Joanna Klećkowska-Nawrot

The Harderian and lacrimal glands are the main orbital glands of the avian lacrimal apparatus and contribute to the tear film, nictitating membrane function, and local protection of the ocular surface. Although the ocular adnexa have been well described in domestic birds, the morphology and function of these organs remain poorly characterized in free-living species. This study aimed to characterize the morphology and histochemistry of these glands in the Great Spotted Woodpecker. The material consisted of 18 individuals found dead in the natural environment in Poland. Gross anatomical, morphometric, histological, and histochemical analyses were performed. Both glands occupied typical orbital positions. The secretory units of the Harderian gland consisted of one predominant epithelial cell type, contrasting with the more heterogeneous epithelial organization reported in some other avian species. Both glands were compound tubuloacinar structures. The Harderian gland opened into the lower conjunctival sac, whereas the smaller lacrimal gland drained into the dorsal conjunctival sac. The Harderian gland had a more homogeneous secretory parenchyma and a well-developed excretory duct system. The overall morphology of both glands was comparable to that described in other birds. However, the histochemical secretory profile differed from that reported in several species: the Harderian gland produced mainly acidic mucosubstances, whereas the lacrimal gland showed a mixed secretory profile. The immune component of both glands had a diffuse and periductal distribution, which contrasted with the pattern described in some birds. These findings show that the Harderian and lacrimal glands are structurally and histochemically distinct and suggest complementary roles in ocular surface maintenance in this species. At the same time, the results indicate selected morphological and functional differences compared with both domestic and other free-living birds.

Morphological data on the eyelids, the third eyelid (nictitating membrane), and the orbital glands remain limited for many Anguimorpha, including the Komodo dragon ( Varanus komodoensis ). The ocular adnexa contribute to eye protection, lubrication, and immune defense, and they may also reflect ecological and phylogenetic variation within Squamata. The objective of this study was to describe the gross anatomical, histological, histochemical, and polarized‐light microscopy characteristics of the upper and lower eyelids, third eyelid, Harderian gland, and lacrimal gland in the Komodo dragon. A panel of histological and histochemical stains was used to evaluate connective tissues (collagen, elastic fibers, and reticulin), muscles, cartilage, pigmentation, and mucins/glycoconjugates. The eyelids showed osteoderms and a multilayered keratin arrangement (β‐keratin layer/fibrous intermediate layer/β‐keratin layer/α‐keratin layer). Intense palpebral scale pigmentation and folded conjunctivae with mucin‐producing goblet cells may contribute to periocular protection, although this functional interpretation requires confirmation in free‐ranging animals. The third eyelid contained hyaline cartilage with Type I collagen‐associated birefringence in the perichondrium, Type III collagen‐associated birefringence in the cartilage matrix, and conjunctiva‐associated lymphoid tissue. The Harderian gland was the dominant orbital gland, but its histochemical profile showed only weak and uneven evidence of acidic mucosubstances, mainly in luminal secretory material; therefore, its secretory phenotype should be interpreted cautiously, whereas the lacrimal gland showed a clearer mucous profile dominated by acidic mucosubstances. By documenting a large non‐spectacled anguimorph, these findings provide comparative data relevant to eyelid support, nictitating‐membrane organization, lacrimal drainage, and orbital gland variation across Squamata.

The orbital glands are part of the ocular surface protective system, but their morphology and secretory profiles remain poorly documented in small wild bovids. This preliminary descriptive study examined nine young animals: four Kirk’s dik-diks (Madoqua kirkii) and five red forest duikers (Cephalophorus natalensis). All animals underwent gross anatomical examination, and bilateral Harderian glands (HGs), lacrimal glands (LGs), and superficial glands of the third eyelid (SGTE) were examined histologically, histometrically, and histochemically. No inferential statistical comparisons between species were performed. In both groups, the HG was located medioventrally, the LG dorsolaterally, and the SGTE medially near the third eyelid. The glands showed compound tubuloacinar or predominantly acinar organization. Descriptive variation involved capsule thickness, septal development, lobular arrangement, secretory epithelial appearance, and plasma cell and lymphocyte distribution. Histochemical reactions demonstrated mixed secretory profiles containing neutral glycoconjugates and acidic mucosubstances consistent with sulfated and/or carboxylated components. Their relative proportions varied among glands and between groups. These findings provide preliminary anatomical and microscopic reference data for rarely examined wild bovids. Because of the small sample sizes, the observations should not be interpreted as definitive species-level differences.

