Comparative morphological analysis of telson and uropods in Penaeus canaliculatus (Olivier, 1811), Penaeus semisulcatus (De Haan, 1844), and Metapenaeus stebbingi (Nobili, 1904) using scanning electron microscopy and EDX analysis.

The telson and uropods collectively form the tail fan, playing crucial roles in locomotion, buoyancy, defense, and respiration. We aimed to compare telson and uropod structures in three shrimp species-Penaeus canaliculatus, Penaeus semisulcatus, and Metapenaeus stebbingi-to identify the species with the most robust telson for its environment. Our analysis involved morphological measurements and scanning electron microscopy (SEM), supplemented by a novel approach-Energy-Dispersive X-ray (EDX) spectroscopy, a technique not previously utilized in studies on these three species. M. stebbingi exhibited the longest telson length, whereas P. semisulcatus had the longest uropod. P. canaliculatus featured a single pair of fixed spines, while P. semisulcatus had evenly spaced small conical spines along the sides of the median elevation and groove. A distinctive feature of M. stebbingi was the telson, which had three pairs of large spines. Diverse setae on telsons included simple, unipennate, and plumose setae. Notably, specialized branched tubular setae on uropods' endopods may aid in grooming or swimming behavior. EDX spectroscopy revealed that the telson cuticle primarily consists of carbon, nitrogen, and oxygen, with significantly high concentrations alongside comparatively lower calcium and phosphorous concentrations. P. semisulcatus exhibited the highest calcium and phosphorus content among the three species. In conclusion, M. stebbingi's telson is structurally robust, emphasizing the importance of morphology, while P. semisulcatus demonstrated a hard telson through EDX analysis. Our study underscores not solely relying on morphology for telson strength assessment but considering telson composition. These variations among species may be attributed to diverse ecological and physiological adaptations.

Macro- and micro-morphological comparison of the detailed structure of the oral cavity roof in two different feeding habits marine fishes: Pagrus pagrus and Boops boops.

The feeding habits and habitats of fish influence the morphology of the oral cavity. This study used gross anatomy, light microscopy, and scanning electron microscopy, in addition to morphometric analysis, to investigate the anatomical characteristics of the oral cavity roof in Pagrus pagrus and Boops boops, which have different dietary habits. The oral cavity roof appeared U-shaped and divided into the palate and upper pharyngeal regions. The upper lip of P. pagrus was broad, while B. boops' upper lip was small and thin. Both species had a stratified squamous epithelium with an irregular shape and a folded surface. P. pagrus had a horseshoe-shaped upper velum with a high middle part, and its surface resembled sea waves with obvious mucous-secreting openings with cilia and many folds and grooves between them. B. boops's upper velum was thin and appeared as a triangle pouch with a pointed cranial apex. The palate in both species was narrow in the front and increased in width backward until it ended. The upper pharyngeal teeth in P. pagrus appeared as two patches, separated by a median longitudinal ridge and an anterior V-shape separator. Meanwhile, in B. boops, they appeared as a ball patch on both sides and a separator ridge in the middle. Because P. pagrus fed on harder structures than B. boops, their feeding habits were reflected in the structure of the oral cavity roof. P. pagrus, a carnivorous species, had several rows of sharp upper jaw and upper pharyngeal teeth, thick spinous tubercles on oblique transverse ridges, and massive mucous glands. On the other hand, B. boops, an omnivorous species, had only one row of upper jaw teeth, a few upper pharyngeal teeth scattered on two oval patches, and thin filaments on the oblique transverse ridges.

Microscopic Focus on the Thyroid Follicles of the One-Humped Camel (Camelus dromedarius).

