediment samples, but less so from riffles than from backwater and beach habitats. Macroinvertebrate taxa from E. virescens stomachs were more strongly correlated with sediment samples from all three habitats than were those from the other two species. The species accumulation curves and higher mean dispersion values, compared with with sediment samples suggest that E. virescens is more efficient than sediment samples and the other fish studied at collecting benthic taxa. We conclude that by analyzing the stomach contents of benthophagous fishes it is possible to assess important characteristics of benthic communities (dispersion, taxonomic composition and diversity. This is especially true

Distribution and transmission of the highly pathogenic parasite Ichthyophonus in marine fishes of Alaska

Science.gov (United States)

Gregg, Jacob L.; Grady, Courtney A.; Thompson, Rachel L.; Purcell, Maureen K.; Friedman, Carolyn S.; Hershberger, Paul K.

2014-01-01

A combination of field surveys, molecular typing, and laboratory experiments were used to improve our understanding of the distribution and transmission mechanisms of fish parasites in the genus Ichthyophonus. Ichthyophonus spp. infections were detected from the Bering Sea to the coast of Oregon in 10 of 13 host species surveyed. Sequences of rDNA extracted from these isolates indicate that a ubiquitous Ichthyophonus type occurs in the NE Pacific Ocean and Bering Sea and accounts for nearly all the infections encountered. Among NE Pacific isolates, only parasites from yellowtail rockfish and Puget Sound rockfish varied at the DNA locus examined. These data suggest that a single source population of these parasites is available to fishes in diverse niches across a wide geographic range. A direct life cycle within a common forage species could account for the relatively low parasite diversity we encountered. In the laboratory we tested the hypothesis that waterborne transmission occurs among Pacific herring, a common NE Pacific forage species. No horizontal transmission occurred during a four-month cohabitation experiment involving infected herring and conspecific sentinels. The complete life cycle of Ichthyophonus spp. is not known, but these results suggest that system-wide processes maintain a relatively homogenous parasite population.

Seasonal variation of assemblage and feeding guild structure of fish species in a boreal tidal basin

Science.gov (United States)

Kellnreitner, Florian; Pockberger, Moritz; Asmus, Harald

2012-08-01

Species composition, abundance, feeding relationships and guild structure of the fish assemblage in the Sylt-Rømø bight, a tidal basin in the northern Wadden Sea, were investigated to show seasonal differences and the importance of functional groups in this area. The tidal flats and in shallow subtidal areas were sampled using a beach seine and a bottom trawl net was used for deeper subtidal areas and tidal gullies. Species richness of fish was highest in summer where 26 species were caught, while the lowest richness was recorded in winter (17 species). Clear differences in species richness and abundance were found between shallow areas and deeper parts of the bight. Clupea harengus and Ammodytes tobianus were the most abundant species in deeper areas, while Pomatoschistus microps and Pomatoschistus minutus dominated shallower waters. Gut contents of 27 fish species were identified and the guild structure analyzed by UPGMA clustering of niche overlaps. Calanoid copepods (19.9%), Crangon crangon (18.2%) and mysid shrimps (8.4%) were the most abundant prey items of all fish species combined. Seven feeding guilds were present in the fall and winter, and eight and six in spring and summer, respectively. Fish feeding on calanoid copepods and C. crangon were present year round, whereas the occurrence of other guilds varied between seasons. Species composition of prey changed through seasons and, for some fish species, even the feeding mode itself varied with season. Most noticeable, 11 fish species changed guilds between seasons. We found a convergence in summer towards abundant prey items, whereas in winter diet overlap was lower. This is the first investigation of guild structure of almost all fish species present in a Wadden Sea area, and shows that consideration of seasonal differences is essential when determining feeding relationships of fish in temperate areas.

Fish species composition, diversity and abundance of the lower New ...

African Journals Online (AJOL)

A thirteen-week investigation to determine the fish species composition, diversity and abundance of the Lower New Calabar River, in Rivers State, aimed at providing information on the fish stock and their status for documentation, knowledge improvement, and development of conservation and management strategies was ...

75 FR 50746 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2010-08-17

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... is intended to increase knowledge of species listed under the Endangered Species Act (ESA) and to..., Chief, Endangered Species Division, Office of Protected Resources, National Marine Fisheries Service...

Na and K Levels in forage species from the communal grazing lands during the dry season at some locations in the Northern Region of Ghana

International Nuclear Information System (INIS)

Gomda, Y.M.; Osae, E.K.; Akaho, E.H.K.; Fianu, F.K.; Karbo, N.

1999-04-01

Forage species were taken, during the dry season, from five districts in the Northern Region of Ghana and analysed for Na and K using the Neutron Activation Analysis (NAA) technique. The Na level varied in plants species as well as location. The level ranged between 0.049 g/kg DM and 1.14 g/kg DM. This was found to be inadequate for the animals and require supplementation during the dry season. Potassium level in the forage species was between 7.8 to 91.3g/kg DM and appeared to be adequate for the grazing animals. (author)

Prevalence of salmonella species in fishes and its control using irradiation

International Nuclear Information System (INIS)

Mohamed, W. S.

2010-01-01

The prevalence of Salmonella species infecting frozen Tilapia fish fillets and whole fishes was determined, during the summer seasons of years 2006 and 2007.Elimination of Salmonella species in Tilapia fishes with different doses of γ-rays was investigated. Doses of 1, 2, 3, 3.5, 5, 4 and 5 kGy were used to find out the least dose that will be sufficient to eliminate the pathogen from the examined samples. Two hundred fish fillet samples and 200 whole fishes were subjected for bacteriological examination for the incidence of Salmonella infection. Out of them 19 fillets and 8 whole fishes were infected with the pathogen in a percentage of 9.5 % and 4 % respectively. The serological determination detected the infection with Salmonella typhimurium in all the affected samples. A dose of 3.5 kGy γ-rays was determined to be the least appropriate dose for elimination of Salmonella typhimurium from Tilapia fishes. The best appearance characteristics were obtained at 3.5 kGy of γ-irradiation. There was a gradual decrease in the count of the micro-organism as the dose of irradiation increased (linear regression). So a dose of 3.5 kGy of γ-irradiation is recommended for healthy, good looking and economic fishes for public health benefits.

Spawning and nursery habitats of neotropical fish species in the tributaries of a regulated river

Science.gov (United States)

Makrakis, Maristela Cavicchioli; da Silva, Patrícia S.; Makrakis, Sergio; de Lima, Ariane F.; de Assumpção, Lucileine; de Paula, Salete; Miranda, Leandro E.; Dias, João Henrique Pinheiro

2012-01-01

This chapter provides information on ontogenetic patterns of neotropical fish species distribution in tributaries (Verde, Pardo, Anhanduí, and Aguapeí rivers) of the Porto Primavera Reservoir, in the heavily dammed Paraná River, Brazil, identifying key spawning and nursery habitats. Samplings were conducted monthly in the main channel of rivers and in marginal lagoons from October through March during three consecutive spawning seasons in 2007-2010. Most species spawn in December especially in Verde River. Main river channels are spawning habitats and marginal lagoons are nursery areas for most fish, mainly for migratory species. The tributaries have high diversity of larvae species: a total of 56 taxa representing 21 families, dominated by Characidae. Sedentary species without parental care are more abundant (45.7%), and many long-distance migratory fish species are present (17.4%). Migrators included Prochilodus lineatus, Rhaphiodon vulpinus, Hemisorubim platyrhynchos, Pimelodus maculatus, Pseudoplatystoma corruscans, Sorubim lima, two threatened migratory species: Salminus brasiliensis and Zungaro jahu, and one endangered migratory species: Brycon orbignyanus. Most of these migratory species are vital to commercial and recreational fishing, and their stocks have decreased drastically in the last decades, attributed to habitat alteration, especially impoundments. The fish ladder at Porto Primavera Dam appears to be playing an important role in re-establishing longitudinal connectivity among critical habitats, allowing ascent to migratory fish species, and thus access to upstream reaches and tributaries. Establishment of Permanent Conservation Units in tributaries can help preserve habitats identified as essential spawning and nursery areas, and can be key to the maintenance and conservation of the fish species in the Paraná River basin.

Thermal tolerance of some important fish species from Kali river, Karnataka

International Nuclear Information System (INIS)

Ayyappan, S.; Pal, A.K.; Das, T.; Bagchi, S.; Dalvi, R.

2002-01-01

Fish catch composition of Kadra reservoir at three different sampling points, viz., end of the hot water discharge channel of the nuclear power station i.e. Mixing Zone (Mz), 500 meters away from mixing zone at Hartuga village (Hv) and 15 km away from mixing zone at Virgae village (Vv) and thermal tolerance studies viz., Critical temperature maximum (CTmax), Critical temperature minimum (CTmin), oxygen consumption rates of different fish were determined for acclimation temperatures of 26, 31, 33 and 36 degC. The enzyme activities viz., Acetylcholine esterase (AchE), Malate dehydrogenase (MDH), Lactate dehydrogenase (LDH), Aspartate amino transferase (AST), Alanine amino transferase (ALT), Acid phosphatase (ACP) and Alkaline phosphatase (ALP) were studied in liver, gill, brain and muscle of Puntius ticto and Rasbora elanga at different acclimatized temperatures in a constant thermostatic aquarium. The fish catch composition varied at different sampling points. The predominant fish species identified from the three sampling points were Etroplus suratensis, Puntius sarana, Rasbora elanga, Chela argenta, Chela sardinella, Danio aequipinnatus at Mixing zone, Etroplus suratensis, Channa striatus, Channa micropeltes, Channa marulius, Ompok bimaculatus, Ompok malabarichus, Horabagrus brachysoma, Nemacheilus Sp., Mastacymbelus armastus at Hartuga village and Puntiu ticto, Labeo calbasu, Citrine cirrhosa, Ambasis dayi, Hemiramphus schlosseri, Periopthalmus limbatus at Virgae village. CT max varied from 38.5 degC to 42.6 degC in different fish species. Oxygen consumption rate of all species of fishes increased with increase in water temperature but magnitudes of increase was different in different species. The enzymatic activities increased concomitantly with increase in temperature up to 33 degC and followed a decrease at 36 degC. (author)

Multi-scale approach for predicting fish species distributions across coral reef seascapes.

