Discovery and genetic characterization of single cohort adult colonies with male aggregations, and preliminary evidence for lekking in a Malagasy kite spider (Isoxya, Gasteracanthinae)

Spiders are notoriously solitary and cannibalistic, with instances of colonial or social lifestyles in only about 50-60, or ~0.1% of 50,000 described species. Population analyses indicate that most colonies consist of multiple cohorts formed by close relatives. Territorial social spiders facultatively form colonies by interlinking individual webs, but further cooperation is infrequent, and only among juveniles or (rarely) females. In spiders, therefore, aggregations of males outside of the male-male competition context have been unknown. Here, we report on a discovery of a kite spider from Madagascar that exhibits unique colonies. We found colonies of the newly described araneid Isoxya manangona n. sp. formed by up to 41 interconnected, single-cohort adult female webs with up to 38 adult males aggregating on a central, single, non-sticky line. With males resting tightly together, we found no evidence of male-male aggression. Genetic analyses from RAD sequencing suggest that most colonie...

蜘蛛素来以独居且同类相食的习性闻名，在已被描述的5万个蜘蛛物种中，仅约50至60种（占比约0.1%）存在群居或社会性生活的案例。种群分析显示，绝大多数蜘蛛群落由近亲个体组成的多个同龄群构成。具有领地性的群居蜘蛛可通过联结个体蛛网选择性地形成群落，但进一步的协作行为却极为罕见，且仅发生于幼蛛之间，或是（极少情况下）雌性成体之间。因此，在蜘蛛类群中，除雄性间竞争场景外的雄性聚集行为此前从未被发现。本研究报道了一项来自马达加斯加的鸢蛛（kite spider）新类群的发现，该物种具有独特的群居习性。我们发现，新描述的金蛛科鸢蛛属新种Isoxya manangona n. sp.所形成的群落，由最多41个相互联结的单同龄群雌性成体蛛网构成，同时有至多38只雄性成体聚集在一条中央的单一非粘性蛛丝上。当雄性个体紧密聚集时，未观察到任何雄性间的攻击行为。通过限制性酶切位点相关DNA测序（Restriction-site Associated DNA Sequencing，RAD sequencing）开展的遗传分析显示，绝大多数群落……