Study on the maturation patterns and cryptic hermaphroditic sexuality in juveniles of polygamous reef fishes

2014 Fiscal Year Final Research Report

• Project/Area Number: 24570027
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Ecology/Environment
• Research Institution: Hiroshima University
• Principal Investigator: SAKAI Yoichi 広島大学, 生物圏科学研究科, 教授 (70309946)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 魚類 / 成熟パターン / 幼魚 / 社会的性決定 / 性転換

Outline of Final Research Achievements

Maturation patterns and sexuality of juveniles of polygamous damselfishes (Pomacentridae) were investigated by tank rearing experiments. Juvenile fishes were captured on reefs of Kuchierabu-jima Island (Dascyllus reticulatus), Yaku Island (Abudefduf vaigiensis) and Okinawa Island (Chrysiptera cyanea and C. glauca), subsequently were kept in tanks in both solitary and pair conditions for 9 months (2012 started exp.) or 12 months (2013 started exp.), and gonadal sex was histologically examined. In D.reticulatus, juveniles all initially matured as females regardless of rearing conditions, due to the protogynous sexuality in adults. In A. vaigiensis, juveniles matured as males or females in the even sex ratio, due to the gonochoristic sexuality in adults. In Chrysiptera species, which have long been believed as gonochores, however, we confirmed hermaphroditic gonads and female-biased maturation patterns in both species, suggesting possibility of protogynous sexuality.

Free Research Field

魚類行動生態学