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Simon J Pittman

Full Text Available Two of the major limitations to effective management of coral reef ecosystems are a lack of information on the spatial distribution of marine species and a paucity of data on the interacting environmental variables that drive distributional patterns. Advances in marine remote sensing, together with the novel integration of landscape ecology and advanced niche modelling techniques provide an unprecedented opportunity to reliably model and map marine species distributions across many kilometres of coral reef ecosystems. We developed a multi-scale approach using three-dimensional seafloor morphology and across-shelf location to predict spatial distributions for five common Caribbean fish species. Seascape topography was quantified from high resolution bathymetry at five spatial scales (5-300 m radii surrounding fish survey sites. Model performance and map accuracy was assessed for two high performing machine-learning algorithms: Boosted Regression Trees (BRT and Maximum Entropy Species Distribution Modelling (MaxEnt. The three most important predictors were geographical location across the shelf, followed by a measure of topographic complexity. Predictor contribution differed among species, yet rarely changed across spatial scales. BRT provided 'outstanding' model predictions (AUC = >0.9 for three of five fish species. MaxEnt provided 'outstanding' model predictions for two of five species, with the remaining three models considered 'excellent' (AUC = 0.8-0.9. In contrast, MaxEnt spatial predictions were markedly more accurate (92% map accuracy than BRT (68% map accuracy. We demonstrate that reliable spatial predictions for a range of key fish species can be achieved by modelling the interaction between the geographical location across the shelf and the topographic heterogeneity of seafloor structure. This multi-scale, analytic approach is an important new cost-effective tool to accurately delineate essential fish habitat and support

78 FR 60254 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2013-10-01

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... regulations governing listed fish and wildlife permits (50 CFR 222-226). NMFS issues permits based on findings... conduct water quality, [[Page 60255

7 CFR 457.117 - Forage production crop insurance provisions.

Science.gov (United States)

2010-01-01

... INSURANCE CORPORATION, DEPARTMENT OF AGRICULTURE COMMON CROP INSURANCE REGULATIONS § 457.117 Forage..., or a mixture thereof, or other species as shown in the Actuarial Documents. Harvest—Removal of forage... different price elections by type, in which case you may select one price election for each forage type...

Individual foraging strategies reveal niche overlap between endangered galapagos pinnipeds.

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Stella Villegas-Amtmann

Full Text Available Most competition studies between species are conducted from a population-level approach. Few studies have examined inter-specific competition in conjunction with intra-specific competition, with an individual-based approach. To our knowledge, none has been conducted on marine top predators. Sympatric Galapagos fur seals (Arctocephalus galapagoensis and sea lions (Zalophus wollebaeki share similar geographic habitats and potentially compete. We studied their foraging niche overlap at Cabo Douglas, Fernandina Island from simultaneously collected dive and movement data to examine spatial and temporal inter- and intra-specific competition. Sea lions exhibited 3 foraging strategies (shallow, intermediate and deep indicating intra-specific competition. Fur seals exhibited one foraging strategy, diving predominantly at night, between 0-80 m depth and mostly at 19-22 h. Most sea lion dives also occurred at night (63%, between 0-40 m, within fur seals' diving depth range. 34% of sea lions night dives occurred at 19-22 h, when fur seals dived the most, but most of them occurred at dawn and dusk, when fur seals exhibited the least amount of dives. Fur seals and sea lions foraging behavior overlapped at 19 and 21 h between 0-30 m depths. Sea lions from the deep diving strategy exhibited the greatest foraging overlap with fur seals, in time (19 h, depth during overlapping time (21-24 m, and foraging range (37.7%. Fur seals foraging range was larger. Cabo Douglas northwest coastal area, region of highest diving density, is a foraging "hot spot" for both species. Fur seals and sea lions foraging niche overlap occurred, but segregation also occurred; fur seals primarily dived at night, while sea lions exhibited night and day diving. Both species exploited depths and areas exclusive to their species. Niche breadth generally increases with environmental uncertainty and decreased productivity. Potential competition between these species could be greater during

[Species composition, diversity and density of small fishes in two different habitats in Niushan Lake].

Science.gov (United States)

Ye, Shao-Wen; Li, Zhong-Jie; Cao, Wen-Xuan

2007-07-01

This paper studied the spatial distribution of small fishes in a shallow macrophytic lake, Niushan Lake in spring 2003, and its relations with habitat heterogeneity. Based on the macrophyte cover condition, distance from lake shore and water depth, two representative habitat types in the lake were selected. Habitat A was near the shore with dense submersed macrophyte, while habitat B was far from the shore with sparse submersed macrophyte. Small fishes were sampled quantitatively by block net (180 m2), and their densities within the net area were estimated by multiple mark-recapture or Zippin's removal method. The results showed that there were some differences in species composition, biodiversity measurement, and estimated density of small fishes between the two habitats: 1) the catches in habitat A consisted of 14 small fish species from 5 families, among which, benthopelagic species Rhodeus ocellatus, Paracheilognathus imberbis and Pseudorasbora parva were considered as dominant species, while those in habitat B consisted of 9 small fish species from 3 families, among which, bottom species Rhinogobius giurinus and Micropercops swinhonis were dominant; 2) the Bray-Curtis index between the two small fish communities was 0.222, reflecting their low structure similarity, and no significant difference was observed between their rank/ abundance distributions, both of which belonged to log series distribution; 3) the total density of 9 major species in habitat A was 8.71 ind x m(-2), while that of 5 major species in habitat B was only 3.54 ind x m(-2). The fact that the spatial distribution of the small fishes differed with habitats might be related to their habitat need for escaping predators, feeding, and breeding, and thus, aquatic macrophyte habitat should be of significance in the rational exploitation of small fish resources as well as the conservation of fish resource diversity.

77 FR 75611 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2012-12-21

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... promulgated under the Endangered Species Act (ESA). The plans specify the propagation of five species of... 10, 2000). Dated: December 17, 2012. Angela Somma, Chief, Endangered Species Division, Office of...

75 FR 23671 - Endangered and Threatened Species; Take of Anadromous Fish; Research Permit Applications

Science.gov (United States)

2010-05-04

... and Threatened Species; Take of Anadromous Fish; Research Permit Applications AGENCY: National Marine... listed under the Endangered Species Act (ESA) and to help guide management and conservation efforts. The... capture, handle, and release juvenile fish from all the species covered by this notice. They would also...

Quantifying tolerance indicator values for common stream fish species of the United States

Science.gov (United States)

Meador, M.R.; Carlisle, D.M.

2007-01-01

The classification of fish species tolerance to environmental disturbance is often used as a means to assess ecosystem conditions. Its use, however, may be problematic because the approach to tolerance classification is based on subjective judgment. We analyzed fish and physicochemical data from 773 stream sites collected as part of the U.S. Geological Survey's National Water-Quality Assessment Program to calculate tolerance indicator values for 10 physicochemical variables using weighted averaging. Tolerance indicator values (TIVs) for ammonia, chloride, dissolved oxygen, nitrite plus nitrate, pH, phosphorus, specific conductance, sulfate, suspended sediment, and water temperature were calculated for 105 common fish species of the United States. Tolerance indicator values for specific conductance and sulfate were correlated (rho = 0.87), and thus, fish species may be co-tolerant to these water-quality variables. We integrated TIVs for each species into an overall tolerance classification for comparisons with judgment-based tolerance classifications. Principal components analysis indicated that the distinction between tolerant and intolerant classifications was determined largely by tolerance to suspended sediment, specific conductance, chloride, and total phosphorus. Factors such as water temperature, dissolved oxygen, and pH may not be as important in distinguishing between tolerant and intolerant classifications, but may help to segregate species classified as moderate. Empirically derived tolerance classifications were 58.8% in agreement with judgment-derived tolerance classifications. Canonical discriminant analysis revealed that few TIVs, primarily chloride, could discriminate among judgment-derived tolerance classifications of tolerant, moderate, and intolerant. To our knowledge, this is the first empirically based understanding of fish species tolerance for stream fishes in the United States.

The differentiation of common species in a coral-reef fish assemblage for recreational scuba diving.

Science.gov (United States)

Chen, Tsen-Chien; Ho, Cheng-Tze; Jan, Rong-Quen

2016-01-01

Recreational scuba diving is a popular activity of the coral reef tourism industry. In practice, local diving centers recommend interesting sites to help visiting divers make their plans. Fish are among the major attractions, but they need to be listed with care because the temporal occurrence of a fish species is difficult to predict. To address this issue, we propose methods to categorize each fish species based on its long-term occurrence and likelihood of being seen. We assume that there are K categories of occurrence of a fish assemblage and propose two methods [an arithmetic-mean method (AM) and a geometric-mean method (GM)] to define the range of species in each category. Experiments based on long term datasets collected at three underwater stations (each having 51-53 surveys and totals of 262-284 fish species) on coral reefs in southern Taiwan showed that when K = 4 (rare, occasional, frequent and common categories), 11-14 species were concurrently assigned to the common category by AM for data sets based on surveys 10, 15, 20, 25, 30, 35, 40, 45, or 51-53 in contrast to the 18-26 species assigned as common by GM. If a similarity index of 0.7 (compared to the total pool of fish species) was the minimum threshold for diver satisfaction, then 20-25 surveys provide sufficient data for listing the common species at a given dive spot. Common fish species, are the most temporally stable, and thus are more appropriate for attracting divers. These can be effectively differentiated by either AM or GM with at least 25 surveys. We suggest regular updating of each fish's category through periodic surveys to assure the accuracy of information at a particular dive spot.

Climate, invasive species and land use drive population dynamics of a cold-water specialist

Science.gov (United States)

Kovach, Ryan P.; Al-Chokhachy, Robert K.; Whited, Diane C.; Schmetterling, David A.; Dux, Andrew M; Muhlfeld, Clint C.

2017-01-01

Climate change is an additional stressor in a complex suite of threats facing freshwater biodiversity, particularly for cold-water fishes. Research addressing the consequences of climate change on cold-water fish has generally focused on temperature limits defining spatial distributions, largely ignoring how climatic variation influences population dynamics in the context of other existing stressors.We used long-term data from 92 populations of bull trout Salvelinus confluentus – one of North America's most cold-adapted fishes – to quantify additive and interactive effects of climate, invasive species and land use on population dynamics (abundance, variability and growth rate).Populations were generally depressed, more variable and declining where spawning and rearing stream habitat was limited, invasive species and land use were prevalent and stream temperatures were highest. Increasing stream temperature acted additively and independently, whereas land use and invasive species had additive and interactive effects (i.e. the impact of one stressor depended on exposure to the other stressor).Most (58%–78%) of the explained variation in population dynamics was attributed to the presence of invasive species, differences in life history and management actions in foraging habitats in rivers, lakes and reservoirs. Although invasive fishes had strong negative effects on populations in foraging habitats, proactive control programmes appeared to effectively temper their negative impact.Synthesis and applications. Long-term demographic data emphasize that climate warming will exacerbate imperilment of cold-water specialists like bull trout, yet other stressors – especially invasive fishes – are immediate threats that can be addressed by proactive management actions. Therefore, climate-adaptation strategies for freshwater biodiversity should consider existing abiotic and biotic stressors, some of which provide potential and realized opportunity for conservation

Identification And Study Of Fish Species In Karkheh River (Iran

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Khoshnood Zahra

2014-10-01

Full Text Available For the investigation of fish from Karkheh River, sampling was performed in a six month period from August 2014 to January 2015. All sampled fish were measured for biometrical values (length and weight. General results of the sampling and identification of the fish showed the presence of 14 species from four fish families of Cyprinidae, Mugilidae, Siluridae and Macrostomidae, out of which the Cyprinidae family were the most frequent of the sampled fish. The most significant abundance belongs to Cyprinus carpio. The fish sampled in the present study were: Liza abu, Ctenopharyngodon idella, Barbel sp., Cyprinion macrostomum, Barbus sharpeyi, Hypophthalmichthys molitrix, Barbus esocinus, Barbus barbulus, Barbus luteus, Barbus grypus, Cyprinus carpio, Silurus triostegus, Mastacembelus circumcinctus and Capoeta trutta. Shannon Index results showed that the fish biodiversity in the studyed area followed a uniform path and additionally that the considered area at the studied period has good fish biodiversity.

