Fine structural studies on the reproductive biology of the anthozoan Bunodosoma cavernata

This investigation is concerned with certain aspects of the reproductive biology of the anthozoan Bunodosoma cavernata. The first portion of the study is a fine structural examination of spermiogenesis and the mature spermatozoon. The young spermatid is located in the peripheral region of the testicular cyst. It possesses a large uncondensed nucleus. The cytoplasm contains multivesicular-like bodies, mitochondria, lipid-like inclusions and a Golgi complex. The flagellum is already present in this early stage of spermiogenesis and is surrounded by two separate centriolar specializations, centriolar satellites and a pericentriolar branching complex. The centriolar satellites, presumably centers for microtubule assembly during maturation, do not persist during spermiogenesis. The pericentriolar branching complex, however, persists and is present in the mature spawned spermatozoon and possibly functions in support. During spermiogenesis the nucleus condenses to form the compact nucleus of the mature spermatozoon. The Golgi complex produces "donut" shaped vesicles which become localized near the nucleus. No distinct acrosome is formed. The second portion of this study is a fine structural analysis of the surface of the oocyte, unfertilized egg and fertilized egg of B. cavernata. [...]