The sperm stored in the uterine tube must reach its lumen for fertilization to occur. The alignment and packing of sperm in H. mabouia do not indicate crypt evacuation as an active process. The sperm release mechanism may be related to the passage of the egg through the uterine tube. Eggs are approximately six millimeters in their largest diameter and exert mechanical pressure against the tube wall, causing its distension and possibly sperm release, as suggested for other species (Fox, 1956; Hoffman and Wimsatt, 1972; Siegel and Server, 2007). The lack of direct contact between the stored sperm and epithelial cells of the crypt ground is a strong evidence to support this hypothe- sis.