Thyasira vulcolutre Rodrigues & Oliver, 2008

Olive, Graham, Rodrigues, Clara F. & Cunha, Marina R., 2011, Chemosymbiotic bivalves from the mud volcanoes of the Gulf of Cadiz, NE Atlantic, with descriptions of new species of Solemyidae, Lucinidae and Vesicomyidae, ZooKeys 113, pp. 1-38 : 12-13

Thyasira vulcolutre Rodrigues & Oliver, 2008

Comments.

Thyasira vulcolutre belongs to a group of thyasirids with relatively large shells with weakly defined posterior sulci. It was concluded that it was most similar to Thyasira southwardae ( Oliver and Holmes 2006b) from the Anyas Garden site. At that time no thyasirid material had been found at cold seep sites along the West African margin. Consequently, unlike the situation for Lucinoma ( Cosel 2006) and Isorropodon ( Cosel and Salas 2001, Cosel and Olu 2008) no further biogeographic comparisons could be made. Recently we were able to examine a thyasirid (Fig. 8 E–F) from the REGAB site (courtesy of Karine Olu) and although it superficially resembles Thyasira vulcolutre it significantly differs in having a minutely spicate periostracum (Oliver in prep).

Thyasira striata Sturany, 1896 has long been known from deep water in the eastern Mediterranean but was recently re-discovered at cold seep sites ( Olu-Le Roy et al. 2004). Small specimens resemble Thyasira flexuosa but larger examples (Fig. 8 G–H) are very tumid with prominent lunule and deep posterior sulci quite unlike Thyasira vulcolutre .

These new data suggest that those thyasirids closely associated with active cold seeps have restricted ranges within the eastern Atlantic/Mediterranean region.