Hatching Management of Berried Female Blue Swimming Crab (Portunus pelagicus) with Dark Gray Eggs to Guidelines for Fishery Occupation

Abstract

The objectives of this experiment were to study the reproduction potential of the berried female blue swimming crab (Portunus pelagicus) that had been obtained by different catching approaches (by crab gill net or collapsible crab trap), and to compare three hatching processes of the crab during the period of March-May 2018. The results showed that the average carapace width, carapace length, eggs weight, and fecundity of the crabs caught by collapsible crab traps were significantly higher than those features of crabs captured by crab gill nets (P<0.05). The average hatching rates and the hatched crab larvae of the crabs caught by both methods were
not significantly different (P>0.05). Besides, the hatching processes comprised of leaving an individual female crab in a hatching tank or a nursery tank, when compared with the combining of a number of female crabs in a nursery tank, demonstrated either advantages or disadvantages, depending upon the availability of farming space. Significantly, the learning from this research into crab hatching processes can be usefully applied in the formation of fishery occupation guidelines concerned with hatching such a unique crab species.