Seed production of commercially valuable portunid crab Portunus Sanguinolentus (Herbst)

Mass seed production technology was tried in the present study in three eyed crab, P. sanguinolentus. To enhance the survival, the larvae were offered with sufficient amount of enriched Artemia nauplii and B. plicatilis. During the experimental period the larvae were provided with cordial environmental parameters. In order to avoid cannibalism shelters were provided in the culture tanks. The total duration for zoea I and II required 3-4 days, while zoea III and IV took 2-3 days and megalopa required 6-7 days to metamorphose into crab instar stage. The complete larval development took a span of 15-18 days. The intermoult duration was 3.62±0.32, 3.68±0.37, 2.75±0.35, 2.56±0.51 and 6.50±0.40 days for zoea I, II, III, IV and megalopa respectively. The final survival rate from megalopa to first crab was 5.25%. The survival rate for each zoeal and megalopal stages are 71.75±2.36, 44.0±3.36, 34.5±4.79, 12.0±2.94 and 5.25% for zoea I, II, III, IV and megalopa respectively. A maximum of 28% of mortality was observed during the first zoeal stage itself and thereafter the mortality was gradually increased.