Structure of the Adult Male Reproductive System in a Pycnogonid, Cilunculus armatus (Pycnogonida : Ammotheidae)

Katsumi Miyazaki
1996 Publications of the Seto Marine Biological Laboratory  
Structure of the male reproductive system in a pycnogonid, Cilunculus armatus is examined under light and scanning electron microscopes. The system consists of aU-shaped trunk testis with four pairs of diverticula (pedal testes) extending into the respective walking legs up to the second coxae and two pairs of spermiducts with respective male genital pores opening in the second coxae of the last two pairs of the legs. The testis and spermiducts are clearly distinguished for the first time in
more » ... he first time in the pycnogonids based on their histological features. Male germ cells in various developmental stages, from the spermatogonia to the spermatozoa, are distributed throughout the trunk and pedal testes. Such equivalency of the testicular regions in spermatogenesis is also described for the first time in the pycnogonid testes.
doi:10.5134/176260 fatcat:bm4ax5jcqfgdjb3xaforqxfwhu