Comparative Histological Characterization of the Venom Apparatus in Five Iranian Scorpion Species.

Background: Scorpion envenomation represents a significant public health concern worldwide. The telson is located at the distal part of the metasoma, where venom is secreted from a pair of venom glands. The curved stinger is responsible for venom delivery. Methods: This study conducted a histological examination of five scorpion species, including Hottentotta juliae, Hottentotta zagrosensis, Odontobuthus kermanus, and Scorpio maurus, which were gathered from Fars Province, as well as Hemiscorpius lepturus, collected from Khuzestan Province. The telson histology was assessed using the hematoxylin-eosin method. Results: The exocuticle, endocuticle, and secretory epithelium, which consists of secretory and supporting cells, were identified in the tissues of all species. Cuticle pores were distributed throughout the telson. Each venom gland possesses a central lumen, where secreted venom accumulates within a venom sac. The intercalated tendon is located beneath the basal membrane and connects the glandular epithelium to the cuticle. The sizes and shapes of the secretory epithelial cells vary depending on the species. Conclusion: While histology elucidates the structural organization of scorpion venom glands, integrating histological findings with proteomic and histochemical approaches would provide a more comprehensive understanding of venom composition and interspecific variation.