Unilateral ablation of Penaeus stylirostris (Stimpson)

Abstract

Wild females of Penaeus stylirostris, captured in August 1990 in the northern region of the Gulf of California, were induced to maturation by unilateral ablation under standard maturation laboratory conditions. Two experimental groups (A, B) and one control without ablation (C) were structured. Unilateral ablation was applied to A at 24 f 2 h and to B at 38 ± 2 h, once the intenmolt stage had begun. The experimental groups registered similar values in number of spawnings per female per month, signifícantly different from the control (p < 0.05). Mean number of eggs per spawn was not different among groups. Ablation had no effect on the quality of eggs and larvae; all groups registered similar percentages of fertilization, hatch and metamorphosis (p > 0.05). Maximum reproductive response was obtained by group A females; 73.3% of ablated females matured and produced one spawn. The number of ablated females that produced subsequent spawns decreased by 20% in the second and approximately 33% in the third. Among the experimental groups, higher survival (86%) and maximum accumulated production of eggs (4.8 million nauplii) was registered by A.