Molecular evidence of intraspecific variability in Lysidice ninetta (Polychaeta: Eunicidae) in the Mediterranean Sea

Aquatic Biology

Maria Alessandra Iannotta¹  Maria Cristina Gambi¹  Francesco Paolo Patti¹ 

关键词: Polychaetes;    Eunicidae;    16S rRNA;    Mitochondrial DNA;    Mediterranean Sea;   

DOI  :  10.3354/ab00160

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: A first study of the phylogeography of the polychaete Lysidice ninetta Audouin & Milne-Edwards (Polychaeta: Eunicidae) in the Mediterranean Sea, based on analyses of the molecular markers ITS1 and COI, indicated the occurrence of strong intraspecific variability and possible sibling species. Here, we report further evidence of the presence of sibling species within L. ninetta, revealed by analysing a new molecular marker (16S rRNA) and supported by preliminary morphological observations. Specimens were collected in association with the seagrass Posidonia oceanica in 6 meadows of the Mediterranean basin; in one of the meadows in which putative siblings co-occurred (Cava meadow off the island of Ischia, Naples, Italy), additional samples were collected for genetic and morphological analysis. The mitochondrial region 16S rRNA of 78 specimens revealed 2 haplotypes (nA and nB); morphological characters, associated with these 2 molecular clades were also observed in a sub-set of the analysed specimens of L. ninetta, revealing the presence of 2 morphotypes. The morphotype termed ‘dark’, characterised by a typical dark colour pattern on the prostomium and first anterior segments, as well as by black aciculae all along the examined body portion, matching quite well with the description of L. ninetta from the Atlantic type locality, corresponded to haplotype nA. The morphotype termed ‘light’, with lighter colouration of the prostomium and first anterior segments, and both black and yellow aciculae on the examined body portion, corresponded to haplotype nB, suggesting the existence of a different species. The hypotheses that can be addressed are the following: (1) only a single new species (the light morph/genotype) is present, while the dark morph corresponds to the original L. ninetta species; (2) both morphs/genotypes (dark and light) are new taxa and need to be fully and properly described; and (3) one or both of the species corresponds to previously described species, synonymised by previous authors as L. ninetta. In all cases there is an urgent need for revision of the genus Lysidice and the nominal species in the Mediterranean Sea basin. This is a complex task far beyond the scope of this work.

【 授权许可】

Unknown