Seasonal and annual variations in egg mass and clutch size for loggerhead sea turtles (Caretta caretta): experienced females lay heavier eggs
Seasonal and annual variations in egg mass and clutch size for loggerhead sea turtles (Caretta caretta): experienced females lay heavier eggs
复制标题
红蠵龟 (Caretta caretta) 的卵量和产蛋量随季节和年度变化：经验丰富的雌性产下更重的卵
DOI：
10.1139/cjz-2019-0019
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发表时间：
2019
影响因子：
1.4
通讯作者：
Hideo Hatase & Kazuyoshi Omuta
中科院分区：
文献类型：
--
作者：
柴尾晴信;石井弓美子;松山茂;嶋田正和;Hideo Hatase & Kazuyoshi Omuta
生物体适应或非适应地改变生殖性状以响应时间环境的变化。长寿命的海龟是研究这种资源分配的时间变化的理想动物。我们分析了在日本屋久岛温带栖息地（屋久岛）筑巢的红海龟（Caretta Caretta (Linnaeus, 1758)）在2年期间的产蛋量和产蛋量的季节变化，以及5年期间产蛋量和产蛋量的年变化。在种群和个体水平上，根据雌性体型调整后的卵量和窝卵数没有随季节变化。调整后的蛋质量显示出显著的年度变化，尽管调整后的窝数缺乏年度变化。因此，红海龟不太可能在繁殖特征上表现出适应性的季节性变化，相反，它们改变卵的大小以非适应性地响应年度环境条件。虽然经验丰富的红海龟产的蛋更重，但每年的蛋量变化既不能归因于雌性的繁殖经验，也不能归因于卵泡发育期间的环境温度，这意味着其他因素也参与其中，比如资源的可用性。我们的数据显示，对于生活在北太平洋的红海龟来说，蛋的大小比窝的大小更具可塑性。
Organisms modify reproductive traits adaptively or non-adaptively in response to temporal environmental variation. Long-lived iteroparous sea turtles are ideal animals to examine such temporal shifts in resource allocation. We analyzed seasonal shifts in egg mass and clutch size for Loggerhead Sea Turtles (Caretta caretta(Linnaeus, 1758)) nesting at a temperate rookery (Yakushima Island, Japan) over a 2-year period, as well as annual variation in egg mass and clutch size over a 5-year period. Egg mass and clutch size, adjusted for female body size, did not vary seasonally at both the population and individual levels. Adjusted egg mass showed significant annual variation, despite a lack of annual variation in adjusted clutch size. Thus, Loggerhead Sea Turtles are unlikely to exhibit adaptive seasonal variation in reproductive traits, whereas they vary egg size non-adaptively in response to annual environmental conditions. Although experienced Loggerhead Sea Turtles laid heavier eggs, the annual variation in egg mass was not attributable either to breeding experience of the sampled females or to ambient temperature during follicular development, implying that other factors are involved, such as resource availability. Our data show that egg size is a more plastic reproductive trait than clutch size for Loggerhead Sea Turtles inhabiting the North Pacific.