Dietary protein and energy requirements of juvenile freshwater angelfish

Jener Alexandre Sampaio Zuanon,Eric Márcio Balbino,Sofia Simões Silveira Moraes,Leandro Moreno De Oliveira Alves,Erick Siqueira Araújo,Ana Lúcia Salaro

doi:10.1590/s1516-35982009000600003

Abstract

Dietary protein and energy requirements of juvenile freshwater angelfish (Pterophyllum scalare) were evaluated. A 3 × 2 factorial design was used, with three dietary crude protein levels being tested (26, 30, and 34% of CP) combined with two digestible energy levels (3,100 and 3,300 kcal DE/kg of diet) in three replicates. Juveniles averaging 2.33 ± 0.26 g were reared in a 25L-aquarium with controlled temperature (26 ± 1ºC), biological filter and stocking density of six fish/aquarium. Fish were fed ad libitum at 09:00 a.m., 2:00 p.m. and 4:30 p.m. The following performance parameters were evaluated: final weight, final length, weight gain, feed intake, feed conversion ratio, specific growth rate, protein efficiency ratio and condition factor. Fish fed diets with 26% CP showed greater protein efficiency values when compared to those fed diets with 34% CP. Diets with 26% of CP and 3100 kcal DE/kg could meet the nutritional requirements of juvenile freshwater angelfish.

Highlights

Ornamental fish culture is a rapidly expanding segment of aquaculture and is one of the most profitable sectors of Brazilian fish culture (Lima et al, 2001)
No significant differences were observed for the productive performance parameters among protein and energy levels, except for the protein efficiency ratio (Table 2)
Similar values for protein efficiency ratio were obtained by Ribeiro et al (2007) for freshwater angelfish fry fed diets with 26, 28, 30 and 32% CP, but no differences were detected among diets

Summary

Introduction

Ornamental fish culture is a rapidly expanding segment of aquaculture and is one of the most profitable sectors of Brazilian fish culture (Lima et al, 2001). Knowing the nutritional requirements of different fish species is one of the first steps to create new technologies for fish production. There are few data and studies on the nutritional requirements of ornamental fish species (Blom et al, 2000; Sales & Janssens, 2003), and they are not conclusive enough to formulate proper balanced diets (Boonyaratpalin & Lovell, 1977). Proteins are the main organic constituent of fish tissues These animals need to ingest protein to obtain amino acids to synthesize new proteins (growth) or replace existing ones (maintenance). An energy-deficient diet would result in the use of protein as energy source for maintenance in detriment to animal growth. The aim in the present study was to assess the nutritional protein and energy requirements for juvenile freshwater angelfish

Material and Methods

Results and Discussion

Literature Cited