SEX RATIO, SIZE AND WEIGHT STRUCTURE, LENGTH-WEIGHT RELATIONSHIP AND CONDITION FACTOROF THREE DEMERSAL FISH SPECIESOF SENEGALESE WATERS, WEST AFRICA

This study examined size and weight structure, length-weight relationship (LWR) and condition factor (K) for three demersal species caught by small-scale fisheries: Cephalopholistaeniops, Boopsboops and Plectorhinchusmediterraneuson the Senegalese coast from September 2013 to August 2014.Driftnets were the most commonly used fishing gear to catch fishes, followed by longlines n° 7 to 12 and gillnets (35-40 mm mesh).Females outnumbered malesin all seasonsin the landingssites and Length-frequency distributions varied significantly between sexes for all seasons (P<0.05). The value of exponent b of length-weight relationship of combined sexesforB.boops, C.taeniopsand P.mediterraneus, were found to be respectively 2.8332, 3.0938 and 2.8511. Slopes of females and males LWRsdid not differ statistically within the same season, while they differed between the warm and the cold season. Analysed data showed that the condition factor (K) of B. boobswas less than 1, indicating that this species was not in good physiological stateKscore of 0.95±0.13), while for C. taeniopsand P.mediterraneus(K score respectively of 1.46±0.20 and 1.30±0.15) the values weregreater than 1,implied that this demersal fish was in good physiologicalcondition.The data collected provided new information on the morphological and physiological characteristics of these species populations.