Influence of sex and age on biochemical parameters of Lophiosilurus alexandri (Steindachner, 1876): First results

Abstract

Biochemical parameters of fish are important indicators of homeostasis as they represent an organism's response to the environment. Lophiosilurus alexandri is an endemic and endangered species of the São Francisco River in Brazil with potential for aquaculture; however, blood biochemical studies of this species are scarce. The present study compared blood biochemical parameters of male and female L. alexandri, at four different ages. The following analytes were evaluated: alanine aminotransferase (ALT), aspartate transaminase (AST), lactate dehydrogenase (LDH), calcium, chlorine, magnesium, total proteins, albumin, urea, glucose, triglycerides and cholesterol. Male fish had higher values than females for ALT at 372 days after hatching (DAH), magnesium at 481 DAH and triglycerides at 372 and 481 DAH (p < 0.05). The other analytes did not differ significantly (p > 0.05) between males and females at any of the collection times. The results allow us to conclude that biochemical differences between males and females are less pronounced than those observed among different ages of the same sex.

Apparent digestibility coefficients of nutrients and energy from diets with different ratios of crude protein and non‐fibrous carbohydrates for Lophiosilurus alexandri , a carnivorous freshwater fish

“…The pacamã, Lophiosilururs alexandri (Steindachner, 1876), is a neotropical carnivorous catfish of high commercial value due to the absence of intramuscular spines and flavour of its meat (Sant'Ana et al, 2017). Thus, this fish species is of great interest to aquaculture (Barros et al, 2007;Meurer et al, 2010;Melillo-Filho et al, 2021). Oliveira-Júnior et al (2021) demonstrated that diets containing CP/NFC ratios between 1.11 and 1.33 improve growth performance and muscle hypertrophy of L. alexandri juveniles.…”