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Jose Marcelo Rocha Aranha - One of the best experts on this subject based on the ideXlab platform.

  • introduction of the african catfish Clarias gariepinus burchell 1822 into southern brazil
    Biological Invasions, 2006
    Co-Authors: Jean Ricardo Simoes Vitule, S C Umbria, Jose Marcelo Rocha Aranha
    Abstract:

    We record here the introduction of the African catfish Clarias gariepinus into the Guaraguacu River basin in Parana State, Brazil, an area with an extremely rich endemic fish fauna, including many catfishes. C. gariepinus was introduced as escapees from ponds built for recreational angling. These catfishes are very large and hard predators, thus posing serious potential for impact on the native fish fauna. The impact of C. gariepinus needs study with emphasis on finding means for controlling its spread.

Cecilie K Skar - One of the best experts on this subject based on the ideXlab platform.

  • cand actinochlamydia clariae gen nov sp nov a unique intracellular bacterium causing epitheliocystis in catfish Clarias gariepinus in uganda
    PLOS ONE, 2013
    Co-Authors: Andreas L Steigen, Are Nylund, Egil Karlsbakk, Peter Akoll, Ingrid Uglenes Fiksdal, Stian Nylund, Robinson Odong, Heidrun Plarre, Ronald Semyalo, Cecilie K Skar
    Abstract:

    Background and Objectives Epitheliocystis, caused by bacteria infecting gill epithelial cells in fish, is common among a large range of fish species in both fresh- and seawater. The aquaculture industry considers epitheliocystis an important problem. It affects the welfare of the fish and the resulting gill disease may lead to mortalities. In a culture facility in Kampala, Uganda, juveniles of the African sharptooth catfish (Clarias gariepinus) was observed swimming in the surface, sometimes belly up, showing signs of respiratory problems. Histological examination of gill tissues from this fish revealed large amounts of epitheliocysts, and also presence of a few Ichthyobodo sp. and Trichodina sp.

Carole Rougeot - One of the best experts on this subject based on the ideXlab platform.

  • thermosensitivity of the sex differentiation process in the african catfish Clarias gariepinus determination of the thermosensitive period
    Aquaculture, 2016
    Co-Authors: Saidou Santi, Vincent Gennotte, Aboubacar Toguyeni, Charles Melard, Nadine Antoine, Carole Rougeot
    Abstract:

    Abstract Gonadal sex differentiation in gonochoristic fish is generally labile and under the control of two interacting processes: genetic sex determination (GSD) and environmental sex determination (ESD). Numerous experimental studies deal with temperature induced-sex differentiation in teleosts, but none focused on the African catfish Clarias gariepinus . The aim of this study was to confirm the thermosensitivity of the sex differentiation process and to determine the thermosensitive period during the African catfish development. Fish were exposed to high temperature (36 °C) for 3 days at different periods during ontogenesis. The treatment was applied every 3 days from fertilization until 29 days post-hatching (dph). Before and after the thermal treatment, fish were reared at 28 °C. Gonadal development was histologically characterized on fish sampled at 10, 15, 20, 25, 35, 45, 55 and 70 dph. Our results demonstrated that the African catfish displays a thermosensitivity of the sex differentiation process, with a masculinizing effect of high temperature (36 °C). The most thermosensitive period extended from 6 to 8 dph. Fish batches exposed to 36 °C during this period showed a sex-ratio skewed towards the male phenotype, ranging from 58 to 100% (high inter-familial variability). The African catfish gonads (male and female) stayed histologically undifferentiated until 20 dph. Obvious signs of gonadal differentiation clearly appeared at 25 dph in females and at 45 dph in males. Variability in sex-ratios between progenies and in the response to thermal treatment suggests a role of minor genetic factors and interactions between genomic and environmental determinants in the expression of the sexual phenotype. Statement of relevance 1. This paper provides novel methods to control African catfish Clarias gariepinus sex differentiation through high temperature exposure and then to produce all-male populations. 2. Our work underlines the possibility to significantly reduce high temperature (masculinizing effect) treatment period to 3 days and consequently increase survival rate of progenies after treatment. 3. This study also shows the inter-family variability of thermosensitivity on the sex differentiation process in Clarias gariepinus .

