Data from: Male investments in high quality sperm improve fertilization success, but may have negative impact on offspring fitness in whitefish

Many ejaculate traits show remarkable variation in relation to male social status. Males in disfavoured (subordinate) mating positions often invest heavily on sperm motility but may have less available resources on traits (e.g., secondary sexual ornaments) that improve the probability of gaining matings. Although higher investments in sperm motility can increase the relative fertilization success of subordinate males, it is unclear whether status-dependent differences in sperm traits could have any consequences for offspring fitness. We tested this possibility in whitefish (Coregonus lavaretus L.) by experimentally fertilizing the eggs of 24 females with the sperm of either highly-ornamented (large breeding tubercles, dominant) or less-ornamented (small tubercles, subordinate) males (split-clutch breeding design). In comparison to highly-ornamented individuals, less-ornamented males had higher sperm motility, which fertilized the eggs more efficiently, but produced embryos with impaired hatching success. Also offspring size and body condition were lower among less-ornamented males. Furthermore, sperm motility was positively associated with the fertilization success and offspring size, but only in highly-ornamented males. Together our results indicate that male investments on highly motile (fertile) sperm is not necessarily advantageous during later offspring ontogeny and that male status-dependent differences in sperm phenotype may have important effects on offspring fitness in different life-history stages.,Raw dataThis file contains raw data for our publication.Raw_data.xls,

诸多射精相关性状会随雄性社会地位呈现显著分化。处于劣势（从属）交配地位的雄性通常会在精子活力上投入大量资源，但在提升交配成功率的性状（如第二性征装饰）上可支配的资源往往更为有限。尽管提升精子活力的投入可提高从属雄性的相对受精成功率，但目前尚不清楚精子性状随社会地位产生的差异是否会对子代适合度造成影响。本研究以白鲑（Coregonus lavaretus L.）为实验对象，采用分群繁殖设计（split-clutch breeding design），分别使用具有显著第二性征（大型繁殖结节，优势地位）与较弱第二性征（小型结节，从属地位）的雄性的精子，对24尾雌性的卵开展人工授精，以此验证这一假说。相较于具有显著第二性征的雄性，从属地位雄性的精子活力更高，授精效率也更强，但其所产生的胚胎孵化成功率更低。此外，从属地位雄性所产后代的体型与身体状况也更差。进一步分析显示，仅在具有显著第二性征的雄性中，精子活力与受精成功率及子代体型呈正相关关系。综合本研究结果可知，雄性对高活力（高受精能力）精子的投入，在子代发育后期未必能带来演化优势；而雄性精子表型随社会地位产生的差异，可能在不同生活史阶段对子代适合度产生重要影响。原始数据 本文件包含本研究论文的原始数据。Raw_data.xls