UPDATE OF ICHTHYOFAUNA AND ITS CONSERVATION STATUS IN THE AGHIEN LAGOON, CÔTE D’IVOIRE

Istraživanje se usredotočilo na raznolikost ihtiofaune te njen status očuvanja i osjetljivosti u slatkovodnoj laguni Aghien (jugoistočno od Obale Slonovače). Za prikupljanje podataka o ribama korištena su dvapristupa uzorkovanja: eksperimentalni i tradicionalni ribolov. Kao rezultat, 80 vrsta zabilježenih u laguni raspoređeno je u 55 rodova, 27 porodica i 10 redova. Najčešće zastupljeni redovi su Perciformes, Siluriformes, Osteoglossiformes, Characiformes, Cyprusinodontiformes i Pleuronectiformes. Cichlidae, Mormyridae i Clupeidae predstavljale su najraznolikije porodice. Sa pojavnošćuod 100%, najčeste vrste su bile: Brycinus longipinnis, Chrysichthys nigrodigitatus, Pellonula leonensis, Schilbe intermedius i S. mandibularis. U ukupnoj ribljoj populaciji, aprema IUCN crvenoj listi, četiri vrste su opisane kao „skoro ugrožene“ (Coptodon walteri, Marcusenius furcidens, Galeoides decadactylus i Cynoglossus senegalensis), četiri su zabilježene kao „osjetljive“ (B. brevis, Rhexipanchax nimbaensis, Enteromius raimbaulti i Tilapia busumana) i jedna vrsta kao „ugrožena“ (Pseudotolithus senegalensis).Kategorije vrsta koje imaju interes za očuvanje prema IUCN crvenoj listi predstavljaju 10,26% od cjelokupne populacije. Populacija ribe u Aghien laguni podijeljena je u sedam klasa u rasponu od „niske“ do „vrlo visoke“ osjetljivosti, u pogledu osjetljivosti na stres i ribolovni pritisak.This study focused on the diversity of fish fauna, its conservation status and its vulnerability in the Aghien freshwater lagoon (southeast of Côte d\u27Ivoire). For the fish data collection, two sampling approaches were used: experimental fishing and artisanal fishing. As a result, 80 species observed in this lagoon are distributed into 55 genera, 27 families and 10 orders. The best represented orders are the Perciformes, Siluriformes, Osteoglossiformes, Characiformes, Cyprinodontiformes and Pleuronectiformes. The Cichlidae, Mormyridae and Clupeidae represented the best diversified family. With an occurrence of 100%, the most frequent species are: Brycinus longipinnis, Chrysichthys nigrodigitatus, Pellonula leonensis, Schilbe intermedius and S. mandibularis. In the whole fish population, according to IUCN red list, four species where described as Near Threatened (Coptodon walteri, Marcusenius furcidens, Galeoides decadactylus and Cynoglossus senegalensis), four as Vulnerable (B. brevis, Rhexipanchax nimbaensis, Enteromius raimbaulti and Tilapia busumana)and one as Endangered species (Pseudotolithus senegalensis). These categories of species that have a conservation interest according to theIUCN Red List represent respectively 10.26% of the whole population. Fish population of the Aghien Lagoon are divided into seven classes ranging from "low" to "very high" vulnerability, regarding the vulnerability to stress due to fishing pressure

Genetic ecotoxicology of Sarotherodon melanotheron from some Sénégal hydrosystems related to level of contamination by some micropollutants

International audienceOn the purpose to study the genetic ecotoxicology of Sarotherodon melanotheron, the degree of contamination due to two micropollutants (Polychlorinated biphenyls (PCBs) and Polybrominateddiphenyl ethers (PBDE)) on seven sites (Foundiougne, Kaolack, Missirah, Koular, HannBay and Niayes (1 and 2) was evaluated. Seven systems (ADH, AAT, IDHP, MDH, PGM, GPI and EST) were analyzed through the technical of enzymatic electrophoresis. The specimens and sediments used for the proportioning pollutants were sampled into 2009.The analysis of indicator PCBs was carried out by gaseous chromatography coupled to a detector with capture of electrons (GC-DCE).-The analysis of the PBDE, was done by gaseous chromatography coupled to mass spectrometry high resolution (GC-MSHR). Highest concentrations of pollutants PCBs (19 ng/g) and PBDE (5 ng/g) were observed in Hann Bay. The analysis of allelic variability revealed an adaptive polymorphism at locus EST-14 and PGM at S. m. heudelotii; PGM at S. m. paludinosus. The presence of allele EST-14*110 in Hann Bay and weakest frequencies particularly of allele PGM*105 in populations of disturbed zones suggest her implication in the response to the undergone environmental stress. A negative correlation was observed between locus EST-14 and PBDE. The fast alleles from this locus (EST-14*110) could be selected against in populations living in contaminated environment

Phytoplankton Composition and trophic state of Guessabo lake (Upstream in Buyo lake, Ivory Coast)

Objectives: The trophic quality of Guessabo Lake (Ivory Coast) under the influence of fishing and agriculture was analysed starting according from the phytoplankton composition. Methodology and results: Sampling spatio-temporal in pelagic zone were made from a plankton net and supplemented with an integrated sampler. A total of three hundred and forty six species were identified. The groups, by orders of prevalence are, Chlorophyta with 164 species (48 %), Euglenophyta with 64 species (19 %), Cyanobacteria represented by 53 species (16 %), Bacillariophyta with 50 species (15 %) and, the other groups (Pyrrophyta, Chrysophyta and Xanthophyta) represented by 15 species (4 %). On the level of sampling stations of Guessabo Lake, 239 species were identified in Guemon sector against 231 and 257 species respectively in bed of the lake and Haut Sassandra sector. Concerning Guemon sector, 181 species were recorded at station G1 and 192 at station G5. In bed of lake (Channel), 154 species were listed at station G2, whereas 157 and 168 species were observed respectively at stations G4 and G6. For Haut Sassandra, stations G3 and G7 respectively presents 208 and 211 species. During this study, 103 species constant were listed against 66 species additional and 170 species accidental. In the floristic list, 73 species are common to all sampling stations. Sorensen index showed a similarity between the sectors and sampling stations. Trophic index based on Phytoplankton composition indicated that lake is from mesotrophy to eutrophy state. Key words: Phytoplankton, lake, mesotrophy, eutrophy; Ivory Coast