親代勝敗經驗對子代的行為、生理與生活史特徵的影響

The importance of parent’s winning/losing experiences on individual’s behavioural, physiological and life-history traits

張毓庭(Chang Yu-Ting)

指導教授 ： 許鈺鸚

國立臺灣師範大學/理學院/生命科學系/碩士(2019年)

https://doi.org/10.6345/NTNU201900994

摘要

個體的經歷除了能影響自身的表型(如：行為)，在許多研究中也被發現能影響後代的表型，進而提升後代的適存度，稱作親代效應。個體先前的打鬥經驗為一種社會經歷，許多的研究都發現先前的獲勝/落敗經驗會提升/降低個體的攻擊性。這些效應一般被認為有利於較強/較弱的個體在面對其他競爭者時適度的調整打鬥策略，提升個體的適存度。然而個體之獲勝/落敗經驗是否會影響其子代之打鬥行為則尚未被探討過。本研究目的之一即為檢測一個體之獲勝/落敗經驗，是否影響其子代的表型。另外，生活步調假說預測個體的行為、生理與生活史特徵具有關聯性：越積極的個體攻擊性越高、具有較高的睪固酮濃度及耗氧量、較低的皮質醇濃度以及展現較快之生長史策略。本研究目的之二則在檢測子代表型之間的相關性是否符合生活步調假說之預期。本實驗使用紅樹林鱂魚為實驗物種，強制給予親代個體指定的打鬥經驗(獲勝/落敗/控制經驗)後，觀察其子代個體的行為、生理及生活史策略，探討親代打鬥經驗是否影響子代的表型以及表型之間的相關性是否符合生活步調假說的預期。本研究結果顯示 (1)子代個體的睪固酮濃度受到親代打鬥經驗影響：親代具有落敗經驗，其子代的睪固酮濃度較高；(2)子代個體的攻擊性及勇敢程度受到親代打鬥能力影響：其親代打鬥能力較好，子代個體的攻擊性越高、勇敢程度越低；(3)子代個體表型之間的相關性和生活步調假說的預期不完全符合：行為特徵之間，攻擊性、勇敢程度及進食行為間，兩兩具有正相關；個體的生長速率、第一次生蛋時的年紀、各項行為均和耗氧量呈現正相關。上述相關性符合生活步調假說之預期。但個體孵化所需時間、第一次生蛋時的年紀和耗氧量呈正相關；個體的皮質醇濃度和耗氧量、攻擊性呈現正相關；此相關性則不符合生活步調假說之預期。總結上述，個體的睪固酮濃度受到親代打鬥獲勝/落敗經驗影響，在紅樹林鱂魚中展現出親代效應。另外在個體表型的相關性中，僅部分符合生活步調假說的預期。

關鍵字

親代效應 ； 打鬥經驗 ； 賀爾蒙 ； 耗氧量 ； 攻擊性 ； 生活史特徵 ； 紅樹林鱂魚

並列摘要

Parental effects occur when the phenotype of an individual is affected by the phenotype or environment of its parents, and may increase the fitness of the offspring. Prior winning/losing experiences are known to increase/decrease individuals’ aggressiveness and modulate their fighting strategy in their next contest. The first purpose in my study is to determine whether winning/losing experiences suffered by parents will modify their offspring’s phenotypes. The pace-of-life syndrome hypothesis predicts that life-history and behavioural and physiological traits will co-vary under clearly defined conditions. The second purpose in my study is to examine whether the phenotypes influenced by winning/losing experiences are consistent with the pace-of-life syndrome hypothesis. Individuals of Kryptolebias marmoratus, a hermaphroditic killifish, were given different contest experiences (winning/ losing/ no experience) and the life-history and behavioural and physiological traits of their offspring were observed to examine the relationships between phenotypes and whether individual phenotypes were influenced by the parents’ winning/losing experiences. The results showed that: (1) individuals’ testosterone levels were influenced by their parents’ fighting experience — individuals whose parents had had losing experiences had higher levels of testosterone; (2) individuals’ aggressiveness and boldness were influenced by their parents’ fighting ability — individuals whose parents had better fighting ability were more aggressive but shyer; (3) the correlation between individuals’ behavioural, physiological and life-history traits partially matched the predictions of the pace-of-life syndrome hypothesis. Behavioural traits were correlated with each other; aggressiveness, boldness and feeding behaviour were positively correlated. The individuals’ growth rate, time to first reproduce and behaviours were positively correlated with oxygen consumption. These findings matched the predictions of the hypothesis. But some life-history traits were positively correlated with oxygen consumption, and cortisol levels were correlated with oxygen consumption and aggressiveness, which did not match the predictions. Overall, this study shows a parental effect in K. marmoratus; individuals’ phenotypes were influenced by parents’ fighting experience. Also, individual phenotypes were correlated with each other, partly matching the predictions of the pace-of-life syndrome hypothesis.

並列關鍵字

Parent effect ； Fighting experience ； Hormones ； Oxygen consumption ； Aggressiveness ； Life-history traits ； Kryptolebias marmoratus

參考文獻

Arnott, G., & Elwood, R. (2009). Probing aggressive motivation in a cichlid fish. Biology Letters 5:762-764.

Arnott, G., & Elwood, R. W. (2007). Fighting for shells: how private information about resource value changes hermit crab pre-fight displays and escalated fight behaviour. Proceedings of the Royal Society B: Biological Sciences 274:3011-3017.

Badyaev, A. V., & Uller, T. (2009). Parental effects in ecology and evolution: mechanisms, processes and implications. Philosophical Transactions of the Royal Society B: Biological Sciences 364:1169-1177.

Bakker, T. C. M., Bruijn, E. F.-D. & Sevenster, P. (1989). Asymmetrical Effects of Prior Winning and Losing on Dominance in Sticklebacks (Gasterosteus aculeatus). Ethology 82:224-229.

Barki, A., Harpaz, S. & Karplus, I. (1997). Contradictory asymmetries in body and weapon size, and assessment in fighting male prawns, Macrobrachium rosenbergii. Aggressive Behavior: Official Journal of the International Society for Research on Aggression 23:81-91.