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Survival, growth and sex ratios of gynogenetic diploid honmoroko
Author(s) -
Fujioka Y.
Publication year - 1998
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/j.1095-8649.1998.tb00809.x
Subject(s) - biology , offspring , ploidy , hatching , sex ratio , genetics , body weight , embryo , zoology , pregnancy , endocrinology , population , gene , demography , sociology
Survival, growth and sex ratios of gynogenetic diploid honmoroko Gnathopogon caerulescens induced by blocking the release of the second polar body were examined. Mean survival of gynogenetic juveniles at 130 days after hatching was about 33% lower than that of the controls. No significant difference was seen in early growth between control and gynogenetic diploids. Standard length and body weight in six groups of gynogenetic progeny were significantly greater but in two groups were significantly smaller than in the controls. Although 69% of gynogenetic diploids had well‐developed gonads, the remaining 30% had undeveloped gonads (small in size or thread‐like), and those gonads were divided into four types. The mean proportion of females in the 10 gynogenetic groups was 87·2% which was significantly ( P <0·01) higher than in the controls (44·7%). Gynogenetic diploids included 3·0–35·3% males. Most of those males produced a high proportion of female progeny, but the proportion of male offspring varied widely. From these results, the sex determining mechanism in honmoroko was presumed to be female homogamety, but other factors resulted in the production of males.