Temperature-dependent morbidity of ‘nicked’ edible crab, Cancer pagurus

Abstract

The combined effect(s) of holding temperature and claw immobilisation (nicking) onCancer paguruswere investigated. Creel captured animals (n=48) were maintained at 4°C, 8°C and 12°C for 14 days in order to mimic environmental conditions in commercial holding facilities. The consequences of nicking on animal health were assessed by measuring physiological and immune-related parameters in the haemolymph: total protein concentration,l-lactate, pH, haemocyte counts and phenoloxidase activities.  Mortality was most severe in nicked crabs held at 12°C (83%) compared to non-nicked crabs held at the same temperature (16.7%) or nicked crabs held at lower temperatures (16.7% at 8°C and 0% at 4°C). Stress-related parameters such asl-lactate and pH were only affected in the most extreme condition (crabs nicked at 12°C). However, phenoloxidase activities increased significantly (even in control groups) with increasing temperature, an effect that was exacerbated by the nicking process.