Considerations on Mediterranean Lucinoma (Bivalvia, Lucinidae)

Based on shell characteristics and differences in their respective habitats, three species ascribed to the genus Lucinoma Dall, 1901 (Lucinidae, Bivalvia) are currently recognized in the Mediterranean Sea. The most widespread and long-known is the Atlantic-Mediterranean Lucinoma borealis (Linnaeus, 1767), mainly recorded from subtidal to circalittoral bottoms. The second, larger species, Lucinoma kazani Salas & Woodside, 2002, is associated with deep-sea hydrocarbon seepage habitats. A third species Lucinoma spelaeum Palazzi & Villari, 2001, was not validly described and is here described as Lucinoma neospelaeum n. sp. It appears to be confined to a small area in the Strait of Messina at shallow depths, although a disjunct eastern Atlantic occurrence has been proposed. Molecular studies are needed to clarify whether more than one species is currently grouped under the names L. borealis and L. neospelaeum, and to explore phylogenetic relationships among Atlantic-Mediterranean Lucinoma.