The microstructure of the thyroid gland of the one-humped camel (Camelus dromedarius) was described using morphometric, histological, immunohistochemical staining, and ultrastructural standard techniques. The follicular secretory units of the thyroid glands displayed comparable and variable sizes where the large follicles were situated at the peripheral margins; however, the small ones were located in the central region. Semisquamous epithelium (low cuboidal) lined the large thyroid follicles, while high cuboidal (columnar) epithelium lined the small ones. Our electron microscopic findings revealed that the low-sized cuboidal follicular cells lack organelles and are hypoactive. The high cuboidal follicular cells are active cells and rich in cellular organelles such as cisternae of rough endoplasmic reticulum, mitochondria, colloid droplets, scrolled Golgi apparatus, and secretory vesicles. A few degenerate follicular cells appeared on rare occasions. The parafollicular cells appeared with a more prominent and conspicuous nucleus than the follicular cells. The follicular cells were classified as active, inactive, or degenerated using transmission electron microscopy. The follicular and parafollicular cells showed calcitonin-positive immunoreactivity. Overall, the presented results showed particular convergences of the morphostructural aspects of the thyroid gland of C. dromedarius to that of other mammals with some distinctive features to cope with their physiology and harsh niche.

A comprehensive exploration of diverse skin cell types in the limb of the desert tortoise (Testudo graeca) through light, transmission, scanning electron microscopy, and immunofluorescence techniques.

The Greek tortoise, inhabiting harsh desert environments, provides a compelling case for investigating skin adaptations to extreme conditions. We have utilized light microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and immunofluorescence analysis to describe the structure of the arid-adapted limb skin in the Greek tortoise. Our aim was to identify the cell types that reflect the skin adaptation of this tortoise to arid conditions. Utilizing seven antibodies, we localized and elucidated the functions of various skin cells, shedding light on how the tortoise adapts to adverse environmental conditions. Our findings unveiled numerous scales on the limbs, varying in size and color, acting as protective armor against abrasions, bites, and other potential threats in their rocky habitats. The epidermis comprises four layers: stratum basalis, stratum spinosum, peri-corneous layer, and stratum corneum. Cytokeratin 14 (CK14) was explicitly detected in the basal layer of the epidermis, suggesting a role in maintaining epidermal integrity and cellular function. Langerhans cells were observed between epidermal cells filled with ribosomes and Birbeck granules. Numerous dendritic-shaped Langerhans cells revealed through E-Cadherin signify strong immunity in tortoises' skin. Melanophores were identified using the Melan-A antibody, labeling the cytoplasm, and the SOX10 antibody, labeling the nucleus, providing comprehensive insights into melanophores morphology and distribution. Two types of melanophores were found: dendritic below the stratum basalis of the epidermis and clustered oval melanophores in the deep dermal layer. Varied melanophores distribution resulted in a spotted skin pattern, potentially offering adaptive camouflage and protection against environmental challenges. Numerous myofibroblasts were discerned through alpha-smooth actin (α-SMA) expression, indicating that the Greek tortoise's skin possesses a robust tissue repair and remodeling capacity. B-cell lymphocytes detected via CD20 immunostaining exhibited sporadic distribution in the dermis, concentrating in lymphoid aggregates and around vessels, implying potential roles in local immune responses and inflammation modulation. Employing Tom20 to identify skin cells with abundant mitochondria revealed a notable presence in melanophores and the basal layer of the epidermis, suggesting high metabolic activity in these cell types and potentially influencing cellular functions. These findings contribute to our comprehension of tortoise skin anatomy and physiology, offering insights into the remarkable adaptations of this species finely tuned to their specific environmental habitats.

The tongue of the red-eared slider (Trachemys scripta elegans): morphological characterization through gross, light, scanning electron, and immunofluorescence microscopic examination.

