Northern Arctic Federal University, Arkhangelsk, Russia.
N. Laverov Federal Center for Integrated Arctic Research of the Ural Branch of the Russian Academy of Sciences, Arkhangelsk, Russia.
Sci Rep. 2020 Nov 16;10(1):19854. doi: 10.1038/s41598-020-76854-0.
Parasites and symbionts of freshwater mussels are poorly understood, although a diverse assemblage of mussel-associated leeches (Glossiphoniidae) was recently described. Here, we report on the discovery of a fish leech (Piscicolidae) in the mantle cavity of the freshwater mussel Cristaria plicata (Unionidae) in the Russian Far East. It is the first member of this leech family being associated with freshwater molluscs. This leech does not match any known genus and species both morphologically and genetically, and is described here as Alexandrobdella makhrovi gen. & sp. nov. It uses mussels as shelter (and probably as a secondary host), while the Amur catfish Silurus asotus (Siluridae) seems to be the primary host. These novel findings indicate that mussel-associated leech assemblage contains at least one piscicolid species. Our fossil-calibrated phylogeny suggests that the crown group of Piscicolidae was originated in the Early Cretaceous. This primarily marine family shares at least five independent colonization events into freshwater environments.
淡水贻贝的寄生虫和共生生物了解甚少，尽管最近描述了一组多样化的贻贝相关蛭类（Glossiphoniidae）。在这里，我们报告了在俄罗斯远东地区淡水贻贝 Cristaria plicata（贻贝科）的套膜腔中发现了一种鱼类蛭类（Piscicolidae）。这是该蛭类家族中第一个与淡水软体动物相关的成员。这种蛭类在形态和遗传上都与任何已知的属种都不匹配，并在此被描述为 Alexandrobdella makhrovi gen. & sp. nov. 它将贻贝用作庇护所（可能也用作次要宿主），而亚洲鲇（Siluridae）似乎是其主要宿主。这些新发现表明，贻贝类蛭类群至少包含一个鱼类蛭类物种。我们的化石校准系统发育分析表明，Piscicolidae 的冠群起源于早白垩世。这个主要是海洋的科至少有五个独立的向淡水环境的演化事件。
