28 Apr 2011

Antarctic Fish Leeches and Antifreeze

From Our Changing World, 9:20 pm on 28 April 2011

The sea surface around Antarctica freezes each winter, and the sea water beneath the ice is almost at freezing point, about -1.9 degrees Celsius.

The presence of ice crystals in the water is a potential hazard to living marine organisms such as fish, which have developed glycoprotein antifreeze to manage any ice which gets inside their body. This work has been the focus of research since the 1960s, by scientists such as Art de Vries and Clive Evans - you can listen to an earlier Our Changing World interview with Clive here.

Massey University PhD student Juergen Kolb is interested in parasitic leeches that live on fish, of which Antarctic has 21 known species. As Juergen tells Alison Ballance he is keen to find out whether fish leeches in Antarctica use antifreeze, and whether they obtain the antifreeze they need from the fish blood they ingest, or whether they produce their own antifreeze.