Listeria species in retail smoked fish at Jos, Nigeria | Chukwu ...

African Journals Online (AJOL)

The prevalence of Listeria species in 65 samples of smoked fish at the retail markets in Jos, Nigeria, is reported. The experimental samples which included 30 catfish (Clarias species) and 35 Tilapia were screened for Listeria monocytogenes and other Listeria species using a two-step enrichment method. Total Listeria ...

Checklist of non-indigenous fish species of the River Danube

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Zorić Katarina

2014-01-01

Full Text Available Twenty non-indigenous fish species were recorded in the Danube River. The manner of their introduction, vectors, pathways, as well as invasive status are discussed. The major modes of introduction and translocation were found to be aquaculture and fish stocking. The main environmental consequences of the spread of alien fish are related to changes in the structure and functioning of the fish community and to the introduction of non-indigenous parasites. [Projekat Ministarstva nauke Republike Srbije, br. ON 173025, TR 37009 and III 43002 and European Commission 6th Framework Program: Integrated Project ALARM (contract GOCE-CT-2003-506675

Use of fish parasite species richness indices in analyzing anthropogenically impacted coastal marine ecosystems

Science.gov (United States)

Dzikowski, R.; Paperna, I.; Diamant, A.

2003-10-01

The diversity of fish parasite life history strategies makes these species sensitive bioindicators of aquatic ecosystem health. While monoxenous (single-host) species may persist in highly perturbed, extreme environments, this is not necessarily true for heteroxenous (multiple-host) species. As many parasites possess complex life cycles and are transmitted through a chain of host species, their dependency on the latter to complete their life cycles renders them sensitive to perturbed environments. In the present study, parasite communities of grey mullet Liza aurata and Liza ramada (Mugilidae) were investigated at two Mediterranean coastal sites in northern Israel: the highly polluted Kishon Harbor (KH) and the relatively unspoiled reference site, Ma'agan Michael (MM). Both are estuarine sites in which grey mullet are one of the most common fish species. The results indicate that fish at the polluted site had significantly less trematode metacercariae than fish at the reference site. Heteroxenous gut helminths were completely absent at the polluted sampling site. Consequently, KH fish displayed lower mean parasite species richness. At the same time, KH fish mean monoxenous parasite richness was higher, although the prevalence of different monoxenous taxa was variable. Copepods had an increased prevalence while monogenean prevalence was significantly reduced at the polluted site. This variability may be attributed to the differential susceptibility of the parasites to the toxicity of different pollutants, their concentration, the exposure time and possible synergistic effects. In this study, we used the cumulative species curve model that extrapolates "true" species richness of a given habitat as a function of increasing sample size. We considered the heteroxenous and monoxenous species separately for each site, and comparison of curves yielded significant results. It is proposed to employ this approach, originally developed for estimating the "true" parasite

Freshwater fishes in Greek lakes: Species richness and body size patterns

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Anthi Oikonomou

2015-11-01

Full Text Available Freshwater ecosystems are widely recognised as hotspots of biodiversity and endemism; thus they are of great value for conservation biogeography. Amongst the taxa found in freshwater ecosystems, fish are the ideal biological model for testing biogeographical patterns and have often been used in large-scale ecological and biogeographical analyses. Lakes of Greece provide a unique opportunity to test biogeographical theories, however, biogeographical studies in Greece at broader, regional, scales, based on the distribution of freshwater species, species richness and endemism, are scarce. The aim of the current study is to test the effect of key environmental factors and spatial variables on species richness of lacustrine fishes and to test their effect on species’ size distributions. We assembled datasets of species richness and body size and environmental (predictor factors for 13 Greek lakes. Model selection procedures revealed that fish species richness increased with ecosystem area and decreased with altitude. In addition, our results showed that latitude per se is a good predictor of body size. Indeed, the mean size of lacustrine communities in the northern and southern lake ecosystems differed significantly. These patterns reflect the biogeographical history of these areas and highlight the crucial role connectivity plays in communities’ species composition.

Alien fish species in upper Sakarya River and their distribution ...

African Journals Online (AJOL)

However, the fact that the flood plains have been reclaimed, excessive hunting, destruction of the ecologic balance and invasion of the area by the alien fish species threatens the fish stocks in Sakarya River. In this study, we aimed to determine the dispersion area of Carassius gibelio (Bloch, 1782), Oreochromis niloticus ...

The Feeding Behaviour of Fish from the Upper Lake Baikal Watershed of the Eroo River in Mongolia

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Sudeep Chandra

2005-06-01

Full Text Available The upper Selenge watershed in Mongolia is home to some of the world’s unique fish species. In this study we determined the feeding behaviour of selected fish species collected from the main stream of the Eroo River and two of its upstream tributaries, the Sharlan and Bar Chuluut rivers. Using stable isotope (carbon and nitrogen measurements combined with qualitative and literature information, we determined that taimen ( Hucho taimen and pike ( Esox luceus were the top predators in the Eroo River. They received a substantial amount of their energy from other fish species as well as terrestrial derived sources. Percent presence of biota in lenok ( Brachymystax lenok stomachs demonstrated they eat zoobenthos, invertebrates, fish, and terrestrial rodents. Siberian dace ( Leuciscus baicalensis , a small forage fish collected from the Sharlan and Bar Chuluut rivers demonstrate these fish eat periphyton, zoobenthos and terrestrial invertebrates. In the Bar Chuluut tributary, lenok eat a combination of foods including zoobenthos and other fish species, while arctic grayling ( Thymallus arcticus fed primarily on zoobenthos. Percent frequency analysis showed the two game fish species collected from the Bar Chuluut tributary fed primarily on zoobenthos (85 % for lenok and 80 % for grayling, with 28 families and 10 orders represented in their stomachs. Interviews with families suggested local people fish for a variety of species and that there has been a decline in the catch of taimen and sturgeon ( Acipenser baeri baicalensis over time. Since fishing was poor below highly disturbed areas (e.g. mine sites, local people fished above mine locations or in areas least impacted by these anthropogenic impacts.

The contribution of migratory mesopelagic fishes to neuston fish assemblages across the Atlantic, Indian and Pacific Oceans

KAUST Repository

Olivar, M. Pilar

2015-08-27

Surface waters are an attractive foraging ground for small fish in the open ocean. This study aims to determine the importance of vertically migrating species in the neuston of oceanic waters across the Atlantic, Indian and Pacific Oceans and to ascertain the influence of environmental variables on their distribution patterns. Neustonic fish assemblages were primarily controlled by light. They were dominated by late-larvae and juveniles of Exocoetidae, Hemiramphidae and Scomberesocidae during the day. At night, the vertical migration of mesopelagic species changed the dominance pattern in favour of Myctophidae and Scomberesocidae. The neustonic families\\' distribution was primarily related to sea surface temperatures, whereas environmental variables at deeper layers were related to mesopelagic migrating families. Canonical correspondence analysis showed a low but statistically significant contribution of several environmental variables to myctophid species composition (10%), with minimum oxygen concentrations ranking first in variance explanation followed by maximum fluorescence, sea surface temperature and 400-m temperature. Spatial autocorrelation also explained 17% of the variance, indicating the influence of other factors such as historical, demographic and dispersal constraints. The low number of myctophid species in the North Pacific Equatorial Countercurrent appears to be related to the low oxygen concentrations observed in this province.

The contribution of migratory mesopelagic fishes to neuston fish assemblages across the Atlantic, Indian and Pacific Oceans

KAUST Repository

Olivar, M. Pilar; Gonzá lez-Gordillo, J. Ignacio; Salat, Jordi; Chust, Guillem; Có zar, André s; Herná ndez-Leó n, Santiago; Ferná ndez de Puelles, M. Luz; Irigoien, Xabier

2015-01-01

Surface waters are an attractive foraging ground for small fish in the open ocean. This study aims to determine the importance of vertically migrating species in the neuston of oceanic waters across the Atlantic, Indian and Pacific Oceans and to ascertain the influence of environmental variables on their distribution patterns. Neustonic fish assemblages were primarily controlled by light. They were dominated by late-larvae and juveniles of Exocoetidae, Hemiramphidae and Scomberesocidae during the day. At night, the vertical migration of mesopelagic species changed the dominance pattern in favour of Myctophidae and Scomberesocidae. The neustonic families' distribution was primarily related to sea surface temperatures, whereas environmental variables at deeper layers were related to mesopelagic migrating families. Canonical correspondence analysis showed a low but statistically significant contribution of several environmental variables to myctophid species composition (10%), with minimum oxygen concentrations ranking first in variance explanation followed by maximum fluorescence, sea surface temperature and 400-m temperature. Spatial autocorrelation also explained 17% of the variance, indicating the influence of other factors such as historical, demographic and dispersal constraints. The low number of myctophid species in the North Pacific Equatorial Countercurrent appears to be related to the low oxygen concentrations observed in this province.

78 FR 4836 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2013-01-23

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... steelhead promulgated under the Endangered Species Act (ESA). The plan specifies fishery management...: January 17, 2013. Angela Somma, Chief, Endangered Species Division, Office of Protected Resources...

76 FR 5338 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2011-01-31

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XA183 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... regulations (50 CFR parts 222-226) governing listed fish and wildlife permits. [[Page 5339

78 FR 77659 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2013-12-24

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XD040 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... NMFS regulations (50 CFR parts 222-226) governing listed fish and wildlife permits. [[Page 77660...

76 FR 6401 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2011-02-04

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XA110 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... and the Washington Department of Fish and Wildlife submitted to NMFS, pursuant to the protective...

77 FR 67796 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2012-11-14

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XC342 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... NMFS regulations governing listed fish and wildlife permits (50 CFR parts 222-226). Those individuals...

Na and K Levels in forage species from the communal grazing lands during the dry season at some locations in the Northern Region of Ghana

Energy Technology Data Exchange (ETDEWEB)

Gomda, Y M; Osae, E K; Akaho, E H.K. [Ghana Atomic Energy Commission, Accra (Ghana); Fianu, F K [University of Ghana, Legon, Accra, (Ghana); Karbo, N [Animal Research Institute, Nyankpala (Ghana)

1999-09-01

Forage species were taken, during the dry season, from five districts in the Northern Region of Ghana and analysed for Na and K using the Neutron Activation Analysis (NAA) technique. The Na level varied in plants species as well as location. The level ranged between 0.049 g/kg DM and 1.14 g/kg DM. This was found to be inadequate for the animals and require supplementation during the dry season. Potassium level in the forage species was between 7.8 to 91.3g/kg DM and appeared to be adequate for the grazing animals. (author) Technical report for year ending 1998. 2 tabs.; 18 refs.

