Condition factor, gonadosomatic index, sex ratio and length weight relationship of Mormyrus rume, Mormyrus hasselquisti, Gnothonemus cyprinoides, Gnathonemus senegalensis and Petrocephalus bane ansorgei (Mormyridae) from Asa Lake, Ilorin, Nigeria were studied. The results showed that the condition factor range were 0.57-1.12, 0.64-1.22, 0.46-0.98, 0.66-1.18 and 0.86-1.28 in G. senegalensis, G. ...

Sex ratio, size at maturity, maturity stages, fecundity and egg diameter of Oreochromis niloticus from Coatetelco Lake, Morelos State, Mexico, were studied from January to December 1993. Sex ratio (male:female) was approximately 1:1.02. Length at maturity was 117 mm (males) and 120 mm (females). The fecundity ranged between 104 and 709 eggs, with egg diameter from 1,000 to 3,000 microns. The go...

Ablation of the telencephalic hemispheres blocked reproductive behavior and decreased the rate of operant responding for conspecific visual reinforcement. Repeated administration of operant conditioning sessions for 4 weeks following the ablation resulted in a partial recovery of the operant rate but not of reproductive behavior. Social isolation, which increases reactivity in Macropodus, had n...

  Gravid wild kutum broodstock, Rutilus frisii kutum, on their upstream migration to Valiabad River (northern Iran) were kept in captivity to allow them to ovulate (captive ripe). Then the impact of captivity on some reproductive and physiological parameters (i.e., plasma cortisol and glucose levels, fertilization percentage, gonadosomatic index and fecundity) were assessed and results were com...

  Gravid wild kutum broodstock, Rutilus frisii kutum, on their upstream migration to Valiabad River (northern Iran) were kept in captivity to allow them to ovulate (captive ripe). Then the impact of captivity on some reproductive and physiological parameters (i.e., plasma cortisol and glucose levels, fertilization percentage, gonadosomatic index and fecundity) were assessed and results were com...

An experiment was conducted for 140 days in earthen ponds to evaluate the effect of three dietary protein levels on the growth and maturity of bagrid catfish Mystus gulio. Three different iso-caloric feeds containing 30%, 35% and 40% dietary protein levels were prepared from indigenous fish feed ingredients and were fed to Mystus gulio at the rate of 5% of total body weight of the fish. The ove...