The red-eared slider (Trachemys scripta elegans) is renowned for its remarkable adaptations, yet much of its complex biology remains unknown. In this pioneering study, we utilized a combination of gross anatomy, scanning electron microscopy (SEM), light microscopy, and immunofluorescence techniques to examine the tongue's omnivorous adaptation in this species. This research bridges a critical knowledge gap, enhancing our understanding of this intriguing reptile. Gross examination revealed a unique arrowhead-shaped tongue with a median lingual fissure and puzzle-piece-shaped tongue papillae. SEM unveiled rectangular filiform, conical, and fungiform papillae, with taste pores predominantly on the dorsal surface and mucous cells on the lateral surface of the papillae. Histologically, the tongue's apex featured short rectangular filiform and fungiform papillae, while the body exhibited varying filiform shapes and multiple taste buds on fungiform papillae. The tongue's root contained lymphatic tissue with numerous lymphocytes surrounding the central crypt, alongside lingual skeletal musculature, blood and lymph vessels, and Raffin corpuscles in the submucosa. The lingual striated muscle bundles had different orientations, and the lingual hyaline cartilage displayed a bluish coloration of the ground substance, along with a characteristic isogenous group of chondrocytes. Our research represents the first comprehensive application of immunofluorescence techniques to investigate the cellular intricacies of the red-eared slider's tongue by employing seven distinct antibodies, revealing a wide array of compelling and significant findings. Vimentin revealed the presence of taste bud cells, while synaptophysin provided insights into taste bud and nerve bundle characteristics. CD34 and PDGFRα illuminated lingual stromal cells, and SOX9 and PDGFRα shed light on chondrocytes within the tongue's cartilage. CD20 mapped B-cell lymphocyte distribution in the lingual tonsil, while alpha smooth actin (α-SMA) exposed the intricate myofibroblast and smooth muscle network surrounding the lingual blood vessels and salivary glands. In conclusion, our comprehensive study advances our knowledge of the red-eared slider's tongue anatomy and physiology, addressing a significant research gap. These findings not only contribute to the field of turtle biology but also deepen our appreciation for the species' remarkable adaptations in their specific ecological niches.

Investigating the role of Purkinje fibers and synaptic connectivity in balance regulation through comprehensive ultrastructural and immunohistochemical analysis of the donkey's (Equus asinus) cerebellum.

The donkey's extraordinary capacity to endure substantial loads over long distances while maintaining equilibrium suggests a distinctive cerebellar architecture specialized in balance regulation. Consequently, our study aims to investigate the intricate histophysiology of the donkey's cerebellum using advanced ultrastructural and immunohistochemical methodologies to comprehend the mechanisms that govern this exceptional ability. This study represents the pioneering investigation to comprehensively describe the ultrastructure and immunohistochemistry within the donkey cerebellum. Five adult donkeys' cerebella were utilized for the study, employing stains such as hematoxylin, eosin, and toluidine blue to facilitate a comprehensive histological examination. For immunohistochemical investigation, synaptophysin (SP), calretinin, and glial fibrillary acidic protein were used and evaluated by the Image J software. Furthermore, a double immunofluorescence staining of SP and neuron-specific enolase (NSE) was performed to highlight the co-localization of these markers and explore their potential contribution to synaptic function within the donkey cerebellum. This investigation aims to understand their possible roles in regulating neuronal activity and synaptic connectivity. We observed co-expression of SP and NSE in the donkey cerebellum, which emphasizes the crucial role of efficient energy utilization for motor coordination and balance, highlighting the interdependence of synaptic function and energy metabolism. The Purkinje cells were situated in the intermediate zone of the cerebellum cortex, known as the Purkinje cell layer. Characteristically, the Purkinje cell's bodies exhibited a distinct pear-like shape. The cross-section area of the Purkinje cells was 107.7 ± 0.2 µm2 , and the Purkinje cell nucleus was 95.7 ± 0.1 µm2 . The length and diameter of the Purkinje cells were 36.4 × 23.4 µm. By scanning electron microscopy, the body of the Purkinje cell looked like a triangular or oval with a meandrous outer surface. The dendrites appeared to have small spines. The Purkinje cells' cytoplasm was rich with mitochondria, rough endoplasmic reticulum, ribosomes, Golgi apparatus, multivesicular bodies, and lysosomes. Purkinje cell dendrites were discovered in the molecular layer, resembling trees. This study sheds light on the anatomical and cellular characteristics underlying the donkey's exceptional balance-maintaining abilities.

Unveiling Cellular Diversity in the Buffalo Corneal Stroma: Insights into Telocytes and Keratocytes Using Light Microscope, Transmission Electron Microscope, and Immunofluorescence Analysis.

