Effects of water temperature and feeding time on growth performance and physiological parameters of Piaractus brachypomus juveniles

• Published in: Aquaculture 2022-02, Vol.548, p.737716, Article 737716
• Main Authors: Favero, Gisele Cristina, dos Santos, Fabio Aremil Costa, da Costa Júlio, Gustavo Soares, Batista, Felipe Soares, Bonifácio, Caroline Teixeira, Torres, Isabela Fernanda Araújo, Paranhos, Camila Oliveira, Luz, Ronald Kennedy
• Format: Article
• Language: English
• Subjects: Characidae; Food management; Neotropical fish; Pirapitinga
• ISSN: 0044-8486; 1873-5622
• DOI: 10.1016/j.aquaculture.2021.737716

This study evaluated the effects two water temperatures and two feeding times on the growth performance, hematology, and blood biochemistry of Piaractus brachypomus juveniles at an early stage of development. Fish (2.99 ± 0.04 g) were distributed in 12 tanks at a density of 0.2 fish L−1, with the water being maintained at 28 °C in six tanks and decreased to 24 °C at the beginning of the experiment in the other six. The following treatments were tested with a commercial diet for 40 days using a 2 × 2 factorial design with three replicates each: 24MF (24 °C and fed at 8 h30 and 13 h30); 28MF (28 °C and fed at 8 h30 and 13 h30); 24AF (24 °C and fed 11 h00 and 16 h00), and 28AF (28 °C and fed at 11 h00 and 16 h00). Final weight (FW), total length (TL), weight gain (WG), daily weight gain (DWG), specific growth rate (SGR), feed intake (FI), hemoglobin, glucose, triglycerides, and cholesterol were evaluated after 20 days and verified an effect of temperature, with higher values for 28 °C, while no significant differences were found for feed conversion ratio (FCR) and protein efficiency rate (PER). None of the growth performance parameters were influenced by feeding time and there was no significant interaction between temperature and feeding time after 20 days. Feeding time influenced cholesterol after 20 days, with higher values for AF strategies. All growth performance parameters and hemoglobin, glucose and triglycerides showed an effect of water temperature after 40 days, with higher values for 28 °C, while no significant differences were found for FCR and PER. Triglycerides and cholesterol were also influenced by feeding time, with higher values for AF strategies. Hepatosomatic, mesenteric fat and viscero-somatic indexes were not influenced by temperature, feeding time, or their interaction. Juvenile P. brachypomus can regulate and adjust their physiological variables in response to low water temperature, showing good FCR and PER. Furthermore, the feeding times evaluated in the present study had little influence on growth performance and physiological parameters, with both feeding times being recommended for commercial production of the species at an early stage of development (initial weight ~ 3 g). •The low water temperature (24 °C) compromised the growth performance of juveniles Piaractus brachypomus.•Juveniles P. brachypomus adjusted their hematological and biochemical variables in response to low water temperature.•Different feeding times did not influe