This study focused on an archaeozoological analysis of the morphology and osteometry of bovine proximal phalanges. The examined material consisted of 446 complete specimens recovered from an archeological site in Wrocław, Poland (St. Vitus and St. Catherine Streets and New Market Square). The assemblage was divided into eight chronological groups spanning the period from the Early Middle Ages to the Modern Era. The archaeozoological investigation included osteometric measurements and an assessment of morphological variation. Observed changes in bone dimensions were interpreted in relation to patterns of animal exploitation, successive stages in the development of proto-urban and urban settlement in Wrocław, and environmental influences. A critical evaluation of the osteometric data demonstrated that the greatest length of the proximal phalanx should not be used as an additional proxy for estimating withers height when complete metapodial bones are absent from an archeological assemblage. Furthermore, computed tomography (CT) analysis revealed the presence of metal alloys within the medullary cavity of several bones, indicating intentional human modification of the material in the past.

Woodpeckers (Picidae) are exposed to repeated mechanical loading and particulate material during climbing, drilling, pecking, and foraging on tree trunks, but the microscopic organization of their eyelids and nictitating membrane remains poorly known. This study asked whether European woodpeckers share a common histological pattern of ocular adnexa and whether selected structural features may be interpreted in the context of ocular surface protection. The upper eyelid, lower eyelid, and nictitating membrane were examined in 40 birds representing six European woodpecker species using routine histological and histochemical methods. In all of these species, the eyelids showed a layered organization with a keratinized anterior palpebral surface, non-keratinized conjunctival surface with goblet cells, marginal zone, musculofibrous stroma, and no tarsal glands. Species-related differences were observed in the examined material in epithelial thickness, skin fold development, melanin pigment distribution, and marginal zone organization. The lower eyelid contained a compact fibrous tarsal plate and CALT represented by lymphoid nodules and diffuse lymphocytes, with morphologically identified HEV-like venules located within or close to lymphoid tissue. The nictitating membrane showed regional variation in the marginal plait, leading edge, epithelial surfaces, stromal pigmentation, and fold organization. These findings provide the first comparative histological baseline for the eyelids and the nictitating membrane of European Picidae and support the cautious interpretation that these structures may contribute to mechanical, mucosal, and immune protection of the ocular surface in woodpeckers. Because sample sizes were unequal, these interspecific observations should be treated as descriptive, sample-level findings rather than definitive species-level traits.

Background: The Felidae family includes diverse species with marked variation in ocular morphology. This study describes and qualitatively compares ocular morphology in a limited number of specimens: the clouded leopard ( Neofelis nebulosa , n = 1), the African lion ( Panthera leo , including two Angola lions, P. l. bleyenberghi , n = 2), and Pallas’s cat ( Otocolobus manul , including O. m. manul , n = 1), whereas morphometric assessment of the orbital region was additionally based on skull material (clouded leopard, n = 1; Pallas’s cat, n = 2; lions, n = 11). Materials and methods: Morphometric analyses were performed for the orbital region, eyeball, and selected accessory organs of the eye, using combined macroscopic and microscopic examinations. Histological staining included Mayer’s hematoxylin and eosin, Heidenhain’s Azan trichrome, Movat pentachrome, Masson-Goldner trichrome, Mallory’s trichrome with aniline blue, and Masson-Fontana, as well as histochemical staining with PAS, alcian blue (pH 1.0 and 2.5), alcian blue pH 2.5/PAS, and colloidal iron. Because of the very limited number of specimens, the study was strictly descriptive, and no statistical comparisons were performed. Results: In the examined specimens, eyeball size generally corresponded to animal body size, whereas eyeball shape varied among individuals: the examined Angola lions had elliptical eyeballs, the examined clouded leopard had a nearly round eyeball, and the examined Pallas’s cat had a slightly elliptical eyeball. Corneal size and shape varied among the examined individuals. Histologically, the cornea consisted of four layers, Bowman’s layer was absent, and epithelial thickness varied among specimens. Palisades of Vogt were identified in the examined material. The tapetum lucidum varied in size among the examined animals and was most pronounced in the Angola lions; its coloration ranged from milky blue to blue-green. The anterior chamber depth appeared to correspond with eyeball size. Pupil shape also differed among the examined animals. Histological and histochemical analyses of the ocular adnexa revealed interindividual and intertaxon differences in microstructure; however, the very limited material did not allow broader interpretation. Orbital morphometric values generally followed overall skull size. Possible sex-related variation was observed in the lion material, but this requires verification in a larger series. Conclusion: The present study provides a descriptive anatomical and histological characterization of the eye and selected ocular adnexa in a small number of representatives of three felid taxa. These findings may serve as baseline reference data for comparative anatomy and veterinary ophthalmology, but they should not be interpreted as species-level patterns. Limitations: Due to the limited sample size, these observations are preliminary and do not allow for species-level or population-level inferences. Because ante-mortem ophthalmic examinations were not available, subclinical ocular abnormalities cannot be excluded. In addition, because the material was collected post-mortem and subjected to fixation, processing, and sectioning, some morphometric values may have been affected by tissue distortion or shrinkage. Further studies based on larger series and standardized clinical evaluation are needed to verify the patterns observed in the present material.

