Effect of Nannochloropsis salina on the survival and growth of phyllosoma of the tropical spiny lobster, Panulirus homarus L. under laboratory conditions

Abstract

The first successful advanced (stage VIII) larval development of the tropical spiny lobster, Panulirus homarus L. under laboratory culture has been achieved in a short span of 42 days. The culture treatments were maintained in two different systems, one with microalgae, Nannochloropsis salina (30-40 million cells/mL) and the other without microalgae. Phyllosoma attained stage VIII (5.25 mm) and stage V (3.36 mm) with an intermoult period of 4-6 and 5-9 days in the two systems respectively. The larvae moulted nine and six times in the microalgal and non-algal systems, respectively. Phyllosoma were fed with freshly hatched live Artemia salina nauplii (0.32 mm) for an initial period of 10 days, followed by juvenile Artemia (1.45 –1.54 mm) enriched with microalgae for the subsequent 15 days. Artemia enriched with commercial polyunsaturated fatty acid concentrate (DHA-Selco) was fed to the larvae for the rest of the culture period. Salinity and temperature were maintained at 33 ± 2 ppt and 28 ± 2 0C, respectively, while the pH recorded an optimum of 7.9 ± 0.5. The microalgal larval rearing system had lower bacterial load (total heterotrophic marine count, 1.0 X 103 CFU m L-1 and total Vibrio sp. count, 20 CFU/mL) compared to the nonmicroalgal system.