Zootechnical performance of white tilapia fingerlings (Oreochromis niloticus x O. aureus) at different temperatures

Abstract

This study aimed to evaluate the efficiency and growth parameters in the early growth phase of white tilapia fingerlings (Oreochromis niloticus x O. aureus var. “Rocky Mountain”) with two different temperature regimes. The experiment was carried out at the Aquaculture Module of the Alfredo Volio Mata Experimental Station (EEAVM) of the University of Costa Rica over a period of 56 days, using 160 fingerlings with an initial averaged weight of 0.304 ± 0.009 g. After a 10-day acclimatization, they were divided into groups of 10 fingerlings per tank based on their weight, in a total of 16 tanks arranged in four rows: each with its own mechanical and biological filtration system and temperature control. Two rows were randomly selected and regulated at 27°C and the other two were maintained at 22°C. Initial and final measurements of length and width were taken. Food consumption was monitored and registered daily. Weighings were conducted every 15 days to assess weight gain (WG), thermal growth coefficient (TGC), specific growth rate (SGR), K condition factor (KF), feed conversion ratio (FCR), and protein efficiency ratio (PER). At the end of the test, viscerosomatic index (VSI) and head-body ratio (H/B) rating were generated; also, mortality was registered. Significant differences (p < 0.05) were observed between the treatments in almost all parameters (WG, TGC, SGR, FCR, PER, VSI, and H/B), except for mortality and the K condition factor. A negative effect of temperature on white tilapia performance was observed under low temperatures, which resulted in weight gains 5 times higher for fish developed at 27°C (2.72 ± 0.19 g), compared to those at 22°C (0.54 ± 0.05 g).