2009/765 Investigation into the molecular composition of the digestive system in Lates calcarifer and Seriola lalandi

By Linda Moss

Lates calcarifer and Seriola lalandi are two important aquaculture species in Australia and have a considerable commercial interest for the industry. Nutrition is one of the key significant considerations in aquaculture operations. Considerable research and funding are invested into the development and assessment of optimal feeds for the various aquaculture species and aquaculture conditions. Understanding the response to nutrition is crucial for the successful culture of these two species.

This study demonstrated that inclusion levels of soy bean meal and high protein soy concentrate in L. calcarifer diets had no negative effect on growth or gene expression. It also indicated poultry oil can be included into diets without any impact on growth in juvenile L. calcarifer, this may lead to the production of cheaper aquaculture diets for this species without putting further pressure on fish meal and fish oil production.

The study has also provided the first observation, through next-generation sequencing, bioinformatic analysis and functional annotation, into the digestive transcriptome of two important aquaculture species. This has resulted in the development of a molecular resource into the digestive tissues of L. calcarifer and S. lalandi. The transcriptome analysis demonstrated the presence of proteases, carbohydrases and lipases of known importance in the digestive system of two non-model teleost species. This has provided a platform for future nutrigenomic studies investigating the nutritional response in L. calcarifer and S. lalandi.