Effect of feeding frequency and water salinization on early development of Pyrrhulina brevis, an Amazonian ornamental fish

Abstract

Pyrrhulina brevis is an endemic fish from the Amazon basin that is valued in the ornamental fish market. In larviculture, fish are very sensitive to stressors and have a high mortality rate. Salinized water may provide more energy to overcome stress and feeding frequency is an important strategy to improve productive performance. Therefore, the aim of this study was to evaluate the best feeding frequency and the best level of water salinization for larval development of P. brevis. A total of 360 post-larvae of P. brevis (5.26 ± 1.65 mg, 5.57 ± 0.68 mm) were randomly distributed in 36 aquariums (1 L) in a 3x4 factorial scheme, to evaluate three concentrations of salt in water (0, 1 and 2 g L-1) and four feeding frequencies (once, twice, three and four times a day). We offered 150 Artemia nauplii per day and per post-larvae during 15 days. The fish kept at 1 g L-1 salinized water, and those fed 3 and 4 times a day presented significantly greater final length and weight, weight gain, and specific growth rate for length and weight. An interaction between salinized water and feeding frequency was observed for survival rate. We conclude that, during the initial rearing phase of P. brevis, feeding frequency of three times a day and salinized water at 1 g L-1 is recommended.

The growth performance and parasite load of angelfish juveniles Pterophyllum scalare kept at different stocking densities in two rearing systems

“…Most water physicochemical attributes were adequate for freshwater angelfish rearing, and the variables did not interfere with the growth performance of the fish (Abe et al, 2016;Çağiltay et al, 2017;Pinheiro-Junior et al, 2023). However, non-ionized ammonia increased the values at higher stocking densities.…”

“…For these reasons, the captive rearing of P. scalare in intensive production systems has been growing annually (Perera et al, 2023). However, some handling procedures from these systems, such as inadequate stocking densities, can reduce fish health and impair profits for fish farmers (Pinheiro-Junior et al, 2023).…”