Histological and histochemical characterization of the venom apparatus of Palestine yellow scorpion,Leiurus quinquestriatusHemprich & Ehrenberg 1828

Phenotypic description of Egyptian endemic centipedes, genus Scolopendra Linnaeus, 1758 with a histological study of its venom glands

Centipedes are widely distributed over all continents. They have significant medicinal value and high toxicity, making them an intriguing subject for evolutionary research. The current study aims to provide the first comprehensive analysis of the morphology, description, and distribution preferences of the Egyptian Scolopendromorpha centipede fauna. According to surveillance research in Egypt, two Scolopendra species have been re-described. Scolopendra canidensNewport.1844 were discovered in only one location, whereas Scolopendra morsitans s Linnaeus,1758 was more abundant. Both venomous glands were histochemically investigated. This study is the first comparative report on the histology and histochemistry of the venom glands of the Egyptian centipede species. Both species’ glands are primarily composed of columnar secretory cells radially arranged side by side and open through pores in a central chitinous duct. Each secretory cell is enclosed in striated muscle fibers. The secretion of both glands takes the shape of small PAS-positive granules, suggesting the presence of neutral polysaccharides. According to this surveillance study, the most abundant species was Scolopendra morsitans s Linnaeus,1758. Scolopendra canidens canidensNewport.1844 were found only on the Northwest coast of Egypt. The findings also revealed that the analyzed species are comparable in terms of their venom morphology and fundamental chemical composition.

Armed stem to stinger: a review of the ecological roles of scorpion weapons

Scorpions possess two systems of weapons: the pincers (chelae) and the stinger (telson). These are placed on anatomically and developmentally well separated parts of the body, that is, the oral appendages and at the end of the body axis. The otherwise conserved body plan of scorpions varies most in the shape and relative dimensions of these two weapon systems, both across species and in some cases between the sexes. We review the literature on the ecological function of these two weapon systems in each of three contexts of usage: (i) predation, (ii) defense and (iii) sexual contests. In the latter context, we will also discuss their usage in mating. We first provide a comparative background for each of these contexts of usage by giving examples of other weapon systems from across the animal kingdom. Then, we discuss the pertinent aspects of the anatomy of the weapon systems, particularly those aspects relevant to their functioning in their ecological roles. The literature on the functioning and ecological role of both the chelae and the telson is discussed in detail, again organized by context of usage. Particular emphasis is given on the differences in morphology or usage between species or higher taxonomic groups, or between genders, as such cases are most insightful to understand the roles of each of the two distinct weapon systems of the scorpions and their evolutionary interactions. We aimed to synthesize the literature while minimizing conjecture, but also to point out gaps in the literature and potential future research opportunities.

Morphological and histological characterization of production structures, storage and distribution of venom in the parasitic wasp Bracon vulgaris

It was described the morphology and histological composition of the structures related to production, storage and distribution of Bracon vulgaris venom, a wasp that parasite their hosts after the inoculation of a venom which causes irreversible paralysis. Were found 22 glandular filaments, coated with secretory epithelium associated with a reservoir coated internally by a chitin layer and externally by striated muscular fibers. A valve mediates the passage of the toxin to venom duct towards the parasitoids sting.