Weight-Length Relationship and Blood Characteristics of Silver Arowana, a Osteoglossidae From the State of Amapá (Brazil)

Abstract

This study investigated the weight-length relationship, plasma biochemical and hematological parameters in Osteoglossum bicirrhosum from the Preto River, in the State of Amapá (Brazil). The weightlength relationship showed a negative allometric growth, with the value of the regression constant (b) equal to 2.539. The relative condition factor (1.00 ± 0.02) indicated good body conditions of fish in their natural environment. In the blood smears of O. bicirrhosum (616.2 ± 209.1 g), erythrocytes, thrombocytes and leukocytes were found with morphological characteristics similar to those of other Brazilian fish. Mean glucose levels were: 46.5 ± 14.6 mg dL-1 (27.1-95.8); total protein 4.2 ± 0.6 g dL-1 (2.3-5.3); total cholesterol 303.9 ± 140.4 mg dL-1 (81.6-718.4); triglycerides 244.8 ± 57.5 mg dL-1 (76.2-361.9); total erythrocytes 2.75 ± 0.37 x 106 μL-1 (1.940-3.350); hemoglobin 8.8 ± 1.2 g dL-1 (6.3-13.0); hematocrit 26.6 ± 2.3% (21.0-32.0); mean corpuscular volume 98.6 ± 15.8 fL-1 (72.4-149.5); mean corpuscular hemoglobin concentration 32.9 ± 3.9 g dL-1 (23.4-44.8); total thrombocytes 90,816