THREATENED FISHES OF THE WORLD: Coptodon walteri (Thys van den Audenaerde 1968) (Perciformes: Cichlidae)

Coptodon walteri, Thys van den Audenaerde, 1968, je endemski ciklid iz Obale Bjelokosti i Liberije koji je ocijenjen kao gotovo ugrožena vrsta zbog ribolovnog pritiska, gubitka staništa i zagađenja vode zbog opsežnog iskapanja zlata u koritu rijeke Cavally. Iskazana je izrazita potreba za izradom planova zaštite i upravljanja za ovu vrstu.Coptodon walteri Thys van den Audenaerde 1968, an endemic cichlid of Ivory Coast and Liberia, is assessed as Near Threatened due to fishing pressure, and loss of habitats and aquatic pollution as a result of extensive clandestine gold mining in the bed of the Cavally River. There is an immediate need for developing conservation and management plans for this species

Genetic Adaptability of Sarotherodon Melanotheron to Polycyclic Aromatic Hydrocarbons (PAHs) in Some Senegal Hydrosystems

The objective of this study is to evaluate the level of Polycyclic Aromatic Hydrocarbons (PAH) contamination at the Sine-Saloum (Foundiougne, Kaolack and Missirah), Hann Bay and Niayes (1 and 2) sites in Sénégal and genetic ecotoxicology of Sarotherodon melanotheron specimens from these sites.The genes of the specimens were studied by the enzymatic electrophoresis technique. Seven enzymatic systems (ADH, AAT, IDHP, MDH, PGM, GPI and EST) were analyzed. The analysis of the PAHs was carried out by gas chromatography coupled to mass spectrometry (GCMS). Populations of Sarotherodon melanotheron and sediments used for PAH measurements were sampled in 2009. Chemical characterization of the sampling sites revealed a high concentration of PAHs at Foundiougne and Hann Bay. The high pollution of environment is characterized by PAH napht (Foundiougne (14 378 ng/g) ; Hann Bay (5856 ng/g). The analysis of allelic variability showed the existence of an adaptive polymorphism at the PGM locus in S. melanotheron. The particularly low frequencies of the PGM * 105 allele in populations of disturbed environment (Foundiougne, Kaolack, Hann Bay, Niayes 1 and Niayes 2) suggest its involvement in the response to environmental stress. A negative correlation was observed between the PGM, IDHP and MDH-1 locus and PAH. The presence of PAHs in the environmentcauses to a decrease in the frequency of the PGM * 105 alleleatS. melanotheronspecimens

PREDVIĐANJE ČIMBENIKA KOJI UTJEČU NA SASTAV STRUKTURA RIBA U ČETIRI OBALNE RIJEKE (JUGOISTOČNA OBALA BJELOKOSTI) POMOĆU UMJETNIH NEURONSKIH MREŽA

The present study is focused on small coastal rivers in southeast Ivory Coast, aimed to predict species richness of fish guilds and to test contribution of environmental variables for explaining guild structure with Self- Organizing Map (SOM) and Backpropagation (BP) algorithms. The former method was applied to pattern the samples based on the richness of six major fish guilds observed (benthivores, invertivores, detritivores, piscivores, herbivores and omnivores). Four clusters were identified: cluster I was characterised by benthivores, cluster II was distinguished by invertivores, detritivores, piscivores and omnivores, cluster III had high richness of benthivores, invertivores and herbivores, and cluster IV had high numbers of omnivore, detritivore and piscivore species. The BP showed high predictability (0.89 for benthivores, 0.85 for omnivores and Odonata, 0.84 for herbivores). There was high correlation between observed and estimated values for piscivores (0.77) and detritivores (0.72); the poorest fit was for invertivores (0.63). The frequency histogram of residuals showed that most residuals lie around zero for all guilds. The most contributing variables in predicting the six fish trophic guilds were water temperature, conductivity, total dissolved solids, dissolved oxygen, depth, width, canopy and distance from source. This underlines the crucial influence of both instream characteristics and riparian environment.Ovo je istraživanje usmjereno prema malim obalnim rijekama na jugoistočnoj Obali Bjelokosti s ciljem predviđanja bogatstva vrsta riba i testiranjem doprinosa varijabli iz okolice kako bi se objasnila struktura populacija pomoću samoorganiziranih karata (SOM) i povratnih (BP) algoritama. Metoda je primijenjena na uzorku temeljenim na bogatstvu šest glavnih zabilježenih tipova ishrane (bentivori, invertivori, detrivori, piscivori, herbivori i omnivori). Identificirane su četiri skupine: klaster I je karakteriziran bentivorima, klaster II se odlikuje invertivorima, detrivorima, piscivorima i omnivorima, klaster III je bogat bentivorima, invertivorima i herbivorima, a klaster IV je imao visok broj omnivora, detrivora i piscivora. BP je pokazao visoku predvidljivost (0,89 za bentivore, 0,85 za omnivore i Odonata, 0,84 za herbivore). Visoka korelacija je zamijećena između promatranih i procijenjenih vrijednosti za piscivore (0,77) i detrivore (0,72), a najmanja za invertivore (0,63). Histogram pokazuje da se većina ostataka kreće oko nule za sve osobine. Varijable koje su najviše doprinijele predviđanju šest trofičkih ribljih struktura su temperatura vode, provodljivost, ukupno otopljene tvari, otopljeni kisik, dubina, širina, zasjenjenost i udaljenost od izvora. To naglašava presudan utjecaj karakteristika vodotoka i priobalnog okoliša

Threatened fishes of the world: Coptodon walteri (Thys van den Audenaerde 1968) (Perciformes: Cichlidae)

Coptodon walteri Thys van den Audenaerde 1968, an endemic cichlid of Ivory Coast and Liberia, is assessed as Near Threatened due to fishing pressure and loss of habitats, and aquatic pollution as a result of extensive clandestine gold mining in the bed of the Cavally River. There is an immediate need for developing conservation and management plans for this species