Bumble bee nest abundance, foraging distance, and host-plant reproduction: implications for management and conservation.

Science.gov (United States)

Geib, Jennifer C; Strange, James P; Galenj, Candace

2015-04-01

Recent reports of global declines in pollinator species imply an urgent need to assess the abundance of native pollinators and density-dependent benefits for linked plants. In this study, we investigated (1) pollinator nest distributions and estimated colony abundances, (2) the relationship between abundances of foraging workers and the number of nests they represent, (3) pollinator foraging ranges, and (4) the relationship between pollinator abundance and plant reproduction. We examined these questions in an alpine ecosystem in the Colorado Rocky Mountains, focusing on four alpine bumble bee species (Bombus balteatus, B. flavifrons, B. bifarius, and B. sylvicola), and two host plants that differ in their degrees of pollinator specialization (Trifolium dasyphyllum and T. parryi). Using microsatellites, we found that estimated colony abundances among Bombus species ranged from ~18 to 78 colonies/0.01 km2. The long-tongued species B. balteatus was most common, especially high above treeline, but the subalpine species B. bifarius was unexpectedly abundant for this elevation range. Nests detected among sampled foragers of each species were correlated with the number of foragers caught. Foraging ranges were smaller than expected for all Bombus species, ranging from 25 to 110 m. Fruit set for the specialized plant, Trifolium parryi, was positively related to the abundance of its Bombus pollinator. In contrast, fruit set for the generalized plant, T. dasyphyllum, was related to abundance of all Bombus species. Because forager abundance was related to nest abundance of each Bombus species and was an equally effective predictor of plant fecundity, forager inventories are probably suitable for assessing the health of outcrossing plant populations. However, nest abundance, rather than forager abundance, better reflects demographic and genetic health in populations of eusocial pollinators such as bumble bees. Development of models incorporating the parameters we have measured

78 FR 4834 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2013-01-23

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XC444 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... species. Dated: January 16, 2013. Angela Somma, Chief, Endangered Species Division, Office of Protected...

77 FR 21084 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2012-04-09

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... under the Endangered Species Act (ESA). The proposed research program is intended to increase knowledge.... Lisa Manning, Acting Chief, Endangered Species Division, Office of Protected Resources, National Marine...

77 FR 34349 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2012-06-11

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... and steelhead under the Endangered Species Act (ESA). The HGMPs specify the operations of four... Somma, Chief, Endangered Species Division, Office of Protected Resources, National Marine Fisheries...

Species persistence: a re-look at the freshwater fish fauna of Chennai, India

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J.D.M. Knight

2010-11-01

Full Text Available Loss of habitat is one of the prime reasons for species extinction. It is generally established that certain classes of animals are more prone to extinction than others due to their restricted use of available habitats. Freshwater fish are among these sensitive animals. While local extinctions have rendered some species rare throughout their geographical range, many others have demonstrated higher levels of persistence. This paper focuses on a recent in-depth study of the primary freshwater fishes in and around Chennai. The study that spanned a period of two years recorded a total of 75 species of primary freshwater fish, of which 17 are new reports.

76 FR 5339 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2011-01-31

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XA182 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... are issued in accordance with and are subject to the ESA and NMFS regulations governing listed fish...

Prevalence of listeria, Aeromonas, and Vibrio species in fish used for human consumption in Turkey.

Science.gov (United States)

Yücel, Nihal; Balci, Senay

2010-02-01

A total of 78 raw retail fish samples from 30 freshwater and 48 marine fish were examined for the presence of Listeria, Aeromonas, and Vibrio species. The overall incidence of Listeria spp. was 30% in freshwater samples and 10.4% in marine fish samples. Listeria monocytogenes (44.5%) was the most commonly isolated species in freshwater fish, and Listeria murrayi (83.5%) was the most commonly isolated species in marine fish samples. Motile aeromonads were more common in marine fish samples (93.7%) than in freshwater fish samples (10%). Vibrio alginolyticus, Vibrio fluvialis, and Vibrio damsela were isolated only in marine fish samples, representing 40.9, 38.6, and 36.3% of Vibrio isolates, respectively. In freshwater and marine fish, the highest incidences of Listeria and Aeromonas were found in skin samples; the highest incidence of Vibrio in marine fish was found in gill samples. The location of Listeria spp. and L. monocytogenes in a fish was significantly different among freshwater fish. A high incidence of these bacterial pathogens was found in the brown trout (Salmo trutta) and horse mackerel (Trachurus trachurus). Handling of contaminated fish, cross-contamination, or eating raw fish might pose a health hazard, especially in immunosuppressed individuals, elderly people, and children. This study highlights the importance of bacterial pathogens in fish intended for human consumption, but more study is needed.

Isotopic niches of fishes in coastal, neritic and oceanic waters off Adélie land, Antarctica

Science.gov (United States)

Cherel, Yves; Koubbi, Philippe; Giraldo, Carolina; Penot, Florian; Tavernier, Eric; Moteki, Masato; Ozouf-Costaz, Catherine; Causse, Romain; Chartier, Amélie; Hosie, Graham

2011-08-01

We used the stable isotope method to investigate the ecological niches of Antarctic fishes, with δ 13C and δ 15N as proxies of fish habitats and dietary habits, respectively. Muscle isotopic signature was measured for each of 237 delipidated tissue samples from 27 fish species collected offshore Adélie Land, East Antarctica. Overall, δ 13C values ranged from -25.3‰ to -18.2‰, thus allowing characterizing of the fish habitats, with inshore/benthic species having more positive δ 13C signatures than offshore/pelagic ones. No clear difference in the δ 13C values of pelagic fishes was found between species living in neritic and oceanic waters. Overall, the δ 15N signatures of neritic pelagic and epibenthic fishes encompassed ˜1.0 trophic level (3.1‰), a higher difference than that (1.4‰) found within the oceanic assemblage. Fishes with the lowest and highest δ 15N values are primarily invertebrate- and fish-eaters, respectively. The isotopic niches of fishes illustrate the different mechanisms allowing coexistence, with most fishes segregating at least by one of the two niche axes (δ 13C and δ 15N). Muscle isotopic values also document interindividual foraging specialization over the long-term in coastal benthic fishes, but not in more offshore pelagic species. Finally, the δ 15N signatures of fishes overlap with those of penguins and seals, indicating that seabirds and marine mammals share the upper levels of the Antarctic pelagic ecosystem with some large fish species. In conclusion, the concept of isotopic niche is a powerful tool to investigate various aspects of the ecological niche of Antarctic fishes, thus complementing the use of other conventional and non-conventional approaches.

Expression levels of parvalbumins determine allergenicity of fish species.

Science.gov (United States)

Griesmeier, U; Vázquez-Cortés, S; Bublin, M; Radauer, C; Ma, Y; Briza, P; Fernández-Rivas, M; Breiteneder, H

2010-02-01

Parvalbumins are the most important fish allergens. Polysensitization to various fish species is frequently reported and linked to the cross-reactivity of their parvalbumins. Studies on cross-reactivity and its association to the allergenicity of purified natural parvalbumins from different fish species are still lacking. In addition, some studies indicate that dark muscled fish such as tuna are less allergenic. Total protein extracts and purified parvalbumins from cod, whiff, and swordfish, all eaten frequently in Spain, were tested for their IgE-binding properties with 16 fish allergic patients' sera from Madrid. The extent of cross-reactivity of these parvalbumins was investigated by IgE ELISA inhibition assays. Additionally, the cDNA sequences of whiff and swordfish parvalbumins were determined. Extractable amounts of parvalbumins from cod were 20 times and from whiff 30 times higher than from swordfish. Parvalbumins were recognized by 94% of the patients in extracts of cod and whiff, but only by 60% in swordfish extracts. Nevertheless, a high cross-reactivity was determined for all purified parvalbumins by IgE inhibition. The amino acid sequence identities of the three parvalbumins were in a range of 62-74%. The parvalbumins of cod, whiff and swordfish are highly cross-reactive. The high amino acid sequence identity among cod, whiff and swordfish parvalbumins results in the observed IgE cross-reactivity. The low allergenicity of swordfish is due to the low expression levels of its parvalbumin.

The bottlenose dolphin Tursiops truncatus foraging around a fish farm: Effects of prey abundance on dolphins’ behavior

Directory of Open Access Journals (Sweden)

Bruno Díaz LÓPEZ

2009-08-01

Full Text Available The extent to which prey abundance influences both bottlenose dolphin foraging behavior and group size in the presence of human activities has not previously been studied. The primary aim of this study was to identify and quantify how wild bottlenose dolphins respond, individually and as groups, to the relative abundance of prey around a fish farm. Detailed views of dolphins’ behavior were obtained by focal following individual animals whilst simultaneously collecting surface and underwater behavioral data. A total of 2150 dive intervals were analyzed, corresponding to 342 focal samples, lasting over 34 hours. Bottlenose dolphins remained submerged for a mean duration of 46.4 seconds and a maximum of 249 seconds. This study provides the first quantified data on bottlenose dolphin diving behavior in a marine fin-fish farm area. This study’s results indicate that within a fish farm area used intensively by bottlenose dolphins for feeding, dolphins did not modify dive duration. Additionally, underwater observations confirmed that dolphins find it easier to exploit a concentrated food source and it appears that hunting tactic and not group size plays an important role during feeding activities. Thus, bottlenose dolphins appear capable of modifying their hunting tactics according to the abundance of prey. When top predators display behavioral responses to activities not directed at them, the task of studying all possible effects of human activities can become even more challenging [Current Zoology 55(4: 243–248, 2009].

How Do Grass Species, Season and Ensiling Influence Mycotoxin Content in Forage?

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Adam Nawrath

2013-11-01

Full Text Available Mycotoxins are secondary metabolites produced by fungal species that have harmful effects on mammals. The aim of this study was to assess the content of mycotoxins in fresh-cut material of selected forage grass species both during and at the end of the growing season. We further assessed mycotoxin content in subsequently produced first-cutting silages with respect to the species used in this study: Lolium perenne (cv. Kentaur, Festulolium pabulare (cv. Felina, Festulolium braunii (cv. Perseus, and mixtures of these species with Festuca rubra (cv. Gondolin or Poa pratensis (Slezanka. The mycotoxins deoxynivalenol, zearalenone and T-2 toxin were mainly detected in the fresh-cut grass material, while fumonisin and aflatoxin contents were below the detection limits. July and October were the most risky periods for mycotoxins to occur. During the cold temperatures in November and December, the occurrence of mycotoxins in fresh-cut material declined. Although June was a period with low incidence of mycotoxins in green silage, contents of deoxynivalenol and zearalenone in silages from the first cutting exceeded by several times those determined in their biomass collected directly from the field. Moreover, we observed that use of preservatives or inoculants did not prevent mycotoxin production.