Telocytes and keratocytes are important cells that maintain the structure and function of the cornea. The buffalo cornea, known for its resilience in harsh conditions, has not been extensively studied regarding the presence and role of telocytes and keratocytes. We used light microscopy, transmission electron microscopy (TEM), and immunofluorescence assays with platelet-derived growth factor receptor alpha (PDGFRα), CD34, and Vimentin markers to investigate their expression and localization in the cornea. TEM analysis confirmed the presence of spindle-shaped keratocytes with intercellular connections, while telocytes exhibited small spindle-shaped bodies with long, thin branches connecting to corneal keratocytes. Immunofluorescence findings showed that CD34 was more abundant near the endothelium, Vimentin was prominently expressed near the epithelium, and PDGFRα was uniformly distributed throughout the corneal stroma. Co-expression of CD34 and Vimentin, PDGFRα and Vimentin, as well as CD34 and PDGFRα, was observed in keratocytes and telocytes within the stroma, indicating the potential presence of mesenchymal cells. These results suggest the involvement of telocytes and keratocytes in corneal wound healing, transparency maintenance, and homeostasis. The co-expression of these markers highlights the critical role of telocytes and keratocytes in regulating corneal physiological functions, further enhancing our understanding of corneal biology in the buffalo model.

Heart ventricles of the dromedary camel (Camelus dromedarius): new insights from sectional anatomy, 3D computed tomography, and morphometry.

BACKGROUND: Dromedary camel heart morphology is a crucial research topic with clinical applications. The study aims to understand the dromedary camel anatomy, morphology, and architecture of the ventricular mass. RESULTS: Sagittal and transverse gross sections were compared to sagittal, transverse, and 3D render volume reconstruction computed tomography (CT) scans. The subepicardial fat, which covered the heart base, the coronary groove (sulcus coronarius), the left longitudinal interventricular groove (sulcus interventricularis paraconalis), and the right longitudinal interventricular groove (sulcus interventricularis subsinuosus), had a relatively low density with a homogeneous appearance in the 3D render volume CT. The pericardium in the color cardiac window was identified better than the black and white window (ghost). Transverse and sagittal CT scans demonstrated the internal structures of the heart, including the right atrioventricular orifice (ostium atrioventriculare dextrum), right atrioventricular orifice (ostium atrioventriculare sinistrum), and aortic orifice (ostium aortae), chordae tendineae, the cusps of the valves (cuspis valvae), and the papillary muscles (musculi papillares). The papillary muscle (musculi papillares) was presented with a more moderate density than the rest of the heart, and the cusps of the valves (cuspis valvae) had a lower density. The ventricular wall (margo ventricularis) exhibited different densities: the outer part was hyperdense, while the inner part was hypodense. The thicknesses of the ventricular mural wall and the interventricular septum (septum atrioventriculare) were highest at the midpoint of the ventricular mass, and the lowest value was present toward the apical part. The coronary groove (sulcus coronarius) circumference measured 51.14 ± 0.72 cm, and the fat in the coronary groove (sulcus coronarius) (56 ± 6.55 cm2) represented 28.7% of the total cross-sectional area. CONCLUSION: The current study provided more information about ventricular mass measurements by gross and CT analysis on the heart, which provides a valuable guide for future cardiac CT investigations in camels in vivo.

Morphology and morphometry of the spinal cord and meninges in Egyptian Baladi goat (Capra hircus): Stereomicroscopy of blue-stained gray matter.

The study objective is to obtain normal morphology and morphometric data from Baladi goat spinal cord segments. Using Tompsett's technique for staining gray matter with a blue stain allowed us to calculate the quantity or area of gray and white matter and thus the total area of each segment. The spinal cord of the goat started at the extent of the middle-third of the occipital condyles, and the tapered end of the spinal cord terminated at the center of the first sacral vertebra. The total length of the spinal cord was 73.3 ± 2.5 cm on average. C3 was the longest spinal segment, measuring 3.95 cm. The gray matter area had a high value at the cervical and lumbar enlargements, with C8 having the highest value of gray matter cross sectional area at 12 mm2 and C7 having the highest value of white matter cross sectional area at 42 mm2 . The area of white matter of the cervical region was higher than that of the other spinal regions. At C7, the total cross section area reached its maximum of 53 mm2 . The cervical enlargement included segments from C6 to T1, while the lumbar enlargement included L5 to S1. The dura mater is connected cranially to the dens of the axis and caudally to the fourth and fifth lumbar vertebrae. The epidural space height between lumbar vertebrae was 2 mm in all lumbar spaces and 3 mm in the lumbosacral space. The normal morphology and morphometric data of the goat spinal cord segments may be useful in pathological conditions of the spinal cord and during epidural anaesthesia technique.

