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

Abstract

Acanthopagrus schlegelii is an autochthonous teleost species concerning the remarkable economic importance and prevalent fish cultivated in China as well as in different nations of South-East Asia. Little is known about the digestive tract (DT) morphology of A. schlegelii. Therefore, anatomical and histomorphological aspects of A. schlegelii DT were examined by light and scanning electron microscope (SEM).Anatomically, DT of A. schlegelii was mainly formed of oesophagus, well-developed stomach and fingers like pyloric caeca (four in number), intestinal regions and rectum. Histomorphologically, oesophagus occurred as a shorter tube-like organ presenting a longitudinal folded mucosa that connects oropharynx cavity to stomach.Stomach was a muscular thick-wall organ that included three regions, thickly longitudinal folds were observed in the first (cardiac) and last (pyloric) regions, whereas the second (fundic) region showed folds in different directions. Long villi were observed within pyloric caeca and anterior intestine. Tunica muscularis appeared narrow in the anterior intestine, whereas thicker in the posterior part of the intestine.Collectively, anatomical and histomorphological aspects of A. schlegelii DT are consistent with the carnivorous habit of this species. These data could be a potential source to modify better methods of nutrition and identify the DT pathogenic conditions in farming of this fish. K E Y W O R D SAcanthopagrus schlegelii, anatomy, digestive system, histomorphology, scanning electron microscope

Morphological study of the gastrointestinal tract of Larimichthys crocea (Acanthopterygii: Perciformes)

“…Sixteen tubular pouches of almost similar sizes were observed in L. crocea. A different amount has been found in different teleost such as 10 in Leporinus friderici (Bloch, 1794), 4 tubular pouches in Acanthopagrus schlegelii (Bleeker, 1854) and 5 in Lates calcarifer (Bloch, 1790) respectively (Albrecht et al 2001, Kalhoro et al 2017, Purushothaman et al 2016. It is predicted that the number of intestinal caeca and the length of the intestine are greater in herbivorous species, intermediate in omnivorous ones, and minimized in carnivorous fish, but is not always consistent (Alonso et al 2015).…”

“…The sample processing method for scanning electron microscopy is described elsewhere in detail (Kalhoro et al 2017). In brief, tissues were fixed in 4% paraformaldehyde and 2.5% glutaraldehyde in phosphate buffer (pH 7.0) (for 24 hour at 4 °C).…”

Description of the unusual digestive tract ofPlatax orbicularisand the potential impact ofTenacibaculum maritimuminfection

“…In spite of the convolutions observed, the RIL or IC is relatively low (1.47 ± 0.14), compared to other species (from 0.5 to 13.0 depending on the species) and is in the range of carnivorous species (Ray & Ringø, 2014;Kalhoro et al, 2019). The RIL or IC is used as a morphometric marker to classify fish according to their feeding habits, age or development (Kalhoro et al, 2018;Kalhoro et al, 2019). However, the link between intestinal morphology (e.g., length) and fish diet due to specific requirements for the digestion is still controversial (Kapoor, Smit & Verighina, 1976;Wilson & Castro, 2010;Dala-Corte, Becker & Melo, 2017;Kalhoro et al, 2018;Kalhoro et al, 2019).…”

“…Strong peristaltic movements and therefore muscles might be involved. In spite of the convolutions observed, the RIL or IC is relatively low (1.47 ± 0.14), compared to other species (from 0.5 to 13.0 depending on the species) and is in the range of carnivorous species (Ray & Ringø, 2014;Kalhoro et al, 2019). The RIL or IC is used as a morphometric marker to classify fish according to their feeding habits, age or development (Kalhoro et al, 2018;Kalhoro et al, 2019).…”

ASPECTOS MORFOFUNCIONAIS DA CAVIDADE BUCOFARINGIANA DE Australoheros cf. facetus (PERCIFORMES, CICHLIDAE)

“…As adaptações na cavidade oral podem ser analisadas com base na forma, posição e tamanho da boca, amplitude da fenda oral, forma da rima oral, presença de barbilhões, estrutura dos lábios, língua, presença de valvas orais, dentes orais e faríngeos, presença de rastros branquiais, dentre outras estruturas MENIN, 2006;KALHORO et al, 2017).…”