Biodiversity of symbiotic gastropods (Mollusca, Eulimidae) in Vietnamese waters barcoded.

Eulimidae is a prominent group within the class Gastropoda, comprising 1087 species that have developed specialised symbiotic relationships with all extant echinoderm classes. At least 47 species of eulimids can be found in the waters of Vietnam. Representatives of the genus Pulicicochlea, the species Vitreobalcis tripneusticola, and four new undescribed species were observed for the first time. In this study, we update the existing checklists of Vietnamese eulimids, emphasising the use of molecular barcoding to determine the phylogenetic relationships among the collected species. The classical taxonomy of molluscs relies heavily on the morphology of the shell and radula. The family Eulimidae presents challenges as in many species these features are poorly developed, and molecular phylogenetic methods have proven to be more informative for the taxonomy and systematics of this family. To understand the evolutionary pathways in Eulimidae, we constructed a COI-based phylogenetic tree, which included original sequences primarily from Vietnam and all available sequences for Eulimidae from GenBank. The newly obtained genetic information is crucial for enhancing our understanding of this family of gastropod mollusсs, as well as for any future revisions that may be necessary. [ABSTRACT FROM AUTHOR]