Light and scanning electron microscopic characterization of the Egyptian buffalo hair in relation to age with analysis by SEM-EDX.

The purpose of this study was to demonstrate a relationship between the microstructure and measurements of Egyptian buffalo hair and age. The buffalo studied ranged in age from young to premature to adult (3-8 months, 1.5-3, 4-6, and 8-10 years). The hair was collected from the animals' withers. Cuticle elements were examined using scanning electron microscopy (SEM), light microscopy, and energy-dispersive X-ray (EDX) analysis. Hair shaft diameter increased with age, according to SEM and light microscopy measurements. The values of shaft diameter obtained by SEM of the same animal were 64%-67% of the values obtained by light microscopy due to shrinkage of the hair during the drying process. Additional microscopy measurements revealed that the width of the cortex and medulla increased with age, while the width of the cuticle decreased slightly. The medulla index of four different age groups ranged from 0.56 to 0.61 µm. The average distance between successive scale values increased from 4.83 µm in the young group to 8.86 µm between the ages of 8 and 10 years. The scale pattern had a distinct personality at each stage of age. The hair medulla was in the center and consisted of a mesh-like structure with large pores divided into smaller pores by septa. The cortex was a bundle of fibers that wrapped around the medulla. Light microscopy revealed small oval granules and large streak-like granules in the cortex. EDX spectra revealed that carbon, oxygen, and nitrogen were shown to be more abundant in all age groups of buffalo. In buffalo hair, oxygen was the second most abundant element after carbon. The carbon mass in the examined samples decreased slightly with age (42.31%, 39.18%, 38.88%, and 38.49%), while oxygen increased with age. We concluded that hair measurements varied with age, scale microstructure, and elements, so we estimated buffalo animals' ages up to 10 years. HIGHLIGHTS: The goal was to show a link between the microstructure and measurements of Egyptian buffalo hair and age. Hair shaft diameter increased with age, according to scanning electron microscopy (SEM) and light microscopy measurements. The hair shaft diameter obtained by light microscopy was higher than that obtained by scanning electron microscopy of the same animal; we hypothesized that the difference in hair shaft diameter measured by light microscopy and scanning electron microscopy of the same animal was due to the shrinkage of the hair during the drying process. The width of the cortex and medulla increased with age, while the width of the cuticle decreased slightly. The average distance between successive scale values increased from 4.83 µm in the young group to 8.86 µm between 8 and 10 years old. At each stage of age, the scale pattern had a distinct personality. Carbon, oxygen, and nitrogen were found to be more abundant in the hair of buffalo of all ages and were detected using energy-dispersive X-ray (EDX) spectra. After carbon, oxygen was the second most abundant element in buffalo hair. The carbon mass in the samples studied decreased slightly with age, while the oxygen mass increased. Hair measurements varied according to age, scale microstructure, and elements.

Morphological and radiological mapping of dental cusps in relation to spatial constraints on tooth shape of one humped camel (Camelus dromedarius).

