Comparison of trends in abundance of guano-producing seabirds in ...

African Journals Online (AJOL)

The abundant guano-producing seabirds in Peru and southern Africa feed mainly on the large populations of anchovy Engraulis spp. and sardine Sardinops sagax supported by the Humboldt and Benguela upwelling systems. Numbers of guanay cormorants Phalacrocorax bougainvillii in Peru and the breeding population ...

The importance of lipid-rich fish prey for Cape gannet chick growth : are fishery discards an alternative?

NARCIS (Netherlands)

Mullers, Ralf H. E.; Navarro, Rene A.; Crawford, Robert J. M.; Underhill, Les G.

2009-01-01

A recent decline in population numbers of Cape gannets (Morus capensis) breeding off the west coast of South Africa coincided with decreased availability of lipid-rich fish prey: anchovy (Engraulis encrasicolus) and sardine (Sardinops sagax). Seabirds can use fishery discards as an alternative, but

QUALITY CHANGES OF SARDINES (Sardinella neopilchardus) AT INDONESIAN AMBIENT TEMPERATURE

OpenAIRE

Farida Ariyani

2018-01-01

In tropical countries such as Indonesia, high ambient temperature and a lack of icing cause very rapid spoilage of fish. Leaving fish uniced while waiting for processing is a common practice resulting in lower quality of the end products, and consequently lower price of the products. To study the spoilage pattern of sardines (Sardinella neophilchardus) in a tropical region, and to investigate a simple and quick method to judge the degree of spoilage, observations on the deterioration of sardi...

QUALITY CHANGES OF SARDINES (Sardinella neopilchardus AT INDONESIAN AMBIENT TEMPERATURE

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Farida Ariyani

2018-01-01

Full Text Available In tropical countries such as Indonesia, high ambient temperature and a lack of icing cause very rapid spoilage of fish. Leaving fish uniced while waiting for processing is a common practice resulting in lower quality of the end products, and consequently lower price of the products. To study the spoilage pattern of sardines (Sardinella neophilchardus in a tropical region, and to investigate a simple and quick method to judge the degree of spoilage, observations on the deterioration of sardines were carried out by incubating fish in a humidity chamber adjusted to 28-30oC. RH 70-80% for up to 14 h. The changes of sensory attributes based on demerit point score. pH, and total volatile base nitrogen (TVB-N were monitored to determine the degree of spoilage. Although the appearance of sardines was still bright after 6-h incubation time, fish were not as fresh as those without incubation and the belly and tissue were softened. After incubation time of 10 h, fish showed slight to moderate signs of spoilage with demerit point score of 25 out of the maximum score of 39, and a TVB-N content of 20 mg%N. This is similar to the fish quality commonly used in the commercial production of dried-salted fish in Indonesia. Fish incubated for 12 h or more appeared completely spoiled and were rejected by sensory panel. A high correlation between demerit point score and TVB-N was noted, therefore the demerit point system which was more suitable, quicker, and easier could be used to determine the degree of fish spoilage.

Breeding success of African penguins Spheniscus demersus at ...

African Journals Online (AJOL)

The reproductive success of African penguins Spheniscus demersus at Dassen Island from 1994 to 2000 was variable, but much higher than previously reported figures for the species. Breeding success was positively related to the abundance of anchovy Engraulis encrasicolus and sardine Sardinops sagax, and the high ...

Spatial variability in branchial basket meristics and morphology of ...

African Journals Online (AJOL)

We examined spatial variability in meristic and morphological characteristics of the branchial basket of sardine Sardinops sagax collected from four geographical regions around the southern African coast, namely Namibia and the South African west, south and east coasts. Our analysis tested the hypothesis of three putative ...

Revised estimates of abundance of South African sardine and ...

African Journals Online (AJOL)

Hydro-acoustic surveys have been used to provide annual estimates of May recruitment and November spawner biomass of the South African sardine Sardinops sagax and anchovy Engraulis encrasicolus resources since 1984. These time-series of abundance estimates form the backbone of the assessment of these ...

Ecosystem considerations of the KwaZulu-Natal sardine run ...

African Journals Online (AJOL)

The annual winter sardine run along the South African east coast impacts the KwaZulu-Natal (KZN) coastal system in a variety of ways. These include ecological impacts, such as enrichment of a largely oligotrophic environment, competition between migrant sardine Sardinops sagax, other migrant and resident small ...

A model of trophic flows in the northern Benguela upwelling system ...

African Journals Online (AJOL)

Ultimately, this type of model may form a basis for multispecies management approaches in the region. By the 1980s, sardine Sardinops sagax and hake Merluccius spp. stocks in the northern Benguela had both undergone a decline, yet were still heavily fished. Horse mackerel Trachurus trachurus capensis had increased ...

Tropical South-East Atlantic response to ENSO as an ecosystem ...

African Journals Online (AJOL)

Cases were selected based on indices of Pacific sea surface temperature and South-East African rainfall. ... an El Niño event, and higher sardine Sardinops sagax catches tend to follow a La Niña event, through the northward and southward shift respectively of the South Atlantic anticyclone and attendant coastal upwelling.

Anchovy Engraulis capensis and sardine Sardinops sagax currently ...

African Journals Online (AJOL)

spamer

Recruitment is thought to be determined largely by ... for forecasting recruitment strength. ..... In March and April, sustained upwelling wind events ... 2 Assumes average current velocities of 10–15 cm.s–1 in a west-north-westerly direction ...

Espermiogênese em Eupemphix nattereri (Anura, Leiuperidae: aspectos ultra-estruturais Spermiogenesis in Eupemphix nattereri (Anura, Leiuperidae: ultrastructural aspects

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Rodrigo Zieri

2008-06-01

Full Text Available A maturação dos espermatozóides envolve um extenso e complexo processo que começa com a proliferação e diferenciação das espermatogônias, passa pela meiose e finaliza com a espermiogênese. Nessa fase, eventos envolvendo alterações morfológicas e bioquímicas transformam espermátides em espermatozóides. Aspectos ultra-estruturais da espermiogênese e do espermatozóide do anuro Eupemphix nattereri (Steindachner, 1863 foram analisados através de microscopia eletrônica de transmissão. A espermiogênese envolve condensação da cromatina e alongamento nuclear, com visível eliminação de citoplasma. Nesse estágio, grande quantidade de microtúbulos e glicogênio podem ser visualizados no citoplasma das células de Sertoli, rodeando cada espermátide. O espermatozóide é fusiforme e o acrossomo forma uma capa na região anterior do núcleo. A bainha mitocondrial é encontrada ao redor da porção proximal da cauda. A cauda apresenta o axonema com o modelo 9+2, uma fibra axonemal, a membrana ondulante e ausência de bastão axial. Esta organização apresenta algumas similaridades com espécies do gênero Physalaemus (Leiuperidae como P. biligonigerus (Cope, 1861, P. gracilis (Boulenger, 1883 e P. fuscomaculatus (Steindachner, 1864.Spermatozoon maturation involves an extense and complex process beginning with proliferation and differentiation of spermatogonia, passing through meiosis, and ending with spermiogenesis. The later event involves morphological and biochemical changes in order to transform spermatids into spermatozoa. Ultrastructural aspects of the spermiogenesis and testicular spermatozoa of the anuran Eupemphix nattereri (Steindachner, 1863 were analyzed by transmission electron microscopy. Spermiogenesis involves chromatin condensation and nuclear elongation, with visible cytoplasmic elimination. At this stage, a large amount of microtubules and glycogen can also be seen in Sertoli cell cytoplasm, surrounding each

The southern African sardine Sardinops sagax supports major purse ...

African Journals Online (AJOL)

spamer

be caused by environmental factors such as light level and currents, as well as by ... 2 Marine & Coastal Management, Department of Environmental Affairs and Tourism, Private Bag X2, Rogge Bay 8012, Cape Town,. South Africa. 3 Institut de ..... An impression, but one that was difficult to quantify, was that the detection rate ...

The southern African sardine Sardinops sagax (also known as ...

African Journals Online (AJOL)

denise

CHANGES IN ABUNDANCE OF THE NORTHERN BENGUELA SARDINE STOCK. DURING THE ... date of young fish, using standard growth rates, indi- ... and catch per unit effort (cpue) is recognized to be a ... is developed, age-based assessment models cannot be ... The methods are described in various cruise reports.

Although South African sardine (or pilchard, Sardinops sagax) were ...

African Journals Online (AJOL)

spamer

was based on assumed reliability of the hydroacoustic estimates of ... of uncertainties about the value of natural mortality) .... TAC only) also to the estimate of sardine recruitment from the ... of sardine recruitment from that survey: rev ad rev.

Brasacanthus sphoeroides gen. n., sp. n. (Acanthocephala, Echinorhynchidae from a coastal marine fish of Paraná State, Brazil

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Vernon E. Thatcher

2001-12-01

Full Text Available Brasacanthus sphoeroides gen. n.. sp. n. is described from the marine fish, Sphoeroides greeleyi (Steindachner, taken in Paranaguá Bay, Paraná State, Brazil. The new genus differs from Acanthocephalus Koelreuter, 1771, the nearest genus in the family Echinorhynchidae, by having very flat and variable lemnisci in both sexes and a uterine egg reservoir in the female. The species is characterized by its spherical body form and in having parallel or diagonal testes.

Metazoários parasitos de seis espécies de peixes do Reservatório de Lajes, Estado do Rio de Janeiro, Brasil Metazoan parasites of six fishes species from Lajes Reservoir in the State of Rio de Janeiro, Brazil

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Aline R. Paraguassú

2007-09-01

Full Text Available Entre abril de 2002 e julho de 2003, foram necropsiados 231 espécimes de peixes: 39 Astyanax bimaculatus (Linnaeus, 1758, 79 A. fasciatus (Cuvier, 1819, 23 Hypostomus affinis (Steindachner, 1877, 26 Hoplias malabaricus (Bloch, 1794, 30 Loricariichthys castaneus (Castelnau, 1855 e 34 Trachelyopterus striatulus (Steindachner, 1876 provenientes do Reservatório de Lajes (22º42' - 22º50'S, 43º53' 44º05'O, Estado do Rio de Janeiro, Brasil, para estudo das suas comunidades parasitárias. A maioria dos espécimes de H. affinis (95,6% e H. malabaricus (84,6% estavam parasitados por pelo menos uma espécie de metazoário. Em A. bimaculatus, A. fasciatus, L. castaneus e T. striatulus 41%, 39,2%, 56,7% e 14,7% dos espécimes estavam parasitados, respectivamente. Foram coletadas oito diferentes espécies de metazoários parasitos: 2 em A. bimaculatus, 3 em A. fasciatus, 3 em H. affinis, 4 em H. malabaricus, 4 em L. castaneus e 1 em T. striatulus. As comunidades de metazoários parasitos das seis espécies de peixes estudadas apresentaram típico padrão de distribuição agregada. Foram observados dois casos de correlação negativa entre a abundância e a prevalência parasitárias e o comprimento total dos hospedeiros. A comunidade parasitária de L. castaneus apresentou os maiores valores de intensidade média, índice de dispersão e diversidade. As comunidades parasitárias dos peixes estudados apresentaram escassez de correlação entre a abundância, riqueza parasitária e diversidade com o comprimento total dos hospedeiros. Os baixos valores de riqueza e diversidade das comuni-dades parasitárias podem ser atribuídos as características oligotróficas do Reservatório de Lajes.From April 2002 to July 2003, 231 freshwater fishes from Lajes Reservoir in the State of Rio de Janeiro, Brazil (22º42' - 22º50'S, 43º53' - 44º05'W were necropsied to study their community metazoan parasites: 39 Astyanax bimaculatus (Linnaeus, 1758, 79 A. fasciatus

Threatened Fishes of the World: Telestes Croaticus (Steindachner, 1866 (Cypriniformes: Cyprinidae

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Jelić Dušan

2017-03-01

Full Text Available Telestes croaticus is a freshwater fish endemic in Croatia. It is a stygophile species, living above ground but occasionally retreating into subterranean waters. This species is found in the southwest region of Croatia, in the Lika-Jadova and Ričica drainages, in cold and clear waters in lowland habitats with little current, and in springs and associated wetlands. It is protected under Croatian law and was listed by the IUCN Red List as Endangered (EN. It has an extremely limited distribution which makes it vulnerable to different kind of traits such as habitat destruction, water extraction, dam construction, agricultural water pollution and especially the introduction of non-indigenous fish species. Suggested conservation actions for this species are: bans on watercourse regulation, reduction of pollution and eradication of alien fish species. Due to its fast decline in the last 10 years, it is our proposition that T. croaticus should be upgraded to a Critically Endangered species under criterion A2ace A4ace.

Characteristic ichthyoplankton taxa in the separation zone of the East Australian Current: Larval assemblages as tracers of coastal mixing

Science.gov (United States)

Syahailatua, Augy; Roughan, Moninya; Suthers, Iain M.

2011-03-01

Ichthyoplankton assemblages were compared between regions dominated by the oligotrophic East Australian Current (EAC) and the inner-shelf waters off southeastern Australia, to determine if the early life history of fish was related to the separation of the EAC from the coast, producing different water masses as well as characteristic taxa. Samples were collected at the surface and in sub-surface waters, at 50 and 100 m isobath stations, during two summer research voyages in November 1998 and January 1999. On both voyages the study region was characterized by coastal and EAC waters in the north (˜31°S), and in the south by topographically induced upwelling (˜31°S), associated with narrowing of the continental shelf and separation of the EAC from the coast. Among the 111 families of larval fish, we observed distinctive assemblages of ichthyoplankton associated with the two different water masses. A greater abundance of the Carangidae, Labridae, Lutjanidae, Microcanthidae, Myctophidae and Scombridae was associated with the nutrient poor EAC water mass, while the Callionymidae, Clupeidae, Platycephalidae and Sillaginidae were mostly found in the cooler and/or fresher inner-shelf water mass. We assessed these patterns with opportunistic samples from an unusual, wind-driven upwelling event in the north (˜31°S) earlier in the November voyage. The relative abundance of these 10 characteristic families distinguished this wind-driven upwelling event from the subsequent relaxation and predominance of the EAC assemblage at this location just 6 d later. Distinctive and abundant families such as larval clupeids, relative to larval carangids, could be a useful marker of inner-shelf, EAC and mixed water masses in the absence of robust hydrographic data. This and related studies indicate contrast in early life histories of Sardinops sagax and Trachurus spp., which appear to spawn respectively in the inner-shelf and outer-shelf waters. The post-flexion stages of S. sagax

Phenological and distributional shifts in ichthyoplankton associated with recent warming in the northeast Pacific Ocean.

