Morphological and histological observation on the digestive tract of Carcinoscorpius rotundicauda

The morphology and histology of digestive tract of Carcinoscorpius rotundicauda have been studied. The digestive tract of C.rotundicauda was divided into three parts： fore-gut（cavum buccale, oesophagus, craw and gizzard）, mid-gut and hindgut（rectum and anus）. The fore-gut and hind-gut were lined with cuticle, which was lacking in the mid-gut. The circular muscle of cavum baccale belong in striated muscle, and there were a number of glands in the cavum baccale. The circular muscle of oesophageal was not continutive, and there were few longitudinal fibers in it. The gizzard was enclosed by a layer of circular muscle, and the longitudinal fibers were arranged in discrete bundles, and there were some radial muscles in the gizzard. There were a number of glands in the intestine wall, and two pairs of hepatopancreas tubes. The circular muscle of retum was continutive, and there were amount of glandular tubes in the layer of cuticle of anus. The connective tissue under the epithelium of anus was packed with glandula integumentaria.