Fig. 3
From: Reproductive system of the genus Crasiella (Gastrotricha, Macrodasyida)
Graphic reconstructions of the mature spermatozoon of Crasiella diplura. a Schematic drawing of the spermatozoon. I-IV: different regions of the acrosome, from the more distal (I) to the more proximal (IV) (see the description in the text). The nucleus is spiralized around the mitochondrion and the flagellum is surrounded by a curled plasma membrane (arrow). b 3D model of the spermatozoon showing the same regions of the spermatozoon represented in the 2D drawing. cs central sheath; f flagellum(* in cross-section); m mitochondrion; n nucleus