Control of malformations in the production of Atlantic cod (Gadus morhua L.) by optimizing temperature and light conditions

Malformations has been identified as a major obstacle in the development of commercal production of Atlantic cod by the industry itself. A survey of the malformation problems presented by Norsk Sjømatsenter later confirmed this situation. NFR states con trol of production related to disorders as a priority, in marine as well as salmonid species. Malformations can cause severe mortalities and affect the profit of the industry negatively, due to reduced growth and survival rates, high numbers of outcasts a t slaughtering and lower prices. Additionally, high frequencies of malformed fish represent an ethical problem for the industry. The project aim to gain knowledge about environmental factors that may induce malformations in Atlantic cod during early deve lopmental stages. The goals of the project is to identify optimal temperature ranges for different developmental stages of Atlantic cod, identify optimal light regimes for normal development of Atlantic cod and, also to design a protocol for rearing of A tlantic cod eggs and larvae with emphasize on normal development. Gross pathology and morphometrical analysis, somatic shape of fish, bone staining and microscopic examination of whole larvae and tissue samples from larger fish and radiography will be use d for evaluation of the experimental results. Molecular markers associated with malformations will be studied in order to increase the understanding of the mechanisms of development of malformations.