Science.gov (United States)

Auth, Toby D; Daly, Elizabeth A; Brodeur, Richard D; Fisher, Jennifer L

2018-01-01

Understanding changes in the migratory and reproductive phenology of fish stocks in relation to climate change is critical for accurate ecosystem-based fisheries management. Relocation and changes in timing of reproduction can have dramatic effects upon the success of fish populations and throughout the food web. During anomalously warm conditions (1-4°C above normal) in the northeast Pacific Ocean during 2015-2016, we documented shifts in timing and spawning location of several pelagic fish stocks based on larval fish samples. Total larval concentrations in the northern California Current (NCC) during winter (January-March) 2015 and 2016 were the highest observed since annual collections first occurred in 1998, primarily due to increased abundances of Engraulis mordax (northern anchovy) and Sardinops sagax (Pacific sardine) larvae, which are normally summer spawning species in this region. Sardinops sagax and Merluccius productus (Pacific hake) exhibited an unprecedented early and northward spawning expansion during 2015-16. In addition, spawning duration was greatly increased for E. mordax, as the presence of larvae was observed throughout the majority of 2015-16, indicating prolonged and nearly continuous spawning of adults throughout the warm period. Larvae from all three of these species have never before been collected in the NCC as early in the year. In addition, other southern species were collected in the NCC during this period. This suggests that the spawning phenology and distribution of several ecologically and commercially important fish species dramatically and rapidly changed in response to the warming conditions occurring in 2014-2016, and could be an indication of future conditions under projected climate change. Changes in spawning timing and poleward migration of fish populations due to warmer ocean conditions or global climate change will negatively impact areas that were historically dependent on these fish, and change the food web structure

Variation of the ichthyofauna along the Goioerê River: an important tributary of the Piquiri-Paraná basin

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Claudenice Dei Tos

2014-03-01

Full Text Available The construction of reservoirs is considered an important source of impacts on the fish fauna, severely altering the structure of the assemblage. This paper aimed to describe the structure of the fish assemblage of the Goioerê River, determining its longitudinal distribution and patterns of species dominance. The evaluation of its longitudinal variation in the diversity and abundance of the fish assemblage was conducted in July and October 2004 and January and May 2005. The collections were carried out near the headwaters (Gurucaia, middle stretch (Olaria, just above the falls (Paiquerê and downstream (Foz. Forty-four species were captured. The Gurucaia fish assemblages differed significantly from Olaria, Paiquerê and Foz. The Olaria assemblages differed significantly from the Foz. Gurucaia showed the lowest diversity and abundance of species. Astyanax aff paranae Eigenmann,1914 (78% of the total was found to be dominant at this site. Almost the same species richness was found at Olaria and Paiquerê, although Olaria had the greatest abundance of individuals. Astyanax aff paranae, Cyphocharax modestus (Fernández-Yépez, 1948 and Astyanax altiparanae Garutti & Britski, 2000 were the top three dominants and comprised over 71% of the total number of fish caught. At Paiquerê, Astyanax altiparanae, Hypostomus aff ancistroides (Ihering, 1911 and Loricariichthys platymetopon Isbrücker & Nijssen, 1979 composed 58% of the catches. Thirty-one species were recorded at Foz, which presented the greatest richness. The most abundant species were Apareiodon affinis (Steindachner, 1879, Galeocharax knerii (Steindachner, 1879 and A.altiparanae, which contributed to 50% of the total catches in this environment.These results record the fish biodiversity and how the community is longitudinally structured in the Goioerê River, and also demonstrate how this type of evaluation is important to understanding the fish community patterns and finding solutions to

Fish farming of native species in Colombia: current situation and perspectives

DEFF Research Database (Denmark)

Cruz-Casallas, P. E.; Medina-Robles, V. M.; Velasco-Santamaria, Y. M.

2011-01-01

. The Colombian pisciculture is based on red Tilapia Oreochromis sp. (Linnaeus), Rainbow trout Oncorhynchus mykiss (Walbaum) and cachama blanca Piaractus brachypomus (Cuvier), which currently represent around 96% of the total national production. The remaining 4% comes from other farmed species such as bocachico......In Colombia and the rest of the world, the decrease in capture fisheries production has turned the aquaculture into an alternative source of protein for the populations food security as well as an important productive activity, generating employment and income for the rural communities...... Prochilodus magdalenae (Steindachner), carp Cyprinus carpio (Linnaeus) and yamu Brycon amazonicus (Spix & Agassiz). From the three main fish species, cachama blanca is the only native species, which has shown excellent performance in pond farming due to its rusticity, omnivorous habits, docility, meat quality...

Parasites of the flatfish Paralichthys adspersus (Steindachner, 1867 (Pleuronectiformes from northern Chile

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Marcelo E Oliva

1996-06-01

Full Text Available Three species of protistan and 22 species of metazoan parasites were obtained from a sample of 179 flatfish, (Paralichthys adspersus taken-off Antofagasta, northern Chile. Prevalence of infection of seven parasites (Protista: 1, Copepoda: 2, Digenea: 1, Acantocephala: 1, Nematoda: 2 was significantly and positively correlated with host size. Host's sex do not seem to affect prevalence of infection, except for Nybelinia surmenicola, Capillaria sp. and Anisakis sp. (prevalence of infection significantly greater in males than females and Philometra sp. (prevalence higher in females. Mean abundance is correlated with size in nine species (Protista: 1, Copepoda: 2, Digenea: 3, Acantocephala: 1, Nematoda: 2. Host's sex do not affect mean abundance, except for Cainocreadium sp. and Philometra sp.(mean abundance higher in females and Nybelinia surmenicola, Capillaria sp. and Anisakis sp. (mean abundance higher in males.

A fuzzy-logic tool for multi-criteria decision making in fisheries: the case of the South African pelagic fishery

DEFF Research Database (Denmark)

Paterson, B.; Jarre, Astrid; Moloney, C.L.

2007-01-01

The present study presents an electronic decision-support tool that uses a fuzzy-logic model of expert knowledge to assist in multi-criteria decision-making in the context of an Ecosystem Approach to Fisheries (EAF). The prototype model integrates the multiple goals and objectives related...... to the evaluation of the ecosystem performance of the South African sardine Sardinops sagax fishery into a NetWeaver knowledge base and provides intuitive visual outputs to communicate results to managers and stakeholders. The software tool was developed in a consultative process with key experts and follows...... on expert opinion. Results show that the model is robust and conservative. The strength of the approach lies in the ability to include variables that are difficult to measure. It provides a means of rendering value judgements explicit and transparent. The tool synthesises a large amount of information...

Heterochromatin heterogeneity in Hypostomus prope unae (Steindachner, 1878 (Siluriformes, Loricariidae from Northeastern Brazil

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Jamille Bitencourt

2011-11-01

Full Text Available Cytogenetic analyses using C-banding and chromosomal digestion by several restriction enzymes were carried out in four populations (named A, B, C and D of Hypostomus prope unae (Loricariidae, Hypostominae from Contas river basin, northeastern Brazil. These populations share 2n=76 and single NORs on the second metacentric pair but exclusive karyotype forms for each locality. Populations A and B presented conspicuous terminal and interstitial heterochromatic blocks on most of acrocentric chromosomes and equivalent to NORs with differences in both position and bearing pair. Population D showed evident marks at interstitial regions and interspersed with nucleolar region while population C presented interstitial and terminal heterochromatin segments, non-coincident with NORs. The banding pattern after digestion with the endonucleases Alu I, Bam HI, Hae III and Dde I revealed a remarkable heterogeneity within heterochromatin, allowing the identification of distinctive clusters of repeated DNA in the studied populations, besides specific patterns along euchromatic regions. The analysis using restriction enzymes has proved to be highly informative, characterizing population differences and peculiarities in the genome organization of H. prope unae.

The renal effects and initial characterization of venom from Philodryas nattereri Steindachner, 1870

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Marinetes Dantas de Aquino Nery

2014-01-01

Full Text Available The venom of the snake Philodryas nattereri is a mixture of proteins and toxic peptides with several important local and systemic actions, which are similar to those occurring in Bothrops snake bites. The mechanisms involved in the local and systemic actions of this venom are unknown. The aims of the work were to initial characterization of P. nattereri venom and investigate the effects of the poison in the renal perfusion system and in cultured renal tubular cells of the type MDCK (Madin–Darby canine kidney. The P. nattereri venom is composed majority of proteins (86.3% and this poison promoted changes in all the evaluated renal parameters, mainly decreasing renal perfusion pressure (PP and renal vascular resistance (RVR and increasing urine flow (UF and glomerular filtration rate (GFR. The most relevant result was that this venom was highly detrimental to the renal tubules independent of the PP reduction, which was shown by a decrease in sodium (Na+, potassium (K+ and chloride (Cl− electrolyte transport in the studied concentrations. The glomeruli and tubules contain protein bodies and blood extravasation, which were observed by histological analysis. The venom of P. nattereri reduced viability of the MDCK cells only at high concentrations (50 and 100 μg/mL with an IC50 of 169.5 μg/mL.

Morphological development of Anchoviella vaillanti (Steindachner, 1908 (Clupeiformes: Engraulidae larvae and early juveniles

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Anailza Cristina G. da Silva

Full Text Available The considerable similarity in the early life stages of different fish species makes egg and larvae identification in fishery biology and ichthyoplankton surveys a difficult task. Knowledge on early larval development of morphologically similar taxa and species-rich orders, such as Clupeiformes, mainly in the Neotropical fresh waters is rather limited. The aim of the present study was to describe morphological and meristic aspects of the larvae and early juveniles of Anchoviella vaillanti, an endemic species of the São Francisco River basin in Brazil. The characterization was based on an ontogenetic series of 132 individuals (1.3-51.0 mm SL. In the larval period, body varies from elongated to very elongated and the head is small, which is typical of Clupeiformes. The finfold is present beginning in the yolk-sac stage, when larvae have a large yolk sac, until the flexion stage. Pectoral fin buds are the first to form during the preflexion stage, when dorsal- and anal-fin pterygiophores and hypural bones are first visible. The total vertebra count ranges from 36 to 39 and the myomere number ranges from 31 to 45. Complete fin formation obeys the following sequence: anal and dorsal fins during flexion stage; and pectoral, pelvic and caudal fins during postflexion stage. Despite being the only freshwater clupeiform representative in the São Francisco River, A. vaillanti may occur sympatrically with A. lepidentostole in the lower stretches of the river basin. Although early larvae characteristics of A. lepidentostole are not known, its late larvae and early juveniles may be distinguished from those of A. vaillanti, by the higher number of dorsal-fin rays (15 or 16 vs. 12 or 13 in A. vaillanti, higher total vertebra count (40 vs. 37 to 40 and shorter pre-pectoral length (14 to 16 vs. 22.8 to 28.9% SL.

Las infracomunidades de parásitos de dos especies de Scartichthys (Pisces: Blenniidae en localidades cercanas del norte de Chile Parasite infracommunities of two blennid species, Scartichthys (Pisces: Blenniidae, at nearby localities off northern Chile

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KAREN FLORES

2009-03-01

Full Text Available Se comparan las infracomunidades de parásitos de dos especies congenéricas y simpátridas de peces marinos: Scartichthys viridis (Valenciennes 1836 y Scartichthys gigas (Steindachner 1876 (Pisces: Blenniidae, en tres localidades del intermareal rocoso de Iquique (20°32' S, 70°11' O, norte de Chile, separadas por no más de 6 km, con muestras recolectadas entre agosto y septiembre de 2005. El objetivo fue evaluar la variabilidad de la riqueza, abundancia, diversidad, dominancia y composición en una escala espacial y temporal reducida. En total, se recolectaron 2.110 individuos parásitos en los 134 hospedadores examinados, los que pertenecían a 14 taxa. Se encontró una gran similitud en la composición y en las propiedades agregadas de las infracomunidades, tanto entre especies de hospedadores como entre sitios de estudio. Se interpreta que las condiciones ambientales, los factores ecológicos como el uso del habitat y de los recursos alimentarios, y los factores evolutivos como el alto grado de parentesco de estas especies de Scartichthys, son las principales influencias en la alta similitud parasitaria encontrada.The infracommunities of metazoan parasites in two congeneric and sympatric marine fish species, Scartichthys viridis (Valenciennes 1836 and Scartichthys gigas (Steindachner 1876, were studied and compared between three localities of the intertidal rocky shore off the coast of northern Chile, near Iquique (20°32' S, 70°11' W, which were separated by no more than 6 km. Samples were collected between August and September 2005. The goal of this study was to assess the variability in richness, abundance, diversity, dominance and parasite composition between close localities sampled within a short period. In all, 2,110 parasite individuals were collected from the 134 hosts examined, and 14 parasite taxa were identified. There was great similarity in the aggregated and compositional properties of the infracommunities, both between

Uso do alimento por duas espécies simpátricas de Moenkhausia (Characiformes, Characidae em um riacho da Região Centro-Oeste do Brasil Food used by two sympatric species of Moenkhausia (Characiformes, Characidae, in a stream of center-western Brazil

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Raffael M Tófoli

2010-09-01

Full Text Available Esse estudo avaliou sazonalmente a dieta de Moenkhausia dichroura (Kner, 1858 e M. sanctaefilomenae (Steindachner, 1907, coletadas em simpatria no riacho Cancela, Mato Grosso, Brasil. Independente do período hidrológico, alimentos de origem alóctone predominaram na dieta de ambas as espécies (>50% do total de itens consumidos, sendo insetos terrestres o recurso principal, embora, para M. dichroura insetos aquáticos tenham contribuído na dieta também. Hymenoptera (Formicidae foi o alimento mais consumido, sendo ambas as espécies caracterizadas como insetívoras terrestres. A dieta restrita dessas espécies é confirmada pelos baixos valores de amplitude de nicho trófico: Ba=0,26 para M. dichroura em ambos os períodos e Ba=0,41 no período de seca e 0,38 no período de chuva, para M. sanctaefilomenae. A sobreposição alimentar foi elevada no período de chuva (Ojk=0,75 e apresentou valor intermediário no período de seca (Ojk=0,41, evidenciando maior partilha do alimento entre as espécies neste período.This study evaluated the seasonality in the diet of Moenkhausia dichroura (Kner, 1858 and M. sanctaefilomenae (Steindachner, 1907, sympatric species of the Cancela stream, state of Mato Grosso, Brazil. Regardless of the seasonal period, allochthonous food source predominated in the diet of both species (>50% of all items consumed and among these terrestrial insects were the dominant resource. However, aquatic insects were important in the diet of M. dichroura as well. Hymenoptera (Formicidae was the dominant item to both species, thus they were characterized as terrestrial insectivorous. The restricted diet of these species is confirmed by the trophic niche breadth, whose values were in general low: Ba=0.26 to M. dichroura in both periods and Ba=0.41 and 0.38 in the dry and rainy period, respectively, to M. sanctaefilomenae. The feeding overlap was high in the rainy period (Ojk=0.75 and intermediate in the dry period (Ojk=0.41, showing

cultivo

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M. García-Ulloa

2004-01-01

Full Text Available Se evaluó el crecimiento de juveniles (2.77 g de peso promedio de la tilapia Oreochromis aureus (Steindachner, cultivados con diferentes raciones alimenticias bajo condiciones experimentales de laboratorio. Los tratamientos consistieron en el suplemento alimenticio de 6, 8 y 10% del peso de la biomasa total, los cuales fueron estudiados por triplicado en peceras de vidrio de 113 L de capacidad, ajustando una densidad inicial de 25 peces por acuario. El ensayo tuvo una duración de 35 días, y se realizaron biometrías (peso húmedo cada 7 días. El crecimiento específico no mostró diferencias significativas (P > 0.05 entre los tratamientos, registrando un promedio de 5.45%/d. Sin embargo, la conversión alimenticia y utilización del alimento obtenida para el grupo del 6% sugieren una mejor eficiencia en el aprovechamiento del alimento

On a New Species of Hysterothylacium (Nematoda: Anisakidae from Cauque mauleanum (Pisces: Atherinidae by Brightfield and Scanning Electron Microscopy

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Torres Patricio

1998-01-01

Full Text Available Hysterothylacium geschei n. sp. (Nematoda, Anisakidae is described from the intestine of Cauque mauleanum (Steindachner (Pisces: Atherinidae from Lake Panguipulli (39º43'S; 72º13'W, Chile. Eleven (78.6% out of 14 fish were infected, with a mean intensity (range of 14.4 (1-55 worms. The new species can be differentiated from the two previously described species of freshwater fishes from South America by the presence of lateral alae, the number of caudal papillae, and the length of the spicules, oesophagus, intestinal caecum, distance vulva-anterior extremity and the length ratio intestinal caecum: ventricular appendix. From the fishes examined in Lake Panguipulli, including the introduced salmonid species Oncorhynchus mykiss (Walbaum and the authochthonous species Basilichthys australis Eigenmann (Atherinidae and Percichthys trucha (Valenciennes (Percichthyidae, only one specimen of P. trucha was found parasitized by a third-stage larva of this species.

