At inadequate stocking density, fish generally show low growth, cortisol hypersecretion, hyperglycemia and other biochemical changes. For the Amazonian species, among them, Arapaima gigas, potential for intensive stocking has not yet been determined. The objective was to contribute for improving A. gigas production by evaluating the effect of stocking density on hematological, biochemical profile and the productive parameters of juvenile A. gigas. One hundred and eighty, twelve months old, A. gigas with a live weight of 2.37 kg were distributed into densities of 106.65 kg/m3 (T1), 142.2 kg/m3 (T2) and 177.75 kg/m3 (T3) with three replicates per treatment and with a water circulation of 7 L/min. They were fed
with a diet of 45% raw protein during four months, at a rate of 3% live weight. Blood samples were taken at thirteen, fourteen and fifteen months old. Hematological profiles, glucose, total protein, Albumin, aspartate transaminase (AST), alanine transaminase (ALT) and urea, were determined with a DIALAB DTN 405 spectrophotometer and 530 nm filters. Final weight (FW), size increase (SI), weight gain (WG), Feed consumption (FC), feed conversion rate (FCR) and volume of biomase (VB) were also evaluated.
Erythrocytes count (ERI) diminished with the increase in stocking density (P<0.01), nonetheless, total leukocytes (LEU), hematocrit (HTO) and hemoglobin (HB), increased as the stocking density increased (p<0.05) (Table 1). Albumin, aspartate transaminase (AST), alanine
transaminase (ALT) and urea diminished with the greater stocking density (p<0.01)
(Table 2). FC diminished and VB increased in relation to the increase in stocking density (p<0.01) (Table 3). Arapaima gigas showed an adaptive sanguineous response to the effects of the greater stocking density.
Keywords: Arapaima gigas, biochemical profiles, stocking density