Ernst T R, Hogers R M H W, Kwant P J C, Korosi A, van Leeuwen J L, Kotrschal A, Pollux B J A
Department of Animal Sciences, Experimental Zoology Group Wageningen University Wageningen the Netherlands.
Swammerdam Institute of Life Sciences, Center for Neuroscience, Brain Plasticity Group University of Amsterdam Amsterdam the Netherlands.
Ecol Evol. 2025 Sep 4;15(9):e72086. doi: 10.1002/ece3.72086. eCollection 2025 Sep.
Sperm storage is a post-copulatory strategy by which females can improve their fecundity by creating asynchrony between mating and fertilization. Sperm storage duration varies across vertebrate species, wherein longer sperm storage is thought to coincide with better reproductive success. Among the vertebrates, live-bearing fishes of the family Poeciliidae are generally assumed to store sperm for extended periods of time, but the temporal dynamics of this process remain unknown for most species. To date, research suggests that superfetatious poeciliids-which give birth to more frequent, temporally overlapping broods-may be able to store sperm longer than non-superfetatious species. However, robust empirical data for superfetatious poeciliids is very limited. Here, we assess the maximum duration of sperm storage and usage in the superfetatious poeciliid by comparing offspring production over time for both sexually isolated (single) and paired fish. We found that (a) the majority of females can store sperm for a maximum of 5 months with a smaller fraction of individuals able to extend this period to nearly 7 months, likely by "skipping broods," and (b) the number of offspring produced decreases over time post-isolation. With this study, we expand our knowledge of post-copulatory strategies by providing an assessment of both sperm storage longevity and its impact on offspring production over time in a superfetatious, live-bearing fish from the family Poeciliidae. We aim to encourage further research to generate and publish data on sperm storage longevity across the family Poeciliidae to elucidate how sperm storage varies across species with different reproductive strategies.
精子储存是一种交配后的策略，通过这种策略，雌性可以通过在交配和受精之间制造不同步来提高生育能力。不同脊椎动物物种的精子储存持续时间各不相同，其中较长的精子储存时间被认为与更好的繁殖成功率相关。在脊椎动物中，人们普遍认为花鳉科的胎生鱼类会长时间储存精子，但大多数物种这一过程的时间动态仍不为人知。迄今为止的研究表明，能进行超数排卵的花鳉科鱼类——即能产出更频繁、时间上重叠的幼体——可能比不能超数排卵的物种储存精子的时间更长。然而，关于能进行超数排卵的花鳉科鱼类的有力实证数据非常有限。在此，我们通过比较性隔离（单独饲养）和配对饲养的鱼类随时间的后代产量，评估了能进行超数排卵的花鳉科鱼类精子储存和使用的最长持续时间。我们发现：（a）大多数雌性最多能储存精子5个月，少数个体可能通过“跳过产卵期”将这一时期延长至近7个月；（b）隔离后随着时间推移，产生的后代数量会减少。通过这项研究，我们通过评估一种能进行超数排卵的胎生花鳉科鱼类精子储存的时长及其对后代产量随时间的影响，扩展了我们对交配后策略的认识。我们旨在鼓励进一步的研究，以生成并发表关于花鳉科鱼类精子储存时长的数据，从而阐明精子储存在具有不同繁殖策略的物种间是如何变化的。
