Tropicultura (Jan 2010)
Caractéristiques de la population de Distichodus rostratus Günther, 1864 (pisces: Distichodontidae) du lac de barrage de Taabo (bassin du Bandama, Côte d'Ivoire). Implications pour une gestion rationnelle du stock
Abstract
Population Characteristics of Distichodus rostratus Günther, 1864 (pisces: Distichodontidae) in the Taabo Man Made Lake (Bandama Basin, Ivory Coast). Implications for a Rational Management of the Stock. Some characteristics of the fish Distichodus rostratus of Taabo lake were studied in order to establish basis of a rational management of the stock. Specimens were sampled in July, October and December 2006 and March and June 2007. Analyses were about the spatio-temporal dynamic of population sex-ratio, size structure, length-weight relationships and condition factor. The global sex-ratio was in favour of the males (3.5 :1) and presented a seasonal variation. Fish size ranged from 47 to 530 mm SL and there was a significant difference (p< 0.05) between individuals sampled in the superior part (Mean= 183.09 ± 75.10 mm SL) of the lake and those sampled in the inferior part (Mean= 110.91 ± 38.30 mm SL). Specimens caught during inflow had length widely higher than those caught during drop in the water level (p< 0.05). The growth of this species appeared positive allometric in almost all the categories (b= 2.98 - 3.33. The condition factor ranged from 0.44 to 5.97 and it was higher for fish collected in the superior part (Mean= 1.92 ± 0.27) than those collected in the inferior one (Mean= 1,64 ± 0.41).
