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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 is the first to use gross anatomy, light, and scanning electron microscopy to describe the oropharyngeal cavity of a bogue (Boops boops Linnaeus, 1758) fish. Fourteen 17–18 cm long bogue fish were used. The lower jaw held the lower lip, labial teeth, tongue, and pharyngeal teeth, and the oral cavity floor appeared u-shaped. The lower jaw was small and narrow in the anterior and wide in the posterior as it approached the esophagus. The lower lip carried different lengths of cilia-like projections that looked like the cactus plant arranged in transverse layers, and its apex appeared as an open rose. These cilia were encircled by ridges that looked like sea waves. The labial teeth were 15 in a row, with long roots placed beneath a pocket-like structure. Long, medium, and short pharyngeal papilliform teeth emerged on the oropharyngeal cavity floor at the level of the fourth gill arch in a small V-shaped arrangement. The tongue was smooth and small, with an apex, body, root, and lateral edges that were all clearly defined. The tongue’s apex was pointed and triangular, with a thin, transparent apical pouch around it. There was a median longitudinal fold on the dorsum of the tongue body and root. On the tongue surface, taste bud types I and II emerged. The bogue fish’s oropharyngeal cavity had unique anatomical characteristics, indicating that it was omnivorous.

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.

The feeding habits and habitat of different fish species influence the morphology and functions of their gill rakers. This study used gross anatomy and scanning electron microscopy to investigate the morphological features of the gill rakers in Siganus luridus, Boops boops, and Pagrus pagrus. The gill rakers appeared as medial and lateral rows in all studied fishes. Except for Pagrus pagrus, which had a unique gill rakers arrangement in which the medial row of the 4th gill arch had the most gill rakers, the longest and most gill rakers were on the 1st gill arch in all studied fishes. The gill rakers of Siganus luridus were smooth, with various spine-like shapes, such as spine-like gill rakers, which were bifid or trifid spines, or duck toe-shaped gill rakers. According to SEM of the Siganus luridus' gill rakers, the trifid end gill rakers resembled caterpillars, and the duck toe-like gill rakers had three or four finger-like spines connected by inter-spine tissue. The Boops boops had long conical gill rakers with pointed ends on the lateral sides of the 1st gill arch, and the remaining rows had short gill rakers. According to SEM of the Boops boops' gill rakers, the long gill rakers were semi-conical and only had needle-like spines on the medial surface. The short gill rakers were projected as a boat and had three different shapes based on spine distributions. Gill rakers include those with a median crest and long spine laterals, those with only lateral spines, those with usually dorsal spines, and those with long wedge-shaped spines. Pagrus pagrus’ gill rakers were short, with fine-needle spines covering their tops. By SEM of the Pagrus pagrus' gill rakers, they appeared as a cylindrical elevation with spines on top. The spines were conical in shape with pointed curved or straight ends. The maximum value of the gill rakers’ lengths was discovered in the lateral row of the 1st gill arch, while the minimum value was in the medial row of the 4th gill arch. As a result, this is the first study of the three fish species' gill rakers. In the studied fishes, the morphological characteristics of gill rakers demonstrated unique structural specifications in feeding behavior.

Background The retinae of diurnal vertebrates have characteristics. Most lizards are strictly diurnal, and their retinal morphology is still unknown. Materials and methods The retina of the African five-lined skink (Trachylepis quinquetaeniata) was studied using light and transmission electron microscopy. Results The retina's ten layers were all detected. The inner nuclear layer was the thickest by an average of 67.66 μm, and the inner plexiform layer was 57.564 μm. There were elliptical, long cylindrical, and spherical melanosomes (small and large) in the pigment epithelial layer of the retina. The cylindrical melanosomes had a large area on the lateral surfaces of cones to increase light scatter absorption. The photoreceptor layer of the retina had cones only. There were single and double cones, with the double cones consisting of principal and accessory cones. The cones had inner and outer segments separated by oil droplets. A spherical paraboloid body existed between the limiting membrane and the ellipsoid. All single cones had a paraboloid, and double cones had a large paraboloid in the accessory cone. The presence of paraboloids and large ellipsoids with mitochondria of varying sizes may have helped focus the light on cone segments. Conclusion The African five-lined skink's eye was light-adapted due to a variety of retinal specializations related to the demands of its diurnal lifestyle in its environment.

This systematic review highlights the similarities and variations in Ossa cordis prevalence, histology and anatomical location between differing veterinary species and in humans. In addition, it also identifies associated factors such as aging and cardiovascular disease for each species in relation to functional roles and developmental mechanisms that these bone structures may play. The potential functions of Ossa cordis are presented, ranging from aiding cardiac contraction and conduction, providing cardiac structure, and protecting components of the heart, through to counteracting high mechanical stress. Furthermore, this review discusses the evidence and rationale behind the theories regarding the formation and development of Ossa cordis in different veterinary species and in people.

The current study aimed to document by computed tomography (CT) the anatomical structures of the one-Humped camel head relative to their adaptability to living environments. Seven adult one-Humped camels' heads were used in this study. The structures of the nasal cavity, paranasal sinuses, oral cavity, orbit, and cranium were investigated using computed tomographic scans, cross, and sagittal sections of the head cadavers, and skulls. The study showed the nasal conchae had special properties where the dorsal nasal concha contained the dorsal conchal sinus, the middle nasal concha contained the middle conchal sinus, while the ventral nasal concha did not contain a sinus. The middle nasal concha was large and extended rostral between the dorsal and ventral nasal concha. The nasal meatuses were narrow spaces that suggested adaptability to a desert environment. The paranasal sinuses comprised maxillary, frontal, sphenoidal, lacrimal, and ethmoidal that were identified and labeled according to cheek teeth landmarks. The topographic description and relationship between nasal, oral, orbital, cranial cavities, pharynx, larynx, and paranasal sinuses were demonstrated. The articular disc, articular surface, and joint capsule of the temporomandibular joint were described by CT and cross sectional images. The current CT, cross, and sagittal sections images provide a reference for normal camel head anatomy.