Serum chemistry analyses represents a fundamental tool for the diagnosis and understanding of diseases in marine mammals. Although several studies are being conducted within the field of clinical pathology, haematological and serum chemistry data for Antillean manatees are deficient. The purpose of this study was to determine serum chemistry values for captive Antillean manatees within the CMA/Ibama facility in Brazil. Serum samples were obtained from five captive adult Antillean manatees fed with seagrass and analysed for aspartate aminotransferase, alanine aminotransferase, bilirubin, alkaline phosphatase, urea, creatinine, glucose, triglycerides, cholesterol, total protein, albumin, globulin, phosphate, chloride, calcium and uric acid. Blood chemistry parameters were determined using a semi-automatic analyzer. Maximum, minimum, mean and standard deviations were calculated for each serum chemistry parameter. Differences on the values of males and females were verified using an unpaired Student's t-test. All the parameters analysed were similar between sexes, with exception of AP, which was higher in females (191.43 +/- 31.86 U/l). Alanine aminotransferase and uric acid values for Trichechus manatus manatus are reported for the first time in this paper. This study is the first to report serum chemistry parameter values for long-term captive male and female Antillean manatees. Therefore, the lower values of albumin, phosphate, chloride, cholesterol and triglycerides obtained here highlight the importance of clinical pathology during health monitoring of captive marine mammals.

The Antillean manatee (Trichechus manatus manatus) is the most endangered aquatic mammal in Brazil. Sampling blood data from such critically endangered marine mammal species is extremely challenging. Although several hematological studies have been developed for captive manatees, captivity studies addressing the environmental and physiological effects on blood values are scarce. The present work describes blood biochemistry values for captive Antillean manatee adults and calves and verifies the occurrence of possible physiological adjustments due to age, sex, and dietary influences. Blood from 13 clinically healthy manatees (eight calves and five adults) were analyzed for 13 blood serum chemistry parameters using a semi-automatic analyzer. Descriptive analysis was performed for all parameters, and differences between sex and age were determined. Calves had higher means of urea (6.29 ± 5.58 mg/dL), total proteins (5.07 ± 0.94 g/dL), globulin (3.06 ± 1.32 g/dL), and alanine aminotransferase (6.19 ± 2.18 U/mL), levels, and lower means of creatinine (1.42 ± 0.64 mg/dL), aspartate aminotransferase (7.24 ± 3.21 U/mL), phosphate (3.03 ± 1.63 mg/dL), and uric acid (0.71 ±0.17 g/dL) than adults. Further studies are necessary, especially when considering handling and alimentary management in captivity, to provide important data for better monitoring and clinical management of manatees.