Female spawning strategy in Rhinogobius sp. OR: how do females deposit their eggs in the nest?
Female spawning strategy in Rhinogobius sp. OR: how do females deposit their eggs in the nest?
复制标题
Rhinogobius sp. 的雌性产卵策略。
作者：
N. Okuda;S. Ito;H. Iwao
摘要 我们试图阐明父巢中的雌性如何育雏虾虎鱼Rhinogohius sp。或者在实验室条件下使用活卵标记技术将卵存放在巢中，其中雄性体细胞状况、巢穴空间和交配模式（一夫一妻制或重婚）受到控制。雌性是否拒绝交配与雄性的品质（例如体型和身体状况）或巢穴空间无关。然而，在允许两只雌性与一只雄性依次产卵的情况下，雌性在第一个产卵时比第二个产卵时拒绝交配的比例更高；这是因为第一代雌性的卵更容易受到父母雄性和第二次雌性的同类相食。即使巢穴空间有限，被第一只雌性的卵占据，第二只雌性也可以利用现有卵的微小间隙将所有卵产在巢中。在有亲代雄性在场的情况下，这样的雌性似乎不太可能因拥挤而导致卵死亡率增加而付出代价，仍然保持着作为第二个产卵者的优势。最后，我们从实验室数据推断出这种鱼的田间繁殖生态。有人认为，同一年龄的单个单层巢通常由多个雌性的卵组成，因此交配模式将比之前预期的更加一夫多妻制。
Abstract We tried to elucidate how females of a paternal nest brooding goby Rhinogohius sp. OR deposit their eggs in a nest, using a marking technique for live eggs under laboratory conditions in which male somatic condition, nest space, and mating pattern (monogamous or bigamous) were controlled. Whether females rejected mating was independent of either male quality, such as body size and somatic condition, or nest space. In a situation in which two females were allowed to spawn sequentially with a male, however, females rejected mating at a higher rate when they were the first to spawn than when they were the second to spawn; this is because eggs from first females were more vulnerable to cannibalism by parental males and second females. Even when nest space was limited and thus was occupied by eggs from the first females, second females could deposit all their eggs in the nest by using the minute interspace of existing eggs. In the presence of the parental male, such a female seemed less likely to suffer a cost from increased egg mortality due to crowdedness, still holding the advantage of being the second spawner. Finally, we extrapolated the field breeding ecology of this fish from the laboratory data. It was suggested that a single monolayer brood of the same age usually consisted of eggs from multiple females and thus the mating pattern would be more polygynous than previously expected.