Searching for factors to cause oogenesis without yolk as a reproductive strategy in Apogon lineatus

2014 Fiscal Year Final Research Report

• Project/Area Number: 25850137
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Aquatic bioproduction science
• Research Institution: Kagoshima University
• Principal Investigator: KUME Gen 鹿児島大学, 水産学部, 助教 (00554263)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: 口内保育 / 卵生産 / 実効性比 / テンジクダイ

Outline of Final Research Achievements

Aggregation and behavioral patterns were examined for wild population of Apogon lineatus in Omura Bay, Nagasaki Prefecture, for two consecutive spawning seasons. Individuals were occurred solitarily on the sandy-muddy bottoms during the nighttime. Sexual differences in behavioral patterns were observed. The increase in mortality rates of males following mouthbrooding care was suspected to be one of the major factors to cause reversed operational sex ratio. For a total of seven apogonid species, ovaries were investigated histologically. The oogenesis pattern similar to A. lineatus (approximately 20% of each brood is constituted by eggs without yolk, which were hydrated without the vitellogenesis phase and eventually ovulated with other normal eggs as a single egg mass.) was not observed, suggesting that it is not prevailing in apogonids.

Free Research Field

魚類生態学