EFFECT OF Chaetoceros sp. DENSITY ON GROWTH AND SURVIVAL RATE OF PEARL OYSTER (Pinctada Maxima) LARVAE

Abstract

Pearl oyster (Pinctada maxima) is an economically valuable mariculture commodity whose natural seed supply is increasingly limited due to overexploitation. The success of hatchery production is largely determined by the quality and density of natural feed provided during the larval phase, one of which is Chaetoceros sp.. This study aimed to determine the effect of Chaetoceros sp density on the growth and survival rate of pearl oyster larvae. The study was conducted for 20 days at the Marine Aquaculture Center (BPBL) of Lombok using a completely randomized design (CRD) with four feed density treatments (A = 4,000 cells/ml, B = 5,000 cells/ml, C = 6,000 cells/ml, D = 7,000 cells/ml) and three replications. D-veliger larvae aged 24 hours were stocked at a density of 1,000 individuals per container. Parameters measured included absolute growth, specific growth rate of dorsal-ventral (DV) and anterior-posterior (AP) dimensions, and survival rate. Data were analyzed using one-way ANOVA and Duncan's multiple range test. Results showed that Chaetoceros sp density significantly affected all growth and survival parameters (P < 0.05). Treatment C (6,000 cells/ml) produced the highest absolute growth (149.39 ± 0.81 μm) and highest survival rate (63.4 ± 1.38%), with DV (6.12 ± 0.02 %/day) and AP (5.54 ± 0.03 %/day) specific growth rates that were statistically comparable to other treatments at densities of 5,000–7,000 cells/ml. A density of 6,000 cells/ml is recommended as the optimal dose of Chaetoceros sp natural feed for pearl oyster larval rearing.