蓋斑鬥魚（Macropodus opercularis）形態、行為特徵與賀爾蒙分泌量對生殖成功率之重要性

The importance of morphology, behavior and hormone profiles to reproductive success in paradise fish (Macropodus opercularis)

胡家怡(Chia-Yi Hu)

指導教授 ： 許鈺鸚

國立臺灣師範大學/理學院/生命科學研究所/碩士(2012年)

摘要

動物的生殖成功率經常與其形態特徵、行為表現以及賀爾蒙分泌量呈現相關性。雖然有許多研究分別探討生殖成功率與不同性狀間的關係，多種特徵以及雄性與雌性之特徵如何共同影響生殖成功率卻鮮少同時被探究。本研究將雌、雄蓋斑鬥魚Macropodus opercularis進行配對，檢測（1）行為表現與形態特徵與賀爾蒙間的相關性；（2）雌、雄個體的形態、行為特徵以及賀爾蒙對生殖成功率的相對重要性。我以雌、雄魚產卵與否、產卵潛伏期（雌、雄魚開始互動至缸中有卵出現的間隔天數）以及產卵量作為生殖成功率指標；以標準體長、肥滿度、尾鰭長代表形態特徵；以攻擊性（攻擊頻率）及親代照顧表現（泡巢面積）作為行為特徵；並測量睪固酮（T）、睪丸硬甾酮（KT）、雌二醇（E2）與皮質醇（Cort）等四種賀爾蒙來進行探討。結果顯示（1）KT越高且T越低之雌魚的產卵量越高，然而與KT較高且T較低之雄魚配對的雌魚則產卵量較低；（2）T越高的雄魚泡巢面積越小，而與泡巢面積較小的雄魚配對之雌魚會較慢產卵；（3）Cort越高的雌魚配對後會越慢產卵；（4）與肥滿度較高的雄魚配對之雌魚有較低的比例會產卵，而與標準體長越長的雄魚配對之雌魚會產下較少的卵；（5）尾鰭越長的雄魚攻擊性越低，而標準體長越長的雌魚攻擊性越高。由本研究得知，親代照顧表現越高以及T分泌量越高的雄魚生殖成功率越高，而體型越大、KT分泌量越高之雄魚的生殖成功率則越低；此外，KT分泌量越高之雌魚的生殖成功率越高，T與Cort分泌量越高之雌魚的生殖成功率則越低。總結而言，雌、雄蓋斑鬥魚的攻擊性以及親代照顧表現與其形態特徵以及賀爾蒙基礎分泌量呈現相關性，而配對的生殖成功率同時與雌、雄魚的多個特徵有關，其中形態特徵及賀爾蒙與生殖成功率有較緊密的關係；而雄魚的特徵在配對生殖成功率上扮演著較雌魚特徵重要的角色。

關鍵字

生殖成功率 ； 形態特徵 ； 攻擊性 ； 親代照顧 ； 賀爾蒙

並列摘要

An individual’s reproductive success can depend on its morphological, behavioral and hormonal traits. Although many studies have explored the importance of each of these three individually to reproductive success, how they combine and how males’ and females’ traits combine to influence reproductive success are rarely explored. I paired up male and female paradise fish Macropodus opercularis to investigate (1) whether male and female fishes’ behavioral traits are related to their morphological traits and hormone levels, and (2) the relative importance of the three types of traits in both the male and the female in determining the reproductive success of a mating pair. I used standard length, condition factor and caudal fin length to represent the fishes’ morphology; aggressiveness (attack frequency) and parental care (bubble-nest area) to represent their behaviors; levels of testosterone (T), 11-ketotestosterone (KT), 17ß-estradiol (E2) and cortisol (Cort) to represent their hormones, and likelihood of spawning, latency to spawn and the number of eggs they produced to represent reproductive success. I had five main sets of results. (1) Egg production was associated positively with the female’s KT levels and the male’s T levels, but negatively with female’s T levels and the male’s KT levels. (2) Males with high levels of T built small bubble-nests. Moreoever, female partners of males which built smaller bubble-nests spawned more slowly. (3) Females with higher levels of Cort were slower to spawn. (4) Female partners of males with greater condition factor were less likely to spawn, and partners of males with longer standard length produced fewer eggs. (5) Males with longer caudal fins were less aggressive, and females with longer standard length were more aggressive. Overall, this study showed that males which provided more parental care or had higher levels of T had higher reproductive success, but that larger males or those with higher levels of KT had lower reproductive success. Moreover, females with high levels of KT had high reproductive success, but those which had higher levels of T or Cort had lower reproductive success. In conclusion, the morphological traits and hormone levels of male and female paradise fish were related to their aggressiveness and parental effort. A pair’s reproduction was correlated with both the male and female fishes’ traits. Morphological traits and hormone levels were more important than aggressiveness and parental effort, and males’ traits had a stronger association with reproduction than females’.

並列關鍵字

reproductive success ； morphology ； aggressiveness ； parental care ； hormone

參考文獻

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