Journal of the Marine Biological Association of India

Repetitive maturation and spawning of the green tiger prawn Penaeus semisulcatus by environmental regulation in closed seawater recirculation systems.

Volume 42 Issue 1&2

E. V. Radhakrishnan, G. Maheswarudu, M. R. Arputharaj and A. Ramakrishnan

Abstract

Maturation and repetitive spawning of the green tiger prawn Penaeus semisulcatus were achieved by pH regulation and on feeding the shrimps with clams, squid and the oligochaete worm Pontodrilus bemudensis. Females and males stocked in a recirculation system at a ratio of 1:l and exposed to an average light intensity of 500 lux spawned an average 3 times in each moult cycle. In Experiment 2 lasting 60 days, 80% of the females responded, whereas in Experiment 3 lasting 90 days 60% of the shrimps matured and spawned viable eggs. Spawning interval varied from 4 to 7 days. Average number of eggs produced by a single female ranged from 15- 20 lakhs from 11-13 spawnings. Though egg production was consistent upto three consecutive spawnings, number of spawnings was decreased beyond moult 3 with no reduction either in spawn size or percent hatch of the eggs. Considerable variability in egg production between spawns within a moult cycle and between spawns of consecutive moult cycles were observed. However, no significant difference in percent egg hatch between the spawns in a moult cycle (P<0.05) and between spawns of different moult cycles (P<0.05) was noticed.

 

These results suggest that P. semisulcatus can be induced to mature and spawn viable eggs in captivity through environmental regulation and by feeding a mixed diet. The advantages of this technique over the conventional eyestalk ablation method and the prospects of its commercial application are discussed.

Date : 30-12-2000