Crescimento do niquim (Lophiosilurus alexandri Steindachner 1876, em diferentes condições de luminosidade e tipos de alimento = Niquim (Lophiosilurus alexandri Steindachner 1876 growth, in different luminosity conditions and types of food

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Ruy Albuquerque Tenório

2006-10-01

Full Text Available O niquim Lophiosilurus alexandri é um peixe endêmico do rio São Francisco e foi prejudicado após o represamento das águas, sendo uns dos peixes mais valorizados na região do Submédio e apresentando potencial para a piscicultura. O trabalho teve por objetivo avaliaro seu crescimento durante as fases ontogênicas iniciais, em diferentes condições de luminosidade e tipos de alimento, fornecendo subsídios técnicos à piscicultura e aos programas de propagação da espécie. O experimento foi realizado em incubadoras com luminosidades de 100% (L, 50% (ML e 0% (SL com quatro repetições e dois critériosalimentares: plâncton+ração e Dendrocephalus brasiliensis+ração. A Análise de Variância (Anova foi realizada para verificar o efeito de diferentes condições de luz e de alimento sobre o comprimento dos niquins. O teste de Tukey (PNiquim Lophiosilurus alexandri is an endemic fish from the San Francisco River and was harmed after the damming up of the waters, being one of the most valuable fish in the Sub-medium region and presenting potential for pisciculture. This study aimed to evaluate its growth during the initial ontogenic phases, under different luminosity conditions and types of food, supplying technical subsidies to the pisciculture and to the species propagation programs. The experiment was conducted in incubators with luminosity at 100% (L, 50% (ML and 0% (SL with four repetitions and two alimentary criteria: plankton+ration and Dendrocephalus braziliensis+ration. The variance analysis (ANOVA was carried out to verify the effect of different light conditions and food on the Niquins' length. The Tukey test (P<0.05 was used to verify the differences between the treatment's averages. There was a significantdifference for the light treatment (ANOVA LUZ: P=0.0030 and the Tukey test indicated the smaller average measurement for the L treatment. The greatest average of the last biometric taken was 74.70±5.95 mm much superior to 25 mm taken for the one that didnot obey the luminosity criterion. The conclusions pointed that by using carnivore's ration, the growth of Niquim was influenced only by luminosity.

Broodstock management of the fine flounder Paralichthys adspersus (Steindachner, 1867 using recirculating aquaculture systems

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Lili Carrera

2013-03-01

Full Text Available The present study describes the methodology used at IMARPE for the capture, acclimation and management of P. adspersus broodstock using recirculating aquaculture systems (RAS. RAS improved the water quality and maintained the environmental parameters during the acclimation period, temperature (17.2±1°C, oxygen (8.1±0.7 mg L-1, pH (7.3±0.2, ammonia (0.004±0.003 mg L-1, nitrite (0.52±0.2 mg L-1 and nitrate (3.45±2.6 mg L-1. Fish began to be fed normally from day 15 post-capture, once or twice a day using live fish (Odonthestes regia regia, Mugil cephalus, crustacean (Emerita analoga, fresh food (Engraulis ringens and Dosidicus gigas and artificial feed. A significant loss in the weight of the fish was registered during the first days of captivity, followed by a continuous increase in both sexes. The specific growth rate was positive from the third month of captivity, being the relative growth rate 24.5% and 16.2% in August 2010 in males and females, respectively. Different internal and external parasites were detected in the fish, being Entobdella sp. and Philometra sp. the prevailing parasites observed during samplings.

Induced spawning and reproductive variables of the catfish Lophiosilurus alexandri Steindachner, 1876 (Siluriformes: Pseudopimelodidae

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Hélio Batista dos Santos

Full Text Available Lophiosilurus alexandri is an endemic fish from the São Francisco River basin, Brazil. The aim of this study was to induce L. alexandri to spawn and to obtain data on several reproductive variables for this species. For induced spawning, adults were submitted to Cyprinus carpio pituitary homogenate (CPH. Nine of the 12 females (75% responded positively to the treatment. The stripping of oocytes was performed 8.4 h after the second dose of CPH with the water temperature maintained at 26ºC. The number of stripped oocytes per gram of ova was 74 ± 5 oocytes g-1, and the mean oocyte diameter was 3.1 ± 0.2 and 3.6 ± 0.2 mm, before and after hydration, respectively. The oocytes were opaque, yellowish, demersal, highly adhesive, and covered by a gelatinous coat. The total fecundity was 4,534 ± 671 oocytes, and the fertilization rate was 59%. The initial and final fertilities were 2,631 ± 740 and 1,542 ± 416 embryos, respectively. Larval hatching occurred up to 56 h after fertilization, and the larvae had a total length of 8.4 ± 0.1 mm. This work provides important biological information for L. alexandri that can be used for management and conservation of this species.

Ectoparasites as numerical dominant species in parasite community of Trachelyopterus striatulus (Siluriformes: Auchenipteridae) from Guandu River, southeastern Brazil.

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Mesquita, R L B; Azevedo, R K; Abdallah, V D; Luque, J L

2011-08-01

Sixty specimens of singing catfish Trachelyopterus striatulus (Steindachner, 1877) (Siluriformes: Auchenipteridae) collected from Guandu River (22º 48' 32" S and 43º 37' 35" W), in the state of Rio de Janeiro, Brazil from October 2006 to March 2009, were necropsied to study their parasites. From the 60 specimens of T. striatulus examined 57 were parasitised by at least one parasite species. The majority of the parasite specimens collected were monogeneans followed by Nematoda, Digenea and Hirudinea. Cosmetocleithrum sp. was the numerically predominant species with highest prevalence and abundance. The parasites of T. striatulus showed the typical pattern of aggregated distribution. No parasite species showed significant correlation between the body total length of the host and their abundance. The mean parasite species richness was not correlated with the host's total body length and sex. Values of the Brillouin index of diversity had a mean of H = 0.083 ± 0.136.

Ecophysiological behavior of Caquetaia kraussii (Steindachner, 1878 (Pisces: Cichlidae exposed to different temperatures and salinities

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M.I. Segnini de Bravo

2001-03-01

Full Text Available Tropical river sardine, Caquetaia kraussii, captured from La Aguá lagoon (Sucre State, Venezuela were acclimatized for four weeks at 22, 24, 30 and 32ºC and at 0, 5, 10, 15 and 17 ‰ salinity. To evaluate effects of thermal response to acclimatization level, the fish were transferred suddenly from lower temperatures (22 and 24ºC to higher ones (32 and 30ºC respectively. Then thermal resistance time was measured at the lethal temperature of 40.9ºC for 30 days. We considered that acclimatization process completed when resistance time was stabilized at the new temperature regime. For the saline effect, the concentrations of sodium and potassium were measured in the tissues at each treatment: gills, white muscle, gut and heart. The results showed that thermal tolerance increased rapidly in 3 h with a 6ºC rise in temperature (from 24 to 30ºC and in 24 h with a 10ºC rise (22 to 32ºC. With decreasing temperatures, the acclimatization level reached its lowest in 11 days with a 6ºC decreases (from 30 to 24ºC and in 14 days with a 10ºC decrease (32 to 22ºC. Caquetaia kraussii regulates as much sodium as potassium in gills and white muscle tissues at all salinity levels tested; however, gut and heart tissues showed significantly different regulations among salinities examined.La sardina tropical de río, Caquetaia kraussii, capturada en la laguna La Aguá (Estado Sucre, Venezuela fue aclimatada durante cuatro semanas a la temperatura de 22, 24, 30 y 32ºC y a 0, 5, 10, 15 y 17 ‰ de salinidad. Para evaluar los efectos de respuestas térmicas a los niveles de aclimatación, los peces fueron transferidos abruptamente desde las temperaturas bajas (22 y 24ºC hasta las altas (32 y 30ºC respectivamente. Se midió entonces la resistencia térmica a la temperatura letal de 40.9ºC durante 30 días. Se consideró que los peces habían alcanzado completamente su aclimatación cuando se estabilizaba al nuevo régimen de temperatura. Para el efecto salino, las concentraciones de sodio y potasio fueron determinadas en los tejidos: branquial, muscular, gástrico y cardíaco. Los resultados mostraron que la tolerancia térmica aumentaba rápidamente en 3 h cuando la diferencia de temperatura era de 6ºC (24 a 30ºC y en 24 h cuando la diferencia era de 10ºC (22 a 32ºC. En los descensos de temperaturas, el nivel de aclimatación se alcanzó a los 11 días cuando el intercambio se hizo desde 30 a 24ºC y en 14 días con un descenso de 10ºC (32 a 22ºC. Los resultados indican que Caquetaia kraussii regula tanto sodio como potasio a nivel muscular y branquial a todos los niveles de salinidad estudiados; sin embargo a nivel gástrico y cardíaco se observaron regulaciones significativamente diferentes entre las salinidades examinadas.

Redescription of Hypostomus johnii, a senior synonym of Hypostomus eptingi (Siluriformes: Loricariidae, Northeastern Brazil

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Telton Pedro Anselmo Ramos

2017-06-01

Full Text Available ABSTRACT Hypostomus johnii (Steindachner was described from the rio Parnaíba basin in the state of Piauí and the rio São Francisco basin in the state of Bahia. Despite the good quality of the original description of H. johnii, it does not currently allow its distinction from congeners. Thus, H. johnii is redescribed based on the analysis of the types and several recently collected specimens. Recent collecting efforts of the rios Parnaíba and São Francisco basins resulted in specimens only being found in the rio Parnaíba basin. This raises doubts about whether H. johnii occurs in the rio São Francisco basin. The species is distinguished from its congeners by having a high number of teeth on the premaxilla and dentary (between 60-115; small to moderate-sized dark spots with a light background; absence of keels on flanks; and abdominal plates more evident on laterals. A lectotype of H. johnii is designated herein and H. eptingi is considered a junior synonym of H. johnii.

Prevalence and intensity of pentastomid infection in two species of snakes from northeastern Brazil

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WO Almeida

Full Text Available This study aimed to evaluate the infection rates of snakes by pentastomids in the semi-arid region of Brazil. Fifteen snakes (four Micrurus ibiboboca (Merrem, 1820 and eleven Philodryas nattereri Steindachner, 1870 were collected between January and April of 2005, in the municipality of Crato (07° 14' S and 39° 24' W, State of Ceará, Brazil. Laboratorial analysis of the respiratory tracts of the sampled snakes indicated differences in host infection rates: four individuals of P. nattereri (36.4% were infected by Cephalobaena tetrapoda Heymons, 1922 (mean infection intensity 1.5 ± 0.28, 1-2 and three specimens (27.3% by Raillietiella furcocerca (Diesing, 1863 (2.3 ± 1.32, 1-5. Only one individual of M. ibiboboca (25% was infected by a non-identified species of Raillietiella sp. These are the first data on pentastomid infection in snakes in Northeastern Brazil and both snake species comprise new host records for the pentastomids. The results also indicate that the generalist parasites C. tetrapoda and R. furcocerca share their definitive hosts.

Morfometría de las especies de Vieja (Cichlidae en ríos de la cuenca del Usumacinta, Chiapas, México Morphometry of Vieja species (Cichlidae in rivers of Usumacinta's basin, Chiapas, Mexico

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Miriam Soria-Barreto

2011-06-01

Full Text Available Se evaluaron y compararon diversas características morfológicas de 6 especies de Vieja Fernández-Yépez, 1969 del río Usumacinta. Se emplearon 20 organismos adultos por especie y 33 medidas corporales que fueron estandarizadas y examinadas con un análisis discriminante. Además se comparó la forma del cuerpo entre las especies, mediante el análisis de morfometría geométrica a partir de imágenes digitalizadas. El análisis con la morfometría tradicional y geométrica permitió diferenciar los seis taxones. Se encontraron 10 medidas discriminantes, que expresan diferencias significativas en la longitud de las aletas y la región cefálica, de las cuales la posición de la boca diferenció estadísticamente más taxones. Las relaciones de similitud con ambos análisis mostraron 2 grupos, siendo V. bifasciata (Steindachner, 1864 y V. synspila (Hubbs, 1935 las especies más parecidas. Las gradillas de deformación mostraron que la mayor variación está en la región cefálica, específicamente en la posición de la boca y los ojos. Las diferencias morfométricas encontradas pueden servir para la determinación taxonómica en trabajos futuros. La variación encontrada en la morfología cefálica y trófica puede ser un mecanismo que favorece la coexistencia de las especies y la diversidad del grupo en la región.We evaluated and compared morphological characteristics among the 6 species of Vieja Fernández-Yépez, 1969 from Usumacinta River. We analyzed 20 adults by specie, obtaining 33 measurements, which were standardized and analyzed with a discriminant analysis. We also performed a comparison of body shape among species, using the geometric morphometric analysis from digitalized images. Traditional and geometric morphometrics allowed distinguishing each taxa. We found 10 discriminants measures, related with the head region and length of fins, only mouth position was different among more taxa. In both analyses, similarity relationships

An Empty Donut Hole: the Great Collapse of a North American Fishery

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Kevin M. Bailey

2011-06-01

Full Text Available Walleye pollock (Theragra chalcogramma is North America's most abundant and lucrative natural fishery, and is the world's largest fishery for human food. The little-known demise of the "Donut Hole" stock of pollock in the Aleutian Basin of the central Bering Sea during the 1980s is the most spectacular fishery collapse in North American history, dwarfing the famous crashes of the northern cod and Pacific sardine (Sardinops sagax. This collapse has received scant recognition and became evident only in 1993 when fishing was banned by an international moratorium; nearly 20 years later it has not recovered. The history of fishing in the North Pacific Ocean after World War II offers some insights into how the Donut Hole pollock fishery developed, and the societal and economic pressures behind it that so influenced the stock's fate. Overfishing was, without a doubt, the greatest contributor to the collapse of the Aleutian Basin pollock fishery, but a lack of knowledge about population biocomplexity added to the confusion of how to best manage the harvest. Unfortunately, the big scientific questions regarding the relationship of Donut Hole fish to other stocks are still unanswered.

Molecular survey and microscopic examination of Hepatozoon Miller, 1908 (Apicomplexa: Adeleorina) in lacertid lizards from the western Mediterranean.

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Maia, João P M C; Perera, Ana; Harris, D James

2012-12-01

The genus Hepatozoon Miller, 1908 (Apicomplexa: Adeleorina) is composed of intracellular haemogregarine parasites that are widely distributed among all tetrapod groups. The present study combines microscopic and molecular data on haemogregarine parasites from lizards in the western Mediterranean. We screened tissue samples and examined blood smears for the presence of species of Hepatozoon from four lizards, namely Algyroides marchi Valverde, endemic to Southeast Spain, Podarcis bocagei Seoane from Spain and Portugal, P hispanica Steindachner from Spain, and P lilfordi Günther from Cabrera, Balearic Islands (Spain). Our results show that prevalence and intensity of Hepatozoon parasites vary between and within lizard species from different regions. Algyroides marchi and P bocagei from Spain had the lowest values, whereas P hispanica had the highest. Phylogeny based on 18S rRNA gene sequences indicates that most of the new Hepatozoon sequences are part of a clade exclusive from North African and Iberian lizards, except for a single P bocagei isolate that is found related to another clade including isolates from other reptile host species and rodents. Interestingly, isolates from Algyroides form a distinct monophyletic subgroup, which could be a signal of strict host-specificity within this host genus.

El cultivo de tilapias: una amenaza a las especies ícticas nativas en Nicaragua.

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McCrary, J.K.

2001-08-01

Full Text Available El cultivo de tilapia del nilo (oreochromis niloticus, linnoeus previamente alimentados con hormonas para producir machos, en la laguna de Apoyo en Nicaragua ha permitido la introducción a la laguna de individuos, incluyendo hembras fecundas. Discutimos las consecuencias de esta introducción, en términos de amenazas de extinción de especies endémicas nativas a través de destrucción de hábitat, competencia por sitios de cortejo y alimentación, proliferación de parásitos en poblaciones de fauna nativa, y la depredación de alevines nativos. Mientras que una liberación anterior de una especie similar (O. aureus Steindachner en la laguna de Apoyo, en 1983, tuvo poco impacto observado, este segundo incidente, aquí documentado, ha resultado en dramáticos impactos negativos en la laguna, amenazando especies endémicas locales y creando posiblemente riesgos en la salud humana. Abogamos por la remoción total de tilapias de ecosistemas naturales como el de Apoyo, y advertimos sobre el peligro de las introducciones de especies no nativas en ecosistemas naturales, aun donde introducciones previas han sucedido.

