Spermogram and Serum Testosterone Levels in Wild-Caught Brazilian Rattlesnakes (Crotalus durissus terrificus)
American Association of Zoo Veterinarians Conference 2005
Rogério Loesch Zacariotti1, DVM, MS; Samuel Eurich Betkowski1, DVM; Katheleen Fernandez Grego2, DVM, MS; Sávio Sant´anna2, Biol.; Wilson Fernandes2, Biol.; Cláudio Alvarenga de Oliveira1, DVM, MS, PhD; Marcelo Alcindo de Barros Vaz Guimarães1, DVM, MS, PhD
1Departamento de Reprodução Animal, Universidade de São Paulo, Cidade Universitária, São Paulo, SP, Brazil; 2Instituto Butantan, São Paulo, SP, Brazil
The Brazilian rattlesnake (Crotalus durissus terrificus) is distributed all over south and southwestern Brazil. This snake is responsible for 10% of the 20,000 annual snakebites in this country. The aims of this study were to collect and evaluate the semen of the Brazilian rattlesnake (Crotalus durissus terrificus) during a 12-month period. The serum testosterone levels were also studied. Samples were obtained from wild-caught adult males from the Sao Paulo state. It was possible to obtain 112 semen samples and 116 serum samples. The spermogram results are as follows: seminal volume 18.49±2.04 µl, sperm concentration 1.39±0.08x109/ml. The highest value for pleomorphic sperm cells occurred in the winter (42.35±4.18%). The lowest value occurred in the spring (17.67±2.45%). In the summer (spermatogenesis peak) and autumn (mating season), we found intermediate values of 28.72±2.73% and 28.53±1.83%, respectively. The seasonal serum testosterone levels were: 8.89±3.81 ng/ml (winter), 12.09±3.58 ng/ml (spring), 52.6±9.24 ng/ml (summer) and 43.12±8.89 ng/ml (autumn). The results during the mating season and spermatogenesis peak (autumn and summer, respectively) matched with the highest testosterone levels.
We thank CNPq, FAPESP.