The phylogeny of the genus Indoplanorbis (Gastropoda, Planorbidae) from Africa and the French West Indies

Abstract

Indoplanorbis exustus is a freshwater snail known as the intermediate host of various trematode parasites, including different species of the genus Schistosoma. Although its genetic diversity is well described in Asia, the phylogenetic diversity of strains from Africa and Guadeloupe (French West Indies) and their relationship to Asian and South‐East Asian strains remain unknown. To tackle this issue, we sampled individuals from Africa and Guadeloupe, and we computed phylogenetic reconstructions using five molecular markers: partial sequences of two mitochondrial genes, cox1 and 16S, and three nuclear markers, ITS1, ITS2 (Internal Transcribed Spacer 1 and 2) and 5.8S. Our results suggest that strains in Africa and Guadeloupe come from Asia and that they all belong to a single clade that is widespread around the globe.

Phylogeographic genetic variation of Indoplanorbis exustus (Deshayes, 1834) (Gastropoda: Planorbidae) in South and Southeast Asia

“…In the latter case, dispersal may occur in clumps of mud stuck to cattle and water buffalo or disperse via water in debris [ 17 ]. Currently, I. exustus is known to be a widely distributed species in tropical and subtropical zones throughout South and Southeast Asia, southern China and across Africa to the French West Indies [ 18 , 19 ]. In addition, seasonal rainfall variations have been shown to influence the distribution of I. exustus in Assam/Bangladesh and both the Southeast Asian mainland and peninsula.…”

“…A series of investigation into the genetic and phylogenetic variations in I. exustus using mitochondrial DNA sequences has revealed that four to five genetically distinct lineages, clades, were always congruent, suggesting I. exustus may comprise more than one species or, in fact, be a species complex [ 5 , 10 , 17 , 19 ]. It was initially classified as clades existing in north India (Assam and Bangladesh) and Cratonic India (Sri Lanka), ubiquitous in Thailand, the Philippines, and Nepal, Sundaic in Indonesia, as well as Arabian and Malaysian clades [ 17 ].…”

“…More recently, the five major clades were categorized into only four clades. The previously classified clade C and D by Gauffre-Autelin et al [ 10 ] were merged as one clade, following examination of new localities from Africa and the French West Indies [ 19 ].…”

“…The mitochondrial cytochrome c oxidase subunit 1 (CO1) has been shown to be the best potential marker to elucidate phylogeographic genetic variations in this snail [ 10 , 19 ]. The majority of previous studies have used the CO1 sequence to examine the molecular systematics of I. exustus .…”

Genetic analysis of Cryptozona siamensis (Stylommatophora, Ariophantidae) populations in Thailand using the mitochondrial 16S rRNA and COI sequences

“…In the last few years, DNA sequencing data has been used to study and clarify the evolution of morphological characteristics of ambiguous organisms [ 15 – 18 ] while genetic studies of land snails using DNA sequence data could be valuable for their identification [ 19 – 21 ]. The most commonly used genes for genetic analysis in land snails are the mitochondrial cytochrome c oxidase subunit I (COI) and 16S rRNA genes [ 20 , 22 – 24 ].…”