Indicadores reprodutivos de Parauchenipterus striatulus (Steindachner (Pisces, Auchenipteridae na Represa de Ribeirão das Lajes, Rio de Janeiro, Brasil Reproductive indicators of Parauchenipterus striatulus (Steindachner (Pisces, Auchenipteridae in the Ribeirão das Lajes reservoir, Rio de Janeiro, Brasil

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Francisco Gerson Araújo

1999-01-01

Full Text Available Parauchenipterus striatulus is a representative of the freshwater catfish with wide distribution in the South America region. Despite of being a very abundant fish in rivers and reservoirs of this region, little is known about its biology and ecology. In Ribeirão das Lajes reservoir (22º42'S - 22º50'S, 43º53'- 44º05' W, Rio de Janeiro, the Rio de Janeiro state's largest hydroelectric reservoir, this species is very abundant, representing about 40% of the total experimental fish catches using gill nets. This paper aims to assess aspects of the reproductive cycle of this species describing the gonadal stages, gonadosomatic index, weight-length relationship and condition factor. Fish sampling were carried out bi-monthly, between April 1996 and May 1997. Gill nets used were 100 m long, 4 m high with mesh size between 25 and 65 mm. Macroscopic analysis of 339 individuais were performed for the determination of 5 maturation stages, for both sexes (immature, maturation I, maturation II, ripe, spawned (females and emptied (males. The gonadosomatic index for both sexes was higher from October to March, suggesting a long spawning period while the condition factor was higher from February to June, showing an inverse relationship between these two parameters. Weight-length relationship for males was W=0,0095L3,C862and for females W= 0,0116L3,126, and no significam differences were shown between sex with reference to the alometry coefficient.

Aspectos biometricos del bagre Arius Furthii Steindachner (Pisces Ariidae, colectado en punta Morales, Golfo de Nicoya, Costa Rica

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Maurizio Protti Quesada

2016-03-01

Full Text Available Se analizan estadísticamente algunos parámetros biométricos de 257 ejemplares de Arius furthii (Ariidae, colectados en una zona de playa y otra de manglar en Punta Morales, Puntarenas, Costa Rica. Las colectas se realizaron por medio de “arrastres” con una red tipo “chinchorro”. La talla de los especímenes capturados osciló entre 55 y 276 mm de longitud total y 1,3 a 176 g en peso fresco. El análisis estadístico mostró que la longitud total es la mejor variable para la estimación del peso fresco a través de una ecuación de regresión logarítmica.  Además, se mostró que no existen diferencias significativas en el peso de los Arius furthii colectados en la playa y los colectados en el manglar.

RELACIÓN LONGITUD-PESO DEL RUBIO (Salminus affinis Steindachner, 1880 EN LA CUENCA DEL RÍO SINÚ, COLOMBIA

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Charles Olaya-Nieto

2008-08-01

Full Text Available Objective. To estimate the length–weight relationship of rubio in the Sinu river basin, as a contribution to the management of their fishery. Materials and methods. Between January 2000 and August 2005, 122 individuals with sizes between 9.3 and 63.0 cm total length (TL and weight (WT ranged between 6.6 to 3966.0 g were collected. Resultados. The length–weight relationship was: TW = 0.005 (± 0.03 TL3.19 (± 0.02, positive allometric growth coefficient (b, and correlation coefficient of 0.99. The growth coefficient varied between 3.34 y 3.21 without statistically significant differences (p£0.05. The condition factor oscillated between 0.003 y 0.005, without statistically significant differences (p£0.05. We found a correlation among the condition factor, the level of the Sinu river, and spawning season of the rubio, which extends from March to September. Conclusions. Rubio have adapted to the new conditions of the Sinu river as determined by lack of significant differences in size and weight.

ACUICULTURA DE PARGO LA MANCHA LUTJANUS GUTTATUS (STEINDACHNER, 1869 EN COSTA RICA DENTRO DE UN ENFOQUE ECOSISTÉMICO

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Angel Herrera-Ulloa

2011-07-01

Full Text Available La sobreexplotación pesquera y la búsqueda de alternativas ante la pobreza crónica han llevado a explorar el campo de la maricultura por medio de un enfoque ecosistémico se abrieron dos procesos paralelos: una estrategia e; investigación en laboratorio para el levantamiento larval de peces marinos tropicales y una estrategia de comanejo para desarrollar el cultivo de peces marinos tropicales. El pargo la mancha muestra gran potencial de producción de larvas y posterior cultivo en el mar. No mostró respuestas positivas a la inducción por medio de hormonas, el desarrollo de un ambiente adecuado para su reproducción espontánea, permitió tener desoves frecuentes y de calidad. La fase de levantamiento larval mostró contratiempos por el tamaño reducido de las larvas de pargo la mancha el manejo en tanques apropiados y el uso de enriquecedores permitieran mejorar los procesos y llegar a incrementar la producción de alevines. El enfoque ecosistémico permitió abrir los espacios necesarios que permitieron la operación de un proyecto piloto. La granja se creó con un enfoque productivo, pero también para turismo rural. Overfishing and the search for alternatives to it, led us to the explore mariculture as an option using an ecosystem-based approach through two parallel processes: an in-laboratory research strategy for larval rearing of tropical marine fish, and a strategy of co-management to develop tropical marine fish aquaculture. The spotted rose snapper shows great potential for larvae production and cage culture. This species showed no responses to hormone induction; however, the set up of a suitable environment allowed frequent, high-quality spontaneous spawnings. The larval rearing phase presented problems due to the small size of the larvae; although, management in appropriate tanks and the use of enrichments improved the processes, increasing the production of juveniles. This ecosystem approach allowed the operation of a profitable farm pilot project with a productive approach, but with rural tourism in mind as well.

Costos metabólicos de Engraulis ringens y Sardinops sagax en relación al peso, temperatura y el nivel de actividad

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Villavicencio R., Zoila; Muck, Peter

1983-01-01

El metabolismo estándar de la anchoveta es más alto que el de la sardina; en .las larvas por un factor promedio de 2.3 y por 2.1 en juveniles y adultos en el rango de temperaturas de 14-20ºC. Lo opuesto sucede en el metabolismo activo: para una velocidad de natación de un cuerpo por segundo( =metabolismo de rutina), la anchoveta adulta con un peso mayor de 20 g a 20ºC y mayor de 50 g a 14ºC gasta menos energía que la sardina de tamaños similares; incrementándose la velocidad a 3 c.p .seg a ...

The snake assemblage (Squamata: Serpentes of a Cerrado-Caatinga transition area in Castelo do Piauí, state of Piauí, Brazil

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Francílio da Silva Rodrigues

2011-08-01

Full Text Available This study records and analyzes the diversity and structure of a snake assemblage in a transition area between Cerrado and Caatinga, in the municipality of Castelo do Piauí, state of Piauí, comparing the distribution and similarity of the species composition with other open localities already studied in Brazil. We used three complementary sampling methods: time constrained search (TCS, pitfall traps with drift fences (PFT, and incidental encounters (IE. During the TCS and PFT, 912 hours/observer and 6,468 days/trap were used, respectively. We estimated 23 species of snakes for the locality, although only 19 species were recorded. Philodryas nattereri Steindachner, 1870 (n = 10, Liophis poecilogyrus (Schlegel, 1837 (n = 9, Liophis viridis Günther, 1862 (n = 8 and Thamnodynastes sp. (n = 8 were the most abundant species. Terrestrial, cryptozoic, and diurnal snakes predominated in the assemblage (Boidae = 2 species, Dipsadidae = 12, Colubridae = 2, Elapidae = 1, Viperidae = 2. The results indicate that the fauna of the locality is similar with that of other open formations, especially the Caatinga, corroborating previous floristic studies. Comparisons between snake assemblages analyzed by different authors suggest structural differences between the assemblages of the Cerrado and the Caatinga, contradicting the hypothesis of mixed composition of fauna in these biomes.

Anuran community composition along two large rivers in a tropical disturbed landscape

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Mauricio Almeida-Gomes

2015-02-01

Full Text Available In this study we evaluated how anuran species were distributed in riparian habitats along two large rivers. Sampling was carried out between January and March 2012 in the municipality of Cachoeiras de Macacu, state of Rio de Janeiro. We delimited 20 plots along each river, ten in portions inside the forest of the Reserva Ecológica de Guapiaçu (REGUA, and with comparatively greater amount of forest cover, and ten outside REGUA, with comparatively lesser forest cover surrounding the rivers. We recorded 70 individuals from 14 frog species in the Manoel Alexandre River and 63 individuals from 15 frog species in the Guapiaçu River. The most abundant species in both rivers was Cycloramphus brasiliensis (Steindachner, 1864, and it was more abundant in sections with greater amount of forest cover. This information, coupled with the occurrence of species that are more adapted to open and more disturbed habitats in river sections that harbor lesser riparian vegetation, help to explain differences in amphibian species composition between river sections with greater and lesser forest cover. The results of our study highlight the importance of preserving riparian vegetation associated with rivers in the Atlantic Forest for the conservation of amphibians.

Non-seasonal reproduction in inseminating species of Mimagoniates (Characidae, Characiformes from southern Brazil

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Vinicius Renner Lampert

2018-03-01

Full Text Available Abstract Some aspects of reproduction in two species of Mimagoniates, M. microlepis (Steindachner 1877 and M. rheocharis Menezes & Weitzman 1990 are herein described. Samples were taken monthly from January 1998 to February 1999 in two streams in the locality of Maquiné, Rio Grande do Sul, Brazil. Results from the analysis of hundreds of specimens of M. microlepis and M. rheocharis in two investigated sites indicated mature specimens and peaks of the gonadosomatic index (GSI along the year. There was a negative and significant correlation between M. microlepis male’s GSI and water temperature. Females of the latter species and both sexes of M. rheocharis, in turn, showed no correlation with any of the tested parameters (relative stomach weight, day length, rainfall. Absolute and relative fecundity are lower than in externally fertilized species of Characidae. Maximum oocyte length was 1.14 mm for M. microlepis and 1.02 mm for M. rheocharis and both species were characterized as total spawners based on the type of oocyte development estimated through oocyte size analysis. Features like non-seasonal reproductive period, low fecundity, and insemination may indicate adaptive advantages, which may enhance the chance of survival even with low energetic investment and improved fertilization.

Ecologia da comunidade de metazoários parasitos da Maria-Luiza, Paralonchurus brasiliensis (Osteichthyes: Sciaenidae do litoral do Estado do Rio de Janeiro, Brasil - DOI: 10.4025/actascibiolsci.v25i2.2009 Community ecology of the metazoan parasites of Banded Croaker, Paralonchurus brasiliensis (Osteichthyes: Sciaenidae, from the coastal zone of the State of Rio de Janeiro, Brazil- DOI: 10.4025/actascibiolsci.v25i2.2009

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Renata da Silva Ribeiro

2003-04-01

Full Text Available Foram examinados 93 espécimes de Paralonchurus brasiliensis (Steindachner, 1875, provenientes da Pedra de Guaratiba (23º01’S, 43º38’W litoral do Estado do Rio de Janeiro, Brasil. No período de setembro de 2001 até março de 2002, sendo necropsiados para estudo da sua comunidade de metazoários parasitos. Quinze espécies de parasitos foram coletadas. Paralonchurus brasiliensis é um novo registro de hospedeiro para 13 espécies de parasitos. Contracaecum sp. foi a espécie dominante, com os maiores índices de prevalência e abundância parasitária. Os componentes da comunidade parasitária de P. brasiliensis apresentaram o típico padrão de distribuição superdispersa. A abundância e a prevalência de Procamallanus (Spirocamallus pereirai apresentaram correlação positiva com o comprimento total do hospedeiro. A abundância de Contracaecum sp. apresentou correlação positiva com o comprimento total do hospedeiro. Um par de endoparasitos adultos (Aponurus laguncula - Procamallanus (S. pereirai apresentou covariação negativa e um par de estágios larvais de endoparasitos apresentou covariação positiva entres as abundâncias. Paralonchurus brasiliensis apresentou uma comunidade de metazoários parasitos composta de espécies generalistas, pouco ordenadas e com poucas evidências de associações interespecíficas. Este padrão está em concordância com os estudos realizados com comunidades parasitárias de siaenídeos da região neotropicalNinety-three specimens of banded croaker, Paralonchurus brasiliensis (Steindachner, 1875, collected from Pedra de Guaratiba (23º01’S, 43º38’W, coastal zone, State of Rio de Janeiro, Brazil, between September 2001 and March 2002, were necropsied to study their infracommunities of metazoan parasites. Fifteen species of metazoan parasites were collected. Paralonchurus brasiliensis is a new host record for 13 parasite species. The majority of fishes were parasitized by one or more metazoan

Espectro trófico de la tilapia Oreochromis aureus (Perciformes: Cichlidae en la presa Infiernillo, Michoacán-Guerrero, México

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Ma. de Lourdes Jiménez-Badillo

2000-06-01

Full Text Available Se determinó el espectro trófico de la tilapia Oreochromis aureus (Steindachner 1864, a través del análisis del contenido estomacal de una muestra de 153 especímenes recolectados durante 1993. El estado de alimentación se evaluó por la proporción de grasa alrededor del estómago e intestino, la replexión gástrica y el coeficiente de condición. La evaluación cuantitativa del alimento, se realizó a través de los métodos Volumétrico (V y Frecuencia de Aparición (FA y los Indices Medio Volumétrico (IMV e Importancia Relativa (IIR, los cuales se combinaron para determinar el espectro trófico de la tilapia. Se determinó que su dieta en la presa Infiernillo está constituida por: detritus y plantas vasculares como alimentos preferentes; algas unicelulares como alimento secundario y peces, insectos, semillas de gramíneas, algas filamentosas, cladóceros, ostrácodos, rotíferos y copépodos, como alimentos ocasionales. Se detectaron diferencias alimentarias entre juveniles y adultos y variaciones en el consumo de elementos alimentarios en la época de secas y lluvias. Se concluye que Oreochromis aureus es una especie omnívora con preferencia hacia el detritus y los restos de plantas vasculares. La alimentación esta determinada por la abundancia de las presas en el medio y en los adultos se basa preferentemente en el detritus. La alimentación no es un factor que limite el desarrollo de la tilapia en la presa Infiernillo.The trophic spectrum of tilapia Oreochromis aureus (Steindachner 1864, was determined by stomach content analysis in 153 organisms collected during 1993 in Michoacán-Guerrero, México. The feeding status of the fish at the time of observation was evaluated by the examination of fat surrounding the gut, gastric replection and the condition coefficient. The quantitative evaluation of the food items was carried out by the combination of the following analysis: Frequency of Occurrence, Volumetric Method, Volumetric

A WELL PRESERVED SKELETON OF THE FOSSIL SHARK COSMOPOLITODUS HASTALIS FROM THE LATE MIOCENE OF PERU, FEATURING FISH REMAINS AS FOSSILIZED STOMACH CONTENTS

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ALBERTO COLLARETA

2017-01-01

Full Text Available Both the preservation of the poorly mineralized skeleton of sharks and the preservation of stomach contents are rarely observed in the fossil record. Here we report on a partial skeleton of a lamniform shark, including portions of the visceral arches and the anterior segment of the vertebral column, collected from the late Miocene beds of the Pisco Formation exposed at Cerro Yesera (Ica Desert, South Peru. Based on the morphology of the preserved teeth, this specimen was determined as a juvenile of the extinct lamnid species Cosmopolitodus hastalis. The shark skeleton includes remains of fish (featuring a pilchard determined as Sardinops sp. cf. S. sagax in the abdominal region. These fish remains are interpreted herein as the fossilized stomach contents of the shark. For the first time, piscivory is demonstrated in a juvenile individual of Cosmopolitodus hastalis. This result is consistent with the current knowledge about the feeding habits of immature individuals of extant lamniform shark species (including Carcharodon carcharias and Isurus oxyrinchus. Our report further outlines the fundamental role of schooling pilchards in the late Miocene trophic chains of the highly productive coastal waters off present South Peru. Moreover, the find of this well preserved shark skeleton strengthens the qualification of the Pisco Formation as a Fossil-Lagerstätte, and emphasizes the role of early mineralization processes in cases of exceptional preservation.

Larval fish variability in response to oceanographic features in a nearshore nursery area.

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Pattrick, P; Strydom, N A

2014-09-01

The influence of oceanographic features on ichthyoplankton assemblages in the warm temperate nearshore region of Algoa Bay, South Africa, was assessed. The nearshore ichthyoplankton comprised 88 taxa from 34 families. Samples were collected at six stations between August 2010 and July 2012 using a plankton ring net of 750 mm diameter and 500 µm mesh aperture. The majority of larvae collected were in a preflexion stage, indicating the potential importance of the nearshore for newly hatched larvae. Engraulidae dominated the catch (38·4%), followed by Cynoglossidae (28·1%) and Sparidae (8·4%). Larval fish abundance was highest during austral spring and summer (September to February). Unique patterns in responses of each dominant fish species to oceanographic features in the nearshore indicate the sensitivity of the early developmental stage to environmental variables. Using generalized linear models, ichthyoplankton abundance responded positively to upwelling and when warm water plumes originating from an Agulhas Current meander entered Algoa Bay. Highest abundances of Engraulis encrasicolus and Sardinops sagax were observed during Agulhas Plume intrusions into Algoa Bay. When a mixed and stratified water column persisted in the nearshore region of Algoa Bay, larval fish abundance decreased. The nearshore region of Algoa Bay appears to serve as a favourable environment for the accumulation of ichthyoplankton. © 2014 The Fisheries Society of the British Isles.

