The Effects of Breeding Environment and Food Type on the Survival and Growth of Red Sea Cucumber (Apostichopus japonicus) Larvae

This study aimed to investigate the effects of water temperature, salinity, and food type on the survival and growth of red sea cucumber (Apostichopus japonicus) larvae, over 14 days. Early Auricularia larvae (average length 475 6 10.3 mu m) were exposed to four different water temperatures (18, 22, 26, and 30 degrees C), four different salinities (25, 30, 35, and 40 psu), and four food types (Chaetoceros calcitrans, Pavlova lutheri, Isochrysis galbana, Rhodotorula+effective microorganisms (EM)). Subsequently, the survival rate, larval developmental stage (early Auricularia-Doliolaria), and the required time (days) to arrive at each stage were observed. The experiment was conducted at a private sea cucumber aquaculture farm in Jeju Special Self-Governing Province, and the results were statistically analyzed using SPSS version 22 (SPSS Inc., USA). This research team evaluated the average significance difference between groups, which was determined in p < 0.05, by applying a Duncan test due to variance heteroscedasticity. The results indicate the following optimum rearing conditions of red sea cucumber larvae: water temperature of 22 degrees C, salinity of 30-31 psu, with Rhodotorula+EM as food. The findings of this study could facilitate increasing seed production of the red sea cucumber A. japonicus.