Frozen zooplankton is efficient as natural food during pirarucu Arapaima gigas weaning

• Autor(a) principal: Lima, Adriana Ferreira
• Data de Publicação: 2021
• Outros Autores: Rodrigues, Ana Paula Oeda, Costa, Vladimir Eliodoro [UNESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1111/are.15261; http://hdl.handle.net/11449/210198
• topic: frozen zooplankton; intestine morphometry; live zooplankton; proximate composition; stable carbon isotope; stable nitrogen isotope

The commercial production of carnivorous fish depends on the feed training that can be made through the direct transition from natural food to inert food. As using live natural food requires care in production, alternative methods of using live food are necessary, such as freezing. Thus, the aim of this study was to evaluate the use of frozen zooplankton as an initial diet in the feed training of pirarucu Arapaima gigas juveniles. Three hundred and twenty pirarucu juveniles (13.94 +/- 4.99 g) were submitted to weaning with two different initial diets (treatments): live zooplankton and frozen zooplankton. The co-feeding period was 12 days, with a progressive increase in the amount of feed offered and a decrease in zooplankton every three days. At the end of the training, all fish were ready to be fed with commercial feed. There was no mortality in the experiment and no significant differences (p > 0.05) for weight, length, weight variation coefficient, specific growth rate, intestinal coefficient, hepatosomatic index, muscle layer thickness and height of the branched folds intestinal mucosa, moisture, crude protein and carcass energy for fish that received live or frozen zooplankton as a starter. Isotopic values of delta N-15 and delta C-13 in the fish's muscle were similar (p > 0.05), reinforcing no feeding preference of the fish between the live or frozen zooplankton. The water quality was not influenced by the use of initial diet (p > 0.05). The frozen zooplankton can be used as initial food for pirarucu juveniles feed training, without impairing fish growth and survival.