EFFECT OF DIFFERENT DENSITY OF Chaetoceros calcitrans IN CONTROLLING LUMINOUS Vibrio SPECIES IN TIGER SHRIMP LARVA REARING
Luminous Vibrio species is still considered as one of the most pathogenic organisms in tiger shrimp larva rearing in the hatchery. This reasearch was aimed at finding out the best density of Chaetoceros calcitrans for controlling pathogenic luminous Vibrio sp. which causes mass mortality in mysis stage of tiger shrimp larva rearing. This experiment was conducted at Biotechnology Laboratory of the Tiger Shrimp Hatchery Station of the Research Institute for Coastal Aquaculture in Barru Regency. Completely Randomized Design was applied in this 4x3 experiment. The densities of C. calcitrans tested here were A = 106 cells/mL, B = 105 cells/mL, C = 104 cells/mL, and D = control (without C. calcitrans). All treatments were inoculated with luminous Vibrio sp. in the resulted density of 105 CFU/mL). Population of Vibrio sp. was checked after 1, 2, 3, and 4-d incubations. Data of the Vibrio population were then analysed using SPSS 19 followed by HSD. The results showed that population of Vibrio sp decreased after one day application of C. calcitrans. The density of C. calcitrans 106 cells/mL gave the best result (P<0.05) for Vibrio inhibition 1-d after application, but there were no significant differences (P>0.05) among the three C. calcitrans treated media 4-d after application. C. calcitrans could be used for inhibitions of pathogenic luminous Vibrio species in the larva rearing media.