| ultrastructural features of spermatogenesis in melanorivulus punctatus (cyprinodontiformes: rivulidae). | fish belonging to the family rivulidae possess one of the most complex reproductive systems. rivulus, a genus of freshwater fish in the rivulidae family, was recently reclassified into five genera, including melanorivulus. its type species, m. punctatus, is widely distributed and probably represents a species complex. the ultrastructure of sperm has been broadly used in systematics, and we hereby describe the ultrastructural features of spermatogenesis in m. punctatus. ten m. punctatus males wer ... | 2014 | 24811986 |