Effect of Long-term Maintenance on Gonad Characteristics and Egg Quality of Collector Sea Urchin Tripneustes gratilla (LINNAEUS 1758)

Abstract

The gonad characteristics and number of eggs of the collector sea urchin Tripneustes gratilla (Linnaeus 1758) are thought to be determined by the accumulated results of the nutrients consumed during feeding. Long-term maintenance in captivity has been suspected to strongly influence the gonad characteristics and egg quality of the collector sea urchin T. gratilla. This research aimed to determine the proper length of maintenance for the collector sea urchin through studying the influence of maintenance time on gonad characteristics and number of eggs produced. This research was conducted at the Laboratory of Marine Aquaculture - Research Center for Deep Sea, Indonesia Institute of Science Ambon. Collector sea urchin (T. gratilla) samples with a test diameter of ± 50mm were obtained from Hative Besar, Ambon, Indonesia. The urchins were maintained for periods of 30 days, 60 days and 90 days. The observations indicate that the most appropriate maintenance time for collector sea urchin (T. gratilla) is 60 days, because after this maintenance period the gonads were orange (dark and light) in colour, with a firm texture. Moreover, the T. gratilla urchins maintained for 60 days produced a greater number of eggs with a larger egg diameter.