Reply to Horizons Article ‘Some ideas about the role of lipids in the life cycle of Calanus finmarchicus’

• Main Author: R. W. Campbell
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Calanus finmarchicus
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.535.9696; http://plankt.oxfordjournals.org/content/26/8/979.full.pdf

The biotic and abiotic factors that modulate the life history of C. finmarchicus are not well described, and Xabier Irigoien (Irigoien, 2004) suggests some interesting hypotheses about what role lipids might play. He does, however, make some questionable assumptions about the role of lipids during overwintering. First, he states that ‘lipid storage determines the diapause depth’. Recent modelling of the effect of lipids on buoyancy depth by myself (Campbell and Dower, 2003) suggests that something approximating neutral buoyancy is only attainable in a very narrow window of lipid composi-tions. Moreover, since lipids are more compressible than seawater, buoyancy due to lipids is unstable, and a quasi-neutral buoyancy (very low sinking/ascent rates) can only be attained if the animals are able to diagnose fairly