| [detection of the hepatitis a virus in fish at a fish farm]. | in this study, we have researched enteroviruses in digestive tract and gills of 106 fishes from farming station, belonging to the five most eaten species in ivory coast (chrisychthys walkeri, chrisychthys nigrodigitatus, tilapia nilotica, tilapia guineensis, sarotherodon melanotheron). hepatitis a virus was found in 12 fishes (11.3%), five times in gills, three times in digestive tract and four times in both. the two species apparently the more contaminated, were chrisychthys nigrodigitatus, sar ... | 1987 | 2836101 |
| [effect of temephos on the acetylcholinesterase activity of the brain of tilapia guineensis. 1: experimental study at operative doses]. | after having exposed during 10 minutes the tilapia guineensis to a concentration of 0,05 mg/l of temephos (concentration of a larvicide used for the field test), the authors note a lowering of the acetylcholinesterastic activity of the brain to an order of 25%. the return to a normal activity is achieved within 20 to 25 days. a new exposure, happening one week after the first, provokes a further lowering before the return to a normal value. the authors question themselves on the consequences of ... | 1982 | 6189264 |
| [effect of temephos on the acetylcholinesterase activity of the brain of tilapia guineensis. 2: experimental study of 24-hour exposure to the toxic compound]. | the exposition of the tilapia guineensis to concentrations used in the field to destroy the simulium larvae in their aquatic biotopes is 0,05 mg/l/10 minutes. the authors have previously remarked a significant lowering of acetylcholinesterasic brain activity in this fish. in the case of a much prolonged contact (24h corresponding 144 times the theoretic time of contact), it is noticed that, if this immediate effect is not more pronounced, on the other hand it is noticeable for a much longer acet ... | 1982 | 6189265 |
| [effect of temephos on acetylcholinesterase activity in the brain of tilapia guineensis. 3: comparative effect of temephos and 3 substitute insecticides]. | the onchocerciasis control programme (ocp) is realized in the major part of the treated area by weekly applications of temephos in biotopes of simulles larvae. this insecticide is very effective and its impact on the aquatic fauna is evaluated by means of periodic samplings of the fauna. therefore, the most sensitive way of tracking down fish poisoning is by studying the brain acetylcholinesterase depression. evaluated on tilapia guineensis this lowering is moderate when operational doses are us ... | 1983 | 6193610 |
| differential response of tilapia guineensis fingerlings to inorganic fertilizer under various salinity regimes. | the influence of salinity on the response of the estuarine teleost, tilapia guineensis fingerlings to acute toxic effects of inorganic nitrogen-phosphorus-potassium (npk) (15: 15: 15) fertilizer was investigated using semi-static bioassay. the toxicity of npk fertilizer was found to increase significantly with increase in the salinity level from 0.05 %. to 32.4 %o. the 96 hr lc50 value at salinity of 32.4 %o was 0.11 mg/l and was found to be significantly (p < 0.05) higher than the toxicity valu ... | 2006 | 17405331 |
| acute toxicity and induced weight changes in laboratory tests with mn and cu against tilapia guineensis (dumeril) and tympanotonus fuscatus (linne). | the acute toxicity of mn and cu against tilapia guineensis and tympanotonus fuscatus and the sub-lethal effects of the metals on weight changes were investigated in laboratory experiments employing standard bioassay techniques. based on 96 hr lc50 values, copper was more toxic than manganese to either test animal by several orders of magnitude. against either test metal, t. guineensis was remarkably more susceptible than t. fuscatus. at sub-lethal concentrations, particularly the two highest con ... | 2006 | 17436519 |
| lethal toxicity of industrial chemicals to early life stages of tilapia guineensis. | the toxic effects of industrial chemicals on three early life stages of an economically important fish, tilapia guineensis were investigated using the organisation for economic cooperation and development (oecd) # 203 recommended semi-static renewal bioassay. the assessment was necessary for the uncontrollable disposal of neatex (liquid detergent) and norust cr 486 (corrosion inhibitor) into the niger delta environment of nigeria. the estimated 96-h lc(50) for 7-, 14- and 28-day-old fish in noru ... | 2008 | 18262353 |
| role of fish as predators of mosquito larvae on the floodplain of the gambia river. | we examined the potential of using native fish species in regulating mosquitoes in the floodplain of the gambia river, the major source of mosquitoes in rural parts of the gambia. fishes and mosquito larvae were sampled along two 2.3-km-long transects, from the landward edge of the floodplain to the river from may to november 2005 to 2007. a semifield trial was used to test the predatory capacity of fish on mosquito larvae and the influence of fish chemical cues on oviposition. in the field, the ... | 2009 | 19496426 |
| factors triggering floodplain fish emigration: importance of fish density and food availability. | emigration is a widespread phenomenon among fish species in seasonal habitats, but little is known about the factors which trigger this behaviour. in controlled experiments using tilapia guineensis, a species widely occurring in the seasonal floodplains of west africa, density of fish played a significant role in triggering fish migration, whereas a lack of food available caused an increase in exploratory behaviour but with no impact on successful emigration. the impact of fish density and subse ... | 2009 | 20161114 |
| habitat associations, reproduction and diet of the guinean tilapia tilapia guineensis of the gambia river floodplains. | the ecology of the guinean tilapia tilapia guineensis a dominant species of the lower gambia river floodplains and an important food source in parts of west africa was studied to better understand the threat posed from construction of a barrage across the river. the catch per unit effort (cpue) of t. guineensis was positively associated with conductivity and dissolved oxygen and negatively associated with water depth and the % vegetation cover. diet studies indicated that the t. guineensis is pr ... | 2010 | 20557603 |
| cichlids of the banc d'arguin national park, mauritania: insight into the diversity of the genus coptodon. | to determine the species diversity of cichlids in the banc d'arguin national park (pnba) and their phylogenetic relationships with other species in west africa, a morphometric and meristic and molecular phylogenetic study was conducted. both approaches not only confirm the presence of sarotherodon melanotheron in pnba but also demonstrate the presence of a second species from the genus coptodon. while morphometric characteristics match the description of the guinean tilapia coptodon guineensis, ... | 2016 | 26856797 |
| bilateral asymmetry in certain morphological characters of sarotherodon melanotheron rüppell 1852 and coptodon guineensis (günther 1862) collected from lake ahémé and porto-novo lagoon bénin, west africa. | asymmetry analysis was carried out for three bilateral characters of two cichlid fish species, sarotherodon melanotheron and coptodon guineensis collected from two localities, lake ahémé and porto-novo lagoon, republic of bénin, west africa. for both s. melanotheron and c. guineensis snout length (sl), eye diameter (ed) and number of scales on lateral line (lls), bilateral asymmetry was higher in the fish specimens collected from porto-novo lagoon compared with that of specimens from lake ahémé. ... | 2016 | 26790602 |