Cryptic species in Gemmuloborsonia (Gastropoda: Conoidea)

Abstract

During a broad molecular taxonomic and phylogenetic survey of the gastropod superfamily Conoidea, 80 specimens of several species of the genus Gemmuloborsonia were sequenced for the cytochrome c oxidase subunit I gene. The genus, originally established for fossil species from the Plio-Pleistocene of the Philippines, now includes living species from bathyal depths of the Indo-Pacific Oceans. The molecular data demonstrated the presence of five separate entities, while only four 'morphospecies' could be isolated by visual examination. The two largest groups, representing separate species from the molecular data, were impossible to distinguish with certainty using shell or anatomical characters. To examine shell morphology in more detail the shape of the last whorl was analysed by Fourier analysis, and the Fourier coordinates were used in canonical variate analysis. The majority of the specimens were separated into two groups, but 21.6% of the specimens were impossible to distinguish by morphological characters. One of these two forms was attributed to the known species Gemmuloborsonia moosai Sysoev & Bouchet, 1996, while the other is described as a new species Gemmuloborsonia clandestina. Bathytoma colorata Sysoev & Bouchet, 2001 is transferred to Gemmuloborsonia on the basis of molecular analysis and radular morphology. Another species, represented in our material by a single specimen, remains undescribed.

Unraveling Cryptic Diversity in the Indo-West Pacific Gastropod GenusLunella(Turbinidae) using Elliptic Fourier Analysis*

“…identify species morphologically, like other authors (e.g. Collin 2005, Puillandre et al 2010, we believe that they should still be recognized as distinct entities and given specifi c status, if genetic divergence is suffi ciently high. The problem of determining cut off levels for genetic divergence is ongoing, although new statistical methods that determine the transition between coalescent and speciation branching patterns may be helpful (e.g.…”

“…More often DNA sequences are seen as another marker for helping to identify species, albeit an important one (e.g. Puillandre et al 2010). However, for comparison with fossils and historical types, it is critical to identify morphological characters that can distinguish species.…”

“…Elliptic Fourier analysis (EFA) has been effectively applied to the analysis of various biological shapes in a variety of organisms including molluscs (e.g. Puillandre et al 2009, Puillandre et al 2010, de Aranzamendi et al 2010, Costa et al 2010, Van Bocxlaer and Schultheiß 2010, González-Wevar et al 2011. Moreover EFA has several important advantages over alternate morphometric analyses (Iwata et al 1998).…”

Loss of planktotrophy and speciation: geographical fragmentation in the deep-water gastropod genusBathytoma(Gastropoda, Conoidea) in the western Pacific

“…However, the current generic allocation of many deep-water turriform gastropods is very unsatisfactory, and it is obvious that not all species currently included in Bathytoma belong there (e.g. Bathytoma colorata Sysoev & Bouchet, 2001 is now recognized as a species of Gemmuloborsonia, based on its radula; Puillandre et al, 2010) and, conversely, species placed elsewhere will ultimately end up in Bathytoma. Alexander Sysoev has examined the primary literature for all Recent deep-water 'turrids' in the context of ongoing broad-scale taxonomical work, thus minimizing the chance that one of the new species described below might have been described in another genus.…”

Mitochondrial and nuclear DNA analysis revealed a cryptic species and genetic introgression in Littorina sitkana (Mollusca, Gastropoda)

“…In shellbearing mollusks, shell characters have contributed to taxonomy and are regarded as useful tools for species identification. However, in some cases, molecular evidence has revealed the existence of cryptic species that cannot be distinguished by shell morphologies (e.g., Liu et al 2011;Puillandre et al 2009). There are several examples of gastropod phenotypes, which can become genetically adapted or plastically changed in response to environmental factors (Dewitt and Scheiner 2004;Piersma and Gils 2010).…”