The present study compared the biochemical and hematological parameters of fingerlings and juveniles Arapaima gigas (Osteoglociformes, Arapaimidae) from a semi-intensive fish farming in Manaus, Amazon State, Brazil. Fingerlings A. gigas had lower levels of total protein, triglycerides, urea and mean cell volume (MCV), but higher (p<0.05) glucose, cholesterol and hemoglobin concentration, red blood cell counts, hematocrit and cell hemoglobin concentration (MCHC) when compared to juveniles. However, there was not significant difference (p>0.05) in the total thrombocytes and total white blood cell counts between fingerlings and juveniles. Juveniles A. gigas presented lower lymphocytes number and higher monocytes, neutrophils and eosinophils number when compared to the fingerlings. In further studies, A. gigas specimens with other ages should also be compared for a better understanding of the ontogenic development in this Amazon fish, because this information besides increase the knowledge of the physiology of this species, can aid in the establishment of strategies for its adequate handling.
Culture; Erythrocytes; Age; Leukocytes; Blood
