Growth Patterns of Camouflage Grouper ( Epinephelus polyphekadion , Bleeker, 1849) Larvae

摘要

Background and Objective: The camouflage grouper (Epinephelus polyphekadion) is considered one of the newly fisheries export commodities of Indonesia with a relatively high economic value. The sustainability of the seeds of camouflage grouper for mariculture is still limited. This study aimed to determine the morphometric, allometric and relative growth of Epinephelus polyphekadion larvae, reared until 35 days after hatching. Methodology: The larval rearing pond were equipped with an aeration system and the vessel was closed with plastic and equipped with a 100 W fluorescent bulbs. Larvae fed 10 individual mL–1 rotifers, 5-10 individual mL–1 copepods, 10-20 individual mL–1 Artemia sp. and 10-20 individual mL–1 mysid. Water exchange was as follows: At age 0-10 days after hatching no water exchange, at 10-15 days after hatching, 10-20% water exchange and at 20-35 days after hatching, 50% water exchange. The morphological observation and body measurements were conducted on 10 fish samples taken randomly from 1, 3, 5, 10, 15, 20, 25, 30 and 35 days after hatching. Relative growth on each body part was examined by expressing it as a percentage to standard length. Allometric growth was calculated as a power function of total length. Growth patterns of larvae were calculated by linear regression analysis to assess the strength of association. Results: Changes of the stage pra-flexion to flexion occurred when the standard length of the fish was 6.91 mm. The. The demersal juvenile stage occurred at the total length of 27.94±3.94 mm and the standard length of 23:23±3.51 mm, body depth of 7.06±0.90 mm and the head length of 7.06±0.80 mm. The morphometric growth pattern was slow at the age of 1-14 days after hatching, while faster at the age of 15-35 after hatching. Relationships between total length and weight at the age 1-35 after hatching were an allometric positive with the equation of W = 0.006 L3.023 (r2 = 0.980). Conclusion: Changes of the stage praflexion to flexion occurred when the fish was at the standard length of 6.91 mm. The growth pattern was an allometric positive and relative growth already fixed at the standard length of 4-6 mm. Growth pattern in M. ladigesi give specific indications on the change in length of the body, it can be linked to the method of feeding for larvae rearing.