Producing false clownfish (Amphiprion ocellaris) male broodstock by administering 17 alpha-methyltestosterone to protandrous hermaphrodite juveniles

Failure to distinguish the sex of hatchery produced fish hinders Amphiprion ocellaris broodstock development in captivity as they need to be paired for breeding. Therefore, this study explored the possibility of producing male A. ocellaris broodstock by exposing the hermaphrodite juveniles to 17 a-methyltestosterone (MT). Two sets of trials were conducted and compared where hermaphrodite A. ocellaris juveniles (3.5-5.5 cm total length) was exposed to MT via immersion (1, 2 and 4 ppm, 0 ppm as control) and oral treatments (30, 60 and 120 mg kg^-1 feed, 0 mg as control). The immersion trials lasted for 15 days while the oral treatment was conducted for 2 months. Gonad samples of three fish from each treatment where sampled for histological studies at the end of the experiments. The remaining fish were reared for another two more months before their gonad were sampled to observe the gonad development post hormone exposure. Comparison between all treatments for both trials showed that immersing A. ocellaris juveniles in 1 ppm of MT showed the most promising result in developing male broodstock. At the end of the trials, the gonads were in the early transitional stages of masculinisation. Testicular cells at different stages such as spermatogonia, spermatocyte and spermatid were observed in all samples. Two months post treatment observation shows that the gonads from this treatment still exhibits successive development of testicular cells compared to others.