Comparative analysis of the sperm ultrastructure of three species ofPhyllomedusa(Anura, Hylidae).

Costa, G.C., Garda, A.A, Teixeira, R.D., Colli, G.R. and Báo, S.N. 2004. Comparative analysis of the sperm ultrastructure of three species ofPhyllomedusa(Anura, Hylidae).— Acta Zoologica(Stockholm)85: 257–262We describe the sperm ultrastructure of three species of frogs in the genusPhyllomedusa. According to micrographs, total size of the spermatozoon ofPhyllomedusa hypochondrialisis significantly smaller than those ofPhyllomedusa bicolorandPhyllomedusa tarsius. The acrosome complex consists of two conical structures covering the nucleus, the acrosome vesicle and the subacrosomal cone. The subacrosomal cone ofP. bicolorandP. tarsiusis less electron-dense and appears more granular in transverse section than inP. hypochondrialis. InP. bicolorandP. tarsius, the nuclear space is reduced and the subacrosomal cone fills most of the space between the acrosome vesicle and nucleus. The anterior region of the nucleus in the spermatozoa ofP. bicolorandP. tarsiusends abruptly, while inP.hypochondrialisit is sharp-ended. InP. bicolorandP. tarsius, the axial fibre is much larger than inP.hypochondrialis. The sperm ultrastructure ofPhyllomedusaappears conservative at the intrageneric level. Future studies on the sperm ultrastructure of hylids can provide new insights on the systematics of the group and a larger database for a cladistic analysis. [ABSTRACT FROM AUTHOR]