Growth and biochemical variables in Amazon catfish ( Pseudoplatystoma reticulatum ♀ x Leiarius marmoratus ♂) under different water pH

Abstract

Although fish may live in different aquatic environments, variations in the water quality parameters, mainly pH, may have a substantial impact in their development and welfare. The objective of this study was to test the effect of different pH levels on the growth performance and biochemical variables in Amazon catfish juveniles (Pseudoplatystoma reticulatum x Leiarius marmoratus). Fish were subjected to four different water pH levels (4.56, 6.0, 7.24, and 8.90) for 40 days. The total ammonia and alkalinity were higher and lower, respectively, in the treatments with water pHs 4.56 and 6.00 than at the other water pH levels. The un-ionized ammonia was higher at water pH 8.90 than at the other water pH levels. Amazon catfish exposed to water pH 4.56 presented specific growth rate and weight gain significantly higher than other water pH values. In general, fish under exposure to water pH 8.90 presented lower growth performance than other water pH values. Biochemical changes were recorded at all water pH. In conclusion, water pH 4.56 is recommended for an Amazon catfish production system, since fish presented higher growth and water quality variables were kept within adequate limits for aquaculture.

Effects of suspended solids in the survival and haematological parameters of pacu juveniles ( Piaractus mesopotamicus ) in a biofloc technology culture system

“…Furthermore, the fish (on day 1) were transferred from the maintenance tank directly to their respective treatments, and the capture management may have likely stressed them. The higher blood glucose levels in stressed fish are directly associated with increased carbohydrate metabolism (Lemos et al, 2018), which was an expected result in this study. Similar evidence has also been reported in different stressful situations for pacu in other studies (Copatti et al, 2019; Nitz et al, 2019; Pinto et al, 2019).…”