Specific testicular morphology in the atherinomorph Odontesthes nigricans (Richardson, 1848): a comparison with the sympatric species Odontesthes smitti (Lahille, 1929)

摘要

In teleosts, testis organization can be classified in different morphological categories (Grier, 1993; Grier and Parenti, 1994). While primitive osteichthyans show anastomosed tubular testes, the derived teleost species (sensuParenti and Grier, 2004)present one of two principal morphologies according to the type of distribution of spermatogonia: spermatogonial non-restricted (SNR) or spermatogonial restricted (SR). The former is common in most teleosts, where the spermatogonia are distributed in thegerminal epithelium along the seminiferous lobule length. The latter, with the spermatogonia restricted at the distal blind end of the testis lobule, is described only in Atheriniformes (Grier, 1981; Parenti and Grier, 2004).