Marine Biodiversity and Ecosystems

Latitudinal Gene Drift in Ross Sea Organisms 

Principal Investigator: Craig Marshall
Organisation: University of Otago

Marine and terrestrial organisms are likely to have been exposed to quite different environments since Antarctica separated from the rest of Gondwana.  Marine systems are well mixed and allow easy movement of individuals from place to place.  Despite this, notothenioid fish dominate the Antarctic fish fauna and form a species flock implying that some mechanism must exist to isolate individual populations.  Marine invertebrates such as echinoderms and pcynogonids seem to be less diverse and more similar to species found in the adjoining landmasses.  In contrast, land organisms inhabit ice-free refugia that comprise only a few percent of the area of the continent.  Animals from these areas may show much stronger regional variation and a different pattern on speciation.  In this programme, we will collect material from both marine and terrestrial animals to determine their phylogenetic histories.

Recent Publications:
Wharton, D. A. et. al. Freezing and cryoprotective dehydration in an Antarctic nematode (Panagrolaimus davidi) visualised using a freeze substitution technique. Cryobiology 50: 21-28. 2005.

Marshall, C. et al. Does the enzyme citrate synthase from several Antarctic fish show evidence of cold adaptation? in Antarctic biology in a global context. Huiskes, A. et al. (eds). 2003. pp.102-106.

Wharton, D. A. Goodall, G. Marshall, C.J. Freezing survival and cryoprotective dehydration as cold tolerance mechanisms in the Antarctic nematode Panagrolaimus davidi. Journal of experimental biology 206: 215-221, 2003.