Physiol Biochem Zool. 2022 Jul-Aug;95(4):279-287. doi: 10.1086/720159.
AbstractIn oviparous reptiles, parental care is often limited to the energy allocated to embryos before oviposition. Reproducing females can allocate energy toward vitellogenesis, determining the number and size of eggs, fertilization, eggshell calcification, retention of eggs within the oviduct after fertilization (oviductal egg retention), and nesting activities. Oviductal egg retention in turtles ranges from 2 wk to half a year, permitting flexibility in the timing of oviposition. The energetic cost of oviductal egg retention in eastern musk turtles () was investigated by measuring the metabolism of females before and after oviposition. Gravid female metabolic rates were elevated relative to male and nongravid female metabolic rates, indicating an associated energetic cost for egg retention. Metabolism of gravid females was 40% higher before oviposition than after oviposition, and it was relatively constant across the period of oviductal egg retention. Metabolic costs associated with egg retention were correlated with clutch mass and female body mass but not with clutch size or the number of days leading up to oviposition. These results suggest that the strategy of oviductal egg retention has considerable energetic costs for eastern musk turtles but that it likely provides critical flexibility in nesting phenology.
摘要 在卵生爬行动物中，亲代照顾通常仅限于产卵前分配给胚胎的能量。繁殖的雌性可以将能量分配给卵黄发生，决定卵的数量和大小、受精、蛋壳钙化、受精后卵在输卵管内的保留（输卵管卵保留）以及筑巢活动。龟鳖类的输卵管卵保留时间从 2 周到半年不等，这使得产卵时间具有灵活性。通过测量产卵前后雌性的代谢率，研究了东部麝香龟（）输卵管卵保留的能量成本。与雄性和非妊娠雌性的代谢率相比，妊娠雌性的代谢率升高，表明卵保留存在相关的能量成本。与产卵后相比，产卵前的妊娠雌性代谢率高出 40%，并且在输卵管卵保留期间相对稳定。与卵保留相关的代谢成本与卵质量和雌性体重相关，但与卵大小或产卵前的天数无关。这些结果表明，东部麝香龟的输卵管卵保留策略对其具有相当大的能量成本，但可能为其筑巢物候学提供了关键的灵活性。
