Morphological study of testis of hybrid alpaca (Lama pacos L. 1758) and llama (Lama glama L. 1758)

In the present study was carried out a description of the basic histological structure of testes in male hybrids of crossings of llama (Lama glama L.1758) and alpaca (Lama pacos L.1758), which is called guarizos or huarizos. As the reproductive physiology of these hybrids is unknown, it seemed important and basic histological studies are needed to predict if they have reproductive capacity because they are considered as sterile hybrids.To do this we have analyzed the left testes of 10 hybrid aged 2 and 5 years, fixing them in Bouin solution and including them in paraffin. Were studied by light microscopy histological sections of 5 microns in thickness, containing in all cases seminiferous tubules to study the germinal epithelium. In some cases, including the epididymis, to determine if the histology is normal and compatible with a possible functionality. These sections were stained with hematoxylin-eosin (HE) and / or HEPAS. The study of these sections allowed the seminiferous tubules observed in all cell types expected: Sertoli cells, Leydig cells, spermatogonia and spermatocytes, all of them look normal. In the case of Sertoli cells, some of which exhibited a high degree of vacuolization, which is also considered normal by the presence of large lipid droplets. At other times in some Sertoli cells were detected hollow spherical bubbles or voids, in the literature is considered to correspond to the spaces occupied by germ cells and missing. The constitution of the epididymis was histologically normal.Therefore, histologic examination of the testes of these hybrids can be concluded that the structure of seminiferous tubules with apparently normal and spermatocytes also appear to be normal, which could suggest the possibility that these hybrids have some degree of fertility.