A new genus of large hydrothermal vent‐endemic gastropod (Neomphalina: Peltospiridae) |
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| Authors: | Chong Chen Katrin Linse Christopher N Roterman Jonathan T Copley Alex D Rogers |
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| Institution: | 1. Department of Zoology, University of Oxford, Oxford, UK;2. British Antarctic Survey, Cambridge, UK;3. Ocean and Earth Science, University of Southampton, European Way, Southampton, UK |
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| Abstract: | Recently discovered hydrothermal vent fields on the East Scotia Ridge (ESR, 56–60°S, 30°W), Southern Ocean, and the South West Indian Ridge (SWIR, 37°S 49°E), Indian Ocean, host two closely related new species of peltospirid gastropods. Morphological and molecular (mitochondrial cytochrome c oxidase subunit I, COI) characterization justify the erection of G igantopelta gen. nov. within the Peltospiroidae with two new species, G igantopelta chessoia sp. nov. from ESR and G igantopelta aegis sp. nov. from SWIR. They attain an extremely large size for the clade Neomphalina, reaching 45.7 mm in shell diameter. The oesophageal gland of both species is markedly enlarged. Gigantopelta aegis has a thick sulphide coating on both the shell and the operculum of unknown function. The analysis of a 579‐bp fragment of the COI gene resulted in 19–28% pairwise distance between Gigantopelta and six other genera in Peltospiridae, whereas the range amongst those six genera was 12–28%. The COI divergence between the two newly described species of Gigantopelta was 4.43%. Population genetics analyses using COI (370 bp) of 30 individuals of each species confirmed their genetic isolation and indicate recent rapid demographic expansion in both species. © 2015 The Linnean Society of London |
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| Keywords: | East Scotia Ridge Gigantopelta Indian Ocean population genetics Southern Ocean |
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