Genomic Perspectives on Growth and Disease Resistance in Gilthead Sea Bream (Sparus aurata): A Comprehensive Exploration of Heritability Estimates and Genetic Correlations

The study investigates the genetic factors associated with lymphocystis disease virus (LCDV) susceptibility and growth in gilthead sea bream aquaculture, considering two fish batches (batch 1 and batch 2). All specimens exhibited LCDV lesions at the time of sampling. Batch 1 displayed higher lesion severity and affected surface area compared to batch 2. The caudal region was least affected in both batches. Batch 1 also had higher LCDV DNA copies in the liver, positively correlated with severity index. Heritabilities for weight, length, and viral DNA copies were determined, showing low heritability for viral DNA copies in both batches. Selective breeding for LCDV susceptibility and growth is feasible in sea bream juveniles, with genetic correlations indicating the possibility, though estimates vary with age. This information is valuable for designing selective breeding programs in sea bream.