Molecular phylogeny and DNA barcoding confirm cryptic species in the African freshwater oysterEtheria ellipticaLamarck, 1807 (Bivalvia: Etheriidae)

Abstract

Recent molecular approaches to taxonomy have led to a steady increase in the identification of cryptic species. Within the Etheriidae, the species Etheria elliptica (freshwater oyster) is widespread and common and exists in most of the major African drainages. Within the African freshwater ecosystems, there are major threats to biodiversity and cryptic species complicate conservation strategies; unknown species exist and no conservation status has been assigned. Our objective here was to determine if E. elliptica from several locations in the Congo drainage are correctly classified as representing a single species. We analysed the genetic diversity at two mitochondrial loci (COI and 16S) and two nuclear loci (H3 and 28S), and estimated evolutionary relationships using phylogenetic and DNA barcoding techniques. Bayesian inference yielded three cryptic species of Etheria, and mismatch analysis revealed discrete differences between the cryptic species. We identified three cryptic species within these collections, and evidence indicates that the third species may resolve further with more sampling. In conclusion, the taxonomic history of E. elliptica makes finding cryptic species unsurprising. However, molecular studies such as this may finally help to resolve the number of species within this genus.

Integrative Taxonomy of the Spinous Assassin Bug Genus Sclomina (Heteroptera: Reduviidae: Harpactorinae) Reveals Three Cryptic Species Based on DNA Barcoding and Morphological Evidence

“…COI has been proven to be an appropriate DNA barcoding marker in the animal kingdom due to its relatively easy amplification and fewer numbers of insertions and deletions [ 12 ], also in suborder Heteroptera [ 13 , 14 , 15 ]. Many studies based on COI DNA barcoding sequences have shown its strength in species identification and defining the cryptic species in known species [ 16 , 17 , 18 , 19 , 20 , 21 , 22 ].…”

Phylogeny of the most species-rich freshwater bivalve family (Bivalvia: Unionida: Unionidae): Defining modern subfamilies and tribes

“…In many of these studies, unionid genera or species that had been identified by morphological characters were not consistent with those revealed through molecular phylogenetic analyses (e.g., Campbell and Lydeard, 2012a,b;Nagel and Badino, 2001;Roe and Hoeh, 2003). Although the vast majority of these molecular studies have focused almost exclusively on North American and European taxa, geographic and taxonomic sampling has recently increased, particularly in Africa (Elderkin et al, 2016;Graf, 2013;Whelan et al, 2011) and Asia (Huang et al, 2002;Graf, 2013, 2015;Zhou et al, 2007;Zieritz et al, 2016).…”

Analysis of mitochondrial genomes resolves the phylogenetic position of Chinese freshwater mussels (Bivalvia, Unionidae)

“…Advances in developing improved phylogenetic hypotheses for the Unionidae have occurred in the past several decades (Davis 1984; Lydeard et al 1996; Nagel and Badino 2001; Hoeh et al 2001, 2002; Giribet and Wheeler 2002; Graf 2002; Campbell et al 2005; Zanatta and Murphy 2006; Graf and Cummings 2007; Campbell and Lydeard 2012a, b; Froufe et al 2014; Prié and Puillandre 2014; Graf et al 2015; Pfeiffer and Graf 2015). Most of these studies have focused on North American, Australian, and European taxa, although more recently, African (Whelan et al 2011; Graf 2013; Elderkin et al 2016) and Asian (Huang et al 2002; Zhou et al 2007; Huang et al 2013; Bolotov et al 2017a, b) taxa have been included, and a global phylogenetic framework of the Unionidae has recently been established (Bolotov et al 2017a; Lopes-Lima et al 2017a). Despite these advances, the incorporation of Asian taxa into unionid phylogenetic hypotheses, particularly those from China has lagged.…”