Morphological characteristics of the digestive tract of Schizodon knerii (Steindachner, 1875, (Characiformes: Anostomidae: An anatomical, histological and histochemical study

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Marcella L. Dos Santos

2015-06-01

Full Text Available The digestive tracts of 44 specimens of Schizodon knerii were studied using anatomical, histological and histochemical techniques. The mouth has terminal position, the lip epithelium is squamous stratified with mucous, claviform cells and taste buds, teeth have an incisive form and the tongue has a stratified squamous epithelium with mucous cells and taste buds. The oropharynx cavity is formed by gill apparatus and pharyngeal teeth. The oesophagus presented pleated mucosa, a stratified squamous epithelium with mucous cells, oesophageal glands and taste buds. The stomach presented cardiac, fundic and pyloric regions, simple prismatic epithelium with tubular glands, with none in the pyloric region. The intestine contains 11-15 pyloric caeca, a simple prismatic epithelium with brush border, goblet cells and lymphocytes. Mucosal cells, oesophageal glands and goblet cells reacted positively to PAS, amylase + PAS, Ab pH 2.5 and Ab pH 0.5. Gastric prismatic cells reacted positively to PAS, amylase + PAS, but only those in the pyloric region reacted positively to Ab pH 2.5 and Ab pH 0.5. The results improve the understanding of the anatomy of S. knerii feeding habits and the presence of mucosubstances in the epithelium, highlights the importance of glycoproteins for passing food through the digestive tract.

Coupling between the environment and the pelagic resources exploited off northern Chile: ecosystem indicators and a conceptual model Acoplamiento entre el ambiente y los recursos pelágicos explotados en el norte de Chile: un modelo conceptual

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Eleuterio Yáñez

2008-01-01

Full Text Available The eastern boundary of the Chile-Peru Current System constitutes one of the most biologically productive ecosystems in the world, due largely to coastal upwelling and the horizontal advection of nutrients. In this ecosystem, El Niño events are of great importance in the interannual variability of the environment. A change was observed in the environmental regime at the beginning of the 1970s with the onset of the 1972-1973 El Niño, marking an important decrease in the anchovy fishery (Engraulis ringens. After the mid-1970s, sardine (Sardinops sagax landings increased noticeably. A second regime shift at the end of the 1980s was seen mostly in the noticeable recovery of anchovy and the decline of sardine. Herein, we present an integrated conceptual model of the different local and large-scale phenomena that affect the marine environment off northern Chile and the distribution and abundance of pelagic resources. The model considers an analysis of environmental and bio-fishery data on different scales and describes how the interdecadal (associated with re-gime shifts and interannual (associated with El Niño events fluctuations in the Equatorial Pacific are mani-fested in the eastern South Pacific and, therefore, in the northern zone off Chile, affecting the annual eyele, the dynamic of the coastal trapped waves, and coastal upwelling. In this framework, interdecadal fluctuations play an important role in the anchovy-sardine-anchovy replacement sequence.El borde oriental del Sistema de Corrientes de Chile-Perú constituye uno de los ecosistemas de mayor productividad biológica del mundo, debido principalmente a la surgencia costera y advección horizontal de nutrientes. En este ecosistema, los eventos El Niño son de mayor importancia en la variabilidad interanual del ambiente. No obstante, un cambio de régimen ambiental es observado a inicio de los 70's el que hubiera comenzado con El Niño 1972-73 y que marca la gran disminución de la

Sex-specific differences in the synaptonemal complex in the genus Oreochromis (Cichlidae).

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Campos-Ramos, Rafael; Harvey, Simon C; Penman, David J

2009-04-01

Total synaptonemal complex (SC) lengths were estimated from Oreochromis aureus Steindachner (which has a WZ/ZZ sex determination system), O. mossambicus Peters and O. niloticus L. (both of which have XX/XY sex determination systems). The total SC length in oocytes was greater than that in spermatocytes in all three species (194 +/- 30 microm and 134 +/- 13 microm, 187 +/- 22 microm and 127 +/- 17 microm, 193 +/- 37 microm and 144 +/- 19 microm, respectively). These sex-specific differences did not appear to be influenced by the type of sex determination system (the female/male total SC length ratio was 1.45 in O. aureus, 1.47 in O. mossambicus and 1.34 in O. niloticus) and do not correlate with the lack of any overall sex-specific length differences in the current Oreochromis linkage map. Although based on data from relatively few species, there appears to be no consistent relationship between sex-specific SC lengths and linkage map lengths in fish. Neomale (hormonally masculinized genetic female) O. aureus and O. mossambicus had total SC lengths of 138 +/- 13 microm and 146 +/- 13 microm respectively, more similar to normal males than to normal females. These findings agree with data from other vertebrate species that suggest that phenotypic sex, rather than genotype, determines traits such as total SC length, chiasmata position and recombination pattern, at least for the autosomes.

Reproductive plasticity of Hypostomus affinis (Siluriformes: Loricariidae as a mechanism to adapt to a reservoir with poor habitat complexity

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Silvana Duarte

2011-10-01

Full Text Available In this work we describe the gonad morphology and spawning season of Hypostomus affinis (Steindachner, 1877 in a tropical reservoir based on 55 males and 125 females. Our aim was to assess eventual adaptations in reproductive tactics developed by this riverine species inhabiting an oligotrophic reservoir with low habitat complexity, few rocks and few other preferred consolidated substrata. We described the stages of cells of reproductive lineage, gonadal development and some reproductive traits which were compared with information in the available literature. Cells from the spermatogenic lineage were spermatogonia, spermatocytes, spermatids and spermatozoa, and cells from the oocytarian lineage were primary oocytes, previtelogenic oocytes, cortical vesicle oocytes and yolk globules or vitellogenic. Five stages were described for the males/females according to the distribution of oocytes and spermatogenic lineage cells: resting; initial maturation; advanced maturation; partially spent/spawned; totally spent/spawn. Females outnumbered males and reached larger size. Synchronic ovary development in two groups was found with diameter of mature oocytes ranging from 2 to 3.35 mm. Indication of early maturation, a longer reproductive period and the production of smaller eggs in small clutches seems to be features of the reservoir population not found in riverine systems. Such changes in tactics may indicate a shift to an opportunistic strategy, helping the population to withstand environmental constraints and to succeed in this oligotrophic and poorly structured reservoir.

2012 Joint U.S.-Canada Integrated Acoustic and Trawl Survey of Pacific Hake (Merluccius productus) and Pacific Sardine (Sardinops sagax) (SH1204, EK60)

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National Oceanic and Atmospheric Administration, Department of Commerce — Scientists from the Fishery Resource Analysis and Monitoring (FRAM) division at the NOAA Fisheries Northwest Fisheries Science Center (NWFSC), the Fishery Resources...

Inseminating dose and water volume applied to the artificial fertilization of Steindachneridion parahybae (Steindachner, 1877 (Siluriformes: Pimelodidae: Brazilian endangered fish

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Eduardo Antônio Sanches

Full Text Available Abstract The Steindachneridion parahybae is an endangered catfish from Brazil and strategies applied for gametes optimization are necessary. The aim of this study was to assess inseminating doses and water volume upon the fertilization, hatching rates and percentage of normal larvae in S. parahybae . Was used a randomized design in factorial scheme (4×4 with four inseminating doses: 1.0×104, 1.0×105, 1.0×106, 1.0×107spermatozoa oocyte-1 and four volumes of water: 1, 35, 65 and 95mL of water g-1 of oocytes. The combination of doses and volumes were performed in triplicates (n=48. Each incubator (1.5L of useful volume with 1g of oocytes was considered as an experimental unit. Significant interaction between inseminating doses and volumes of water to the values of the fertilization rates and quadratic effect of doses and volume for the values of hatching rates were observed. The doses and volumes did not influence the percentage of normal larvae (87.70±5.06%. It is recommended the use of 5.5×106 spermatozoa oocyte-1 and 1mL of water g-1 of oocytes during in vitro fertilization procedure. These results allowed us to develop new biotechnological strategies applied to the conservation of S. parahybae .

Reproductive indicators of Parauchenipterus striatulus (Steindachner) (Pisces, Auchenipteridae) in the Ribeirão das Lajes reservoir, Rio de Janeiro, Brasil

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Araújo, Francisco Gerson; Duarte, Silvana; Goldberg, Rubens Sterental; Fichberg, Liana

1999-01-01

Parauchenipterus striatulus is a representative of the freshwater catfish with wide distribution in the South America region. Despite of being a very abundant fish in rivers and reservoirs of this region, little is known about its biology and ecology. In Ribeirão das Lajes reservoir (22º42'S - 22º50'S, 43º53'- 44º05' W, Rio de Janeiro), the Rio de Janeiro state's largest hydroelectric reservoir, this species is very abundant, representing about 40% of the total experimental fish catches using...

Macro-Scale Patterns in Upwelling/Downwelling Activity at North American West Coast.

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Romeo Saldívar-Lucio

Full Text Available The seasonal and interannual variability of vertical transport (upwelling/downwelling has been relatively well studied, mainly for the California Current System, including low-frequency changes and latitudinal heterogeneity. The aim of this work was to identify potentially predictable patterns in upwelling/downwelling activity along the North American west coast and discuss their plausible mechanisms. To this purpose we applied the min/max Autocorrelation Factor technique and time series analysis. We found that spatial co-variation of seawater vertical movements present three dominant low-frequency signals in the range of 33, 19 and 11 years, resembling periodicities of: atmospheric circulation, nodal moon tides and solar activity. Those periodicities might be related to the variability of vertical transport through their influence on dominant wind patterns, the position/intensity of pressure centers and the strength of atmospheric circulation cells (wind stress. The low-frequency signals identified in upwelling/downwelling are coherent with temporal patterns previously reported at the study region: sea surface temperature along the Pacific coast of North America, catch fluctuations of anchovy Engraulis mordax and sardine Sardinops sagax, the Pacific Decadal Oscillation, changes in abundance and distribution of salmon populations, and variations in the position and intensity of the Aleutian low. Since the vertical transport is an oceanographic process with strong biological relevance, the recognition of their spatio-temporal patterns might allow for some reasonable forecasting capacity, potentially useful for marine resources management of the region.

Metals and metalloids in Little Penguin (Eudyptula minor) prey, blood and faeces.

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Finger, Annett; Lavers, Jennifer L; Dann, Peter; Kowalczyk, Nicole D; Scarpaci, Carol; Nugegoda, Dayanthi; Orbell, John D

2017-04-01

Piscivorous species like the Little Penguin (Eudyptula minor) are particularly at risk of being negatively impacted by pollution due to their heightened exposure through aquatic food chains. Therefore, determining the concentration of heavy metals in the fish prey of seabirds is an essential component of assessing such risk. In this study, we report on arsenic, cadmium, mercury, lead and selenium concentrations in three fish species, which are known to comprise a substantial part of the diet of Little Penguins at the urban colony of St Kilda, Melbourne, Australia. Metal concentrations in the fish sampled were generally within the expected limits, however, arsenic and mercury were higher than reported elsewhere. Anchovy (Engraulis australis) and sandy sprat (Hyperlophus vittatus) contained higher Hg concentrations than pilchard (Sardinops sagax), while sandy sprat and pilchard contained more selenium. We present these findings together with metal concentrations in Little Penguin blood and faeces, sampled within weeks of the fish collection. Mercury concentrations were highest in the blood, while faeces and fish prey species contained similar concentrations of arsenic and lead, suggesting faeces as a primary route of detoxification for these elements. We also investigated paired blood - faecal samples and found a correlation for selenium only. Preliminary data from stable isotope ratios in penguin blood indicate that changes in penguin blood mercury concentrations cannot be explained by trophic changes in their diet alone, suggesting a variation of bioavailable Hg within this semi-enclosed bay. Copyright © 2017 Elsevier Ltd. All rights reserved.

The 2012 Joint U.S.-Canada Integrated Acoustic and Trawl Survey of Pacific Hake (Merluccius productus) and Pacific Sardine (Sardinops sagax) (SH1204, ME70)

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National Oceanic and Atmospheric Administration, Department of Commerce — Scientists from the Fishery Resource Analysis and Monitoring (FRAM) division at the NOAA Fisheries Northwest Fisheries Science Center (NWFSC), the Fishery Resources...

Distribution, feeding and ecomorphology of four species of Auchenipteridae (Teleostei: Siluriformes in Eastern Amazonia, Brazil

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Tiago M. S. Freitas

Full Text Available ABSTRACT Fish exhibit morphological, physiological and behavioral specializations which enable them to display different ways to explore the environments and resources. Thus, the aim of this study was to verify how four Auchenipteridae species differ in the distribution, feeding habits and morphological traits: Auchenipterichthys longimanus (Günther, 1864, Auchenipterus nuchalis (Spix & Agassiz, 1829, Tatia intermedia (Steindachner, 1877 and Trachelyopterus galeatus (Linnaeus, 1766. This study was conducted in rivers and bays of the Anapú Basin, Pará State (Brazil, where these species are abundant. Specimens were collected using gillnets, and after caught the stomachs were removed for the contents analyzes. Eighteen morphometric measurements from ten adult specimens of each species were taken, combined into fifteen ecomorphological attributes. The species distribution showed that A. longimanus was restricted to rivers, while the others were exclusively caught in the bays. All four species had their diet composed of allochthonous insects, but A. longimanus also exhibited a great frugivorous habit. The most important ecomorphological attributes were relative to the consumption of larger food items (for A. longimanus and T. galeatus and to the longer swimming capacity (for A. longimanus and T. intermedia. These morphological differences and the trophic diversity presented in this study highlighted some important information about how ecomorphological similar species behave and share resources, which may play a significant role on the coexistence of these species in the Anapú Basin.

Contributions to the herpetofauna of the Albertine Rift: Two new species of chameleon (Sauria: Chamaeleonidae) from an isolated montane forest, south eastern Democratic Republic of Congo.

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Tilbury, Colin R; Tolley, Krystal A

2015-01-13

Two new species of chameleons from the genera Rhampholeon and Kinyongia are described from an isolated montane forest remnant situated toward the southern end of the Albertine Rift bordering Lake Tanganyika. The closest known localities of species from these genera are 200km and 400km to the north respectively, separated by large intervening tracts of lowland savannah and Brachystegia (Miombo) woodland - habitats not normally inhabited by species of these genera. Rhampholeon hattinghi sp. nov. and Kinyongia mulyai sp. nov. bear superficial resemblances to previously described species (Rh. boulengeri Steindachner and K. adolfifriderici  (Sternfeld)). Rhampholeon hattinghi sp. nov. has a relatively smooth supra-orbital ridge, deep axillary but absent inguinal mite pockets, prominent white spots on the base of the tail and a uniquely derived hemipenal morphology with billowing parasulcal evaginations. Like K. adolfifriderici, Kinyongia mulyai sp. nov. is devoid of a rostral appendage but differs in having a longer and narrower head, a higher upper labial scale count and by the absence of a dorsal crest in the male. To place these new chameleons within the context of their respective genera, Bayesian and maximum likelihood phylogenetic analyses were carried out utilising two mitochondrial (ND2 and 16S) and one nuclear marker (RAG1).  Both chameleons were found to have morphological features that distinguish them from other congeners. Based on phylogenetic analysis they are clearly separate evolutionary lineages and are described as new species. 

