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Hormonal Sex Reversal and Evidence of Female Homogamety in Black Crappie
Author(s) -
Gomelsky Boris,
Mims Steven D.,
Onders Richard J.,
Bean William B.
Publication year - 2002
Publication title -
north american journal of aquaculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 41
eISSN - 1548-8454
pISSN - 1522-2055
DOI - 10.1577/1548-8454(2002)064<0066:hsraeo>2.0.co;2
Subject(s) - biology , methyltestosterone , fish <actinopterygii> , androgen , sex ratio , hatching , sex reversal , medicine , endocrinology , hormone , zoology , genetics , population , demography , fishery , gene , sociology
This study reports the results on hormone‐induced sex reversal in black crappie Pomoxis nigromaculatus and the sex ratios of progenies obtained from test crosses of androgen‐treated males with normal females. The androgen 17α‐methyltestosterone (MT) was orally administered to fish with an artificial diet (30 mg/kg) for 30 d beginning 37 d after hatching; mean fish lengths were 35 and 55 mm at the beginning and conclusion of the treatment, respectively. The MT‐treated group consisted of 95% males and 5% intersex fish, while the sex ratio in the control group was not significantly different from 1:1. Four males from the androgen‐treated group were individually test‐crossed with normal females to identify sex‐reversed males according to the sex ratios in progenies and to reveal the chromosomal mechanism of sex determination in black crappie. Two out of three analyzed progenies consisted of females only, while one progeny had a sex ratio not significantly different from 1:1. The appearance of all‐female progenies in test crosses of MT‐treated fish indicated the existence of female homogamety (females, XX; males, XY) in black crappie.