A comparative study of serum biochemical and hematological parameters from Andinoacara rivulatus and Ichthyoelephas humeralis in Los Ríos Province, Ecuador, was carried out. Two of the native species that are the most commercialized in Quevedo, Mocache and Fumisa, were identified; 60 specimens were captured in each area (180 total). A factorial design (3×2) was used: three habitat zones (Fumisa, Quevedo, and Mocache) and two species (A. rivulatus and I. humeralis). Sex, weight, length, serum biochemistry (total protein, albumin, globulin, albumin/globulin ratio, aspartate aminotransferase (AST), alanine aminotransferase (ALT), calcium, phosphorus, sodium, magnesium, and potassium), hematological parameters (hemoglobin, hematocrits, erythrocytes, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), total leukocytes, granulocytes leukocytes, and agranulocytes leukocytes) in fishes were determined. There was zone-species interaction for all indicators except MCH and MCHC (P < 0.05). For total proteins, albumins and ALT were for I. humeralis in Fumisa and Mocache zones (2.81, 1.57, and 326.67 g dL-1, respectively). In comparison, A. rivulatus was higher in Fumisa and Quevedo in globulins and the albumins/globulins ratio with 2.28 g dL-1 and 2.14, respectively. Electrolytes were found in low concentrations in the two species. For the hematological parameters, all presented significant differences (P < 0.05) except MCH and MCHC. For I. humeralis, its highest values were presented in hemoglobin with 13.37 g dL-1 in Fumisa, for MCV and total leukocytes (93.11 fL-1 and 8.03×103 μL-1) respectively, in the Mocache area. This study will provide essential tools in monitoring the health status of these fish species in particular and fish species in general.