Abstract

Stress events stimulate the hypothalamus-pituitary-adrenocortical axis and the sympatho-adrenomedullary system, increasing glucocorticoid and catecholamine secretions that protect the organism from stressful conditions.⁵ Consequently, the action of these hormones in the organism produces alterations in the concentration of blood components.^3,4 Transportations, as well as changes in the captivity, have been reported as temporary stressful situations in various animals.^2,6 The Amazonian manatee is an aquatic mammal endemic in the Amazon basin, and there is no information about stress responses for this species. Therefore, in this study we report the hematology and biochemistry parameters of a captive Amazonian manatee measured before transport, immediately after transport, and during adaptation to a new facility. On December 3rd, 2009, a healthy juvenile male Amazonian manatee (8 years old; 108kg) was transported from the Laboratory of Aquatic Mammals of the National Institute of Amazonian Research--LMA/INPA, Manaus--AM / Brazil, to the Aquário de São Paulo, São Paulo--SP / Brazil. At LMA/INPA, the manatee was housed in a circular pool (3m deepX10m diameter), along with 14 other manatees. It was fed paragrass and vegetables, not less than 8% of its body weight per day. The water temperature varied between 27-29°C. The transportation was carried out at night, in a cargo truck to Manaus airport (12km). After that, the animal was transported by a cargo airplane to São Paulo (2,689km-3h30 hours trip). In São Paulo, the animal was transported, again in a cargo truck, to the aquarium (32km). While being transported, the manatee was kept on a thick mattress covered with a wet towel, and its skin was periodically wetted. The internal airplane temperature was acclimatized on 24°C, and all aerial transport procedures were performed under the IATA (International Air Transport Association) regulations. All operations were carried out within 6h and were monitored by a veterinarian. At the Aquário de São Paulo, the manatee was fed vegetables and kept in a handling pool. On the following day, the animal was transferred to the exhibition pool (rectangular, 4.9m deep X 16.25m long X 9.50m wide). This pool is environmentally enriched to mimic Amazon rivers. On the 7th, 8th and 9th of December, 11, 10 and 28, large Amazonian fishes were introduced into the pool. Blood samples were collected before transport on November 19th, December 3rd and on the 4th, immediately after arrival in São Paulo, and also on the 10th and the 18th. Blood samples were collected and analyzed in two different laboratories (Fundação de Hematologia e Hemoterapia do Estado do Amazonas--HEMOAM, Manaus; and LAB&VET, São Paulo). Differential leucocyte counts were conducted manually. All results were compared with normal values for the species.¹ Among all parameters analyzed, we observed, a clear neutrophilia, lymphopenia, and increases in the neutrophil: lymphocyte ratio, serum glucose and aspartate aminotransferase (AST) levels after transportation. These parameters remained high after the addition of the fishes into the pool. On day 18, all of these parameters returned to normal. Other parameters were within the normal range, however, and low variations were considered individual characteristics or differences between laboratories. Intense manipulation of the Amazonian manatee, such as transport, appeared to be a stressful situation. Introduction to an enriched environment, initially, was also stressful, but, after the habituation phase, the animal adapted to the new environment.⁶ Glucocorticoids and catecholamines can cause a transient leukocytosis with neutrophilia, monocytosis and lymphocytosis by shifting cells from the peripheral into the principal vessels.³ Those hormones also increase the blood glucose concentration by mobilizing energy reserves such as tissue glycogen through glycogenolysis.⁴ Although there were some increases in AST levels, the values remained within normal parameters. This is the first report on the clinicopathological monitoring of long distance transportation for an Amazonian manatee. These results suggest that transports are temporary stressful events, as well as changes in the environment. We, therefore, recommend monitoring the hematological and biochemistry parameters before and after translocation in order to evaluate the animal's adaptation to the new condition.

Acknowledgements

We thank HEMOAM and LAB&VET for samples analyses; PREVET staff and the Aquário de São Paulo staff for help with the samples collection; Petrobras S.A., IBAMA, INPA and Associação Amigos do Peixe-boi (AMPA) for all support and to Mr. Anael Fahel (Director of the Aquário de São Paulo) for funding the trip to the IAAAM Conference.

References

1.  Carmo TLL. 2009. Hematologia e bioquímica sanguínea do peixe-boi da Amazônia, Trichechus inunguis (Natterer, 1883). MSc Thesis. Instituto Nacional de Pesquisas da Amazônia. Brazil.

2.  Fazio E, Ferlazzo A 2003. Evaluation of stress during transport. Vet Res Commun 27:519-524.

3.  Jain NC 1993. Essentials of Veterinary Hematology. Philadelphia: Lea & Febiger, 494p.

4.  Mormede P, Andanson S, Aupérin B, Beerda B, Guémené D, Malmkvist J, Manteca X, Manteuffel G, Prunet P, van Reenen CG, Richard S, Veissier I 2007. Exploration of the hypothalamic-pituitary-adrenal function as a tool to evaluate animal welfare. Physiol Behav 97:317-339.

5.  Möstl E, Palme R 2002. Hormones as indicators of stress. Domest Anim Endocrinol 23:67-74.

6.  Pizzutto CS, Nichi M, Sgai MGFG, Corrêa SHR, Viau P, Beresca AM, Oliveira CA, Barnabé RC, Guimarães MABV 2008. Effect of environmental enrichment on behavioral and endocrine aspects of a captive orangutan (Pongo pygmaeus). Lab Prim Newsl 47:10-14.