Hermaphrodite sex role preferences:: the role of partner body size, mating history and female fitness in the sea slug Chelidonura sandrana
Hermaphrodite sex role preferences:: the role of partner body size, mating history and female fitness in the sea slug Chelidonura sandrana
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DOI：
10.1007/s00265-006-0173-5
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发表时间：
2006-07-01
影响因子：
2.3
通讯作者：
Michiels, NK
中科院分区：
文献类型：
--
作者：
Anthes, N;Putz, A;Michiels, NK
与交配相关的成本和收益以及交配频率对健康的影响通常在性别之间有所不同。因此，异型杂交的同时雌雄同体可能更喜欢以更有价值的性角色进行交配，从而在配偶之间产生精子捐赠和精子接收的冲突。由于最近的性别角色偏好模型仍然存在争议，我们在这里对比了它们在海蛞蝓 Chelidonura sandrana 中的一些假设和预测。对于这种具有精子储存和体内受精功能的雌雄同体，风险规避模型假设，在任何一次交配中，雌性的健康回报始终高于雄性功能。此外，排除共同伴侣的评估，这些模型预测雄性交配行为与接受者特征无关。竞争性性别比例假说假设相对适应度回报以及首选的交配角色会发生变化，并且可能在交配之间逆转，并预测射精策略与接受者质量共同变化。我们发现 C. sandrana 的田间交配率大大超过了维持雌性生育力和繁殖力所需的水平，这表明交配之间的直接雌性利益存在很大差异。我们进一步证明，雄性交配持续时间随着伴侣体型（即繁殖力）的增加而适应性增加，但随着伴侣最近的乱交而减少。这些发现与性别比例假设相符，但与风险规避模型相矛盾。
Costs and benefits associated with matings and the effects of mating frequency on fitness commonly differ between the sexes. As a result, outcrossing simultaneous hermaphrodites may prefer to copulate in the more rewarding sex role, generating conflicts over sperm donation and sperm receipt between mates. Because recent sex role preference models remain controversial, we contrast here some of their assumptions and predictions in the sea slug Chelidonura sandrana. For this hermaphrodite with sperm storage and internal fertilisation, risk-averse models assume that fitness pay-offs are constantly higher in the female than in the male function in any single mating. Moreover, excluding mutual partner assessment, these models predict male mating behaviour to be independent of receiver traits. The competing gender ratio hypothesis assumes that relative fitness pay-offs, and thus the preferred mating roles, vary and may reverse between matings and predicts that ejaculation strategies co-vary with receiver quality. We found that field mating rates of C. sandrana substantially exceeded what is required to maintain female fertility and fecundity, indicating large variation in direct female benefits between matings. We further demonstrate that male copulation duration adaptively increased with partner body size (i.e. fecundity) but decreased with recent partner promiscuity. These findings are compatible with the gender ratio hypothesis but contradict risk-averse models.