Environmental parameters affecting the structure of leaf-litter frog (Amphibia: Anura communities in tropical forests: a case study from an Atlantic Rainforest area in southeastern Brazil

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Carla C. Siqueira

2014-04-01

Full Text Available Despite a recent increase of information on leaf litter frog communities from Atlantic rainforests, few studies have analyzed the relationship between environmental parameters and community structure of these animals. We analyzed the effects of some environmental factors on a leaf litter frog community at an Atlantic Rainforest area in southeastern Brazil. Data collection lasted ten consecutive days in January 2010, at elevations ranging between 300 and 520 m above sea level. We established 50 quadrats of 5 x 5 m on the forest floor, totaling 1,250 m² of sampled area, and recorded the mean leaf-litter depth and the number of trees within the plot, as well as altitude. We found 307 individuals belonging to ten frog species within the plots. The overall density of leaf-litter frogs estimated from the plots was 24.6 ind/100m², with Euparkerella brasiliensis (Parker, 1926, Ischnocnema guentheri (Steindachner, 1864, Ischnocnema parva (Girard, 1853 and Haddadus binotatus (Spix, 1824 presenting the highest estimated densities. Among the environmental variables analyzed, only altitude influenced the parameters of anuran community. Our results indicate that the study area has a very high density of forest floor leaf litter frogs at altitudes of 300-500 m. Future estimates of litter frog density might benefit from taking the local altitudinal variation into consideration. Neglecting such variation might result in underestimated/overestimated values if they are extrapolated to the whole area.

Morphological, histological and histochemical analysis of the digestive tract of Trachelyopterusstriatulus (Siluriformes: Auchenipteridae

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Marcella L. dos Santos

2015-08-01

Full Text Available ABSTRACT The digestive tract of Trachelyopterus striatulus (Steindachner, 1877 was studied using morphological, histological, and histochemical techniques. The barbels, lips and tongue had stratified squamous epithelium with mucous, claviform cells, and taste buds. Trachelyopterus striatulus had a dental plaque with villiform teeth. The bucopharyngeal cavity was formed by the gill apparatus and pharyngeal teeth with vilifform denticles. The oesophagus presented stratified squamous epithelium with mucous cells and taste buds. The stomach included cardiac, fundic, and pyloric regions and a simple prismatic epithelium with prismatic cells that reacted positively to periodic acid-Schiff (PAS and amylase+PAS. Only the cardiac and pyloric regions responded positively to alcian blue pH 2.5 (Ab pH 2.5 and alcian blue pH 0.5 (Ab pH 0.5. The cardiac and fundic regions exhibited tubular gastric glands. The intestine was 118.90 ± 22.49 mm long with an intestinal coefficient (CO of 0.83 ± 0.13. The epithelium was simple prismatic with a brush border and goblet cells, and a greater number of goblet cells were found in the caudal region of the intestine. The mucous cells and goblet cells reacted positively to PAS, amylase+PAS, Ab pH 2.5, and Ab pH 0.5. We analysed if the function of the mucosubstances and morphological characteristics of the digestive tract of T. striatulus are compatible with omnivorous feeding habit.

Use of electromyogram telemetry to assess the behavior of the Iberian barbel (Luciobarbus bocagei Steindachner, 1864) in a pool-type fishway

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Alexandre, C.M.; Quintella, B.R.; Silva, A.T.; Mateus, C.S.; Romão, F.; Branco, P.; Ferreira, M.T.; Almeida, P.R.

2013-01-01

Decline in fish species populations due to river regulation by dams and weirs promoted the development of fishways, which are becoming one of the most common measures for the restoration of connectivity in rivers. Fishways efficiency can be species specific and thus monitoring and evaluation, and subsequent adjustments to design and hydraulic features, are required to inform potential users prior to installation. In this study we tested the applicability of electromyogram telemetr...

Managing small-scale commercial fisheries for adaptive capacity: insights from dynamic social-ecological drivers of change in Monterey Bay.

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Aguilera, Stacy E; Cole, Jennifer; Finkbeiner, Elena M; Le Cornu, Elodie; Ban, Natalie C; Carr, Mark H; Cinner, Joshua E; Crowder, Larry B; Gelcich, Stefan; Hicks, Christina C; Kittinger, John N; Martone, Rebecca; Malone, Daniel; Pomeroy, Carrie; Starr, Richard M; Seram, Sanah; Zuercher, Rachel; Broad, Kenneth

2015-01-01

Globally, small-scale fisheries are influenced by dynamic climate, governance, and market drivers, which present social and ecological challenges and opportunities. It is difficult to manage fisheries adaptively for fluctuating drivers, except to allow participants to shift effort among multiple fisheries. Adapting to changing conditions allows small-scale fishery participants to survive economic and environmental disturbances and benefit from optimal conditions. This study explores the relative influence of large-scale drivers on shifts in effort and outcomes among three closely linked fisheries in Monterey Bay since the Magnuson-Stevens Fisheries Conservation and Management Act of 1976. In this region, Pacific sardine (Sardinops sagax), northern anchovy (Engraulis mordax), and market squid (Loligo opalescens) fisheries comprise a tightly linked system where shifting focus among fisheries is a key element to adaptive capacity and reduced social and ecological vulnerability. Using a cluster analysis of landings, we identify four modes from 1974 to 2012 that are dominated (i.e., a given species accounting for the plurality of landings) by squid, sardine, anchovy, or lack any dominance, and seven points of transition among these periods. This approach enables us to determine which drivers are associated with each mode and each transition. Overall, we show that market and climate drivers are predominantly attributed to dominance transitions. Model selection of external drivers indicates that governance phases, reflected as perceived abundance, dictate long-term outcomes. Our findings suggest that globally, small-scale fishery managers should consider enabling shifts in effort among fisheries and retaining existing flexibility, as adaptive capacity is a critical determinant for social and ecological resilience.

Biomasa acústica y distribución del jurel Trachurus murphyien el Perú

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Marceliano Segura

2013-10-01

Full Text Available Se analizan los resultados de las evaluaciones hidroacústicas del recurso jurel Trachurus murphyi Nichols 1920 realizadas en aguas peruanas entre 1983 – 2012. Desde 1983 se incluyó al T. murphyicomo especie de estudio durante los cruceros de evaluación de recursos pelágicos ejecutados por el Instituto del Mar del Perú. Debido al énfasis en la estimación de biomasa de la anchoveta Engraulis ringens y de la sardina Sardinops sagax cuando esta última es más abundante, los cruceros se llevan a cabo durante el verano austral y las áreas de evaluación están circunscritas a las zonas más costeras hasta 100 mn, con sólo algunas exploraciones en otras estaciones y hasta 200 millas. El máximo valor de biomasa de 8.51 millones de toneladas de T. murphyien aguas peruanas estimado con las evaluaciones hidroacústicas fue encontrado durante el crucero realizado en otoño (marzo-mayo de 1983. En los años siguientes los estimados de biomasa acústica fluctuaron entre 180 mil toneladas en 1985 y otro máximo de 8.47 millones de toneladas en 1993, para luego disminuir gradualmente hasta un mínimo de 1239 t en 2010, con una ligera recuperación en los años 2011 y 2012. El área de distribución de T. murphyifue muy fluctuante en todo el periodo observado.

Ecotoxicological analysis during the removal of carbofuran in fungal bioaugmented matrices.

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Ruíz-Hidalgo, Karla; Masís-Mora, Mario; Barbieri, Edison; Carazo-Rojas, Elizabeth; Rodríguez-Rodríguez, Carlos E

2016-02-01

Biomixtures are used for the removal of pesticides from agricultural wastewater. As biomixtures employ high content of lignocellulosic substrates, their bioaugmentation with ligninolytic fungi represents a novel approach for their enhancement. Nonetheless, the decrease in the concentration of the pesticide may result in sublethal concentrations that still affect ecosystems. Two matrices, a microcosm of rice husk (lignocellulosic substrate) bioaugmented with the fungus Trametes versicolor and a biomixture that contained fungally colonized rice husk were used in the degradation of the insecticide/nematicide carbofuran (CFN). Elutriates simulating lixiviates from these matrices were used to assay the ecotoxicological effects at sublethal level over Daphnia magna (Straus) and the fish Oreochromis aureus (Steindachner) and Oncorhynchus mykiss (Walbaum). Elutriates obtained after 30 d of treatment in the rice husk microcosms at dilutions over 2.5% increased the offspring of D. magna as a trade-off stress response, and produced mortality of neonates at dilutions over 5%. Elutriates (dilution 1:200) obtained during a 30 d period did not produce alterations on the oxygen consumption and ammonium excretion of O. mykiss, however these physiological parameters were affected in O. aureus at every time point of treatment, irrespective of the decrease in CFN concentration. When the fungally colonized rice husk was used to prepare a biomixture, where more accelerated degradation is expected, similar alterations on the responses by O. aureus were achieved. Results suggest that despite the good removal of the pesticide, it is necessary to optimize biomixtures to minimize their residual toxicity and potential chronic effects on aquatic life. Copyright © 2015 Elsevier Ltd. All rights reserved.

Medidas de conservación y ordenación pesquera del jurel Trachurus murphyien el Perú

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Jorge Zuzunaga

2013-10-01

Full Text Available Las pesquerías peruanas como actividades realizadas sobre recursos naturales renovables son reguladas por un marco jurídico, cuyo objetivo es asegurar su conservación y uso sostenible. La Ley General de Pesca (DL N°. 25977 señala que para cada tipo de pesquería y según la situación del recurso explotado debe establecerse un sistema de ordenamiento que concilie el principio de sostenibilidad de los recursos pesqueros o conservación en el largo plazo, con la obtención de los mayores beneficios económicos y sociales. En el ordenamiento pesquero del jurel Trachurus murphyi, las medidas incluyen entre otras, el régimen de acceso constituido por las autorizaciones de incremento de flota y permisos de pesca, que se otorgan solo a los buques cuyas capturas son destinadas únicamente para el consumo humano directo, de acuerdo a lo dispuesto en el Reglamento de Ordenamiento Pesquero (DS N.° 011-2007-PRODUCE. La obligación de destinar los recursos sardina Sardinops sagax, jurel T. murphyiy caballa Scomber japonicus al consumo humano directo rige desde septiembre 2002 (DS N°. 001-2002-PRODUCE. Otras medidas vigentes restringen el tamaño mínimo de malla de las redes, prohíben la captura de ejemplares menores de 31 cm de longitud total, determinan el inicio y cierre de las temporadas de pesca, los límites de captura o cuotas anuales. Estas disposiciones son complementadas por medidas de seguimiento, control y vigilancia para la efectiva conservación y uso sostenido del recurso.

Quantifying mercury isotope dynamics in captive Pacific bluefin tuna (Thunnus orientalis

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Sae Yun Kwon

2016-02-01

Full Text Available Abstract Analyses of mercury (Hg isotope ratios in fish tissues are used increasingly to infer sources and biogeochemical processes of Hg in natural aquatic ecosystems. Controlled experiments that can couple internal Hg isotope behavior with traditional isotope tracers (δ13C, δ15N can improve the applicability of Hg isotopes as natural ecological tracers. In this study, we investigated changes in Hg isotope ratios (δ202Hg, Δ199Hg during bioaccumulation of natural diets in the pelagic Pacific bluefin tuna (Thunnus orientalis; PBFT. Juvenile PBFT were fed a mixture of natural prey and a dietary supplement (60% Loligo opalescens, 31% Sardinops sagax, 9% gel supplement in captivity for 2914 days, and white muscle tissues were analyzed for Hg isotope ratios and compared to time in captivity and internal turnover of δ13C and δ15N. PBFT muscle tissues equilibrated to Hg isotope ratios of the dietary mixture within ∼700 days, after which we observed a cessation in further shifts in Δ199Hg, and small but significant negative δ202Hg shifts from the dietary mixture. The internal behavior of Δ199Hg is consistent with previous fish studies, which showed an absence of Δ199Hg fractionation during Hg bioaccumulation. The negative δ202Hg shifts can be attributed to either preferential excretion of Hg with higher δ202Hg values or individual variability in captive PBFT feeding preferences and/or consumption rates. The overall internal behavior of Hg isotopes is similar to that described for δ13C and δ15N, though observed Hg turnover was slower compared to carbon and nitrogen. This improved understanding of internal dynamics of Hg isotopes in relation to δ13C and δ15N enhances the applicability of Hg isotope ratios in fish tissues for tracing Hg sources in natural ecosystems.

Long-term variation in a central California pelagic forage assemblage

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Ralston, Stephen; Field, John C.; Sakuma, Keith M.

2015-06-01

A continuous 23 year midwater trawl survey (1990-2012) of the epipelagic forage assemblage off the coast of central California (lat. 36°30‧-38°20‧ N) is described and analyzed. Twenty taxa occurred in ≥ 10% of the 2037 trawls that were completed at 40 distinct station locations. The dominant taxa sampled by the 9.5 mm mesh net included a suite of young-of-the-year (YOY) groundfish, including rockfish (Sebastes spp.) and Pacific hake (Merluccius productus), two clupeoids (Engraulis mordax and Sardinops sagax), krill (Euphausiacea), cephalopods (Doryteuthis opalescens and Octopus sp.), and a variety of mesopelagic species, i.e., Diaphus theta, Tarltonbeania crenularis, "other" lanternfish (Myctophidae), deep-sea smelts (Bathylagidae), and sergestid shrimp. Annual abundance estimates of the 20 taxa were obtained from analysis of variance models, which included year and station as main effects. Principal components analysis of the abundance estimates revealed that 61% of assemblage variance was explained by the first three components. The first component revealed a strong contrast in the abundance of: (a) YOY groundfish, market squid (D. opalescens), and krill with (b) mesopelagics and clupeoids; the second component was associated with long-term trends in abundance. An evaluation of 10 different published oceanographic data sets and CTD data collected during the survey indicated that seawater properties encountered each year were significantly correlated with abundance patterns, as were annual sea-level anomalies obtained from an analysis of AVISO satellite information. A comparison of our findings with several other recent studies of biological communities occurring in the California Current revealed a consistent structuring of forage assemblages, which we conjecture is primarily attributable to large-scale advection patterns in the California Current ecosystem.

The impact of a biomanipulation experiment on the ichthyofauna diet from a neotropical reservoir in Brazilian semiarid

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Cristiane de Carvalho Ferreira Lima Moura

2018-04-01

Full Text Available Abstract Aim To evaluate the impact of a biomanipulation experiment on the feeding of fish species from a neotropical semiarid reservoir, before and after the removal of the exotic species Oreochromis niloticus. Methods The values of Food Index were analyzed for six species: Oreochromis niloticus , Prochilodus brevis Steindachner,1875, Hypostomus cf. paparie Fowler,1941, Hoplias gr. malabaricus Bloch,1794, Astyanax bimaculatus Linnaeus,1758 and Leporinus piau Fowler,194. All data were obtained in two periods, before of the removal O. niloticus (May 2012 to January 2013 and after its removal (April 2013 to November 2013. The Morisita-Horn index was used to evaluate the feeding similarity among the six species and determine trophic categories (insectivorous, omnivorous, iliophaga and piscivora. To establish the probable variations due the presence of O. niloticus species, the Food Index of the six species was used in a Bray-Curtis similarity matrix. Through the Non-metric Multidimensional Scaling (NMDS we could not observe any differences among items consumed by different species. The Canonical Correspondence Analysis (CCA was used to assay the influence of environmental variables on the dietary, from the Food Index data. Results All species were classified in four trophic categories that do not shown any variation among the formed groups during studied periods. After the removal of Nile tilapia some species showed changes in food items, according to NMDS. The CCA indicated low association among the monthly Food Index of species and the environmental changes. Conclusion The process of biomanipulation on the Ecological Station from Serra Negra reservoir, which compares the dietaries from five local species before and after removal of exotic species Oreochromis niloticus, resulted in modification of dietary composition from three of five studied species.

The relationship between habitat complexity and nursery provision for an estuarine-dependent fish species in a permanently open South African Estuary

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Leslie, Timothy; James, Nicola C.; Potts, Warren M.; Rajkaran, Anusha

2017-11-01

Estuarine-dependent marine fish species rely on shallow, sheltered and food rich habitats for protection from predators, growth and ultimately recruitment to adult populations. Hence, habitats within estuaries function as critical nursery areas for an abundance of fish species. However, these habitats vary in the degree of nursery function they provide and few studies have quantitatively assessed the relative nursery value of different habitat types within estuaries, particularly in the context of habitat complexity. This study aimed to assess the nursery value of the dominant vegetated habitats, namely the submergent Zostera capensis (Setch.) (seagrass) beds and emergent Spartina maritima (Curtis) Fernald (salt marsh) beds in the Bushmans Estuary, South Africa. Biomass and stem density were sampled seasonally in order to gain insight into the vegetation dynamics of seagrass and salt marsh beds. Aerial cover, canopy height and underwater camera imagery were used to develop multiple complexity indices for prioritizing habitat complexity. The relatively consistent results of the dimensionless indices (interstitial space indices and fractal geometry) suggest that Z. capensis exhibits an overall greater degree of complexity than S. maritima, and hence it can be expected that fish abundance is likely to be higher in Z. capensis beds than in S. maritima habitats. Underwater video cameras were deployed in seagrass, salt marsh and sand flat habitats to assess the relative abundance and behaviour of the estuarine-dependent sparid Rhabosargus holubi (Steindachner 1881) in different habitats. The relative abundance of R. holubi was significantly higher in Z. capensis seagrass than S. maritima salt marsh and sand flats, whilst the behaviour of R. holubi indicated a high degree of habitat use in structured habitats (both Z. capensis and S. martima) and a low degree of habitat use in unstructured sand flat habitats.

Crecimiento en jaulas del pargo lunarejo Lutjanus guttatus (Steindachner, 1869 con dos tipos de dieta en Bahía Málaga, municipio de Buenaventura, Colombia

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Edgardo Andrés Banguera Gil

2010-01-01

Full Text Available Para dar continuidad al “Programa de desarrollo de la maricultura en el Pacífico colombiano” adelantado por la Universidad del Pacífico, en un cerramiento natural ubicado en la vereda La Sierpe, Bahía Málaga, municipio de Buenaventura, se comparó la tasa de crecimiento de 204 ejemplares silvestres de pargo lunarejo Lutjanus guttatus , alimentados con pescado fresco y concentrado comercial al 35% en proteína, con peso y longitud total promedio de 13,79 cm y 32,21 g, respectivamente. El trabajo se realizó por espacio de 40 días en cuatro jaulas flotantes, de 3 x 1,5 x 0,75 m, dos para cada tratamiento, a densidades de 15 individuos/m 3 , utilizando el 12% de la biomasa corporal para el suministro de los alimentos a evaluar; el crecimiento se analizó mediante los siguientes índices: IPD = Incremento en Peso Diario; TCE = Tasa de Crecimiento Específico. Los peces alcanzaron un peso promedio final de 64,9±5,9 y 58,49±5,9 g para el alimento natural y balanceado comercial respectivamente, lo cual es equivalente a un IPD de 0.8 y 0.7 g/d y una TCE de 1,58 y 1,67 g/d, valores considerados buenos teniendo en cuenta su etapa de desarrollo y comparaciones con otros estudios realizados en Colombia. Los peces aceptaron los dos tipos de alimento de manera satisfactoria, durante el período de cultivo y mostraron gran tolerancia a la manipulación, resistencia a las enfermedades y a las fluctuaciones de la calidad del agua, en especial la salinidad. Los resultados señalan que existen diferencias significativas (P>0.05 entre los dos tratamientos a favor del alimento natural. Los índices de sobrevivencia fueron de 90,2% para peces alimentados con pescado fresco y 85,3% para los alimentados con concentrado. Se concluye que el pargo lunarejo Lutjanus guttatus presenta una importante ventaja para su cultivo como es la fácil aceptación de un concentrado comercial. pero el crecimiento de los peces alimentados con este producto fue significativamente menor que los peces alimentados con alimentos naturales y ambos presentaron valores relativamente en comparación con cultivos de pargo efectuados en otras latitudes por lo que se sugiere realizar cultivos empleando concentrados con mayores niveles de proteínas balanceados para la especie.

Trends in spatio-temporal distribution of Peruvian anchovy and other small pelagic fish biomass from 1966-2009 Tendencias espacio-temporales en la distribución de la biomasa de anchoveta peruana y de otros peces pelágicos pequenos entre 1966 y 2009

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Mariano Gutiérrez

2012-09-01

Full Text Available Changes in abundance and distribution of anchovy and other species of pelagic fish of the Northern Humboldt Current System (NHCS are driven by environmental forcing variations in different time and spatial scales between the coastal 'cold' ecosystem and the 'warm' oceanic one. Data to study these fluctuations have come mostly from the fishery to show how anchovy (Engraulis ringens increases when sardine (Sardinops sagax declines and vice versa. However, using acoustic data on latitudinal biomass we show that other species as mackerel (Scomber japonicus and jack mackerel (Trachurus murphyi also follow the same opposed trend, then the fishery data hides the true dimension of the balance of abundance among species. Based on Hovmoller diagrams we scrutinized the changes in interannual latitudinal acoustic biomass, landings and influence of El Nino events from 1966 to 2009 in order to describe: 1 how the anchovy decadal distribution pattern moved from south to north since the 1960's; 2 how there have been produced concomitant changes in the latitudinal abundance and distribution of other species such as sardine, jack mackerel and mackerel before, during and after El Nino events; and 3 what was the overall effect of the succession of El Nino events on all these pelagic species. We concluded that: a every El Nino event has had an effect on the expansion or contraction of pelagic species distribution and abundance, with different latitudinal effects; and b the El Nino 1997-98 did not trigger but accelerated a decline phase on the abundance of sardine, jack mackerel and mackerel by a reduction of their ideal habitat due to an expansion of the coastal ecosystem caused by a shallower location of the upper limit of the Oxygen Minimum Zone (OMZ These findings observed using past data might be taken into consideration for fishery management purposes when considering future scenarios.Los cambios en la abundancia y distribución de anchoveta y de otras especies

Preservación y abundancia de escamas de peces en sedimentos del margen continental de Chile (21-36° S Fish scale preservation and abundance in sediments from the continental margin off Chile (21-36° S

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JAVIER A DÍAZ-OCHOA

2008-12-01

Full Text Available Con el objetivo de evaluar la relación entre la preservación de escamas de peces y las variaciones en las condiciones redox en sedimentos del margen continental de Chile, este trabajo presenta recuentos de escamas de peces y concentraciones normalizadas de elementos redox sensibles (Mo/Al, S/Al, Fe/Al en ocho testigos de sedimento recolectados en la zona de minimo oxígeno frente a Chile (Iquique: 20°15' S, bahía de Mejillones: 23° S y Concepción: 36° S. En el norte de Chile (Iquique y Mejillones predominan las escamas de anchoveta (Engraulis ringens y de peces de la familia Myctophidae (media = 90 y 120 escamas 1.000 cm-3, respectivamente mientras que en Chile centro-sur (Concepción son más abundantes las escamas de jurel (Trachurus murphy; media = 140 escamas 1.000 cm-3. La abundancia de escamas de merluza común (Merluccius gayi gayi y de sardina (Sardinops sagax es aproximadamente un orden de magnitud más baja que la de anchoveta o jurel. En general, los valores más altos y los rangos más amplios de variación en las razones Mo/Al, S/Al y Fe/Al se encuentran en Mejillones (Mo/Al ~0,8-12 mg g-1, S/Al 0,2-4,6 g g-1, Fe/Al 0,3-0,7 g g-1 seguidos por Iquique (Mo/Al -0,2-1,8; S/Al 0,2-0,7, Fe/Al 0,5-0,8, mientras que Concepción revela valores más bajos y poco variables (Mo/Al ~0,07, S/Al ~0,15 y Fe/Al ~0,5. La razón Mo/Al, utilizada como indicador de paleo-oxigenación, permite inferir condiciones reductoras relativamente más intensas en los sedimentos de la Bahía de Mejillones e Iquique que en Concepción. En las tres localidades de muestreo se evidencia una asociación estadísticamente significativa entre la abundancia de escamas de anchoveta y el logaritmo de la razón Mo/Al (r²= 0,46; P 1 mg g-1.The relationship between fish scale preservation and variations in the sediment redox conditions on Chile's continental shelf are evaluated herein through fish scale counts and normalized concentrations of redox sensitive elements

Immunological cross-reactivity between four distant parvalbumins-Impact on allergen detection and diagnostics.

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Sharp, Michael F; Stephen, Juan N; Kraft, Lukas; Weiss, Thomas; Kamath, Sandip D; Lopata, Andreas L

2015-02-01

Fish are the largest and most diverse group of vertebrates. Fish are also a part of the eight food groups that cause the majority of IgE mediated food reactions. Detection tools for fish allergens are however limited due to the great diversity of fish species, despite fish allergy and its major allergen parvalbumin being well documented. The most commonly studied fish are frequently consumed in North America and Europe. However, much less is known about fish allergens in the Australasian region although fish is widely consumed in this region. A comprehensive phylogenetic analysis was performed of known parvalbumin amino acid sequences to determine possible candidate antigens for new cross-reactive antibodies to be used to detect most fish parvalbumins. Polyclonal rabbit antibodies were raised against parvalbumins from frequently consumed barramundi (Lates calcarifer), basa (Pangasius bocourti), pilchard (Sardinops sagax) and Atlantic salmon (Salmo salar). These were evaluated for cross-reactivity against a panel of 45 fish extracts (raw, heated and canned fish). Anti-barramundi parvalbumin proved to be the most cross-reactive antibody, detecting 87.5% of the 40 species analyzed, followed by anti-pilchard and anti-basa antibody. In contrast the anti-salmon antibody was very specific and only reacted to salmonidae and a few other fish. All analyzed fish species, except mahi mahi, swordfish, yellowfin tuna and all 5 canned fish had parvalbumin detected in raw extracts. However antibody reactivity to many fish was heat liable or susceptible to denaturation, demonstrating that some parvalbumins have most likely conformational epitopes, which lose antibody reactivity after heat treatment. We have demonstrated the generation of highly cross-reactive anti-parvalbumin antibodies that could be used for the detection of allergenic fish parvalbumin in contaminated food products. This cross-reactivity study thus shows processing of fish, especially canning, can have on impact

Karyotypic diversity in four species of the genus Gymnotus Linnaeus, 1758 (Teleostei, Gymnotiformes, Gymnotidae): physical mapping of ribosomal genes and telomeric sequences

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Scacchetti, Priscilla Cardim; Pansonato-Alves, José Carlos; Utsunomia, Ricardo; Oliveira, Claudio; Foresti, Fausto

2011-01-01

Abstract Conventional (Giemsa, C-Banding, Ag-NORs, CMA3) and molecular (5S rDNA, 18S rDNA, telomeric sequences) cytogenetic studies were carried out in specimens of ten distinct fish populations of the genus Gymnotus (Gymnotus sylvius Albert and Fernandes-Matioli, 1999, Gymnotus inaequilabiatus Valenciennes, 1839, Gymnotus pantherinus Steindachner, 1908, and G. cf. carapo Linnaeus, 1758) from different Brazilian hydrographic basins. Gymnotus sylvius presented a diploid number of 40 chromosomes (22m+12sm+6st), Gymnotus pantherinus presented 52 chromosomes (32m+18sm+2st), while Gymnotus inaequilabiatus (42m+10sm+2a)and Gymnotus cf. carapo (38m+12sm+4st) presented 54 chromosomes. The C-banding technique revealed centromeric marks in all chromosomes of all species. Besides that, conspicuous blocks of heterochromatin were found interstitially on the chromosomes of Gymnotus inaequilabiatus, Gymnotus cf. carapo,and Gymnotus pantherinus. All four species showed single nucleolus organizing regions confirmed by results obtained through Ag-NORs and FISH experiments using 18S rDNA probes, which showed the NORs localized on the first chromosome pair in Gymnotus inaequilabiatus, Gymnotus cf. carapo,and Gymnotus pantherinus, and on pair 2 in Gymnotus sylvius. CMA3 staining revealed additional unrelated NORs marks in Gymnotus sylvius and Gymnotus pantherinus. The 5S rDNA probes revealed signals on one pair in Gymnotus sylvius and two pairs in Gymnotus pantherinus; Gymnotus inaequilabiatus had about seventeen pairs marked, and Gymnotus cf. carapo had about fifteen pairs marked. It is considered that the high amount of heterochromatin identified in the chromosomes of Gymnotus inaequilabiatus and Gymnotus cf. carapo could have facilitated the dispersion of 5S rDNA in these species. Interstitial signals were detected on the first metacentric pair of Gymnotus sylvius by telomeric probes (TTAGGG)n indicating the possible occurrence of chromosomal fusions in this species. The present

Karyotypic diversity in four species of the genus Gymnotus Linnaeus, 1758 (Teleostei, Gymnotiformes, Gymnotidae: physical mapping of ribosomal genes and telomeric sequences

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Priscilla Scacchetti

2011-08-01

Full Text Available Conventional (Giemsa, C-Banding, Ag-NORs, CMA3 and molecular (5S rDNA, 18S rDNA, telomeric sequences cytogenetic studies were carried out in specimens of ten distinct fish populations of the genus Gymnotus (G. sylvius Albert and Fernandes-Matioli, 1999, G. inaequilabiatus Valenciennes, 1839, G. pantherinus Steindachner, 1908, and G. cf. carapo Linnaeus, 1758 from different Brazilian hydrographic basins. G. sylvius presented a diploid number of 40 chromosomes (22m+12sm+6st, G. pantherinus presented 52 chromosomes (32m+18sm+2st, while G. inaequilabiatus (42m+10sm+2a and G. cf. carapo (38m+12sm+4st presented 54 chromosomes. The C-banding technique revealed centromeric marks in all chromosomes of all species. Besides that, conspicuous blocks of heterochromatin were found interstitially on the chromosomes of G. inaequilabiatus, G. cf. carapo, and G. pantherinus. All four species showed single nucleolus organizing regions confirmed by results obtained through Ag-NORs and FISH experiments using 18S rDNA probes, which showed the NORs localized on the first chromosome pair in G. inaequilabiatus, G. cf. carapo, and G. pantherinus, and on pair 2 in G. sylvius. CMA3 staining revealed additional unrelated NORs marks in G. sylvius and G. pantherinus. The 5S rDNA probes revealed signals on one pair in G. sylvius and two pairs in G. pantherinus; G. inaequilabiatus had about seventeen pairs marked, and G. cf. carapo had about fifteen pairs marked. It is considered that the high amount of heterochromatin identified in the chromosomes of G. inaequilabiatus and G. cf. carapo could have facilitated the dispersion of 5S rDNA in these species. Interstitial signals were detected on the first metacentric pair of G. sylvius by telomeric probes (TTAGGGn indicating the possible occurrence of chromosomal fusions in this species. The present study reveals valuable cytotaxonomic markers for this group and allows a more precise evaluation of the processes involved in the

Infection of the muscle tissue of the filter-feeding cichlid, Chaetobranchopsis orbicularis Steindachner, 1875, by Kudoa orbicularis (Myxozoa: Multivalvulidae on Marajó Island in the Brazilian Amazon region

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J.L. Sindeaux-Neto

Full Text Available ABSTRACT This study describes aspects of infections caused by the myxosporidian Kudoa orbicularis in filter-feeding cichlids, Chaetobranchopsis orbicularis, caught in the Arari River in the municipality of Cachoeira do Arari, on Marajó Island, Pará, Brazil. The parasite forms pseudocysts scattered throughout the striated epaxial and hypaxial muscles. Samples embedded in paraffin were analyzed histologically using hematoxylin-eosin, Gömöri, Ziehl-Neelsen, and Giemsa staining. Necropsy of the C. orbicularis specimens revealed that 100% (50/50 were infected with K. orbicularis. The specimens presented grossly abnormal muscle texture, resulting in extensive inconsistencies and weakness. Progressive softening of the muscles was observed during necropsy, indicating the rapid enzymatic autolysis of the tissue. The parasite found in the muscle tissue of C. orbicularis was identified as K. orbicularis, with clinical signs of disease being observed in the fish. The necropsy revealed extensive damage to the host organism, with well-established fibrocystic infections in the muscle fibers, associated with post mortem myoliquefaction.