The effect of prey density on foraging mode selection in juvenile lumpfish: balancing food intake with the metabolic cost of foraging.

Science.gov (United States)

Killen, Shaun S; Brown, Joseph A; Gamperl, A Kurt

2007-07-01

1. In many species, individuals will alter their foraging strategy in response to changes in prey density. However, previous work has shown that prey density has differing effects on the foraging mode decisions of ectotherms as compared with endotherms. This is likely due to differences in metabolic demand; however, the relationship between metabolism and foraging mode choice in ectotherms has not been thoroughly studied. 2. Juvenile lumpfish Cyclopterus lumpus forage using one of two modes: they can actively search for prey while swimming, or they can 'sit-and-wait' for prey while clinging to the substrate using a ventral adhesive disk. The presence of these easily distinguishable foraging modes makes juvenile lumpfish ideal for the study of foraging mode choice in ectotherms. 3. Behavioural observations conducted during laboratory experiments showed that juvenile lumpfish predominantly use the 'cling' foraging mode when prey is abundant, but resort to the more costly 'swim' mode to seek out food when prey is scarce. The metabolic cost of active foraging was also quantified for juvenile lumpfish using swim-tunnel respirometry, and a model was devised to predict the prey density at which lumpfish should switch between the swim and cling foraging modes to maximize energy intake. 4. The results of this model do not agree with previous observations of lumpfish behaviour, and thus it appears that juvenile lumpfish do not try to maximize their net energetic gain. Instead, our data suggest that juvenile lumpfish forage in a manner that reduces activity and conserves space in their limited aerobic scope. This behavioural flexibility is of great benefit to this species, as it allows young individuals to divert energy towards growth as opposed to activity. In a broader context, our results support previous speculation that ectotherms often forage in a manner that maintains a minimum prey encounter rate, but does not necessarily maximize net energy gain.

Movement patterns for a critically endangered species, the leatherback turtle (Dermochelys coriacea, linked to foraging success and population status.

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Helen Bailey

Full Text Available Foraging success for pelagic vertebrates may be revealed by horizontal and vertical movement patterns. We show markedly different patterns for leatherback turtles in the North Atlantic versus Eastern Pacific, which feed on gelatinous zooplankton that are only occasionally found in high densities. In the Atlantic, travel speed was characterized by two modes, indicative of high foraging success at low speeds (<15 km d(-1 and transit at high speeds (20-45 km d(-1. Only a single mode was evident in the Pacific, which occurred at speeds of 21 km d(-1 indicative of transit. The mean dive depth was more variable in relation to latitude but closer to the mean annual depth of the thermocline and nutricline for North Atlantic than Eastern Pacific turtles. The most parsimonious explanation for these findings is that Eastern Pacific turtles rarely achieve high foraging success. This is the first support for foraging behaviour differences between populations of this critically endangered species and suggests that longer periods searching for prey may be hindering population recovery in the Pacific while aiding population maintenance in the Atlantic.

77 FR 27188 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2012-05-09

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... regulations promulgated for Pacific salmon and steelhead under the Endangered Species Act (ESA). The HGMPs...). Dated: May 3, 2012. Angela Somma, Chief, Endangered Species Division, Office of Protected Resources...

The diet and consumption of dominant fish species in the upper Scheldt estuary, Belgium

DEFF Research Database (Denmark)

Maes, J.; De Brabandere, Loreto; Ollevier, F.

2003-01-01

Seasonal changes in the diet composition and trophic niche overlap were examined for the dominant members of the fish assemblage of the turbid low-salinity zone of the Scheldt estuary (Belgium). Samples of fish were taken in the cooling water of a power plant. Juveniles of eight species dominated...... of trophic niche overlap showed that, in general, niche overlap between individuals of the same species was significantly higher than overlap between individuals from different species, suggesting that the available food resources were partitioned. The total annual prey consumption by the dominant fish...

MACROZOOBENTHOS OF MOUNTAIN RIVERS OF THE TRANSCARPATHIAN REGION AS A FORAGE BASE OF BENTHOPHAGOUS FISHES AND SAPROBITY INDICATOR

Directory of Open Access Journals (Sweden)

S. Kruzhylina

2014-12-01

Full Text Available Purpose. To study qualitative and qualitative indices of macrozoobenthos as one of main components of the forage base of benthophagous fishes in mountain river reaches of the Transcarpathian region and determination of their saprobity level. Methodology. Thhj,9.e study was carried out in summer period of 2009 in mountain river reaches of the Tisa river catchment. Zoobenthos samples were collected by a Surber sampler (25 × 25 cm on the bottoms of different fractions with different water flow rate (riffle, run, pool. Collection, processing and interpretation of the obtained data was carried out according to generally accepted hydrobiological methods developed for mountain river studies. Saprobity was of the studied rivers was calculated by Pantle-Buck formula. The Zelinka-Marvan saprobity index was used for calculations. Findings. Qualitative and quantitative macrozoobenthos indices have been studied. The number of zoobenthos on the investigated river sections ranged from 416 to 7712 ind./m2 with biomasses from 2.96 to 83.84 g/m2. The major portion of the zoobenthic biomass in the majority of rivers was due to caddis fly larvae composing up to 93% of the total biomass. An important role in the total biomass of the zoobenthos also belonged to mayfly (up to 53% and stonefly (up to 55% larvae and in lower degree amphipods (up to 39%, chironomid larvae (up to 14% and aquatic coleopterans (up to 5%. According to the calculated potential fish productivity, the mountain rivers can be apparently separated into three groups: little productive (4.2–12.7 kg/ha, medium productive (13.2–21.6 kg/ha and high productive (25.3–85.3 kg/ha. Mountain river reaches of the Transcarpathian region were found to belong to pure χ-saprobic, and о- і β-mesosaprobic zones, the saprobity index in which ranged from 0.35 (Rika river to 1.7 (Shipot river. Originality. For further calculation and assessment of brown trout (Salmo trutta and European grayling (Thymallus

The influence of environmental variables on the functional structure of headwater stream fish assemblages: a study of two tropical basins in Central Brazil

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Rodrigo Assis Carvalho

Full Text Available We investigated functional patterns of fish assemblages of two adjacent basins (Araguaia and Tocantins to test whether their headwater stream fish assemblages are more functionally (dissimilar than expected by chance and whether these (dissimilarities are related to differences of environmental conditions between basins. We used an analysis of similarities (ANOSIM on a functional dissimilarity matrix to test for (dissimilarities between fish assemblages of both basins. We performed RLQ and fourth-corner analyses to determine fish species trait-environment relationship. Our results revealed functional dissimilarities between fish assemblages of both basins and significant species trait-environment relationships, suggesting that environmental conditions are driving such dissimilarities. Inter-basin dissimilarities are mainly driven by altitudinal and water temperature gradients, whereas dissimilarities among streams within the basins are influenced by channel depth, turbidity and conductivity. These five environmental variables mostly affected six fish species traits (body mass, water column position, substrate preference, parental care, foraging locality and migration in different manners. This study is an attempt to understand functional trends of fish assemblages in a tropical region that remains poorly known but severely threatened.

DNA barcoding commercially important fish species of Turkey.

Science.gov (United States)

Keskın, Emre; Atar, Hasan H

2013-09-01

DNA barcoding was used in the identification of 89 commercially important freshwater and marine fish species found in Turkish ichthyofauna. A total of 1765 DNA barcodes using a 654-bp-long fragment of the mitochondrial cytochrome c oxidase subunit I gene were generated for 89 commercially important freshwater and marine fish species found in Turkish ichthyofauna. These species belong to 70 genera, 40 families and 19 orders from class Actinopterygii, and all were associated with a distinct DNA barcode. Nine and 12 of the COI barcode clusters represent the first species records submitted to the BOLD and GenBank databases, respectively. All COI barcodes (except sequences of first species records) were matched with reference sequences of expected species, according to morphological identification. Average nucleotide frequencies of the data set were calculated as T = 29.7%, C = 28.2%, A = 23.6% and G = 18.6%. Average pairwise genetic distance among individuals were estimated as 0.32%, 9.62%, 17,90% and 22.40% for conspecific, congeneric, confamilial and within order, respectively. Kimura 2-parameter genetic distance values were found to increase with taxonomic level. For most of the species analysed in our data set, there is a barcoding gap, and an overlap in the barcoding gap exists for only two genera. Neighbour-joining trees were drawn based on DNA barcodes and all the specimens clustered in agreement with their taxonomic classification at species level. Results of this study supported DNA barcoding as an efficient molecular tool for a better monitoring, conservation and management of fisheries. © 2013 John Wiley & Sons Ltd.

77 FR 2037 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2012-01-13

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XA928 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... advises the public that a direct take permit has been issued to the Washington Department of Fish and...

Current status of non-native fish species in the St. Louis River estuary

Science.gov (United States)

The fish community of the St. Louis River estuary is well characterized, thanks to fishery assessment and invasive species early detection monitoring by federal, state, and tribal agencies. This sampling includes long-standing adult/juvenile fish surveys, larval fish surveys beg...

77 FR 41168 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2012-07-12

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... available for review pursuant to section 10(c) of the Endangered Species Act (ESA). DATES: Comments and... the ESA. NMFS regulations governing permits for threatened and endangered species are promulgated at...

Explorations on Temperature, Oxygen, Nutrients and Habitat Demands of Fish Species Found in River Coruh

Directory of Open Access Journals (Sweden)

Bilal Akbulut

2009-04-01

Full Text Available For the protection of our natural resources, fish species being economic and ecological richness of the natural in the basin of the Çoruh to know their request is extremely a vital important issue. In this study, temperature and oxygen demand, food and habitat of 18 fish species in six families found in river Çoruh assessed and discussed with the literature and database. Limiting the impact of water temperature on the reproductive, growth and nutrition emphasized. The fish species in the basin spawn at temperatures between 14-30°C according to database. Three species belonging to a family feed with animal food floating in the water. The species belonging to the other families more feed mixed with plant and animal foods diet in the floor or near the ground. Importance of their environmental demands has clarified for conservation and sustainable use of these fish species inhabiting in Çoruh River.

Plant Functional Traits Associated with Mycorrhizal Root Foraging in Arbuscular Mycorrhizal and Ectomycorrhizal Trees

Science.gov (United States)

Eissenstat, D. M.; Chen, W.; Cheng, L.; Liu, B.; Koide, R. T.; Guo, D.