Background: The aardwolf skulls were analyzed and compared to the spotted hyena, the brown hyena and the striped hyena, using specimens from Polish and South African collections. Addressing gaps in detailed anatomy and morphometrics, this study used extensive analyzes, encompassing 64 morphometric parameters and 7 indices, to examine the morphology and morphometrics of cranial and mandibular structures and quantify interspecific and intraspecific variation. Results: The comparative analysis of hyena skulls revealed significant differences between the aardwolf and the other three species. The aardwolf consistently had the smallest and proportionally narrowest skull, characterized by high morphological stability and a wide neurocranium. The brown hyena and spotted hyena had the largest skulls; however, the brown hyena showed greater homogeneity, while the spotted hyena displayed higher absolute variability. Morphologically, the aardwolf’s basilar part was cylindrical, unlike the pyramidal shape in the spotted hyena, and it possessed prominent nuchal tubercles that were reduced in the brown and spotted hyenas. Conclusions: This study demonstrates that the morphological and morphometric features of the aardwolf’s skull are highly specialized and fundamentally distinct from the other three hyena species, reflecting its unique dietary niche. The powerful skulls of the spotted and brown hyenas, in contrast, correlate with their roles as apex predators and scavengers.

The cornea is essential for proper ocular function, yet its histological structure varies considerably among animal species. Of particular importance are the palisades of Vogt in the limbal region, as they serve as a niche for limbal epithelial stem cells involved in corneal epithelial regeneration. This study was conducted on 73 eyeballs collected from 18 species of non-human primates originating from the Wrocław Zoological Garden (Poland). Eyeballs were fixed, processed, and embedded in paraffin. Four-micrometer sections were stained with Mayer’s H&E and PAS. Microscopically, the cornea showed either a four-layered pattern (anterior corneal epithelium, corneal stroma, Descemet’s membrane, posterior corneal epithelium) or a five-layered pattern when Bowman’s layer was present. A four-layered cornea occurred in the ring-tailed lemur, gray mouse lemur, Guianan squirrel monkey, Angolan colobus, and L’Hoest’s monkey, while the remaining species showed a five-layered structure with Bowman’s layer. The anterior corneal epithelium varied between species in thickness and number of cell layers (central region: 2–3 to 10–15 layers; 11.81 ± 0.43 µm to 44.23 ± 0.69 µm; peripheral region: 4–5 to 9–11 layers; 8.63 ± 2.57 µm to 42.45 ± 8.61 µm). Bowman’s layer ranged from 1.18 ± 0.01 µm to 3.22 ± 0.05 µm. The corneal stroma thickness differed markedly (237.96 ± 9.64 µm to 1438.29 ± 16.38 µm), as did Descemet’s membrane (4.92 ± 0.20 µm to 43.45 ± 0.49 µm), along with PAS reaction intensity. In the limbus, palisades of Vogt ranged from weakly to clearly developed; well-defined crypt-like structures were observed in the red-bellied lemur, red ruffed lemur, black-and-white ruffed lemur, Guianan squirrel monkey, L’Hoest’s monkey, Celebes crested macaque, and yellow baboon. The limbal epithelium also varied in thickness (5–6 to 15–17 cell layers). These results confirm distinct species-specific differences in corneal and limbal morphology that may reflect ecological conditions and functional adaptation. The presented data provides a comparative reference for veterinary ophthalmology and for studies on corneal epithelial regeneration involving limbal stem cells.

The primary goal of regional anesthesia in exotic animals is to alleviate postoperative pain. It also enables a painless surgery and stands a safer option for surgeries than general anesthesia. Due to the varying anatomy of the head among different species of exotic mammals, anesthesia techniques can differ significantly. Therefore, it is crucial to understand the topography of each species individually. This study describes the location of the cranial foramina associated with the trigeminal nerve, the topography of the surrounding bony structures (Table 1) and soft tissues in three red pandas (Ailurus fulgens fulgens) from the Wrocław Zoological Garden (Poland). It also presents techniques for anesthetizing nerves that pass through these foramina to alleviate postoperative pain after head surgeries as well as dental and orofacial procedures. The procedures described in this study were modified from known veterinary anesthesia techniques for cranial nerves in other animals. The results demonstrated variations in injection methods due to differences in the topography of the cranial foramina of the red panda.