X. Mattei et al., UNUSUAL MIDPIECE IN THE SPERMATOZOON OF A TELEOST FISH, CITHARINUS SP, Journal of submicroscopic cytology and pathology, 27(2), 1995, pp. 189-191
In Citharinus sp. the spermatozoon exhibits an unusual midpiece which
comprises two parts. The proximal part contains the centrioles and som
e small mitochondria. The second part contains a globular structure ma
de up of regularly arranged tubules. These tubules originate from vesi
cles which migrate to the base of the nucleus during spermiogenesis. T
his is the first time such a structure is described in a spermatozoon.