“These two divergent forms of resistance are fascinating examples of evolutionary novelty.” “So – unlike the slow, vulnerable blue-tongue lizard – there’s no pressure for goannas to evolve resistance natural selection has invested in their armour and it’s clearly working for them. “Goannas are heavily armoured and their scales act like medieval chain mail, with each containing a piece of bone, meaning venomous snakes’ fangs struggle to pierce this armour. “Snake venom can only cause harm to goannas if it’s injected into its body by the snake’s fangs, it can’t be absorbed directly through the skin. “You’d think that a goanna would be significantly resistant to the venom of any snake it was hunting and eating, but that isn’t the case,” Dr Fry said. The research team analysed the effects of seven different Australian snake venoms on the plasma of two species of blue-tongued skinks and three species of monitor lizards that would interact with these snakes in the wild.Īssociate Professor Bryan Fry, who heads UQ’s Venom Evolution Lab, said the results also revealed that monitor lizards – or goannas – were not resistant to the snake venoms. “Much like how a COVID-19 vaccine doesn’t mean you don’t get sick at all, it just means you are less likely to die.” “This resistance doesn’t mean they’re completely immune, but it would give them a greater chance of survival, allowing them to escape or fight back. “This prevents specific toxins in red-bellied black snake venom from clotting the lizards’ plasma, which would lead to a rapid death in most other animals. “Since their resistance was so specific to only this snake species, it seems these lizards have evolved a special plasma component – known as a serum factor – in their blood. “It was a shock discovering that the eastern blue-tongue, along with the shingleback, showed resistance specifically to red black snake venom,” Mr Youngman said. UQ PhD candidate Nicholas Youngman said mammalian – and particularly, human – reactions had been heavily investigated, but very little was known about snake venom effects on other reptiles. The surprising finding was revealed after University of Queensland scientists compared the effects of various reptile blood plasmas when exposed to the venom. Slowly regrow over a period of months or years.Scientists have discovered that the humble blue-tongue lizard is largely resistant to the venom of the deadly red-bellied black snake, while giant carnivorous monitor lizards which feed on Australia’s most venomous snakes are not. That these pieces can rejoin is a myth, although the tail will Notes: Glass lizards earned their name by their propensity to "shatter"īy breaking their tail, often in several pieces. The female apparently attends the eggs until they hatch later in the summer.Ībundance: Eastern glass lizards can be quite common in Reproduction: In early summer, female glass lizards lay several eggs under a log, board, or other cover object. Prey: Glass lizards eat a wide variety of insects, spiders, and other invertebrates as well as small reptiles and probably young rodents. With the predator distracted by the wriggling Of their tail (which makes up more than half of their total length)Īnd will later regrow. When seized, glass lizards commonly break off all or part Habits: Glass lizards forage actively by day in open habitatsīut are commonly found taking refuge beneath boards and otherĭebris. Additionally, eastern glass lizards are very common in coastal dune habitats and are sometimes even found beneath debris at the tide line. Although these lizards may be found in a variety of habitats they are most common in flatwoods and around wetlands in sandy habitats. Range and Habitat: Eastern glass lizards are found throughout the southern and eastern portions of Georgia and South Carolina but are most common in sandy areas of the Coastal Plain. Older individuals are less boldly patterned than younger individuals, often developing a greenish or speckled coloration. This species is best distinguished from other glass lizards by the absence of a dark dorsal stripe or dark markings below the lateral groove and the presence of several vertical whitish bars just behind the head. The eastern glass lizard is the longest and heaviest glass lizard in our region and is generally light brown or yellowish to greenish in coloration. They differ from snakes, though, in that they have moveable eyelids, external ear openings, and inflexible jaws. Glass lizards are long, slender, legless lizards that superficially resemble snakes. Willson unless otherwise notedĭescription: 18 - 43 in (46 - 108 cm). Eastern Glass Lizard ( Ophisaurus ventralis)
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |