Cryptic species within the rotifer Lecane bulla (Rotifera: Monogononta: Lecanidae) from North America based on molecular species delimitation

Abstract

The littoral rotifer Lecane bulla is one of the most eurytopic members of the Lecane genus and is found in a wide variety of water bodies around the world. Taxonomic orthodoxy dictates that all specimens of this widespread taxon represent a single morphospecies. We analyzed a dataset of previously published and newly generated sequences of the mitochondrial COI gene of the L. bulla complex to examine cryptic diversity in the taxon. We undertook phylogenetic analyses and applied 3 methods of species delimitation (ABGD, PTP and GMYC) to identify cryptic species within L. bulla . Our results revealed the existence of 13 cryptic species based on the agreement of the different delimitation methods. Genetic distances between the 13 cryptic species ranged from 4.6 to 16.8%. We found a barcoding gap where the intraspecific divergences (within cryptic species) were smaller than interspecific divergences (among cryptic species), thus supporting the 13 cryptic species delimited by the species delineation methods as independent entities. Our work reveals high levels of cryptic diversity in L. bulla and highlights the need to further studies to resolve the taxonomic status of these cryptic species (and genetic lineages).