Histological features of the digestive tract of the adult European hakeMerluccius merluccius(Pisces: Merlucciidae)

Histology of the digestive system of the garfishBelone belone(Teleostei: Belonidae)

“…It is known that the morphology of the digestive tract in fishes is in accordance with differences in their feeding habits, as was studied in numerous fish species (Al-Hussaini 1949;Bishop & Odense 1966;Bucke 1971;Clarke & Witcomb 1980;Cataldi et al 1987;Grau et al 1992;Albrecht et al 2001;Nazlić et al 2014;Bočina et al 2016). In vertebrates, the digestive system consists of the alimentary canal and ancillary organs such as liver, gallbladder and pancreas (Stevens & Hume 1995).…”

“…It seems that, due to its lack of a stomach, the oesophagus in B. belone is a well-developed glandular organ with mucosa deeply protruding into the lumen and containing abundant goblet cells, mostly organised in glandular acini and containing neutral polysaccharides. The main function of the oesophagus of different teleost fishes, as well as of most vertebrates, is transporting food bolus, so it is usually lined by stratified squamous epithelium and contains cells secreting mucus, thus enabling lubrication and extension of the organ when large prey is passed through (Cataldi et al 1987;Abdulhadi 2005;Nazlić et al 2014;Bočina et al 2016). In some fish such as freshwater stingray Himantura signifer, the oesophagus is covered by stratified columnar epithelium (Chatchavalvanich et al 2006).…”

“…Morphology of the intestines varies among carnivorous fishes (Buddington et al 1996). According to published data, intestine is usually divided into anterior and posterior parts (Abdulhadi 2005;Chatchavalvanich et al 2006;Dai et al 2007;Bočina et al 2016). Via evolution the guts of carnivorous fishes have been adapted to a diet high in protein and low in carbohydrate (Buddington et al 1996).…”

“…The absorptive processes generally take place in the intestinal parts containing complex mucosa, and the absorption area of the intestine is increased by intestinal caeca of pyloric region (Canan et al 2012). Generally, in fishes, the intestine wall is a three-layered structure containing mucosa, muscularis externa and serosa (Nazlić et al 2014;Bočina et al 2016). In garfish B. belone, all portions of the intestine show the same histological features.…”

Comparative histochemical analysis of intestinal glycoconjugates in the blunthead pufferfish Sphoeroides pachygaster and grey triggerfish Balistes capriscus (Teleostei: Tetraodontiformes)

“…General organisation of the intestine in both species showed the basic features of the teleost intestine, with a small intestine and a rectum scarcely differentiated and goblet cells secreting neutral and acidic mucins increasing in number posteriorly (Wilson & Castro, ). The distribution and mucin composition of goblet cells varies widely among teleosts (Bočina et al ., , ; Cao & Wang, ; Çinar, K., & Şenol, ; Petrinec et al ., ; Reifel & Travill, ; Wang et al ., ) and several attempts have been made to relate the mucous composition to environmental, dietary and pathologic factors (Domeneghini et al ., ; Petrinec et al ., and references therein). Differences in the composition of the mucins observed between the sampled species probably reflect different functional requirements resulting from the agastric v .…”