Comparative Histomorphological Studies on Oesophagus of Catfish and Grass Carp

Abstract

The present work was carried out on 40 specimens of oesophaguses of both sexes of catfish (carnivorous fish) and grass carp (herbivorous fish) in order to observe the morphological and histological differences between the two species. Oesophagus of catfish was divided into 2 parts: anterior and posterior ones. The anterior part of the oesophagus of catfish was characterized by the presence of numerous mucosal folds. It was lined by stratified epithelium with goblet cells. In addition to club cells were observed in between the stratified epithelium. Scanning electron examination of the oesophageal epithelium of catfish demonstrated the presence of microvilli and fingerprint-like microridges in the superficial cell layer. The posterior part of the oesophagus of catfish was characterized by simple columnar mucus-secreting epithelium. The oesophagus of grass carp had shown the same structure along its entire length. It consisted of less folded mucosa than that observed in the oesophagus of catfish. The epithelium was characterized by the presence of taste buds. In conclusion, the present work revealed some differences in the structure of catfish oesophagus and grass carp oesophagus. These differences are related to type of food and feeding habits of each species.

Transmission Electron Microscopy of the Gastrointestinal Tract of Nile Perch Lates niloticus

“…2) are rich with mucous substances (MG) concentrated at the apical ends, suggesting their secretory nature (Ikpegbu et al, 2013). The cells also have villi-like projections, mitochondria and intercellular spaces; similar structures were reported in Solea senegalensis (Arellano et al, 2001) and in Clarias gariepius (El Hafez et al, 2013). These have been suggested to possibly be important for active ion transport; with solutes moving via the intercellular spaces in the epithelia cells.…”

Gross anatomical and histomorphological features of the Acanthopagrus schlegelii digestive tract (Bleeker 1854) Perciformes, Sparidae

“…The oesophagus of A. schlegelii was divided into cranial and caudal regions parts. The distinction of oesophagus into two morphologically distinct zones based on type and thickness of the epithelium and tunica muscularis has been previously reported in Seriola dumerili and Clarias gariepinus (Abd El Hafez, Mokhtar, Abou‐Elhamd, & Hassan, ; Grau, Crespo, Sarasquete, & de Canales, ). Functionally, cranial part of oesophageal epithelium acts as a shield sheath of the wall against the chemical and mechanical damages and by anchoring the neutral mucopolysaccharides, thereby producing a lubricated epithelial surface for the entrance of food in the alimentary canal during swallowing.…”

“…A noteworthy characteristic is the absence of taste buds in oesophagus in our study, as observed in Sparus aurta, Solea senegalensis, Leporinus spp and Seriolu dumerili (Albrecht et al., ; Arellano, Storch, & Sarasquete, ; Elbal & Agulleiro, ; Grau et al., ). However, taste buds have been detected in Glyptosternum maculatum, Ctenopharyngodon idella and Amatitlania nigrofasciata (Abd El Hafez et al., ; Hopperdietzel et al., ; Xiong et al., ) being common structures of the oesophagus wall. However, their presence might be irrelevant in fish, such as in the A. schlegelii , which display a well‐elaborated pattern of folding of the oesophageal surface (i.e., primary longitudinal folds and secondary villi form projections), which may aid in swallowing the food into the stomach.…”

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

“…The oesophagus was comparatively smaller in size than the adjacent proximal intestinal tube, suggesting an additional role of effectively preventing the back flow of food items. The presence of taste buds in the cranial part of the oesophagus has been also reported in some species such as sturgeon (Domeneghini et al, 1999), and in grass carp, Ctenopharyngodon idella (Abd El Hafez et al, 2013). Their presence indicated that unpalatable food items could still be expelled.…”

“…The noted tough short oesophagus with its numerous epithelial goblet mucous cells seems to facilitate a quick swift movement of the crushed feed material into the intestine. The increased number of goblet mucus cells in the buccal pharyngeal cavity and the oesophagus in fish species, is generally an adaptation that compensates the absence of salivary glands found in other vertebrates to facilitate food lubrication and movement (Cataldi et al, 1988;Albrecht et al,, 2001;Abd El Hafez et al, 2013).…”