The present work was aimed to study the gastrointestinal tract in Garganey from the oesophagus to coprodeum by the aid of the gross morphology, scanning electron microscopy and histology. At the level of the thoracic inlet, the oesophagus had a thick part which had numerous tortuous longitudinal folds carried transverse folds on them. Histologically, the thick part had thick epithelium and appeared more folded with more and larger glands. The mucosa of the proventriculus had mucosal folds appeared as a leaf‐like with rounded tips. The openings of the proventriculus glands were projected with papillae on the epithelial surface. The gizzard lined with horizontal layer of cuticle which sent vertical parts of cuticle. The duodenal villi were pentagonal in shape with sharply pointed tips, while the jejunal villi were triangular with rounded ends, and the ileal villi were wide and pentagonal in shape with pointed tips. The mucosa of the duodenum, jejunum and ileum was thrown into villi lined by simple columnar epithelium with goblet cells with difference in the form, length, density and number. The apical points of the duodenal and ileal villi appeared pointed, while the jejunal villi had rounded ends. The jejunal villi were longer and numerous than the duodenal villi, but the ileal villi appeared with different length and less numerous. The mucosa of the caecum had numerous mucous glands which surrounded by circular crypts. The rectal mucosa had longitudinal folds and semilunar and circular crypts. The mucosa of the coprodeum had longitudinal folds surrounded by crypts.

Bagrus Bayad (Forskal, 1775) is a bottom feeder fish feeds on different food items. Its oral cavity anatomy has many types of teeth adapted to the capacity and varieties of feeding. The aim of the present study was to use the gross anatomy and scanning electron microscopy to identify the anatomical characteristic, especially of the teeth and taste buds distributed on the roof and floor of the oropharyngeal cavity. The results clarified that Bagrus Bayad has two types of teeth; curved pointed and blunt teeth of different sizes. The teeth appeared on epithelial protrusions. The pharyngeal region had upper and lower pharyngeal teeth, the upper arranged into two oval prominences while the lower ones arranged into two triangular areas. The higher number of the pointed teeth is prove the carnivorous nature of the Bagrus Bayad. Three types of taste bud (I, II, & III) were found in the oropharyngeal cavity. The tongue present in the floor and free from teeth and characterized by the presence of taste bud type I and II. Many microridges of different arrangement observed on the surface epithelium of oropharyngeal cavity. The upper and lower valve characterized by the microridges, pores and taste buds. The knowledge of the nature of the oropharyngeal cavity of the Bagrus Bayad helps in identifying new and better methods for feeding in aquaculture.

The work under investigation is carried out to describe the gross morphology and ultrastructure of the gills of the species Bagrus bayad grossly and with the help of scanning electron microscopy. The current work carried on ten fresh adult Bagrus bayad. Bagrus bayad is a genus of the Bagridae family. Our results revealed that the operculum opened caudoventrally. The wide interbranchial septum consisted of four transverse raised areas on each side that connected by transverse lines caudal to the base of the tongue. The gill arch is divided into long ceratobranchial and the short epibranchial clearly and formed an angle between them in the first three gill arches but in the fourth-gill arch is not clear.The first two gill arches have only lateral rackers. The first arch carried well-developed long rackers while rackers on the following rows were short. The majority of gill rackers were short as an adaptation of the carnivorous feeding habit of the Bagrus bayad. The gill arch and rackers were covered by pavement cells with chloride and mucus cells. The pavement cell surface has numerous microridges giving them the fingerprint's appearance. The gill filament's length is nearly fixed along the entire gill arch. Along the gill arch, and the gill filament carried leaf-like gill lamellae. At higher magnification, the gill filament appeared covered by irregular polygonal cells that have concentric microridges.

The present study represents the first attempts to give a full anatomical comparison of the vascular pigmented pectin oculi of the diurnal activity Anas querquedula and Gallinula chloropus chloropus. For achievement of this work, 10 mature birds from each species were examined under stereo‐ and electron microscope. The pecten oculi of A. querquedula is triangular fan‐like, while in Gallinula c. thin like‐fold. In both examined birds, the pecten oculi located postero‐anteriorly intraocular just adjacent to optic nerve disc and attached to the retina by its base, while the free apex projected into vitreous body. A. querquedula had 14–15 pleats, while Gallinula c. chloropus had 22–24 pleats. In A. querquedula, all pecten pleats connected to each other apically by a connecting bridge. The pecten oculi was plicated type in A. querquedula, but folded type in Gallinula c. chloropus. In A. querquedula, the external surface of the pleats head carried 8–10 transverse ridges, in addition to the external and lateral surface of the pleat body carried numerous round prominences that indicated the presence of numerous afferent and efferent vessels. In both examined birds, there is a retinal elevated fold situated parallel to the slightly elevated basal fold which is clear and thicker in A. querquedula than in Gallinula c. chloropus. In Gallinula c. chloropus, the transverse section shows that the pleats had numerous afferent and efferent vessels capillaries. Statistical analysis comparing the relative measurements of the pecten oculi in the two examined birds showed that there was a significant difference.

The current work considers the first anatomical description of oropharyngeal cavity of Garganey, which was performed on eight heads with the help of scanning electron microscopy (SEM). The round apex of elongated tongue has anterior spatula‐like named lingual nail. SEM of dorsal surface of lingual nail carry microtubercles and micropores on its rostral part, while its caudal part carry numerous microridges and micropores, while lateral apical surface only without lingual nail carrying filiform papillae, but its ventral surface carry exfoliated scales‐like projections. Lateral lingual tip carries numerous laterally directed hairs‐like structures. Rostral part of body carry region of small conical papillae in between them small hairs‐like papillae on its lateral surface. Middle part of body carry lingual comb on its dorsal surface, while its lateral surfaces carry region of small conical papillae in between them hairs‐like papillae in addition to filiform papillae, and large conical with small filiform papillae begin to appear laterally to the heads of lingual comb. Lateral surface of lingual prominence carry region of large conical and small filiform papillae on its rostral part, while its caudal part occupied by laterally situated spinated border from the root. Lingual root has two triangular smooth middle and spinated lateral and caudal. Laryngeal entrance divided into papillary and nonpapillary regions. Roof of oropharyngeal cavity divided into lamellar and papillary regions. Choanal cleft divided into rostral narrow ¼ and wide caudal ¾ parts. In conclusion, feeding process depend on the filter feeding mechanism that performed by the help of lateral situated papillae with lingual prominence.