Hematological and biochemical parameters of Spix's Saddleback Tamarin (Leontocebus fuscicollis) raised in captivity

The Spix's Saddleback Tamarin, Leontocebus fuscicollis is widely distributed across the Amazon region, but is endangered. This species is serving an important role in biomedical research in captivity. However, reference values for hematological and biochemical parameters are required for the proper characterization of the species. It was therefore the objective of our research to establish these parameters taking into consideration sex and body mass differences in healthy adult Spix's saddleback tamarins. Collecting 2 mL of blood from each individual, 20 animals were examined (7 males, 13 females), and hematological and biochemical parameters were determined using commercial kits. Of the sixteen variables measured, only red blood cell (RBC), hemoglobin (Hb) and hematocrit (Ht) values were significantly higher in males (7.12 ± 0.98 106/mm, 14.98 ± 1.25 g/dL and 48.71 ± 4.91%, respectively), while red cell distribution width (RDW) was higher in females (14.58 ± 1.89%). Of the biochemical parameters measured, only gamma-glutamyl transferase (GGT) enzyme showed higher activity in females (8.08 ± 4.87 U/L), and a high glucose concentration range was observed (102.0 to 521.0 mg/dL) for both sexes. These parameters established with reference ranges for healthy adults provide a reliable reference source for the interpretation of laboratory housed saddleback tamarin.