Anatomical aspects of the pacas male genital apparatus

Abstract

ABSTRACT. Stradiotti C.G.P., Silva J.F.S., Cunha I.C.N., Stradiotti Junior D., Cóser A.C., Rangel C.C., Rodrigues T.F. & Almeida F.M. [Anatomical aspects of the pacas male genital apparatus.] Aspectos anatômicos do aparelho genital masculino de pacas. Revista Brasileira de Medicina Veterinária, 37(3):217-221, 2015. Programa de Pós-Graduação em Reprodução e Nutrição Animal, Universidade Federal do Espírito Santo, Rua Alto Universitário, s/n, Alegre, ES 29500-000, Brasil. E-mail: [email protected] The objective was to describe the constituent bodies of the male paca reproductive system and understand their functions in order to contribute to the adoption of appropriate reproductive techniques for rearing in captivity. An evaluation of the morphological macroscopic regional of reproductive characteristics of six males was done. The specimens were subjected to the anatomical dissection techniques, which allowed its visualization, description and biometry. The study confirmed that the typical characteristics of other hystricomorphos occurred, like the absence of scrotum, presence of a ridge or diverticulus located on the dorsal surface of the penis gland and the penis bone. But, some penis characteristics are more emphasized in pacas. The gland is totally covered by horny papillae, which gives it a rough aspect. There is a pair of horny plaques with serrated edges located latero ventrally and in the distal region of the gland, inside the diverticulus, and a pair of well-developed, cone-shaped horny spikes, which project beyond the gland when penis is erect. The function of these differentiated structures is not yet well described. It is believed that may be related to ovulatory stimulus, when in contact with the reproductive system of the female during copulation. The presence of accessory genital glands, compared with pre-existing study on them, could see the presence of Ampulla ductus deferentis (deferent duct blister). It is understood that these findings may contribute to the development of management techniques that would allow better reproduction of the species in captivity.