A mitochondrial phylogeny uncovers taxonomic ambiguity and complex phylogeographic patterns in the eastern Australian land snail Austrochloritis (Stylommatophora, Camaenidae)

Abstract

We analyzed the mitochondrial differentiation of the southeast Australian land snail genus Austrochloritis Pilsbry, 1890, family Camaenidae, which encompasses 34 currently accepted species. These species were exclusively described and delimited based on comparative shell morphology, while their reproductive anatomy has remained undocumented. Phylogenetic analyses of partial fragments of the cytochrome c oxidase subunit 1 gene (COI) and 16S rRNA (16S) genes revealed widespread incongruence between the shell‐based species taxonomy and the branching patterns of phylogenetic trees indicating the urgent need of more comprehensive systematic review. The phylogeographic patterns in Austrochloritis are consistent with well‐documented biogeographic barriers in southeastern Australia, namely the Hunter River Valley and the McPherson Range, which demarcate concomitant biogeographic breaks in the biota of the region. These breaks are thought to result from past expansions and contractions of mesic forests caused by the climatic oscillations during the mid to late Neogene. Our study also provides evidence for potentially widespread sympatry of Austrochloritis species in the northern part of their distribution, which is in conflict with contemporary paradigms that presume predominantly allopatric distributions in congeneric land snails in eastern Australia.

Genetic diversity of a short‐ranged endemic terrestrial snail

“…The degree of divergence found within the small range covered by this study (30–50 km) suggests that the Austrochloritis specimens used in this study may not belong to the same species, A. kosciuszkoensis . The sites studied cover only a portion of the currently accepted distribution of A. kosciuszkoensis (Köhler et al., 2020 ; Stanisic et al., 2010 ) and are over 100 km away from the type locality in Kosciuszko National Park. Given the patterns of substantial genetic turn‐over across rather short geographic distances, the taxonomic identity across A. kosciuszkoensis is in need of further scrutiny.…”

“…Given an aim of this study was to use A. kosciuszkoensis as a proxy for other, even more poorly known and less mobile taxa, the results presented here provide a level of concern for other, especially smaller SRE species, which are likely to exhibit even more distinct isolated populations. These taxa are at risk due to increasing disturbance events, both natural and anthropogenic (Brooker et al., 2007 ; Köhler et al., 2020 ). Clearly, more work is required to understand our terrestrial invertebrate fauna.…”

“…The purpose of this study was to increase our understanding of SRE organisms, by examining gene flow and population structure in the terrestrial land snail, the Kosciuszko Bristle Snail ( Austrochloritis kosciuszkoensis Shea and O. L. Griffiths, 2010). The genus Austrochloritis encompasses 34 described species, distributed throughout rainforests, wet sclerophyllous forests and woodlands in south‐eastern Australia (Köhler et al., 2020 ; Shea & Köhler, 2019 ; Stanisic et al., 2010 ). These species are narrowly distributed throughout fragmented forest environments with most described as SREs (Shea & Köhler, 2019 ), and as such, a number of these species, including A. kosciuszkoensis , were identified for priority research following the recent 2019/2020 Australian megafires (Legge et al., 2021 ), in which over 10 million hectares were burnt country‐wide, 81% identified as native forests (Davey & Sarre, 2020 ; Saunders et al., 2021 ), and it was estimated over 240 trillion invertebrates were killed (Dickman, 2021 ) as a result of this unprecedented event (Boer et al., 2020 ).…”

Systematic revision of the limestone karst-restricted land snail genus Aenigmatoconcha (Eupulmonata: Helicarionidae), with description of a new species

“…While genitalia of Aenigmatoconcha lack dart apparatus, but contain the flagellum, and genitalia of Chalepotaxis lack both organs. Generally, some characters of genital anatomy, such as a penial caecum, penial verge, dart apparatus, or flagellum, have been hypothesized to evolve repeatedly during the evolution of land snails, and have been noticed in many groups of terrestrial pulmonate snails (Solem 1966;Hausdorf 1998;Hyman & Ponder 2010;Hirano et al 2014;Köhler & Criscione 2015;Köhler et al 2020;Sutcharit et al 2020a). However, the classification of these three genera based on the presence or absence of the dart apparatus and flagellum is consistent with the molecular phylogeny (Sutcharit et al 2020a).…”

Multigene phylogeny reveals the ribbed shell morphotypes in the land snail genus Sarika (Eupulmonata: Ariophantidae), with description of two new species from Thailand and Myanmar

“…To this end, future studies should explore the lineage differentiation, speciation, and ecological niche occupancy of these closely related species. (Köhler et al, 2020b;Sutcharit et al, 2020a). Family Ariophantidae Godwin-Austen, 1883…”