Sexual conflict and mating system in sex-role reversed fishies

无精体和合胞体鱼类是性别角色颠倒的代表性群体。在性别角色颠倒的物种中，与大多数动物不同，雌性的繁殖成功通常受到雄性可用性的限制。本文对日本四国Uwa海的一些单卵体和合卵体鱼类的生活史和繁殖策略进行了研究。在研究最深入的物种阿波贡（Apogon doederleini）中，从已确定的个体中获得了关于生长、迁徙、繁殖成功、配偶变化和子代同类相食的详细数据。通过对这些数据的分析，我们发现口育雄性的同类相食是一种特定年龄的生殖策略。通过对杜氏白鲟身体各部位脂肪、蛋白质和碳含量的初步分析，研究了进行同类相食行为的雄性白鲟的身体状况，并估算了其口腔哺育所需的能量消耗。在管鱼（Corythoichthys haernatopterus）中，我们发现在整个繁殖季节，配对关系通常保持不变，而连续一夫一妻制主要是由于雌性保护配偶。

Apogonid and syngnatid fishes are representative groups in which sex-roles are reversed. In the sex-role reversed species, female reproductive success is generally limited by availability of males, unlike in the majority of animals. We have investigated life histories and reproductive strategies of some apogonid and syngnatid fishes in Uwa Sea, Shikoku, Japan for these several years. In Apogon doederleini, the most intensively studied species, detailed data were obtained on growth, migration, reproductive success, mate change and filial cannibalism from identified individuals. From analysis of these data, we found that filial cannibalism by mouthbrooding males is the age-specific reproductive stragegy. From the preliminary analysis of fat, protein and carbon contents in body parts of A.doederleini, we examined the physical condition of males who performed filial cannibalism and estimated energetic costs entailed in mouthbrooding. In the pipefish Corythoichthys haernatopterus, we found that pair-bond is usually maintained throughout the entire breeding season and that serial monogamy is due primarily to mate guarding by females.