New mechanism for filial cannibalism: an endocrinological approach

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K07224
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Ecology/Environment
• Research Institution: Nagasaki University
• Principal Investigator: TAKEGAKI Takeshi 長崎大学, 水産・環境科学総合研究科(水産), 准教授 (50363479)
• Co-Investigator(Kenkyū-buntansha): 阿見彌 典子 北里大学, 海洋生命科学部, 講師 (20588503) ; 加川 尚 近畿大学, 理工学部, 准教授 (80351568)
• Research Collaborator: MATSUMOTO Yukio ; NAKATAKE Yosuke
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 繁殖戦略 / 行動生態 / 魚類 / 全卵食 / 内分泌 / プロラクチン / 子の保護 / 子殺し

Outline of Final Research Achievements

(1-1) Melanin-concentrating hormone (MCH) had a slight suppressing effect on feeding behavior of Rhabdoblennius nitidus males, but there was no significant difference in MCH levels between males cannibalizing eggs and males consuming food. (1-2) Administration of prolactin-releasing peptide (PrRP) showed a suppression effect on feeding during the breeding season and food provisioning experiments induced increase in parental care behaviors. These results are consistent with the prolactin hypothesis. (2) In the experiments inducing total-filial cannibalism, males cannibalizing all eggs showed significantly lower plasma 11-KT levels than males who did not, suggesting that males cannibalize eggs when they become incapable of courting due to the low levels of 11-KT. (3) The egg-water exposure experiments induced non care-giving males to parental care behaviors. This suggests the possibility that some kind of chemicals released from eggs stimulate the expression of parental care of males.

Free Research Field

行動生態学