2016-12-01

Root foraging for nutrient "hot spots" is a key strategy by which some plants maximize nutrient gain from their carbon investment in root and mycorrhizal hyphae. Foraging strategies may depend on costs of root construction, with thick roots generally costing more per unit length than thin roots. Investment in mycorrhizal hyphae, which are considerably thinner than roots, may represent an alternative strategy for cost-effective nutrient foraging, especially for thick-root species. Type of mycorrhiza may matter, as ectomycorrhizal (EM) fungi are more associated with longer hyphae and ability to mineralize organic matter than arbuscular mycorrhizal (AM) fungi. Among AM trees in both subtropical forests in SE China and in temperate forests in central Pennsylvania, USA, we found that tree species with thin roots proliferated their roots in soil patches enriched with mineral nutrients to a greater extent than species with thick roots. In addition, thick-root species were consistently colonized more heavily with mycorrhizal fungi than thin root species, although nutrient addition tended to diminish colonization. In a common garden in central Pennsylvania of both AM and EM tree species, we found that nutrient patches enriched with organic materials resulted in greater root and mycorrhizal fungal proliferation compared to those enriched with inorganic nutrients and that thick-root species proliferated more with their mycorrhizal fungi whereas thin-root species proliferated more with their roots. We further examined with many more species, patterns of root and mycorrhizal fungal proliferation in organic-nutrient-enriched patches. Foraging precision, or the extent that roots or mycorrhizal hyphae grew in the enriched patch relative to the unenriched patch, was related to both root thickness and type of mycorrhiza. In both AM and EM trees, thick-root species were not selective foragers of either their roots or hyphae. In thin-root species, there was strong selectivity in

Diversitas Dan Hilangnya Jenis-jenis Ikan Disungai Ciliwung Dan Sungai Cisadane [Study of Fish Diversity and the Lost of Fish Species of River Ciliwung and R. Cisadane

OpenAIRE

Hadiaty, Renny Kurnia

2011-01-01

The fish research in Indonesian waters has been begun since 16 century ago. Most of the research collected fish around Batavia.Many new species was described and the type specimens deposited at the museums in Europe or America.The study of fish diversity and the lost of fish species was conducted at River Ciliwung and R. Cisadane in 2009. The aim of this study is to describe the recent fish diversity in both river drainages, then make a comparison with the number of species recorded based on ...

76 FR 43986 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2011-07-22

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS..., in the form of Hatchery and Genetic Management Plans (HGMPs) pursuant to the Endangered Species Act... the ``taking'' of a species listed as endangered or threatened. The term ``take'' is defined under the...

75 FR 14133 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2010-03-24

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS..., in the form of Hatchery and Genetic Management Plans (HGMPs) pursuant to the Endangered Species Act... the ``taking'' of a species listed as endangered or threatened. The term ``take'' is defined under the...

75 FR 82212 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2010-12-29

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... Chinook salmon under Limit 6 of the Endangered Species Act (ESA) 4(d) Rule for salmon and steelhead, a.... Dated: December 22, 2010. Susan Pultz, Acting Chief, Endangered Species Division, Office of Protected...

75 FR 14132 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2010-03-24

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... Endangered Species Act of 1973, as amended (ESA). The proposed modification is to extend the existing permit... regulations prohibit the ``taking'' of a species listed as endangered or threatened. The term ``take'' is...

76 FR 39856 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2011-07-07

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... permits and permit modifications, as required by the Endangered Species Act of 1973 (16 U.S.C. 1531-1543... and wildlife permits. Species Covered in This Notice This notice is relevant to federally endangered...

76 FR 20956 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2011-04-14

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... regulations promulgated for salmon and steelhead listed under the Endangered Species Act (ESA). The FMEP... July 10, 2000, Endangered Species Act (ESA) 4(d) rule for salmon and steelhead (65 FR 42422) and...

Identification of tetrodotoxin and fish species in a dried dressed fish fillet implicated in food poisoning.

Science.gov (United States)

Hwang, Deng-Fwu; Hsieh, Yu-Wen; Shiu, Yu-Cheng; Chen, Shu-Kong; Cheng, Chao-An

2002-02-01

There were five victims of neurotoxic food poisoning from a dried dressed fish fillet in Changhua County, Taiwan, in February 2000. The toxicity of the dried dressed fish fillets was 243 mouse units per g according to a tetrodotoxin bioassay. The partially purified toxin was identified as tetrodotoxin and anhydrotetrodotoxin. The sequence of the 376-nucleotide region in the cytochrome b gene of the mitochondrial DNA exhibited the same genotype as that of the toxic puffer fish Lagocephalus lunaris. The same single restriction site for Hinfl was found in the polymerase chain reaction (PCR) products from the dried dressed fish fillet and the muscle of L. lunaris, yielding two DNA fragments of 170 and 206 bp. However, no restriction site for Hinfl was found in the PCR products from other toxic puffer fishes, including Takifugu niphobles, Takifugu oblongus, and Takifugu rubripes. Therefore, the species of the dried dressed fish fillet was identified as L. lunaris and its causative agent was identified as tetrodotoxin.

The Foraging Ecology of the Endangered Cape Verde Shearwater, a Sentinel Species for Marine Conservation off West Africa.

Science.gov (United States)

Paiva, Vitor H; Geraldes, Pedro; Rodrigues, Isabel; Melo, Tommy; Melo, José; Ramos, Jaime A

2015-01-01

Large Marine Ecosystems such as the Canary Current system off West Africa sustains high abundance of small pelagic prey, which attracts marine predators. Seabirds are top predators often used as biodiversity surrogates and sentinel species of the marine ecosystem health, thus frequently informing marine conservation planning. This study presents the first data on the spatial (GPS-loggers) and trophic (stable isotope analysis) ecology of a tropical seabird-the endangered Cape Verde shearwater Calonectris edwardsii-during both the incubation and the chick-rearing periods of two consecutive years. This information was related with marine environmental predictors (species distribution models), existent areas of conservation concern for seabirds (i.e. marine Important Bird Areas; marine IBAs) and threats to the marine environment in the West African areas heavily used by the shearwaters. There was an apparent inter-annual consistency on the spatial, foraging and trophic ecology of Cape Verde shearwater, but a strong alteration on the foraging strategies of adult breeders among breeding phases (i.e. from incubation to chick-rearing). During incubation, birds mostly targeted a discrete region off West Africa, known by its enhanced productivity profile and thus also highly exploited by international industrial fishery fleets. When chick-rearing, adults exploited the comparatively less productive tropical environment within the islands of Cape Verde, at relatively close distance from their breeding colony. The species enlarged its trophic niche and increased the trophic level of their prey from incubation to chick-rearing, likely to provision their chicks with a more diversified and better quality diet. There was a high overlap between the Cape Verde shearwaters foraging areas with those of European shearwater species that overwinter in this area and known areas of megafauna bycatch off West Africa, but very little overlap with existing Marine Important Bird Areas. Further

Investigation of sensory profiles and hedonic drivers of emerging aquaculture fish species.

Science.gov (United States)

Alexi, Niki; Byrne, Derek V; Nanou, Evangelia; Grigorakis, Kriton

2018-02-01

The aquaculture sector needs to increase the diversity fish species and their processed products to cover rising consumer demands. Candidates for this diversification have been identified to be meagre, greater amberjack, pikeperch and wreckfish. Yet scientific knowledge on their sensory profiles and consumer hedonic responses is scarce. The aim of the current study was to investigate these aspects, since they are essential for product development and market targeting. Species exhibited different sensory profiles with the exception of the odor/flavor profiles of meagre and greater amberjack, which were similar. Texture was more important than odor/flavor in explaining interspecies differences. Yet the hedonic responses were equally related to texture and odor/flavor. None of the species received negative hedonic scores. Both positive and negative hedonic drivers were identified within the odor/flavor and texture modalities. The distinct profiles of meagre, greater amberjack, pikeperch and wreckfish make these fish species valuable first materials for new product development and for covering markets with different sensory preferences. Differences in fish texture are more easily perceivable, yet small variations in fish odor/flavor can have a great impact on consumers' hedonic responses. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Selenium and mercury molar ratios in saltwater fish from New Jersey: Individual and species variability complicate use in human health fish consumption advisories☆

Science.gov (United States)

Burger, Joanna; Gochfeld, Michael

2014-01-01

Balancing risk versus benefits to humans and other organisms from consuming fish is a national concern in the USA, as well as in many other parts of the world. Protecting public health is both a federal and state responsibility, and states respond by issuing fish consumption advisories, particularly for mercury. Recently it has been emphasized that the protective role of selenium against mercury toxicity depends on their molar ratios, which should be evaluated as an indication of selenium’s protective capacity, and incorporated in risk assessments for fish consumption. However, there is no single “protective” ratio agreed upon. In this paper we examine the selenium:mercury (Se:Hg) molar ratios in a wide range of saltwater fish caught and eaten by recreational fishers along the New Jersey coast. We were particularly interested in interspecific and intraspecific variability, and whether the molar ratios were consistent within a species, allowing for its use in managing risk. The selenium–mercury molar ratio showed significant variation among and within fish species. The molar ratio decreased with the size of the fish species, decreased with the mercury levels, and within a fish species, the selenium:mercury ratio decreased with fish size. As an essential element, selenium undergoes some homeostatic regulation, but it is also highly toxic. Within species, mercury level tends to increase with size, accounting for the negative relationship between size and ratio. This variability may make it difficult to use the selenium:mercury molar ratio in risk assessment, risk management, and risk communication at this time, and more information is needed on how mercury and selenium actually interact and on the relationship between the molar ratios and health outcomes. PMID:22405995

Quantifying the effect of colony size and food distribution on harvester ant foraging.

Directory of Open Access Journals (Sweden)

Tatiana P Flanagan

Full Text Available Desert seed-harvester ants, genus Pogonomyrmex, are central place foragers that search for resources collectively. We quantify how seed harvesters exploit the spatial distribution of seeds to improve their rate of seed collection. We find that foraging rates are significantly influenced by the clumpiness of experimental seed baits. Colonies collected seeds from larger piles faster than randomly distributed seeds. We developed a method to compare foraging rates on clumped versus random seeds across three Pogonomyrmex species that differ substantially in forager population size. The increase in foraging rate when food was clumped in larger piles was indistinguishable across the three species, suggesting that species with larger colonies are no better than species with smaller colonies at collecting clumped seeds. These findings contradict the theoretical expectation that larger groups are more efficient at exploiting clumped resources, thus contributing to our understanding of the importance of the spatial distribution of food sources and colony size for communication and organization in social insects.

Inability to demonstrate fish-to-fish transmission of Ichthyophonus from laboratory infected Pacific herring Clupea pallasii to naïve conspecifics.

Science.gov (United States)

Gregg, J L; Grady, C A; Friedman, C S; Hershberger, P K

2012-06-13

The parasite Ichthyophonus is enzootic in many marine fish populations of the northern Atlantic and Pacific Oceans. Forage fishes are a likely source of infection for higher trophic level predators; however, the processes that maintain Ichthyophonus in forage fish populations (primarily clupeids) are not well understood. Lack of an identified intermediate host has led to the convenient hypothesis that the parasite can be maintained within populations of schooling fishes by waterborne fish-to-fish transmission. To test this hypothesis we established Ichthyophonus infections in Age-1 and young-of-the-year (YOY) Pacific herring Clupea pallasii (Valenciennes) via intraperitoneal (IP) injection and cohabitated these donors with naïve conspecifics (sentinels) in the laboratory. IP injections established infection in 75 to 84% of donor herring, and this exposure led to clinical disease and mortality in the YOY cohort. However, after cohabitation for 113 d no infections were detected in naïve sentinels. These data do not preclude the possibility of fish-to-fish transmission, but they do suggest that other transmission processes are necessary to maintain Ichthyophonus in wild Pacific herring populations.

Helminth communities of four commercially important fish species from Chetumal Bay, Mexico.

Science.gov (United States)

Aguirre-Macedo, M L; Vidal-Martínez, V M; González-Solís, D; Caballero, P I

2007-03-01

The relative importance of ecology and evolution as factors determining species richness and composition of the helminth communities of fish is a matter of current debate. Theoretical studies use host-parasite lists, but these do not include studies on a temporal or spatial scale. Local environmental conditions and host biological characteristics are shown to influence helminth species richness and composition in four fish species (Eugerres plumieri, Hexanematichthys assimilis, Oligoplites saurus, and Scomberomorus maculatus) in Chetumal Bay, Mexico. With the exception of H. assimilis, the helminth communities had not been previously studied and possible associations between environmental and host biological characteristics as factors determining helminth species richness and composition using redundancy analysis (RDA) are described. Thirty-four helminth species are identified, with the highest number of species (19 total (mean = 6.3 +/- 2.1)) and the lowest (9 (4.0 +/- 1.0)) occurring in H. assimilis and S. maculatus, respectively. The larval nematodes Contracaecum sp. and Pseudoterranova sp. were not only the helminth species shared by all four host species but also were the most prevalent and abundant. Statistical associations between helminth community parameters and local ecological variables such as host habitat use, feeding habits, mobility, and time of residence in coastal lagoons are identified. Phylogeny is important because it clearly separates all four host species by their specialist parasites, although specific habitat and feeding habits also significantly influence the differentiation between the four fish species.

78 FR 52487 - Atlantic Highly Migratory Species; 2014 Atlantic Shark Commercial Fishing Season

Science.gov (United States)

2013-08-23

.... 130402317-3707-01] RIN 0648-XC611 Atlantic Highly Migratory Species; 2014 Atlantic Shark Commercial Fishing... establish opening dates and adjust quotas for the 2014 fishing season for the Atlantic commercial shark... management measures to provide, to the extent practicable, fishing opportunities for commercial shark...

Composition of Mix Species Foraging Flocks of Birds in Riverstan of Montane Region, Sri Lanka

Directory of Open Access Journals (Sweden)

W.G.D.D.M. Shermila

2013-04-01

Full Text Available Montane zone mixed-species bird flock system is distinct from that of low-land wet zone of SriLanka, although some species are present in both systems. The present study identified the mixed speciesflocks of birds in Riverstan at Knuckles Region, Sri Lanka. Monthly transect counts and opportunisticobservations were made between January and May, 2012. A total of 78 flocks and 27 bird species wereencountered at Riverstan during the study period. The flock size varied between 2 to 13 species and 4 to58 individuals. The mean number of species per flock was 6.03 ± 2.25 and the mean number ofindividuals in a flock was 18.41±9.87. The flock size was positively correlated with the number of speciespresent (r = 0.756, P <0.05. Grey-headed Canary Flycatcher was the most abundant species (mean2.68±1.02 birds per flocks while Sri Lanka White-eye was the most frequent species (mean 5.69±3.92birds per flocks. Grey-headed Canary Flycatcher and Sri Lanka Scimitar-babbler were the nuclear speciesin Riverstan. The leading species were Sri Lanka white-eye and Sri Lanka Yellow-eared Bulbul. Differentbird species used different heights within flocks.Keywords: Mixed-species flock, Nuclear species, Abundance, Foraging flocks

78 FR 18273 - Draft Guidance for Industry on Purchasing Reef Fish Species Associated With the Hazard of...

Science.gov (United States)

2013-03-26

.... FDA-2013-D-0269] Draft Guidance for Industry on Purchasing Reef Fish Species Associated With the... availability of a draft guidance entitled ``Guidance for Industry: Purchasing Reef Fish Species Associated With... seafood processors who purchase reef fish how to minimize the risk of ciguatera fish poisoning (CFP) from...

76 FR 61344 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2011-10-04

... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... modifications, as required by the Endangered Species Act of 1973 (16 U.S.C. 1531-1543) (ESA), is based on a.... Species Covered in This Notice This notice is relevant to federally endangered Central California Coast...

Early life of key fish species, capelin Mallotus villosus and Atlantic cod Gadus morhua, in West Greenland

DEFF Research Database (Denmark)

Malanski, Evandro

for the fish larvae during the summer. The duration of the productive season is of great importance for the early life of fish. The present thesis investigates the diets of capelin and cod in the subarctic Kapisigdlit, as well as the feeding of non-commercial larval fish in the entire Godthåbsfjord system...... species were found in the area, and 3 main assemblages were identified according to their similarities, which are related to the hydrographic zones. Fish larvae may benefit from the estuarine circulation to distribute themselves from the spawning areas through the Godthåbsfjord. The diet of the larval...... fish species varied markedly along the fjord. Prey size preferences of fish larvae were positively correlated to their mouth sizes. American plaice and sandeel were probably do not compete for food with other fish species since these, contrary to other species, had high preference for microplankton...

Selective food preferences of walleyes of the 1959 year class in Lake Erie

Science.gov (United States)

Parsons, John W.

1971-01-01

Stomachs were examined from 1,473 walleyes (Stizostedion vitreum vitreum) of the 1959 year class collected in western Lake Erie from June 1959 to October 1960. In the same period, the relative abundance and lengths of potential forage species were determined from trawl catches. The walleye fed almost entirely on fish. In 1959 the food was dominated first (in June and July) by yellow perch (Perca flavescens) and then, in sequence, by spottail shiners (Notropis hudsonius) and emerald shiners (Notropis atherinoides). In 1960, the walleyes fed mostly on yearling spottail shiners and emerald shiners in the spring and summer but young alewives (Alosa pseudoharengus) became the dominant food in the fall. The length of forage fish increased with the length of walleyes and walleyes of a given length usually ate forage fish within a restricted range of lengths. This size preference was shown by walleyes of the same length in the same and different months. The increased in length of forage fish with length of walleye was not proportionate. Walleyes 2.5 inches long ate forage fish 0.44 times their length whereas walleyes 15.5 inches long ate forage fish only 0.28 times their length. The diet of the walleyes changed according to species and lengths of forage fish available. Since young of several species hatched in different months and grew at different rates, abundance and suitability as forage sometimes changed rapidly.

78 FR 6298 - Endangered and Threatened Species; Take of Anadromous Fish; Correction

Science.gov (United States)

2013-01-30

... and Threatened Species; Take of Anadromous Fish; Correction AGENCY: National Marine Fisheries Service... listed species under the Endangered Species Act of 1973. NMFS also announced the availability for public... provided above in the addresses section. Dated: January 24, 2013. Angela Somma, Chief, Endangered Species...

Feeding ecology of some fish species occurring in artisanal fishery of Socotra Island (Yemen).

Science.gov (United States)

Hassan Ali', Mohammed Kaed; Belluscio, Andrea; Ventura, Daniele; Ardizzone, Giandomenico

2016-04-30

The demersal species Lethrinus borbonicus, Lethrinus mahsena, Lethrinus microdon, Lethrinus nebulosus, Lutjanus bohar, Lutjanus gibbus, Lutjanus kasmira, Epinephelus fasciatus, Epinephelus stoliczkae, Carangoides gymnostethus and Euthynnus affinis are important coastal fishes species of the northern coast of Socotra (Yemen), exploited by local fishery. The biology and feeding ecology of these species are poorly known in the area. A total of 1239 specimens were sampled from the main fishing landing site of the island (Hadibo). Total length and weight were measured, stomach contents were analyzed, diet overlap, Fulton's Condition index, and trophic levels were estimated. C. gymnostethus, L. microdon and L. kasmira occupied the highest position (T=4.50), L. nebulosus occupied the lower one (TL=3.41). The role of the increasing abundance of small pelagic fish in the diet of many species after the upwelling event is evident, but also different feeding strategies are reported, according to fish ecology. Copyright © 2016 Elsevier Ltd. All rights reserved.

The regulation of ant colony foraging activity without spatial information.

Directory of Open Access Journals (Sweden)

Balaji Prabhakar

Full Text Available Many dynamical networks, such as the ones that produce the collective behavior of social insects, operate without any central control, instead arising from local interactions among individuals. A well-studied example is the formation of recruitment trails in ant colonies, but many ant species do not use pheromone trails. We present a model of the regulation of foraging by harvester ant (Pogonomyrmex barbatus colonies. This species forages for scattered seeds that one ant can retrieve on its own, so there is no need for spatial information such as pheromone trails that lead ants to specific locations. Previous work shows that colony foraging activity, the rate at which ants go out to search individually for seeds, is regulated in response to current food availability throughout the colony's foraging area. Ants use the rate of brief antennal contacts inside the nest between foragers returning with food and outgoing foragers available to leave the nest on the next foraging trip. Here we present a feedback-based algorithm that captures the main features of data from field experiments in which the rate of returning foragers was manipulated. The algorithm draws on our finding that the distribution of intervals between successive ants returning to the nest is a Poisson process. We fitted the parameter that estimates the effect of each returning forager on the rate at which outgoing foragers leave the nest. We found that correlations between observed rates of returning foragers and simulated rates of outgoing foragers, using our model, were similar to those in the data. Our simple stochastic model shows how the regulation of ant colony foraging can operate without spatial information, describing a process at the level of individual ants that predicts the overall foraging activity of the colony.

Characterization of Ras k 1 a novel major allergen in Indian mackerel and identification of parvalbumin as the major fish allergen in 33 Asia-Pacific fish species.

Science.gov (United States)

Ruethers, T; Raith, M; Sharp, M F; Koeberl, M; Stephen, J N; Nugraha, R; Le, T T K; Quirce, S; Nguyen, H X M; Kamath, S D; Mehr, S S; Campbell, D E; Bridges, C R; Taki, A C; Swoboda, I; Lopata, A L

2018-04-01

Fish is a well-recognized cause of food allergy and anaphylaxis. The evolutionary and taxonomic diversity of the various consumed fish species pose a challenge in the identification and characterization of the major fish allergens critical for reliable diagnostics. Globally, fish is a rising cause of food allergy complicated by a large under-investigated variety of species as well as increasing global tourism and trade. This is the first comprehensive study on allergen profiles of heat-processed fish from Vietnam. The aim of this study was to identify the major heat-stable allergens from frequently exported Asia-Pacific freshwater and marine fish and to characterize the major allergen parvalbumin (PV) from one of the most consumed and exported fish species from Asia, the Indian mackerel (Rastrelliger kanagurta). Heated protein extracts from 33 fish species were separated by gel electrophoresis. PV isoforms were identified by immunoblotting utilizing 3 different PV-specific monoclonal and polyclonal antibodies and further characterized by mass spectrometry. IgE reactivity was investigated using sera from 21 patients with confirmed fish allergy. Heat-stable IgE-reactive PVs, with up to 5 isoforms per species, were identified in all 33 analysed fish species. In the Indian mackerel, 7 PV isoforms were identified by 2D-gel electrophoresis combined with mass spectrometric analyses. The amino acid sequence deduced from cDNA of the most expressed isoform showed a high identity (>90%) to PVs from 2 other mackerel species. Different PVs were identified as the major heat-stable allergens in all 33 analysed freshwater and marine fish species from Vietnam, many of which are exported world-wide and 21 species that have never been investigated before. The Indian mackerel PV represents a novel fish allergen, now officially registered as Ras k 1. Improved diagnostics for fish allergy against Asia-Pacific species should be developed with focus on PV. © 2017 John Wiley & Sons Ltd.

