A Ultrastructural Study on the Axoneme Formation in the Spermatozoa of the Edible Giant Snail, Achatina fulica

식용 왕달팽이 (Achatina fulica) 정자의 축사형성 (Axoneme formation)에 관한 미세구조

The spermatogenetic process in the edible giant snail is similar to those in the other snails, except for the axoneme formation process. In this study, the axoneme formation process in the giant snail was mainly examined by means of electron microscopy. The tail portion of a spermatozoon is about $160{\mu}m$ long, and extends straight to the rear, surrounded by two large and long mitochondria in spiral forms. A number of glycogen particles $(40\sim70nm)$ are found in the swollen matrix of the mitochodria. The axoneme which composes the tail of a spermatozoon is surrounded by $7\sim10$ lamella-form fibrous sheaths of about $0.2{\mu}m$ in thickness. Most of the mature spermatozoa are found to be clustered into a group of $5\sim7$ ea in syncytial bridges formed by cytoplasmic processes. Sertoli cells contain glycogen particles, endoplasmic reticulum, a lot of mitochondria, and lipids in their cytoplasm. They protrude their filiform pseudopodia and phagocytize abnormal spermatids or spermaozoa.