A phylogeny ofVesiculariidae (Bryozoa,Ctenostomata) supports synonymization of three genera and reveals possible cryptic diversity

Abstract

Compared to their calcified sister group, order Cheilostomata, uncalcified ctenostome bryozoans exhibit relatively simple and often inconsistent morphologies, making them particularly suitable candidates for the use of molecular tools to delimit species and examine their interrelationships. The family Vesiculariidae is composed of six genera, three of which,Zoobotryon,AvenellaandWatersianaare monotypic, and one,Vesicularia, encompasses four species. The majority of vesiculariid diversity, however, is found inAmathia(39 species) andBowerbankia(21 species). The respective monophyletic status forAmathiaandBowerbankiahas recently been put into question by molecular evidence and is being further examined in this study. Multigene (ssrDNA,rrnL,cox1) phylogenetic analysis revealed thatBowerbankiais paraphyletic to the inclusion ofZoobotryonandAmathia, where the latter was resolved as non‐monophyletic. AlthoughVesiculariaalso nested within this paraphyletic assemblage in some of the analyses, Bayesian topology testing did not support this result. Our results are discussed within the context of published morphological evidence and lead to the conclusion thatBowerbankiaandZoobotryonshould be classified as junior subjective synonyms ofAmathia. A revised nomenclature is provided. Furthermore, we examined genetic divergences between widely distributed supposed conspecific species and discovered possible cryptic diversity in the outgroup taxonAnguinella palmataand inBowerbankia citrina,Amathia vidoviciandAmathia crispa.