Cannibalism of Atlantic cod Gadus morhua larvae and juveniles on first-week larvae

Aquatic Biology

†¹  Benjamin J. Laurel¹  Joseph A. Brown¹  Velmurugu Puvanendran¹ 

关键词: Conspecifics;    Cannibalistic behaviour;    Atlantic cod;    Intra-cohort;   

DOI  :  10.3354/ab00044

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: Cannibalism in Atlantic cod Gadus morhua is widespread under both field and culture conditions, but no studies have been conducted on the behavioural ontogeny of cannibalism in this species. We carried out an experiment to investigate the onset and ontogenetic changes in cannibalistic behaviour of Atlantic cod during early developmental stages. Cod larvae were separated into 4 size classes (6, 9, 12 and 15 mm) to monitor cannibalistic activity on first-week (~4 mm) conspecific larvae. Five cannibalistic behaviours (fixation, aggression, fin nipping, attacking and engulfing) were monitored when the predator was introduced to the observation chamber. Cannibalistic attacks initially appeared in 9 mm predators, although 6 mm larvae showed prey interest and engaged in fin nipping behaviour. The 9 and 12 mm larvae engaged in similar rates of cannibalistic activity, while 15 mm fish demonstrated a significant increase. These behavioural changes appear to coincide with the morphological and physiological changes associated with juvenile metamorphosis, namely fin ray, vertebrae and stomach development. More importantly, our observations indicate that cannibalism reduces survival of conspecifics at earlier developmental stages than indicated by diet analyses alone.

【 授权许可】

Unknown