Spermatozoa Morphological Structure of Sinonovacula Constricta

The morphological structure of spermatozoa of Sinonovacula constricta is investigated using light and electron microscopy.The mature spermatozoa consists of a head and a tail.The head is composed of acrosome,acrosomal rod and nucleus.The bowling-shaped acrosome located at the front of nucleus is about 1.1μm in length and 0.41μm in width.The content of the acrosome is homogeneous.The acrosomal rod is slim and is 5～6μm in length.,which is composed of fibroid materials.The nucleus is tubbish-shaped,about 1.3μm in length and 1.8μm in width.The caryoplasm is highly condensed,and the vesicle is found in nucleus.The tail is made up by a mid-piece and an end piece,six mitochondria surround the proximal and distal centrioles in the mid-piece.The slim and whip-like end piece comprises an central axoneme which is a typical 9+2 structure,and plasma membrane which is around the axoneme.