Species Richness, Molecular Taxonomy and Biogeography of the Radicine Pond Snails (Gastropoda: Lymnaeidae) in the Old World

Olga V Aksenova,Alexander V Kondakov,Yulia V Bespalaya,Dmitry M Palatov,Alena A Tomilova,Maxim V Vinarski,Mikhail Yu Gofarov,Ivan N Bolotov,Ilya V Vikhrev,Vitaly M Spitsyn,Oksana V Travina,Yulia S Kolosova,Svetlana E Sokolova

doi:10.1038/s41598-018-29451-1

Abstract

The radicine pond snails represent a species-rich and widely distributed group, many species of which are key vectors of human and animal trematodoses. Here we clarify the taxonomy, distribution and evolutionary biogeography of the radicine lymnaeids in the Old World based on the most comprehensive multi-locus molecular dataset sampled to date. We show that the subfamily Amphipepleinae is monophyletic and contains at least ten genus-level clades: Radix Montfort, 1810, Ampullaceana Servain, 1881, Peregriana Servain, 1881, Tibetoradix Bolotov, Vinarski & Aksenova gen. nov., Kamtschaticana Kruglov & Starobogatov, 1984, Orientogalba Kruglov & Starobogatov, 1985, Cerasina Kobelt, 1881, Myxas G. B. Sowerby I, 1822, Bullastra Bergh, 1901, and Austropeplea Cotton, 1942. With respect to our phylogeny, species-delimitation model and morphological data, the Old World fauna includes 35 biological species of radicines. Tibet and Eastern Europe harbor the richest faunas, while East Asia and Africa appear to be the most species-poor areas. The radicine clade could have originated near the Cretaceous – Paleocene boundary. The Miocene great lakes in Eurasia seems to be the most important evolutionary hotspots shaping spatial patterns of recent species richness. Finally, we present the first DNA barcode reference library for the reliable molecular identification of species within this group.

Highlights

The pond snails (Lymnaeidae Rafinesque, 1815) represent one of the most diverse and practically important families of freshwater snails, almost cosmopolitan in its distribution[1,2,3]
The molecular studies undertaken in 2000–2010s have revealed a high level of cryptic diversity within this group[14,20,21], but in most papers authored by molecular taxonomists only nameless clades or Molecular Operational Taxonomic Units (MOTUs) are presented, without any attempt to attach these molecular entities to nominal species previously described on the basis of the shell and soft body morphology
Species richness of the radicine pond snails in the Old World based on the COI barcode data

Summary

Introduction

The pond snails (Lymnaeidae Rafinesque, 1815) represent one of the most diverse and practically important families of freshwater snails, almost cosmopolitan in its distribution[1,2,3]. Bargues et al.[11] discuss another informal group, the ‘fossarine’ snails (taxa related to the genus Galba Schrank, 1803 = Fossaria Westerlund, 1885) Among these groups, that of radicine snails is restricted almost totally to the Old World in its distribution, with one species, Radix auricularia (L., 1758), introduced into North America, Australia and New Zealand[12,13], and with a few taxa native to Australasia[7,14]. That of radicine snails is restricted almost totally to the Old World in its distribution, with one species, Radix auricularia (L., 1758), introduced into North America, Australia and New Zealand[12,13], and with a few taxa native to Australasia[7,14] It includes several genera (or subgenera) characterized by a shell with relatively short spire, more or less inflated body whorl and low whorls number (typically 3–4). Sometimes, such an approach had led researchers to accept a huge amount of varieties within a small number of species[22] or even to elevate many of these varieties to the full species rank[23]

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