Lordosis is a significant problem in the aquaculture of several species, including sea bass. The development of skeletal abnormalities in reared fish exerts disadvantageous influences upon fish biological performance, welfare, market image and acceptability by the consumers, and therefore on fish commercial value, and on the productivity and efficiency of the aquaculture industry. Sea bass (Dicentrarchus labrax L.) is one of the two main species of the Mediterranean marine aquaculture and its farming is extending to other parts of Europe. It is an extremely popular fish, not only in the Mediterranean but also on the Atlantic coast, and the market demands for it are increasing in other European countries because of market diversification during the last few years.
When intensive aquaculture of sea bass first started, up to 70% of fish presented serious vertebral lordosis (requiring sorting and discarding) due to inadequate knowledge on the biological and technological mechanisms of swimbladder inflation. The application of adequate rearing conditions solved this problem. However, lordosis continued developing in reared sea bass with functional swimbladders, reaching frequencies of 25-70%. Other studies have implicated a range of possible factors that might influence this, which include dietary deficiencies, notochordal distortions during early development, pollutants, myopathies, and high swimming activity due to great velocity of water currents.
The increasing contribution of sea bass to the aquaculture industry but with decreasing financial return per unit stresses the importance of improving the efficiencies of production by minimising the significant loss-increasing problems of lordosis. The objective of this project is to apply a multidisciplinary scientific investigation on the influence of environmental and nutritional factors on the incidence of lordosis and on the development and function of the musculoskeletal system.
The specific objectives are:
1) to assess the influence of rearing temperature, nutrition (mainly vitamins C and E, and Selenium), current velocities and their interactions on the incidence of lordosis
2) to assess the influence on musculoskeletal development and growth at tissue, cell, protein and molecular level, as an informed basis for reducing the problem of lordosis and for optimising musculoskeletal growth
3) to provide a tool for standardised assessment of quality in a commercial environment, which will take into account not only the presence or absence of skeletal deformities, but also the real effects of their different expression-intensities on both biological performance and final product image.
Although the species to be investigated is the sea bass, it is expected that the principles derived will be applicable to other species.
Progress to Date
The project is progressing well. There are six work packages:
Work Package 1: Manipulation of environmental conditions towards the development of fish without lordosis presence
Work Package 2: Manipulation of sea bass nutrition towards the development of fish without lordosis presence
Work Package 3: Differential allometric growth of bones and muscle under different environmental and nutritional conditions, and consequences for musculoskeletal biomechanics
Work Package 4: Cellular ontogeny of bone, muscle, and connective tissue under different environmental and nutritional conditions
Work Package 5: Molecular biology of musculoskeletal ontogeny under different environmental and nutritional conditions
Work Package 6: Standardisation and assessment of fish quality under industrial scale.
The results will help in the understanding of the reasons for vertebral deformities including lordosis and will indicate the optimum rearing conditions for its elimination and for improved musculoskeletal growth. The findings of this project will lead to benefits for the consumer, producer and animal, namely:
1. for the consumer - optimisation of production will lead to improved product quality;
2. for the producer - by optimising production and improving product quality, the
competitiveness of European aquaculture will be increased;
3. for the animal - the well-being of cultured stocks will be improved.
Although the species to be investigated is the sea bass, it is expected that the principles
derived will be applicable to other species.
FISHERIES AND AQUACULTURE
Scientist responsible for the project
Professor NEIL STICKLAND
Royal College Street
NW1 0TU London
United Kingdom (The) - GB
Phone: +44 207 468 5300
Fax: +44 207 388 1027
||THE ROYAL VETERINARY COLLEGE, UNIVERSITY OF LONDON (RVC)
||01 November 2001
||1 377 749 €
|Total EC contribution
||1 023 613 €