Effects of different sex ratios on maturation, fecundity and hatching rates of ablated Penaeus monodon wild stock

Abstract

The minimum number of males per female that would still ensure high maturation, fecundity and hatching rates in Penaeus monodon broodstock, is determined. Wild stock P. monodon were stocked in 4 m diameter circular tanks at different sex ratios (0:1, 1:1, 1:2 and 1:4 male to female) for a duration of 55 days. All females were ablated on one eyestalk. Males remained unablated. The 1 male: 2 females ratio is recommended on the basis of highest percentage of first, second and third spawners, total and average fecundity. In the all-female treatment (0:1 ratio), 19.65% of the females spawned, but the 3.3 million eggs produced were not fertilized, resulting in a 0% hatching rate.