Alarie Yves, Michat Mariano C, Gomez R Antonio, Dettner Konrad
School of Natural Sciences; Laurentian University; Ramsey Lake Road; Sudbury; Ontario; Canada.
University of Buenos Aires; Faculty of Exact and Natural Sciences; Department of Biodiversity and Experimental and Applied Biology (IBBEA); Buenos Aires; Argentina.
Zootaxa. 2025 Mar 10;5601(3):401-428. doi: 10.11646/zootaxa.5601.3.1.
All larval instars of Platambus apache Young, 1981 and P. maculatus (Linnaeus, 1758), and the third instar larva of P. semivittatus (LeConte, 1852) are described, illustrated in detail and compared to larvae of other known Platambus Thomson, 1859 species. The descriptions use the now generalized larval descriptive format of aquatic Adephaga, which includes chaetotaxic characters. Based on larval characters, a cladistic analysis is conducted using the program TNT to test the monophyly of Platambus and its relationship with five other agabine genera (Agabus Leach, 1817, Agabinus Crotch, 1873, Hydrotrupes Sharp, 1882, Ilybiosoma Crotch, 1873, Platynectes Régimbart, 1879). The monophyly of Platambus as currently defined is not corroborated in our analysis, as the relationships with some species of Agabus are inconclusive. There is a basal split between Palearctic and Nearctic species of Platambus, whereas all five Palaearctic species studied are recovered as monophyletic with very strong support, the Nearctic P. semivittatus and P. apache are deemed to potentially represent distinct evolutionary lineages as reflected by their contrasting larval morphology.
描述了1981年的阿帕奇普拉坦步甲（Platambus apache Young）和黄斑普拉坦步甲（P. maculatus (Linnaeus, 1758)）的所有龄期幼虫，以及半带普拉坦步甲（P. semivittatus (LeConte, 1852)）的三龄幼虫，并进行了详细的图示，还与其他已知的1859年汤姆森普拉坦步甲（Platambus Thomson）物种的幼虫进行了比较。这些描述采用了现在通用的水生肉食亚目幼虫描述格式，其中包括毛序特征。基于幼虫特征，使用TNT程序进行了支序分析，以检验普拉坦步甲的单系性及其与其他五个沼梭甲属（Agabus Leach, 1817；Agabinus Crotch, 1873；Hydrotrupes Sharp, 1882；Ilybiosoma Crotch, 1873；Platynectes Régimbart, 1879）的关系。在我们的分析中，目前所定义的普拉坦步甲的单系性没有得到证实，因为与某些沼梭甲属物种的关系尚无定论。普拉坦步甲的古北区物种和新北区物种之间存在一个基部类群分支，而所研究的所有五个古北区物种都被高度支持为单系类群，新北区的半带普拉坦步甲和阿帕奇普拉坦步甲因其截然不同的幼虫形态被认为可能代表不同的进化谱系。
