Very early weaning of common sole (Solea solea L.) larvae by means of different feeding regimes and three commercial microdiets: Influence on performances, metamorphosis development and tank hygiene

We studied the feasibility of weaning common sole (Solea solea L.) larvae at 13 days post hatching (dph) using commercial microdiets (MDs) while reducing live-feed utilization. Four dph larvae were fed two kinds of experimental weaning feeding regimens (FRs): control FR-C (AgloNorse, Ewos) where larvae were weaned onto MD at 27 dph; whilst the other FRs provided live feed until 13 dph, employing AgloNorse, Ewos (FR-A), Gemma, Skretting (FR-G) and O.range Large, INVE (FR-O). The trial lasted 29 days. No statistical differences among groups were observed in survival rates at the end of the trial. FR-A, FR-G and FR-O showed significantly lower weight and length increase when compared to control, whereas metamorphosis development was not influenced. Fatty acids larvae profile was significantly influenced by FR. The total number of Vibrio spp. was significantly higher in FR-C tanks at 21 dph. Salinity stress test values were not influenced by treatments. In conclusion, a very early weaning at 13 dph using commercial MDs in common sole larvae affects growth performance but not survival rate and metamorphosis development. A shorter live feed utilization improved tank hygiene.

► Common sole larvae were weaned at 13 days post hatching using three commercial diets.
► Survival and metamorphosis were not affected by early weaning.
► Early weaned larvae showed lower growth performance.
► Early weaning reduced Vibrio spp. load in water.