Characteristics of nutrition for helmet catfish (Cranoglanis bouderius Richardson, 1846)

Abstract

The study on nutritional characterectics of helmet catfish (Cranoglanis bouderius Richardson,1846) in Nghe An Province has some highlight results as follows: i) For the structure of digestive system of helmet catfish, their mouth locates under toward with curved shape, upper jaw longer than lower-jaw. Molar teeth are like villus matterial, curved, elongated, shrinked toward the rear, and interrupted in the middle. The short esophageal tube has a thick wall. The interious of the esophagus has many folds which are able to stretch, so the fish can swallow large preys. Its stomach is J-shaped, large, thick-walled, and has many folds so that it can strongly expand and shrink. The gut of helmet catfish is folded and short with a thick wall; ii) For the nutritional characterectics of helmet catfish, this is an omnivorous species, which has a high frequency of sufficient food at levels of 1, 2, 3. The ratio between the intestine and the fish length was on the average of 1.23.