Impact of El Niño events on pelagic fisheries in Peruvian waters

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Ñiquen, Miguel; Bouchon, Marilú

2004-03-01

Using data from stock assesment surveys on pelagic resources during El Niño events of 1972/73, 1982/83, 1997/98, we analyze biological changes on pelagic ecosystems and pelagic fisheries during different stages of development of El Niño phenomenon: emergence, full, final and post-Niño. Results indicate changes in spatial distribution of resources, their concentration and size structure. In anchovy (Engraulis ringens) a decrease in biomass was observed, which was estimated at 1.2 million tons in September 1998, the lowest throughout the 1990s. This resource showed an asymmetric distribution towards the south of Peru. Other pelagic resources increased their biomass during or after Niño events, primarily sardine (Sardinops sagax), jack mackerel (Trachurus murphyi), pacific mackerel (Scomber japonicus), and longnose anchovy (Anchoa nasus). At the end of the El Niño phenomenon we found less productivity but more diversity in the pelagic ecosystem. During the 1997/98 El Niño, the diversity index (Manual de Ecologia, 1a Edition, Editorial Trillas, Mexico, 267pp) increased from 0.87 to 1.23-1.70. In both the emergence stage and fully developed stages of El Niño we found large numbers of sardine and longnose anchovy present simultaneously. Size structure of sardine, jack mackerel, and pacific mackerel showed an increase in juveniles. Anchovy during El Niño showed a single modal group composed of adults, but the post-Niño phase indicated an increase in juveniles with an average length of 6-7 cm. In El Niño conditions spawning among anchovy was low, but among sardine and pacific mackerel it was high. We observed, for the first time during full spawning, juvenile sardines with a total length of 18-20 cm. The anchovy spawning season during the post-Niño phase was considerably lengthened, from April to December 1998. Drastic change occurred in fisheries when monospecific fisheries, based on anchovy before El Niño, became multispecific fisheries based on sardine, jack

Estudos sobre estrutura, ciclo de vida e comportamento de Sardinella brasiliensis (Steindachner, 1879, na área entre 22ºS e 28ºS, Brasil: 3. morfologia e histologia de ovários e escala de maturidade Studies on the structure, life cycle and behaviour of Sardinella brasiliensis (Steindachner, 1879, in the region between 22ºS and 28ºS, Brazil: 3. Morphology and histology of ovaries and maturity scale

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Victoria Judith Isaac-Nahum

1983-01-01

Full Text Available Uma melhor compreensão da dinâmica do processo reprodutivo de Sardinella brasiliensis e obtida através da associação de aspectos micro e macroscópicos das gonadas durante o ciclo sexual. O presente trabalho apresenta uma descrição das fases de desenvolvimento ovocitarias e dos estadios de maturidade dos ovarios de 119 fêmeas de S. brasiliensis, coletados na costa brasileira entre 22ºS e 28ºS. São descritas seis fases ovocitarias e duas estruturas derivadas, analisando-se as características citologicas das células germinativas durante o processo de maturação. Foram estabelecidos sete estadios: A (virgem, Bi (em início de maturação, Bf (em maturação avançada, Cf (maduro inicial, Cf (maduro desovado, D (es vaziado e R (em repouso, sendo discutida sua correspondência com outras es calas aplicadas as espécies.A better understanding of the reproductive process is obtained when histologic analysis of gonades is associated with macroscopic observations during the sexual cycles. This paper describes the developmental stages of the oocytes of the ovaries in 119 females of S. brasiliensis sampled along the Brazilian coast, between 22ºS and 28ºS. The cytologic characteristics of the germinative cells during the maturation process are given and six oocyte phases are described. Seven maturity stages are established: A (virgin, Bi (incipient maturation, Bf (advanced maturation, Ci (mature, Cf (ripe, D (spent and R (repose. These stages are compared to those presently used with respect to S. brasiliensis.

Elucidating dynamic responses of North Pacific fish populations to climatic forcing: Influence of life-history strategy

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Yatsu, A.; Aydin, K. Y.; King, J. R.; McFarlane, G. A.; Chiba, S.; Tadokoro, K.; Kaeriyama, M.; Watanabe, Y.

2008-05-01

In order to explore mechanistic linkages between low-frequency ocean/climate variability, and fish population responses, we undertook comparative studies of time-series of recruitment-related productivity and the biomass levels of fish stocks representing five life-history strategies in the northern North Pacific between the 1950s and the present. We selected seven species: Japanese sardine ( Sardinopus melanostictus) and California sardine ( Sardinopus sagax) (opportunistic strategists), walleye pollock ( Theragra chalcogramma, intermediate strategist), pink salmon ( Oncorhynchus gorbuscha, salmonic strategist), sablefish ( Anoplopoma fimbria) and Pacific halibut ( Hippoglossus stenolepis) (periodic strategists) and spiny dogfish ( Squalus acanthias, equilibrium strategist). The responses in terms of productivity of sardine, pink salmon, sablefish and halibut to climatic regime shifts were generally immediate, delayed, or no substantial responses depending on the particular regime shift year and fish stock (population). In walleye pollock, there were some periods of high productivity and low productivity, but not coincidental to climatic regime shifts, likely due to indirect climate forcing impacts on both bottom-up and top-down processes. Biomass of zooplankton and all fish stocks examined, except for spiny dogfish whose data were limited, indicated a decadal pattern with the most gradual changes in periodic strategists and most intensive and rapid changes in opportunistic strategists. Responses of sardine productivity to regime shifts were the most intense, probably due to the absence of density-dependent effects and the availability of refuges from predators when sardine biomass was extremely low. Spiny dogfish were least affected by environmental variability. Conversely, spiny dogfish are likely to withstand only modest harvest rates due to their very low intrinsic rate of increase. Thus, each life-history strategy type had a unique response to climatic

A LATE SANTONIAN FISH-FAUNA FROM THE EUTAW FORMATION OF ALABAMA RECONSTRUCTED FROM OTOLITHS

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WERNER W. SCHWARZHANS

2018-01-01

Full Text Available The otoliths described here from the Late Santonian of the Eutaw Formation of Alabama, represent one of the earliest association of teleost otoliths known from North America and it is remarkable for its good preservation and species diversity. They were collected by the late C.K. Lamber in 1969 from a road cut on the Hurtsboro-Marvyn highway south of Marvyn in Russell County, eastern Alabama. It contains 18 taxa based on sagittae otoliths, of which 14 are identifiable to the species level, 10 species are new to science and five new genera. The new otolith-based genera are: Allogenartina n. gen. (Stomiiformes family indet., Pseudotrichiurus n. gen. (Aulopiformes family indet., Eutawichthys n. gen. (Beryciformes family indet., Cowetaichthys n. gen. (Polymixiidae and Vox n. gen. (Teleostei family indet.; the new species are: Elops eutawanus n. sp., Genartina cretacea n. sp., Allogenartina muscogeei n. sp., Pseudotrichiurus sagax n. sp., Apateodus? assisi n. sp., Eutawichthys compressus n. sp., Eutawichthys stringeri n. sp., Cowetaichthys alabamae n. sp., Cowetaichthys lamberi n. sp. and Vox thlotlo n. sp. In addition, 8 different morphologies are recognized based on lapilli otoliths, which however cannot be identified to a distinct taxonomic level except for a species of the Ariidae. Two taxa can be related to otoliths recently recorded in situ, pertaining to the genera Osmeroides and Apateodus. The otolith association bears much similarity with those of the Campanian to Maastrichtian of the USA described previously as indicated by the dominance of otoliths of the genera Eutawichthys and Osmeroides. Differences with those faunas are on the species level as well as in the accessory components. The abundance of otoliths of the albuliforms (Osmeroides, putative stomiiforms (Allogenartina, beryciform (Eutawichthys and polymixiids (Cowetaichthys characterizes a rather stable faunal composition through the entire Late Cretaceous of locations studied in

Effects of dam operation on the endangered Júcar nase, Parachondrostoma arrigonis, related to mesohabitats, microhabitat availability and water temperature regime, in the river Cabriel (Spain)

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Martinez-Capel, Francisco; Costa, Rui; Muñoz-Mas, Rafael; Diego Alcaraz-Hernandez, Juan; Hernandez-Mascarell, Aina

2010-05-01

The presence of large dams affects habitat availability, often regarded as the primary factor that limits population and community recovery in rivers. Physical habitat is often targeted in restoration, but there is often a paucity of useful information. Habitat degradation has reduced the complexity and connectivity of the Mediterranean streams in Spain. These changes have diminished the historical range of the endangered Júcar nase, Parachondrostoma arrigonis (Steindachner, 1866), isolated the populations of this species, and probably contributed to its risk of extinction. In the Júcar River basin (Spain), where this fish is endemic, the populations are mainly restricted to the river Cabriel, which is fragmented in two segments by the large dam of Contreras. In this river, 3 main lines of research were developed from 2006 to 2008, i.e., microhabitat suitability, mesohabitat suitability, and water temperature, in order to relate such kind of variables with the flow regime. The main goal of the research project, funded by the Spanish Ministry of Environment, was to detect the main reasons of the species decline, and to propose dam operation improvements to contribute to the recovery of the species. The flow and water temperature regimes were also studied in the river Cabriel, upstream and downstream the large dam of Contreras. During the three years of study, below the dam it was observed a small and not significant variation in the proportions of slow and fast habitats; the regulated flow regime was pointed out as the main reason of such variations. At the microhabitat scale, optimal ranges for average depth and velocity were defined; these data allowed us to develop an estimation of weighted useable area under natural and regulated conditions. The Júcar nase were found majorly at depths no greater than 1,15 meters with slow water velocities. It was possible to observe a clear alteration of the flow and water temperature regime below the dam, due to the cold

A study of the life history of brazilian sardine, Sardinella brasiliensis.: III. development of sardine larvae

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Yasunobu Matsuura

1975-01-01

Full Text Available Larvae and juveniles of S. brasiliensis (Steindachner, 1879, ranging from 6.4 mm to 35.5 mm, were identified from plankton samples taken in waters off the southern Brazilian coast from 1969 through 1971. Changes in the pattern of pigmentation, body proportions and formation of fin rays are described. During transformation stage a considerable advancement of the dorsal and anal fins was observed. Changes in body proportions are pronounced at the size of 19 mm. Complete ossification of all fin rays is attained at the size of 20 mm, but ossification of the ventral scutes is delayed and completed only at the size of 30 mm. Ossification of the vertebral column was completed at the size of about 16 mm.O presente trabalho é parte do projeto SOL e tem por objetivo descrever a morfologia das larvas da sardinha verdadeira, Sardinella brasiliensis (=S. aurita, com o intuito de determinar um padrão que possibilite a identificação das mesmas. São feitas considerações sobre a morfologia das larvas de outros clupeídeos existentes na região e ressaltadas as diferenças com relação as larvas de S. brasiliensis. Os resultados, posteriormente, serão usados como base para o estudo quantitativo da abundância de larvas de sardinha. O material foi coletado na costa sul do Brasil de 1969 a 1971, com uma rede de plâncton do tipo cônico-cilíndrico. Durante o desenvolvimento das larvas, foi observado um considerável deslocamento das bases das nadadeiras dorsal e anal, para uma posição mais anterior. Com o tamanho de 19 mm (comprimento padrão, ocorre uma mudança geral, considerável, nas proporções corporais. A ossificação de todos os raios das nadadeiras completa-se quando a larva atinge 20 mm, mas a ossificação dos escudos ventrais só se completa quando ela atinge 30 mm de comprimento. A ossificação das vertebras completa-se a 16 mm de comprimento. O tamanho de 19 mm foi considerado como o fim do estagio larval, e, apos este comprimento

Diversidade e distribuição espaço-temporal de anuros em região com pronunciada estação seca no sudeste do Brasil Temporal and spatial distribution and diversity of anurans in a region with pronounced dry season in southeastern Brazil

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Tiago Gomes dos Santos

2007-03-01

Full Text Available As atividades antrópicas têm alterado profundamente os ambientes naturais e muitas vezes afetado a diversidade e distribuição dos anuros. O objetivo deste estudo foi investigar as seguintes questões: (1 qual a composição da anurofauna em uma região de pastagem com clima marcadamente sazonal no extremo noroeste paulista? (2 como adultos e girinos das espécies se distribuem temporal e espacialmente? (3 a riqueza de espécies está correlacionada com descritores da heterogeneidade dos hábitats de reprodução? Na área estudada foram registradas 20 espécies de anuros, distribuídas em 11 gêneros de quatro famílias: Leptodactylidae (9, Hylidae (8, Microhylidae (2 e Bufonidae (1. Destas, Chaunus schneideri (Werner, 1894, Physalaemus centralis Bokermann, 1962 e Physalaemus fuscomaculatus (Steindachner, 1864 foram registradas apenas por coleta de girinos, enquanto Dendropsophus minutus (Peters, 1872 e Leptodactylus labyrinthicus (Spix, 1824 ocorreram somente em corpos d'água próximos aos selecionados. As espécies registradas são conhecidas por sua ampla distribuição geográfica e por colonizarem áreas alteradas em outras localidades. Não houve correlação entre a riqueza de espécies e a complexidade estrutural dos corpos d'água. Entretanto, a maior riqueza de espécies foi registrada nos corpos d'água de longa duração. As poças temporárias de hidroperíodo instável foram colonizadas inicialmente por leptodactilídeos, enquanto que as poças permanentes ou temporárias estáveis foram colonizadas por hilídeos. A atividade de vocalização e de reprodução da maioria das espécies foi restrita ao período quente e chuvoso do ano, um padrão típico de ambientes tropicais sazonais. Cinco espécies [Chaunus schneideri, Dendropsophus nanus (Boulenger, 1889, Hypsiboas albopunctatus Spix, 1824, Leptodactylus podicipinus (Cope, 1862 e Pseudopaludicola aff. saltica (Cope, 1887] vocalizaram durante a estação seca e chuvosa, mas

Sardinella brasiliensis: tipo de desova, fecundidade e potencial reprodutivo relativo. I. Área entre 23º40's e 24º20's, Brasil Sardinella brasiliensis: spawning, fecundity and relative spawning power. I. Area between 23º40's and 24º20's, Brazil

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A. E. A. de M Vazzoler

1976-01-01

Full Text Available 1 Sardinella brasilieneis apresenta desova individual do tipo total; entretanto as fêmeas desovantes nao maturam todas ao mesmo tempo, ocorrendo maturação e desovas sucessivas de grupos de indivíduos (cardumes, o que determina um período de desova prolongado; 2 Durante o período de desova de 1964-65 foram constatados valores para os índices de maturidade e gonadal, e para o fator de condição, mais eleva dos que durante 1963-64, o que sugere melhores condições alimentares durante tal período; 3 Os pesos médios por classe de comprimento, para as fêmeas, também foram mais elevados durante 1964-65, bem como o comprimento médio, a fecundidade média por fêmea e o potencial reprodutivo relativo; 4 Os valores dos índices.considerados foram distintos dentro de um mes mo período, entre as varias fases, mas também variaram significativamente para uma mesma fase, entre os dois períodos, indicando não poderem ser utilizados como fator isolado para a caracterização do grau de desenvolvimento dos ovarios; 5 As relações entre fecundidade e comprimento total, peso total, peso das gonadas e peso do corpo mostraram-se significativamente diferentes entre os dois períodos; 6 O tamanho dos óvulos, para uma mesma fase, variou de um período para o outro, sendo mais elevado durante 1964-65; 7 Os resultados mostram que, apesar dos índices e relações terem um significado biológico, referem-se a organismos vivos submetidos à ação do meio ambiente variável, e não podem ser encarados como fixos; sua utilização deve ser associada a observações puramente biológicas, servindo apenas como "auxiliares" na determinação ou avaliação de um processo biológico qualquer.This paper is a contribution to the knowledgment of some aspects of the reproduction of Sardinella brasiliensis (Steindachner, 1879 from the area between 23º40'S and 24º20'S, Brazil. The individual spawning, fecundity, maturation and gonadal indexes, condition factor

The Length-Weight, Length-Length Relationship and Condition Factor of Angora Loach, Oxynoemacheilus angorae (Steindachner, 1897 Inhabiting Kılıçözü Stream in Kızılırmak River Basin (Central Anatolia-Turkey

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Okan Yazıcıoğlu

2016-12-01

Full Text Available In this study, length-weight relationship (LWR, length- length relationship (LLR and condition factor (K of Angora loach, Oxynoemacheilus angorae were determined. A total of 103 specimens were sampled from Kılıçözü Stream in 2014. The length and weight of specimens were ranged 3.5-9.8 cm and 0.38-6.58 g, respectively. Length-weight relationships for female, male and all samples were found as W= 0.01056.TL2.896 (r²= 0.923, W= 0.00963.TL2.940 (r²= 0.978 and W= 0.00987.TL2.929 (r²= 0.963, respectively. LWRs indicated an isometric growth in female, male and all samples. The values of Fulton’s condition factor (K ranged from 0.699 to 1.246 for females and from 0.654 to 1.072 for males. All length-length relationships were statistically significant.