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Precocious sex change and spermatogenesis in the underyearling Malabar grouper Epinephelus malabaricus by androgen treatment
Author(s) -
Murata Ryosuke,
Karimata Hirofumi,
Alam Mohammad Ashraful,
Nakamura Masaru
Publication year - 2010
Publication title -
aquaculture research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.646
H-Index - 89
eISSN - 1365-2109
pISSN - 1355-557X
DOI - 10.1111/j.1365-2109.2009.02332.x
Subject(s) - grouper , biology , spermatogenesis , sex change , sperm , androgen , reproduction , epinephelus , zoology , fishery , fish <actinopterygii> , ecology , endocrinology , botany , hormone
The Malabar grouper Epinephelus malabaricus is an important candidate species for commercial aquaculture in tropical and subtropical areas. In nature, this species requires more than 10 years to change sex from female to male and have active spermatogenic tissues in the testis. Thus, it is essential to find a means of producing sperm for seed production. This is the first report of artificial sex change in underyearling E. malabaricus . Female E. malabaricus with immature ovaries at 144 days post‐hatch (DPH) were fed a diet with 17α‐methyltestosterone (MT) at 50 μg g −1 diet for 6 months. Sex change occurred in most of the treated fish, which had testis with all stages of spermatogenic germ cells including spermatozoa. In contrast, most of the control fish had immature ovaries. These results, which reveal that germ cells in the underyearling grouper have the ability to produce spermatozoa in response to exogenous androgen, demonstrate that sex change can be artificially induced during ovarian development.