Alarie Yves, Michat Mariano C, Short Andrew E Z, Watts Chris H S
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. 2024 May 29;5458(3):301-331. doi: 10.11646/zootaxa.5458.3.1.
In this contribution we describe and illustrate for the first time the larvae of three species of Platynectes Régimbart, 1879 (P. agallithoplotes Gustafson, Short & Miller, 2016, P. bakewelli (Clark, 1863), and P. reticulosus (Clark, 1863)) including detailed morphometric and chaetotaxic analyses of selected body structures in order to discover useful characters for distinguishing Platynectes larvae from those of other known Agabinae (Coleoptera: Dytiscidae). A parsimony analysis based on larval characteristics of 19 Agabinae species in six genera (Agabus Leach, 1817, Agabinus Crotch, 1873, Hydrotrupes Sharp, 1882, Ilybiosoma Crotch, 1873, Platynectes, and Platambus Thomson, 1859) was conducted using the program TNT. The results support Platynectes as a natural group whilst the six species studied split into two well supported clades: P. agallithoplotes + P. decemnotatus (Aubé, 1838) and P. curtulus (Régimbart, 1899) + P. davidorum Hájek, Alarie, Šťastný & Vondráček, 2019 + P. reticulosus + P. bakewelli. Larvae of P. agallithoplotes have proven to be characterized by a large number of unique character states, several of which were never observed until now in the Agabinae. Evidence is provided to the effect that the Neotropical species of Platynectes s. str. evolved as a unique lineage within Platynectes.
在本论文中，我们首次描述并展示了三种扁水龟属（Platynectes Régimbart，1879）物种的幼虫，即阿加利托水龟（P. agallithoplotes Gustafson, Short & Miller, 2016）、贝克韦尔水龟（P. bakewelli (Clark, 1863)）和网纹水龟（P. reticulosus (Clark, 1863)），包括对选定身体结构的详细形态测量和刚毛序分析，以便找出能将扁水龟属幼虫与其他已知的阿加比inae亚科（鞘翅目：龙虱科）幼虫区分开来的有用特征。使用TNT程序对六个属（阿加比水龟属（Agabus Leach, 1817）、阿加比尼水龟属（Agabinus Crotch, 1873）、水鼩鼱龙虱属（Hydrotrupes Sharp, 1882）、伊利亚博索马水龟属（Ilybiosoma Crotch, 1873）、扁水龟属和普拉坦布斯水龟属（Platambus Thomson, 1859））的19种阿加比inae亚科物种的幼虫特征进行了简约分析。结果支持扁水龟属作为一个自然类群，而所研究的六个物种分为两个得到充分支持的分支：阿加利托水龟 + 十斑水龟（P. decemnotatus (Aubé, 1838)）以及短体水龟（P. curtulus (Régimbart, 1899)） + 大卫水龟（P. davidorum Hájek, Alarie, Šťastný & Vondráček, 2019） + 网纹水龟 + 贝克韦尔水龟。事实证明，阿加利托水龟的幼虫具有大量独特的特征状态，其中有几种特征在阿加比inae亚科中至今从未被观察到。有证据表明，狭义的新热带扁水龟属物种是扁水龟属内一个独特的进化分支。
