Welcome back to the multi-legged world of centipedes: Where one step can feel like a hundred!
The topic of today’s post focuses on a primary research article about the study into the venom from a particular taxon in Chilopoda. Titled “Phenotypic description of Egyptian endemic centipedes, genus Scolopendra Linnaeus, 1758 with a histological study of its venom glands”, it reads as quite of a mouthful terms that describe its study about the morphology and venom of Scolependra Morsitans s Linneus, more commonly known as the Red-headed centipede. The article was authored by Many Mohammed Mona and Aalaa I. Atlam, as they hypothesized that the anatomical and biological differences found in this taxon compared to other species is the result of their geographical isolation in Egypt.
To proceed with their study, specimens of Scolopendra Morsitans and Scolopendra Canidens from various regions in Egypt were collected and maintained in captivity for a period from July 2019 to August 2020. after these subjects were sedated, their color, head features and appendages were under examination to check for their morphological differences. In a separate examination, their venom glands were removed, decalcified, stained, subjected to a PAS test, and were then photographed under a microscope. The results showed that the morphological and histological characteristics of both of the species were almost identical, and both showed a presence of PAS-positive venom. the findings also showed more examples of Scolopendra Moristans than its counterpart.
None of the specimens collected showed any significant differences between each other, while the distribution of Scolpendra Morsitans is more prevalent than that of Scolopendra Canidens. Both of these findings could be indicative of a number of things. While both species are known to be in the same subfamily in which they may already owe some of their similarities to, an additional reason that they may resemble each other so closely may be convergent evolution due to the adaptations they have made for a particular lifestyle shaped by their geographical location. Assuming that this is true, that would mean that Scolopendra Moristans may have a more widespread distribution due to subtle differences in their biology and behavior that give them a competitive advantage over Scolopendra Canidens. The PAS positive nature of the Venom observed in the specimens is a trait associated with the most venomous arthropods known to science, which could possibly indicate that this level of potency is needed to incapacitate relatively formidable prey items.
What makes the results of this study so important is that it makes a hallmark as the first comprehensive investigation into both of these species in Egypt since they were first described, while a comparative predation study between these species and other centipedes that are not known to carry PAS-postive venom might offer more insight into the epiphanies about their predatory lifestyle.
Key Terms
- PAS– Abbreviated form of Periodic-acid Schiff, which is a stain used to test for complex carbohydrates, and in this case is applied to the venom samples
- Morphology– The physical characteristics of a species
- Histology– the microscopic arrangement of tissues in an animal or taxon
- Convergent Evolution– the independent evolution of a shared feature between two or more organisms as a response to their similar lifestyle
Source
Mona, M.M., Atlam, A.I. Phenotypic description of Egyptian endemic centipedes, genus Scolopendra Linnaeus, 1758 with a histological study of its venom glands. Zoomorphology 141, 273–281 (2022).