A significant extent of researches in veterinary study have been focused on dental structure; however, there are scanty ones on the orientation and identification of their cusps. Therefore, the present article aimed to spot a light on arrangement pattern of dental cusps in the camel as a folivorous and graminivorous animal. This study was conducted on eight heads of adult, healthy camel of both sexes, collected from slaughter houses. To perform exact orientation of cusps of molar teeth, additional radiological and CT scans were performed on the mandible as a landmark that should facilitate the reading of cusps map. It was evident that, the cusps are arranged in crescentic appearance, seledontal form, with two cusps on each side, paracone and hypocone on the lingual surface and protocone and metacone on the vestibular aspect. Thus, camels cannot wear bite like equines, which would interfere with their constant chewing method. The camels' dental cusps provide some of the finest examples of convergent evolution, which offer insights both into correlates between form and function, and into how the ability of euthomorphic cusps in intrapability and stabilization of food items and its comminution between formidable cusps and occlusal spillway in between. Further studies should be done on the brachydontteeth and tropospheric cusps to fill the functional anatomy gap of teeth, in addition to diversity of cusps form. This study is considered a basic comparative anatomical study for normal healthy dentition and forensic practice, in addition to its importance in detection of local aspects of dental problems in camels.

Anatomical oropharyngeal cavity specialisations in the cutlassfish (Trichiurus lepturus, Linnaeus, 1758).

Trichiurus lepturus is a carnivorous fish, and most of the previous anatomical research has focused on computed tomography imaging and histology of their teeth and fangs, while the remaining structures of pharyngeal cavity remain unexplored. The present research is the first to use anatomical examinations alongside scanning electron microscopy to investigate the T. lepturus oral cavity. The oropharyngeal roof included teeth, upper lip, rostral and caudal velum and the palate. The middle of the palate showed a median groove flanked by two folds, followed by a median band flanked by micro-folds, thereafter the palate became crescent shaped. The lateral regions of the palate exhibited longitudinal folds that extended rostrally towards the fangs. The oropharyngeal floor had two cavities which acted as a scabbard for the premaxillary fangs and upper velum, while the caudal sublingual cavity contained two oyster-shaped structures on the outer surface plus sublingual ridges and sublingual clefts. The tongue apex exhibited a spoon-like shape, its body demonstrated a median elevation and the root with two lateral branches contained only dome-shaped papillae. Taste buds were located on the upper velum, lower lip and the caudal part of the interbranchial septum. Images and descriptions of T. lepturus tooth structure are also provided. The present research, using anatomical dissection and morphological observation using scanning electron microscopy, has identified the structures of the dentition system, a variety in shapes of the folds and microridges, and identified the taste buds and mucous pores in the T. lepturus oropharyngeal cavity.

New insights into the retinal microstructure-diurnal activity relationship in the African five-lined skink (Trachylepis quinquetaeniata) (Lichtenstein, 1823).

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.

Ossa cordis and os aorta in the one-humped camel: Computed tomography, light microscopy and morphometric analysis.

The present study describes the morphological characteristics of the camel heart Ossa cordis, and os aorta using computed tomography soft tissue window (CT) alongside 3D render volume reconstructions and light microscopy. The current study techniques demonstrated the Ossa cordis and os aorta in the cardiac window with more precision than the black and white (ghost), and angiography images. Transverse and sagittal CT images additionally demonstrated the presence of Ossa cordis and os aorta. This study is the first to record two small Ossa cordis sinistrum and one os aorta in the camel heart, in addition to the more commonly observed singular, large, os cordis dextrum. The os cordis dextrum was always located in the upper part of the interventricular septum, near to its junction with the atrium, forming an elongated rectangular shape when observed transversally. The wider cranial part was composed from bone, whereas the caudal aspect was narrow and contained both bone and cartilage. Light microscopy identified that the os cordis dextrum consisted of trabecular bone, marrow spaces, and hyaline cartilage. Two Ossa cordis sinistrum were detected on the left side of the heart, one in the right fibrous ring and another in the interventricular septum, microscopy showed that both contained only trabecular bone with osteocytes, osteoblasts, and osteoclasts. At the level of ascending aorta, there was also trabecular bone containing osteocytes, an os aorta.

Micro-morphology of the retina of the light-adapted African catfish (Clarias gariepinus).

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.

Ultrastructure of the palatine tonsils of the donkey (Equus asinus): New insights by light, scanning, and transmission electron microscopy.

