The curious case of Hermodice carunculata (Annelida: Amphinomidae): evidence for genetic homogeneity throughout the Atlantic Ocean and adjacent basins

TitleThe curious case of Hermodice carunculata (Annelida: Amphinomidae): evidence for genetic homogeneity throughout the Atlantic Ocean and adjacent basins
Publication TypeJournal Article
Year of Publication2013
AuthorsAhrens JB, Borda E, Barroso R, Paiva PC, Campbell AM, Wolf A, Nugues MM, Rouse GW, Schulze A
JournalMolecular Ecology
Volume22
Pagination2280-2291
Date Published2013/04
Type of ArticleArticle
ISBN Number0962-1083
Accession NumberWOS:000317137200017
KeywordsAtlantic Ocean, connectivity, fireworm, Hermodice, Polychaete; baltic sea; caulerpa-taxifolia chlorophyta; e-commerce; maximum-likelihood; mitochondrial-dna; molecular-data; mura k, 1993, molecular biology and evolution, v10, p512; phylogenetic analyses; polymerase chain-reaction; population expansion; provide evidence
Abstract

Over the last few decades, advances in molecular techniques have led to the detection of strong geographic population structure and cryptic speciation in many benthic marine taxa, even those with long-lived pelagic larval stages. Polychaete annelids, in particular, generally show a high degree of population divergence, especially in mitochondrial genes. Rarely have molecular studies confirmed the presence of ‘cosmopolitan’ species. The amphinomid polychaete Hermodice carunculata was long considered the sole species within its genus, with a reported distribution throughout the Atlantic and adjacent basins. However, recent studies have indicated morphological differences, primarily in the number of branchial filaments, between the East and West Atlantic populations; these differences were invoked to re-instate Hermodice nigrolineata, formerly considered a junior synonym of H. carunculata. We utilized sequence data from two mitochondrial (cytochrome c oxidase subunit I, 16S rDNA) markers and one nuclear (internal transcribed spacer) marker to examine the genetic diversity of Hermodice throughout its distribution range in the Atlantic Ocean, including the Mediterranean Sea, the Caribbean Sea, the Gulf of Mexico and the Gulf of Guinea. Our analyses revealed generally low genetic divergences among collecting localities and between the East and West Atlantic, although phylogenetic trees based on mitochondrial data indicate the presence of a private lineage in the Mediterranean Sea. A re-evaluation of the number of branchial filaments confirmed differences between East and West Atlantic populations; however, the differences were not diagnostic and did not reflect the observed genetic population structure. Rather, we suspect that the number of branchial filaments is a function of oxygen saturation in the environment. Our results do not support the distinction between Hcarunculata in the West Atlantic and H. nigrolineata in the East Atlantic. Instead, they re-affirm the older notion that H. carunculata is a cohesive species with a broad distribution across the Atlantic Ocean.

DOI10.1111/mec.12263
Short TitleMol. Ecol.
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