Spermiogenesis in the shrimp, Crangon septemspinosa, Say

Abstract

The spermatozoa of Crangon septemspinosa are composed of an oblong nucleus, an electron-dense acrosome and a cluster of mitochondria and (or) mitochondrial derivatives near each nuclear pole. All components of each spermatozoa are ensheathed by a membrane. The secondary spermatocytes give rise to extensive syncytia within which the spermatid nuclei become organized into clusters. The acrosome develops from a reticulum derived from vacuoles within the core of syncytial cytoplasm common to each spermatid cluster. As spermiogenesis proceeds, the base of the acrosome spreads over the nuclear envelope, each spermatid becomes enclosed in a membrane, and syncytial cytoplasm diminishes in volume and the original clustering of spermatids is lost. The spermatozoa remain within a portion of the syncytial cytoplasm in which they developed and are stored within the ejaculatory tube. According to the fine structural details the differentiation process of spermiogenesis has been divided into four stages.