Growth pattern, diet and reproductive biology of the clownfish Amphiprion ocellaris in waters of Pulau Tioman, Malaysia

The growth pattern, diet and reproductive biology of the clownfish Amphiprion ocellaris collected from waters of Pulau Tioman were investigated. The length-weight relationship showed an isometric growth pattern (b = 3) in A. ocellaris. The stomach contents mainly consisted of zooplankton and algae, which showed that the fish is omnivorous and was confirmed by trophic level analysis (2.98 ± 0.29). Fecundity of A. ocellaris ranged from 23-1518 with mean egg count of 582 ± 478, and has positive relationships with body length, body weight, eviscerated weight and ovary weight. The gonads were also described and examined histologically. The ovaries showed 4 stages of maturity, displaying different colours for each stage. The different developments of oocytes were also found in each stage of maturity. The males and non-breeders comprised of both testicular and ovarian tissues. In the males, the testicular tissues were more prominent in the ovotestes, whereas in non-breeders the primary oocytes were more prominent. Absence of testicular tissue in ovaries of females showed that the fish is a protandrous hermaphrodite and sex change may not be reversible. Similar observations have been reported in A. ocellaris of other countries and other Amphiprion species indicating that Amphiprion species show consistency in their reproduction strategy throughout their range.