Inbreeding–outbreeding trade offs: sex specific effects on mate preference and offspring fitness in a wolf spider

Inbreeding is widespread in the animal kingdom, yet its preference and fitness consequences in spiders remain largely unexplored. In this study, we investigated mating preferences, mating and oviposition behaviors, and offspring fitness in the wolf spider Pardosa laura. Our results revealed that: (1) males preferred related females, whereas females preferred unrelated males; (2) stronger courtship behavior by related males led to significantly higher mating success in inbreeding than in outbreeding; (3) oviposition behavior did not differ significantly between inbred and outbred females, but outbred females produced significantly more offspring; (4) inbred male offspring were significantly larger than outbred male offspring, whereas inbred female offspring were significantly smaller in body size; and (5) inbred male offspring reached sexual maturity earlier than outbred males. Collectively, these findings suggest a trade‑off in the mating strategies of wolf spiders, with males and females favoring inbreeding and outbreeding, respectively, to produce high‑fitness male and female offspring.近交（inbreeding）在动物界广泛存在，但其在蜘蛛类群中的偏好性及适合度后果迄今仍未得到充分探索。本研究以拉氏狼蛛（Pardosa laura）为研究对象，调查了其交配偏好、交配与产卵行为以及后代适合度。研究结果显示： 1. 雄性偏好亲缘雌性，而雌性偏好非亲缘雄性； 2. 亲缘雄性的求偶行为更强，使得近交组的交配成功率显著高于远交（outbreeding）组； 3. 近交雌性与远交雌性的产卵行为无显著差异，但远交雌性所产后代数量显著更多； 4. 近交雄性后代的体型显著大于远交雄性后代，而近交雌性后代的体型则显著小于远交雌性后代； 5. 近交雄性后代的性成熟时间早于远交雄性后代。 综上，这些发现表明狼蛛的交配策略存在权衡（trade-off）：雄性偏好近交、雌性偏好远交，以分别产生高适合度的雄性和雌性后代。