THE POTENTIAL OF MOLECULAR TOOLS TO IMPROVE AQUACULTURE PRODUCTIVITY

The Aquaculture Research Station in Olhão (EPPO) is part of the National Institute of the Ocean and Atmosphere (IPMA) and stands out for the unique experimental conditions on aquaculture at the national level. EPPO facilities allows from the most fundamental research to pilot studies that can help to give answers to the aquaculture sector. In analytic terms the EPPO has well equipped laboratories to perform a number of techniques, such as biochemistry, microbiology and molecular biology, among others. In recent years the advance on molecular biology of aquatic animals has provided useful information that can be used to improve aquaculture and the welfare conditions of farmed fish.

Some of the techniques that have been developed at EPPO facilities during the last few years include:

• The parental contribution of several breeder species:  molecular markers (e.g. microsatellite sequences) present in  genomic DNA extracted from breeders and offspring samples are analyzed and compared in order to infer the parental contribution of progenitors;
• Identification of molecular biomarkers to evaluate welfare conditions of farmed fish: molecular biomarkers are identified combining literature search and transcriptomic-based approaches. S elected molecules are validated for their potential  to predict welfare conditions of farmed fish;
• Molecular identification of fish pathogens (e.g. Amyloodinium ocellatum) in order to increase the certainty and reduce the time of the diagnosis.
• Gene expression analysis of growth-related genes: gene expression of growth-related genes is evaluated in RNA extracted from fish grown in different farming conditions (e.g. with different feeds, different growth profile) and in selected time periods. The figure presented bellow shows the results of one long-term experience performed in EPPO facilities where the insulin growth factor 1 (IGF1) gene expression was evaluated at 350 days after hatching (DAH).

A tendency for an increase of IGF1 expression in RP and for a decrease in 38HP treatment was observed at 350 DAE and was in agreement with growth data collected, suggesting that this kind of approach is a suitable tool to evaluate the growth performance of juvenile fishes.

Acknowledgments: The authors thank to J. M. Mancera and K. Mohammed-Geba for supplying the transcript sequences used in the study. The research was funded by DIVERSIAQUA project (Mar2020 16-02-01-FMP-0066), DIVERSIAQUA II (Mar2020-P02M01-0656P) and Saude&Aqua ((MAR-02.05.01-FEAMP-0009)