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The current research aim is an ultrastructural examination of the floor of the oropharyngeal cavity of the red porgy fish. The study used gross morphology, light and scanning electron microscopy, and morphometric analysis. The teeth are arranged in anterior and posterior rows with differing heights along the entire length of the lower jaw. The labial teeth were long papilliform (canine like), medium, and short papilliform teeth. The teeth had a central pulp cavity and were surrounded by a thick dentine ridge covered in enamel. The pharyngeal teeth appeared in a V-shaped structure after the end of the interbranchial septum. There were three sizes of pharyngeal teeth: long, medium, and short. The apical pouch appeared on the lateral sides of the tongue. The tongue had a bulged mountaintop in the center and lateral sides with sea-wave-like longitudinal ridges with sloping grooves between them. The whole tongue surface had longitudinal ridges and sharp transverse ridges that appeared thorn like at the tongue root. Many sizes of pointed papillae were visible along the tongue surface. Ruffini corpuscles have been discovered in the tongue’s conical and dome-shaped papillae. The red porgy’s teeth and tongue papillae have distinct structural characteristics that are reflected in their carnivorous behavior.

The current study aimed to investigate the ultrastructure of the retinal photoreceptors of the African catfish and to demonstrate their adaptation to nocturnal or diurnal visions or by the two ways. The eyes of eight adult catfish were collected during the daytime, and the retinae were separated and examined by light and transmission electron microscopy. The photoreceptors' layer appeared in contact with the retina's pigmented epithelium. Two photoreceptors were detected in cones and hidden rods. Cones predominate in light-adapted retinae. The outer segments of cones appeared between the retinal pigmented epithelium protrusions, which indicates the movement of melanosomes away from the photoreceptors as a retinomotor response of the catfish. The two types of retinal tapetum were in between cones. The first type, the cored granules, were large, spherical, and had black peripheral parts and central lucent parts, and contained some granules. The second type was Guanine crystallites of tapetum lucidum, which were small electron-lucent, and their shape varied from spherical to rectangular. Melanosomes vary in shape from spherical to elliptical. The Müller cells were darkly stained elongated cells that measured about 5.5-8.5 μm in length and 2.2-2.5 μm in width, and their microvilli appeared between the inner segments of the rods and cones. Müller cell processes were extended from the photoreceptor layer to the inner limiting membrane. Zonula occludentes appeared between the Müller cell processes and the internal segment of the rods and cones. African catfish have eyes which are adapted not only for nocturnal but also for daytime light.