The study aimed to explore the ultrastructure of the donkeys' palatine tonsils. Palatine tonsils of five male donkeys (5 years old) were investigated macroscopically and microscopically. The tonsils appeared as a dome shape with slight elevation and a circular opening on the surface of the oropharynx. The central tonsillar crypt appeared on the medial side of the palate-pharyngeal folds and the floor of the oropharynx. The external surface of the palatine tonsil had different sizes of mucosal folds, some grooves directed to drainage at the tonsillar opening, and the tonsil crypt opening was a crescentic or irregular oval shape. The outer surface was covered by stratified squamous epithelium and modified to be reticular epithelium invaded by lymphocytes in the crypt called lympho-epithelium. The tonsil crypt had aggregated lymphoid nodules, and the cryptal epithelium has surrounded by diffused lymphocytes and hassles corpuscles-like structures. The lymphocytes infiltrated into different layers of the cryptal epithelium and transformed into reticular or lympho-epithelium. The organized lymphoid nodules were primary and secondary, and the secondary ones had a light germinal center. The interfollicular area had many high endothelial venules and blood capillaries. The endothelial venules were lined by simple cuboidal epithelium and had lymphocytes. The blood capillaries had red blood cells and neutrophils. The tonsil was surrounded incompletely by a connective tissue capsule with mucous glands under that capsule. In conclusion, the epithelial lymphocyte infiltration, crypt epithelium, lymphoid nodules, and intra-follicular area of the donkey's palatine tonsils indicate the humoral and cell-mediated immunological process.

Morphology and morphometry of the inner ear of the dromedary camel and their influence on the efficiency of hearing and equilibrium.

BACKGROUND: The inner ear morphology and size are linked to hearing and balance ability. The goal of this study was to determine the morphology and morphometrics of the dromedary camel's inner ear and how it influences hearing accommodation and equilibrium in the desert environment. MATERIALS AND METHODS: Gross morphology, computed tomography images, and the endocast were used to show the inner ear morphology. A caliper and ImageJ software were used to take measurements on a plastic endocast. RESULTS: The presence of the subarcuate fossa, flat cochlea, radii curvature of the semicircular canals, particularly the lateral semicircular canal, orthogonality, and the union between the semicircular canals, along with slightly increased saccule and utricle size, maintains camel balance on sandy ground, even during heavy sandstorms. The cochlear basilar membrane length and cochlea radii ratio aided low-frequency hearing and perception over a wide octave range. CONCLUSION: The camel's cochlear characteristics revealed a lengthy basilar membrane, a high radii ratio, 3.0 cochlear canal turns, and a very broad cochlea. The orthogonality of the semicircular canals, the high curvature of the lateral semicircular canal, the presence of the subarcuate fossa, and the confluence between the lateral and posterior semicircular canal were particular specifications that allowed the inner ear of the camel to adapt to desert living.

Anatomy, histology, development and functions of Ossa cordis: A review.

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.

Ultrastructural focus on the oral cavity roof of the juvenile and adult white grouper (Epinephelus aeneus): Novel view of its development with carnivorous adaptation.

The present study aims to characterize the ultrastructural roof of the oral cavity roof in juvenile and adult Epinephelus aeneus using SEM. The investigation used 10 roofs of the oral cavity of juvenile and adult stages of age. The results in both age groups showed that the roof had five tooth bands, an upper valve, and a palatine region. The upper lip was divided into the anteriorly median and two lateral parts. The posterior margin of the anterior labial part is not attached to the incisive or canine teeth. The anterior surface of the canine teeth was attached to the transverse part of the upper incisive ridge that was separated from the posterior labial part by a deep groove. The semilunar upper velum showed two surfaces, two borders, and two parts. The median part of the oral surface of the velum carried the extension of the longitudinal part of the upper incisive ridge that had some variation among the two examined age stages. In addition, the median part of the oral surface of the upper velum had two rough areas located laterally on each side of the longitudinal part of the upper incisive ridge. The oral surface had several slightly elevated fungiform papillae with taste buds. The palatine region was divided into the peripheral semilunar part and the wide median part, by palatine teeth and the palatine groove laterally and by vomer teeth anteriorly. The results provided important data for the aquaculture in Egypt in relation to their diet.