New species of chemosymbiotic clams (Bivalvia: Vesicomyidae and Thyasiridae) from a putative 'seep' in the Hatton–Rockall Basin, north-east Atlantic. (March 2014)

• Record Type: Journal Article
• Authors: Oliver, P. Graham; Drewery, Jim
• Is Part Of: Journal of the Marine Biological Association of the United Kingdom. Volume 94:Number 2(2014:Mar.)
• Page Start: 389
• Page End: 403
• Publication Date: 2014-03
• Subjects: Biology -- Periodicals; Marine biology -- Periodicals; 578.77
• DOI: 10.1017/S0025315413001136
• Languages: English
• ISSNs: 0025-3154

Abstract

<abstract abstract-type="normal"> <title> <x content-type="archive" xml:space="preserve">Abstract</x> </title> <p>Two new species of chemosymbiotic bivalves are described from a poorly localized site in the Hatton–Rockall Basin at 1187–1200 m. The new species <italic>Isorropodon mackayi</italic> sp. nov. is compared with others of the genus from the North and South Atlantic. A novel anatomical structure, suggested to be a secondary gill, is described. The second bivalve <italic>Thyasira scotiae</italic> sp. nov. is compared with other species known to inhabit cold seeps in the Atlantic and most resembles <italic>Thyasira sarsi</italic>. Other than the minor morphological differences, the bathyal range and presence of commensal polychaetes, <italic>Antonbrunnia</italic>, never reported in <italic>T. sarsi</italic> support the erection of a new species. In the North Atlantic <italic>Isorropodon</italic> species and the larger thyasirids, with the exception of <italic>T. sarsi</italic>, are typically found at hydrocarbon seeps associated with pockmarks and mud volcanoes. If correct, then this is the first indication of active sulphidic seepage in the Hatton–Rockall Basin.</p> </abstract>