Histo-morphological description of the digestive system of the Rippon Barbel Barbus altianals (Boulenger 1900): A potential species for culture

Abstract

Morphology of the digestive system can help define the feeding adaptation habits of a given fish species in a given environment. In a study to describe the nature and functionality of the digestive system of Barbus altianalis, samples of B. altianalis were taken from River Nile. Their Lengths and weights were measured and the gut structure preserved. The structure of the digestive tract of the B. altianalis was described using simple morphological observations and standard histological procedures. The digestive tube of B. altianalis is stomachless and valveless, progressively and uniformly reducing in size from the proximal to distal end. The digestive tract is on average 2.22 ± 0.37 times longer than its body length. The mouth is terminal and protrusible and pharyngeal palatal organ is well developed. The last gill arch is modified into pharyngeal teeth and the eosophagus is short and muscular. Histological sections revealed the presence of taste buds from the lips to the cranial eosophagus and these regions of the digestive tract are lined by a stratified squamous epithelium. The intestines are lined by simple or pseudo stratified columnar epithelial layer which is highly folded. Goblet cells containing both acidic and neutral mucins are present throughout the entire digestive tract and are more numerous in the pharynx and the proximal part of the intestine. Lobes of pancreatic acini are discrete and scattered among liver cells, around the intestine and few are seen in the spleen surrounding blood vessels. Thus, the liver could most accurately be termed a hepatopancreas structure.

Key words: Goblet cells, hepatopancreas, intestine, mucins