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Morphological and genetic evidence supports the existence of two species in the genus Ophelia (Annelida, Polychaeta) from the Western Mediterranean

Maltagliati, Ferruccio and Casu, Marco and Castelli, Alberto (2004) Morphological and genetic evidence supports the existence of two species in the genus Ophelia (Annelida, Polychaeta) from the Western Mediterranean. Biological Journal of the Linnean Society, Vol. 83 (1), p. 101-113. eISSN 1095-8312. Article.

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DOI: 10.1111/j.1095-8312.2004.00374.x


About 900 individuals of the intertidal polychaete Ophelia cf. bicornis were collected at four sandy beaches in Corsica, ten in Sardinia and one in Tuscany (Western Mediterranean). They were analysed morphologically and genetically to clarify the taxonomic status of the littoral species of Ophelia in the study area and to assess the population genetic structuring. Two morphotypes were distinguished on the basis of the number of nephridiopore pairs (five or six). Genetic distances, F-statistics and analysis of molecular variance based on eight allozyme genetic markers were consistent in showing the two morphotypes to separate at species level. Thus, the two morphotypes which most authors have included in O. bicornis s.l. are not one morphologically variable taxon, but instead constitute two valid species, namely O. bicornis Savigny, 1818, with six pairs of nephridiopores, and O. barquii Fauvel, 1927, with five pairs of nephridiopores. Mechanisms of ecological speciation in a background of gene flow can be taken into account to explain the origin of the two species. Moderate genetic differentiation was found among populations within each species, suggesting that dispersal may not be effective over large distances, or that local selection plays an important role in population differentiation.

Item Type:Article
ID Code:1972
Uncontrolled Keywords:Allozymes, dispersal, genetic structure, meristic characters, polychaetes, spatial variation, speciation, systematics
Subjects:Area 05 - Scienze biologiche > BIO/05 Zoologia
Divisions:001 Università di Sassari > 01 Dipartimenti > Zoologia e genetica evoluzionistica
Publisher:Blackwell / Wiley
Copyright Holders:© 2004 The Linnean Society of London
Deposited On:18 Aug 2009 10:06

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