Jean Ricardo Simoes Vitule - One of the best experts on this subject based on the ideXlab platform.

  • a review of Clarias gariepinus invasions in brazil and south africa
    Journal of Fish Biology, 2016
    Co-Authors: Vanessa S Daga, Olaf L F Weyl, Bruce R Ellender, Jean Ricardo Simoes Vitule
    Abstract:

    African sharptooth catfish Clarias gariepinus is native to most of Africa and small parts of Asia, but has been introduced to 37 countries mainly for aquaculture. This review of introductions, establishment, spread and impact of C. gariepinus in Brazil and outside of its native range in South Africa provides evidence that the species has been able to overcome all barriers to invasion in both countries. Following initial introductions across geographical barriers, containment seems to have been impossible and escape from aquaculture facilities and spread by illegal introductions is an invasion pathway in both countries. There is evidence of individuals dispersing rapidly following escape, and surviving and reproducing at multiple sites in a wide spectrum of habitats in both countries. There is a severe paucity of research on impacts, many of which are inferred from field and laboratory observations, but have not been demonstrated at population or community level. Such impact studies are urgently required to better understand the consequences of these invasions and to develop appropriate strategies to mitigate impacts and spread.

  • introduction of the african catfish Clarias gariepinus burchell 1822 into southern brazil
    Biological Invasions, 2006
    Co-Authors: Jean Ricardo Simoes Vitule, S C Umbria, Jose Marcelo Rocha Aranha
    Abstract:

    We record here the introduction of the African catfish Clarias gariepinus into the Guaraguacu River basin in Parana State, Brazil, an area with an extremely rich endemic fish fauna, including many catfishes. C. gariepinus was introduced as escapees from ponds built for recreational angling. These catfishes are very large and hard predators, thus posing serious potential for impact on the native fish fauna. The impact of C. gariepinus needs study with emphasis on finding means for controlling its spread.

Ibrahim O Ganiyu - One of the best experts on this subject based on the ideXlab platform.

  • substituting fishmeal with hermetia illucens in the diets of african catfish Clarias gariepinus effects on growth nutrient utilization haemato physiological response and oxidative stress biomarker
    Aquaculture, 2020
    Co-Authors: Femi John Fawole, Lateef Oloyede Tiamiyu, Ayodeji A Adeoye, Khadijah I Ajala, Saudat O Obadara, Ibrahim O Ganiyu
    Abstract:

    Abstract A 60-day experiment was conducted to examine the effect of fishmeal substitution with black soldier fly larvae (BSFL) meal on the growth performance, nutrient utilization, haematology, serum biochemistry, and oxidative status of Clarias gariepinus fingerlings. Four diets were formulated to be isonitrogenous (418 g Kg−1 crude protein), isolipidic (95 g Kg−1 crude lipid) and isocaloric (20.14 MJ Kg−1 gross energy). The control diet was formulated using fishmeal (FM) as the principal protein source and was progressively substituted with Hermetia illucens (hereafter referred to as HP) larvae meal at 25%, 50%, and 75%, on equivalent protein basis, corresponding to dietary inclusion level of 57, 115, and 172 g Kg−1, respectively. A total of 180 fingerlings of African catfish (Clarias gariepinus) was used for the trial and distributed randomly to twelve plastic tanks each containing 15 (4.0 ± 0.01 g/fish) fish. At the end of the trial, the fish fed HP 50% recorded the highest final body weight, weight gain, weight gain percentage, and specific growth rate compared to other groups (p   .05) was noticed on the feed intake. A significantly higher whole-body protein was recorded in HP 50%, whereas lipid and ash contents showed no variation (p > .05). The blood parameters and differential leucocyte counts were not statistically different; however, serum total protein, globulin, glucose, triglycerides, and total bilirubin differed significantly among the dietary groups (p