Notodiscus (Charopidae) on South Georgia: some implications of shell size, shell shape, and site isolation in a singular sub-Antarctic land snail

Multivariate analysis shows that shells of Notodiscus sp. (Charopidae: Pulmonata) reported from South Georgia are smaller and proportionately taller than, but otherwise similar to, populations of Notodiscus hookeri (Reeve) from Iles Crozet and Iles Kerguelen. The origin of this solitary, and spatial...

Full description

Saved in:
Bibliographic Details
Published in:Antarctic science 2011-10, Vol.23 (5), p.442-448
Main Authors: Pugh, P.J.A., Lewis Smith, R.I.
Format: Article
Language:English
Subjects:
Animal and plant ecology
Animal, plant and microbial ecology
Animals
Anthropogenic factors
Aquatic birds
Biological and medical sciences
Charopidae
Demecology
Fundamental and applied biological sciences. Psychology
Invertebrates
Larus dominicanus
Marine
Mollusca
Morphology. Histology. Cytology
Multivariate analysis
Phalacrocorax atriceps
Phoebetria palpebrata
Protozoa. Invertebrata
Pulmonata
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Multivariate analysis shows that shells of Notodiscus sp. (Charopidae: Pulmonata) reported from South Georgia are smaller and proportionately taller than, but otherwise similar to, populations of Notodiscus hookeri (Reeve) from Iles Crozet and Iles Kerguelen. The origin of this solitary, and spatially limited, South Georgia population is enigmatic. It is confined to a remarkably small coastal lowland site which was glaciated at Last Glacial Maximum, precluding a Tertiary relict origin, and on the leeward north-east coast, ruling out post-glacial ocean rafting. The site is close to the King Edward Point settlement, yet the absence of any logistics connections with the Iles Crozet or Iles Kerguelen mitigates against anthropogenic introduction. The close proximity of the population to nests of blue-eyed shag (Phalacrocorax atriceps), Dominican gull (Larus dominicanus) and light-mantled sooty albatross (Phoebetria palpebrata) could imply the snail was originally introduced to South Georgia via these ocean transiting seabirds.
ISSN:0954-1020
1365-2079
DOI:10.1017/S0954102011000289