From wood to vent: first cocculinid limpet associated with hydrothermal activity discovered in the Weddell Sea. Issue 5 (October 2020)

• Record Type: Journal Article
• Authors: Chen, Chong; Linse, Katrin
• Is Part Of: Antarctic science. Volume 32:Issue 5(2020)
• Page Start: 354
• Page End: 366
• Publication Date: 2020-10
• Subjects: Cocculina, -- Cocculinidae, -- Cocculiniformia, -- mollusc, -- new species, -- South Sandwich Arc; Science -- Antarctica -- Periodicals; 509.989
• DOI: 10.1017/S095410202000022X
• Languages: English
• ISSNs: 0954-1020

Abstract

Abstract: Lush 'oases' of life seen in chemosynthetic ecosystems such as hot vents and cold seeps represent rare, localized exceptions to the generally oligotrophic deep ocean floor. Organic falls, best known from sunken wood and whale carcasses, are additional sources of such oases. Kemp Caldera (59°42'S, 28°20'W) in the Weddell Sea exhibits active hydrothermal vents and a natural whale fall in close proximity, where an undescribed cocculinid limpet was found living in both types of chemosynthetic habitats. This represents the first member of the gastropod order Cocculinida discovered from hot vents, and also the first record from the Southern Ocean. Here, we applied an integrative taxonomy framework incorporating traditional dissection, electron microscopy, genetic sequencing and 3D anatomical reconstruction through synchrotron computed tomography in order to characterize this species. Together, our data revealed an unusual member of the genus Cocculina with a highly modified radula for feeding on bacterial film, described herein as Cocculina enigmadonta n. sp. Its phylogenetically derived position within the largely wood-inhabiting Cocculina indicates that it probably evolved from an ancestor adapted to living on sunken wood, providing a compelling case of the 'stepping stone' evolutionary trajectory from organic falls to seeps and vents.