Today in our security talk Jose mentioned some facts about snakes; unfortunately we will not cover herps in depth in the course. This is one of my favourite groups especially venomous snakes. Since I consider important to have some knowledge about them I would like to give you some relevant facts about this group.
Venomous snakes have specialized teeth called fangs, which they use to inject venom. This venom delivery system has two main functions:
- Get food
- As defense against predators
The fangs can be located in front or rear in the upper jaw.
Snakes with fangs in the rear upper jaw are called Opistoglyph, you don’t need to worry about them. The venom is not very harmful to humans, but reactions vary from person to person.
Snakes with front fangs can also be divided in two main groups:
- Proteroglyphous, Coral snakes and marine snakes are the only ones with these fangs in America. Both belong to the elapidae family, are closely related to Mambas and Cobras.
- Solenoglyphous, this is the most amazing group, called vipers. These snakes have a complex venom delivery system. The fangs fold inside the mouth. To attack preys they unfold the fangs and direct them towards the prey. The pressure caused by the bite and some muscles inject the venom rapidly. Rattlesnakes, cotton mouths and lanceheads belong to this group.
I added a very cool image to ilustrate the types of fangs.
Image Modified from FJ Vonk et al. Nature 454, 630-633 (2008) doi:10.1038/nature07178
This is just to remind you about the composition of venom, which was mentioned. It is mainly made of proteins and peptides. The composition of the venom is similar in closely related species. And can be classified in two main categories, neurotoxic and cytotoxic.
In Coral snakes (elapids) venom is mainly neurotoxic, which inhibits neuromuscular transmission leading to rapid immobilization.
On the other hand Vipers’ venom activity is cytotoxic. It acts mainly on cells, causing apoptosis, necrosis and haemorrhage.
If you would like to know more about venomous snakes you can find some further information here:
Mackessy, S. P. (2010). Handbook of venoms and toxins of reptiles. Boca Raton: CRC Press/Taylor & Francis.
Vonk, F. J., Admiraal, J. F., Jackson, K., Reshef, R., de, B. M. A., Vanderschoot, K., van, . B. I., … Richardson, M. K. (January 01, 2008). Evolutionary origin and development of snake fangs. Nature, 454, 7204, 630-3