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 Gigantopelta gen. nov. within the Peltospiroidae with two new species, Gigantopelta chessoia sp. nov. from ESR and Gigantopelta aegis sp. nov. from SWIR. They attain an extremely large size for the clade Neomphalina, reaching 45.7mm 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 (370bp) of 30 individuals of each species confirmed their genetic isolation and indicate recent rapid demographic expansion in both species.
Original language | English |
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Pages (from-to) | 319-335 |
Number of pages | 17 |
Journal | Zoological Journal of the Linnean Society |
Volume | 175 |
Issue number | 2 |
Early online date | 23 Sept 2015 |
DOIs | |
Publication status | Published - 1 Oct 2015 |
Keywords
- East Scotia Ridge
- Gigantopelta
- Indian Ocean
- population genetics
- Southern Ocean
- UKRI
- NERC
- NE/DO1249X/1
- NE/H012087/1