A comprehensive phylogeography of the widespread pond snail genus Radix revealed restricted colonization due to niche conservatism

Abstract

To clarify the effect of niche conservatism on evolutionary history, we focused on freshwater snails, which have different ecological and phylogenetic properties from previously tested taxa. We conducted a phylogenetic analysis using 750 lymnaeid individuals from 357 sites of eleven Radix species. Then, we estimated the ancestral distribution using the geographic coordinates and colonization routes. In addition, a statistical test of the colonization distances in the latitudinal and longitudinal directions was performed. We also conducted ecological niche modeling for two widely distributed species using climatic data. Ancestral geographic reconstruction estimated the origin of the genus to be around the Indian subcontinental region and showed that latitudinal immigration distances were shorter than longitudinal immigration distances in the diversification process. Ecological niche models suggested that the current distribution was restricted by climate, with annual mean temperature and precipitation of the driest month as particularly strong factors. Niche conservatism to the climate can affect the diversification of freshwater snails.

Radix rufescens (J. E. Gray, 1822) (Gastropoda: Lymnaeidae), a new species for Oman and Arabian Peninsula

“…How R. rufescens colonized Wadi Tiwi remains enigmatic. One of the excellent maps of Saito et al (2021) we have completed with our finding (Fig. 5).…”

“…The evolutionary history of Radix and main colonization routes are well known (Saito et al 2021). The first diversification area was situated in east India, the rufescens/natalensis group split then into two lines.…”

“…Such studies were summarized and completed by Hubendick (1951), and continued (e.g., Falniowski 1980a, b, c, 1981. However, many ambiguities still remained in the lymnaeid taxonomy, most of them solved later with application of the molecular data (e.g., Correal et al 2010, Vinarski et al 2020, Saito et al 2021.…”

Invasion history of Gyraulus chinensis (Gastropoda: Planorbidae) in Europe: a molecular and literature-based approach

“…This suggests that temperature differences between the native range and introduced areas were important in maintaining populations during the early stages of the invasion. In general, temperature can be a major factor determining the success or failure of an alien species introduction and establishment (Hayes & Barry, 2008;Petitpierre et al, 2012;Guisan et al, 2014), and it has also been suggested that niche conservatism for temperature may influenced the formation of the distribution of Hygrophila snails (Saito et al, 2021).…”