76 FR 67121 - Atlantic Highly Migratory Species; 2012 Atlantic Shark Commercial Fishing Season

Science.gov (United States)

2011-10-31

.... 110913585-1625-01] RIN 0648-BB36 Atlantic Highly Migratory Species; 2012 Atlantic Shark Commercial Fishing... establish opening dates and adjust quotas for the 2012 fishing season for the Atlantic commercial shark... 2011 Atlantic commercial shark fishing seasons. In addition, NMFS proposes season openings based on...

Food and foraging preferences of three pteropodid bats in southern India

Directory of Open Access Journals (Sweden)

M.R Sudhakaran

2012-01-01

Full Text Available A study on the food, foraging and flight height in three species of pteropodid bats, namely Cynopterus sphinx, Rousettus leschenaultii and Pteropus giganteus was conducted in Tirunelveli and Tuticorin districts of southern Tamil Nadu, India. A total of 37 species of plants were identified as potential food plants of the pteropodid bats. The preference for fruits by pteropodids varied according to the developmental stages of fruits namely, immature, unripe and ripe. There is a relationship between the foraging activities of bats and the moon phase. Bats exhibit a varied foraging pattern and flight height. A variation in the foraging flight height was observed in C. sphinx and R. leschenaultii. R. leschenaultii was observed to have a higher foraging echelon than that of the C. sphinx. In our study we found that the C. sphinx forages normally at canopy level (up to 3.5m, R. leschenaultii forages at upper canopy levels (up to 9m and P. giganteus at a height above the canopy area (>9m.

Forage herbs improve mineral composition of grassland herbage

DEFF Research Database (Denmark)

Pirhofer-Walzl, Karin; Søegaard, Karen; Jensen, Henning Høgh

2011-01-01

there is limited information about mineral concentrations in forage herbs. To determine whether herbs have greater macro- and micromineral concentrations than forage legumes and grasses, we conducted a 2-year experiment on a loamy-sand site in Denmark sown with a multi-species mixture comprised of three functional...

A hard-knock life: the foraging ecology of Cape cormorants amidst ...

African Journals Online (AJOL)

A hard-knock life: the foraging ecology of Cape cormorants amidst shifting prey resources and industrial fishing pressure. MH Hamann, D Grémillet, PG Ryan, F Bonadonna, CD van der Lingen, L Pichegru ...

Spatio-temporal dynamics of ocean conditions and forage taxa reveal regional structuring of seabird–prey relationships.

Science.gov (United States)

Santora, Jarrod A; Schroeder, Isaac D; Field, John C; Wells, Brian K; Sydeman, William J

Studies of predator–prey demographic responses and the physical drivers of such relationships are rare, yet essential for predicting future changes in the structure and dynamics of marine ecosystems. Here, we hypothesize that predator–prey relationships vary spatially in association with underlying physical ocean conditions, leading to observable changes in demographic rates, such as reproduction. To test this hypothesis, we quantified spatio-temporal variability in hydrographic conditions, krill, and forage fish to model predator (seabird) demographic responses over 18 years (1990–2007). We used principal component analysis and spatial correlation maps to assess coherence among ocean conditions, krill, and forage fish, and generalized additive models to quantify interannual variability in seabird breeding success relative to prey abundance. The first principal component of four hydrographic measurements yielded an index that partitioned “warm/weak upwelling” and “cool/strong upwelling” years. Partitioning of krill and forage fish time series among shelf and oceanic regions yielded spatially explicit indicators of prey availability. Krill abundance within the oceanic region was remarkably consistent between years, whereas krill over the shelf showed marked interannual fluctuations in relation to ocean conditions. Anchovy abundance varied on the shelf, and was greater in years of strong stratification, weak upwelling and warmer temperatures. Spatio-temporal variability of juvenile forage fish co-varied strongly with each other and with krill, but was weakly correlated with hydrographic conditions. Demographic responses between seabirds and prey availability revealed spatially variable associations indicative of the dynamic nature of “predator–habitat” relationships. Quantification of spatially explicit demographic responses, and their variability through time, demonstrate the possibility of delineating specific critical areas where the

77 FR 61562 - Atlantic Highly Migratory Species; 2013 Atlantic Shark Commercial Fishing Season

Science.gov (United States)

2012-10-10

.... 120706221-2481-01] RIN 0648-XC106 Atlantic Highly Migratory Species; 2013 Atlantic Shark Commercial Fishing... establish opening dates and adjust quotas for the 2013 fishing season for the Atlantic commercial shark... the 2011 and 2012 Atlantic commercial shark fishing seasons. We propose to keep the porbeagle shark...

Distribution Species Composition And Size Of Flying Fish Exocoetidae In The Ceram Sea

Directory of Open Access Journals (Sweden)

Friesland Tuapetel

2015-03-01

Full Text Available Abstract Ceram Sea is new resources area of catching flying fish. The purpose of study is to determine the species composition size and distribution of flying fish caught by drifting baits. Flying fish data collection was conducted in June until October 2013 in three locations i.e Kaimana East Ceram and Fak-Fak. There are three flying fish species collected namely Hirundichthys oxycephalus Torani Cypselurus poecilopterus Banggulung and Chellopogon abeia yellow wing. The results was showed that in Fak-Fak and Kaimana there are two types of fly fishing that H. oxycephalus andC. poecilopterus whereas in East Ceram found three types including H. oxycephalus C. poecilopterus and C. abeia. The dominant type of flying fish in three locations is H. oxycephalus. Flying fish has a variety size range of body size from 195.6 to 243.6 mm in Kaimana East Ceram range from 206.3 to 284.3 mm while Fak-Fak range from 187.1 to 243.1 mm. The result is expected to be a reference literature as basic data for the management and sustainable utilization of flyling fish in Ceram sea.

Novel mobbing strategies of a fish population against a sessile annelid predator.

Science.gov (United States)

Lachat, Jose; Haag-Wackernagel, Daniel

2016-09-12

When searching for food, foraging fishes expose themselves to hidden predators. The strategies that maximize the survival of foraging fishes are not well understood. Here, we describe a novel type of mobbing behaviour displayed by foraging Scolopsis affinis. The fish direct sharp water jets towards the hidden sessile annelid predator Eunice aphroditois (Bobbit worm). We recognized two different behavioural roles for mobbers (i.e., initiator and subsequent participants). The first individual to exhibit behaviour indicating the discovery of the Bobbit directed, absolutely and per time unit, more water jets than the subsequent individuals that joined the mobbing. We found evidence that the mobbing impacted the behaviour of the Bobbit, e.g., by inducing retraction. S. affinis individuals either mob alone or form mobbing groups. We speculate that this behaviour may provide social benefits for its conspecifics by securing foraging territories for S. affinis. Our results reveal a sophisticated and complex behavioural strategy to protect against a hidden predator.

A global comparison of the nutritive values of forage plants grown in contrasting environments.

Science.gov (United States)

Lee, Mark A

2018-03-17

Forage plants are valuable because they maintain wild and domesticated herbivores, and sustain the delivery of meat, milk and other commodities. Forage plants contain different quantities of fibre, lignin, minerals and protein, and vary in the proportion of their tissue that can be digested by herbivores. These nutritive components are important determinants of consumer growth rates, reproductive success and behaviour. A dataset was compiled to quantify variation in forage plant nutritive values within- and between-plant species, and to assess variation between plant functional groups and bioclimatic zones. 1255 geo-located records containing 3774 measurements of nutritive values for 136 forage plant species grown in 30 countries were obtained from published articles. Spatial variability in forage nutritive values indicated that climate modified plant nutritive values. Forage plants grown in arid and equatorial regions generally contained less digestible material than those grown in temperate and tundra regions; containing more fibre and lignin, and less protein. These patterns may reveal why herbivore body sizes, digestion and migration strategies are different in warmer and drier regions. This dataset also revealed the capacity for variation in the nutrition provided by forage plants, which may drive consumer species coexistence. The proportion of the plant tissue that was digestible ranged between species from 2 to 91%. The amount of fibre contained within plant material ranged by 23-90%, protein by 2-36%, lignin by 1-21% and minerals by 2-22%. On average, grasses and tree foliage contained the most fibre, whilst herbaceous legumes contained the most protein and tree foliage contained the most lignin. However, there were individual species within each functional group that were highly nutritious. This dataset may be used to identify forage plant species or mixtures of species from different functional groups with useful nutritional traits which can be cultivated

Mayfly and fish species identification and sex determination in bleak (Alburnus alburnus) by MALDI-TOF mass spectrometry.

Science.gov (United States)

Maasz, G; Takács, P; Boda, P; Varbiro, G; Pirger, Z

2017-12-01

Besides food quality control of fish or cephalopods, the novel mass spectrometry (MS) approaches could be effective and beneficial methods for the investigation of biodiversity in ecological research. Our aims were to verify the applicability of MALDI-TOF MS in the rapid identification of closely related species, and to further develop it for sex determination in phenotypically similar fish focusing on the low mass range. For MALDI-TOF MS spectra analysis, ClinProTools software was applied, but our observed classification was also confirmed by Self Organizing Map. For verifying the wide applicability of the method, brains from invertebrate and vertebrate species were used in order to detect the species related markers from two mayflies and eight fish as well as sex-related markers within bleak. Seven Ephemera larvae and sixty-one fish species related markers were observed and nineteen sex-related markers were identified in bleak. Similar patterns were observed between the individuals within one species. In contrast, there were markedly diverse patterns between the different species and sexes visualized by SOMs. Two different Ephemera species and male or female fish were identified with 100% accuracy. The various fish species were classified into 8 species with a high level of accuracy (96.2%). Based on MS data, dendrogram was generated from different fish species by using ClinProTools software. This MS-based dendrogram shows relatively high correspondence with the phylogenetic relationships of both the studied species and orders. In summary, MALDI-TOF MS provides a cheap, reliable, sensitive and fast identification tool for researchers in the case of closely related species using mass spectra acquired in a low mass range to define specific molecular profiles. Moreover, we presented evidence for the first time for determination of sex within one fish species by using this method. We conclude that it is a powerful tool that can revolutionize ecological and