Histology observation in digestive tract of Eleutherollema tetradactylum at different developmental stages

The study investigates the construction of digest tract of Eleutheronema tetradactylum at different developmental stages by using conventional paraffin section and HE staining. Results show that the body shapes of 35 dah and 43 dah juveniles were similar, with scales covering, dorsal fin, pectoral fin, anal fin and tail fin well constructed. The total lengths of former and the latter were ( 12.850 1.280) mmand ( 15.600 1.600) mm, respectively. The digest tract in 65 dah fish composted of esophagus, stomach and intestine; the stomach consisted of cardiac stomach, pyloric stomach, fundic stomach and gastric caeca; four pyloric caeca scattered between pyloric and intestine; intestinal coefficient was 0. 630 0.002; the intestine consisted of foregut, midgut and hindgut. The diameters of esophagus, stomach, intestine increased in adult fish with intestinal coefficient of 0.300 0.010. The histological analysis reveals that the structures of digest tract in 35 dah and 43 dah juveniles were functionally similar to those of young and adult fish. The pipe wall consisted of mucosal, submucosal, muscular layer and serosa. The number of mucosal fold, gastric gland and goblet cell in the epitheliummucosal showed increasing regularity among juvenile, young fish and adult fish, which shows that the digestive tract developed gradually in structure and funtion.