South American crustaceans as organic extractive species of omnivorous fish culture: effects of fish feed on growth, survival and proximal composition

BACCON, M.; CARVALHO D. A.; MUSIN G.; COLLINS P. A.; CALVO N.S.

Shangai

Congreso; Global Conference on Aquaculture 2020; 2021

FAO

Aquaculture expansion has led to environmental consequences worldwide, among which the discarding of large amounts of organic waste, derived from intensive feeding, could be mitigated through the species diversification in integrated multitrophic aquaculture (IMTA). The incorporation of freshwater decapods, native to South America with a broad trophic spectrum, could biomitigate the discharge of nutrients in fish culture and increase profits. The aim of this study was to evaluate the effect of a commercial feed used in culture of omnivorous fishes (PA 27-Garay SRL, Argentina), on growth, survival and proximal composition of three species of crustaceans (prawn-Macrobrachium borellii, crab-Trichodactylus borellianus, anomuran-Aegla uruguayana).Juveniles of the three species were captured in the wild and placed in nine 90L-tanks with PVC tubes and nets as shelters (initial weights: prawn=0.2g; crabs=0.13g; anomuran=0.5g). A 84-day experiment was carried out with controlled parameters (±25°C, photoperiod 12:12) and individuals fed ad libitum twice a day. Monthly biometric measurements were taken to estimate growth increment (GI), survival (S) and biomass (B). When the experiment ended, the juveniles were killed and pooled. The proximal composition of crustacean bodies was estimated for each tank. Under these experimental conditions, anomurans showed the best zootechnical performances (GI and S). However, prawns presented the most interesting proximal composition (64% of total protein in dry matter) and high survival. The results obtained provide useful information to choose species of crustaceans that could biomitigate feed waste in an IMTA culture integrated with omnivorous fish, enhance water quality and generate profits through species diversification.