Growth and survival of enriched free-living nematode, Panagrellus redivivus as exogenous feeding for larvae of blue swimming crab, Portunus pelagicus

Abstract

Free-living nematode, Panagrellus redivivus, was tested as live food for blue swimming crab, Portunus pelagicus larvae during the first feeding stage. A series of experiments were conducted to determine the acceptability of the free-living nematodes in P. pelagicus larvae at first feeding. The optimum nematode density and the response of the larvae to nutritionally enriched nematode were also been examined. Newly hatched P. pelagicus, distributed into each 50 mL experiment plastic containers contains 30 individual P. pelagicus larvae. Microworms will be given four times day−1 at around 0800 h, 1100 h, 1400 h and 1600 h after the water exchange. Duration of feeding experiments was up to day 10–15 and results show that their survival rate of zoea 1: 56%, zoea 2: 74%, zoea: 3 84% and zoea 4: 66%. The results also showed that P. redivivus exhibited better Specific Growth Rate from Zoea 2 to Zoea 3 stage compared to the Artemia based diets. Observations indicated that the P. pelagicus, larvae readily fed on free-living nematodes as early as 2 days post-hatching, the start of exogenous feeding. Studies focusing on the alternative live food at the early larval stages can improve culture information for future and mass aquaculture commercialization of portunid crabs.