Comparative study of survival and growth in classical clear water and multi-trophic recirculating systems during Pseudoplatystoma puntifer larval rearing

International audienceIn this study, two rearing systems and two formulated diets were compared on survival and growth of Pseudoplatystoma punctifer ex. fasciatum sibling larvae over a period of 41 days. In this species the artificial breeding relies on the adaptation to dry food (weaning) after a period of Brine shrimp (Artemia nauplii) feeding. The main objective of the current research was the development of a larvae breeding protocol that will lower, the use of Artemia nauplii, weaning time and mortality. A classic recirculated clear water system with mechanical and biological filtration, and an integrated Multi-trophic recirculated Aquaculture facility, were used simultaneously in the IIAP field station of Quistococha, Peru. Live Artemia nauplii, decapsulated brine shrimps eggs or commercial dry feeds were distributed in excess to all treatments from 3 dpf to 15 dpf, then best treatment group (3 replicates) received semi-humid diets for 10 days, and posteriorly juveniles were progressively adapted to commercial dry feeds from 28 to 41 dpf. Samplings were performed at 15, 27 and 41 dpf. Total larvae numbers and individual sizes were determined from digital photographs, subsequently processed using NIH IMAGE J freeware. Mean total length (TL), calculated for each replicate at each sampling time, was analyzed using one-way ANOVA and post-hoc tests to compare treatments. The results indicated that it was possible to obtain in 41 days, juveniles between 50 and 65 mm TL. Artemia has proved, in both systems, to be the best feeding alternative for early larvae phase (up to 18 mm, 14 dpf)). Classical clear water system performed better from 3 to 18 dpf, then both systems are comparable in terms of survival while growth is significantly higher in classical clear water system over the 41-days rearing period