The microscopic anatomy of the oesophagus, stomach and intestine of the channel catfish, Ictalurus punctatus

Abstract

An anatomical study of the digestive tract of the channel catfish revealed that the oesophageal mucosa was longitudinally folded and that secondary folds were occasionally located on the primary longitudinal folds. The infoldings were more numerous near the stomach. The stratified squamous epithelium covering the folds was made up of a basal layer, large mucous cells and simple squamous cells on the surface. The epithelium on the side of the folds consisted primarily of mucous secreting cells. Taste buds were observed between mucous cells on the apical portion of the oesophageal folds and were more prevalent in the cranial part of the oesophagus. The remaining layers of the oesophagus were: a lamina propria-submucosa, tunica muscularis and adventitia or serosa.The J-shaped stomach had two regions: a large sac-shaped region containing gastric glands and a smaller, nonglandular pyloric region. The large rugae of the stomach became gradually smaller near the pylorus. There was a well developed pyloric sphincter. The mucosa included a simple columnar epithelium, a lamina propria and adventitia or serosa.The intestine could be differentiated into a thick ascending segment, a descending segment, a thin convoluted segment and a thicker terminal segment, the rectum. Many mucosal folds containing branched villi characterized the ascending segment of the intestine. The descending and convoluted segments contained fewer folds with shorter and lessbranching villi and were smaller in diameter and thinner walled. Descending and convoluted segments were also mildly convoluted and accounted for 80% of the total length of the intestine. An intestinal valve with a sphincter marked the beginning of the rectum. There was an approximately four-fold increase in the thickness of the tunica muscularis of the terminal segment of the intestine.

Anatomia Funcional e Morfometria do Intestino no Teleostei (Pisces) de Água Doce Surubim (Pseudoplatystoma coruscans- Agassiz, 1829)

“…Vários autores tiveram o mesmo procedimento em relação a estes segmentos intestinais (BÉRTIN, 1958;SIS et al, 1979;MENIN, 1988;MORAES e BARBOLA, 1995).…”

Anatomia do tubo digestivo de Salminus brasiliensis (Cuvier, 1817) (Pisces, Characidae, Salmininae)

“…Entretanto, não se deve estabelecer relação entre a presença dessa estrutura e o hábito alimentar carnívoro de S. brasiliensis, uma vez que ela ocorre em espécies carnívoras (Blake, 1930;Mohsin, 1962;Bucke, 1971;Menin, 1988, Menin, 1989Amaral, 1990;Menin e Mimura, 1993a), planctófagas (Khanna e Mehrotra, 1971;Reifel e Travill, 1978), onívoras (Mohsin, 1962;Menin, 1988;Menin e Mimura, 1992b;Rodrigues et al, 2002;Rodrigues et al, 2004), iliófagas (Blake, 1936;Menin, 1988) e herbívoras (Pasha, 1964). A função atribuída ao esfíncter pilórico é o controle da passagem do alimento para o intestino médio (Sis et al, 1979;Menin, 1988;Rodrigues et al, 2002;Rodrigues et al, 2004).…”

Comparative Histomorphological Studies on Oesophagus of Catfish and Grass Carp

“…The gastrointestinal tract of grass carp consisted of oesophagus, stomach, and intestine that ends at the anus. Food enters a short, often greatly distensible esophagus leading into a thick-walled stomach [5,6]. The histological structure of the gastrointestinal tract of numerous fish species generally consists of mucosa, submucosa, muscularis, and serosa.…”