Pertumbuhan dan Kelulushidupan Juvenil Kima Sisik (Tridacna squamosa) yang dipelihara dalam Kurungan yang diletakkan pada Habitat Terumbu Karang Hidup dan Terumbu Karang Mati di Perairan Teluk Kupang -Nusa Tenggara Timur
Ernes D. Hamel, Ricky Gimin dan Fonny J.L Risamasu 2013

The scaly giant clam (Tridacna squamosa) is one of coral reef animals which is protected as endangered species. The success of their hatchery technology can be a source of juveniles for retocking depleted reefs. Retocking programs carried out so far were mainly done on the reefs of good condition. As an filter feeder, which food extracted from water column, this study aimed at testing a hypothesis that the clams could also be restocked in devastated reefs. This hypothesis was tested during the study by comparing the growth and survival rate of juveniles in the good condition reefs consisting of live corals and devastated ones of primary coral rubbles. The study also tried to identify water quality affecting the growth and survival. Hatchery produced juveniles T. squamosa aged six months of 20-30 mm in shell length were placed into net cages (dimension 50 x 50 x 30 cm3) set up at the depth of 4–5 m. A number of 10 cages were placed randomly in the good reefs and another 10 in the devastated reefs. Each cage was stocked with 170-180 juveniles. Shell growth measurement was carried out weekly for eight weeks. Results of the study showed that juvenile T. squamosa stocked in the devastated reefs had mean absolute growth rate of 20.11 mm and specific growth rate of 0.82 mm/day which were significantly higher than those in the good reefs (absolute growth of 12.77 mm and specific growth rate of 0.78 (Student t-test; P<0.05). For the survival rate, there were no significant differences between the two reefs and 67 – 88% of the juveniles survived until the end of the experiment. The differences in the growth rates between the two reef habitats were probably due to the significant differences in water flow rate, turbidity, and biofouling. In the devastated reefs, the flow rate was higher; the turbidity was lower; and biofouling was lesser than those in the good reefs. This study recommended that the giant clams restocking programs should be done in devastated reefs to increase the economic value of the reefs.