The germ cell types and spermiogenesis in rose-ringed parakeetPsittacula krameri (Scopoli)

Abstract

By employing haematoxylin-eosin, iron haematoxylin, PAS and Feulgen reaction techniques, a morphological study has been made of spermatogenic cells in sexually matured parakeetPsittacula krameri. Type-A, intermediate and B spermatogonia occur in addition to type Ao (stem spermatogonia). The Ao spermatogonia is the major constituent of the testis during the regression period. Types A and B are further subdivided on the basis of nuclear size and appearance. The leptotene, zygotene, pachytene and diplotene are also differentiated into early and late stages. The spermatocytes at metaphase have also been observed but their number is very few indicating their very short life period. The round spermatids have also been subdivided into two types (i) spermatids with distinct chromatin (ii) spermatids with homogenously stained nuclei. Spermiogenesis has been subdivided into seventeen stages. The study will serve as a fundamental tool in establishing the correlation between gonadotrophins and seasonal reproductive cyclicity of the parakeets.