Vertebrates: Snakes

Welcome back to evolution of venom, Today’s blog topic, we will be coving what vertebrates are and land/sea snakes that use venom. A brief recap: we covered bees, wasps, centipedes and moths and how they use their venom.

Vertebrates are animals that have a backbone or spinal column, a closed circulatory system, a heart divided into 2,3, or 4 chambers, and a brain enclosed in a cranium. There are 5 classes of vertebrates: birds, fish amphibians, reptiles and mammals (Vertebrate, 2017).

Snakes belong to the order Squamata (Scaled reptiles) which also includes lizards, but belong to the suborder Serpentes. Snakes have no limbs, eyelids or external ears, forked tongue that allows them to taste the air around themselves and a long slender body (snake, 2017). Venomous snakes have fangs located in their upper jaw which contain venom ducts that run along the inside of the fangs. Below is a diagram of the venom ducts of a snake.

Diagram of snake venom ducts by www.newtonsapple.org.uk

Venom is introduced to the human body in a number of ways, the most common way is a snakebite which leaves two puncture holes in the skin. Some venomous snakes spray venom at their prey from their mouth causing the venom to be introduced through the mouth or eyes. Depend on the species of snake, venom can cause blindness, severe pain, necrotic tissue, swelling and death (Warrell, 2015).

 
In next week’s blog, we will be covering more reptiles that use venom. Below are the articles used in this week’s blog post for more information about snake venom.

 References
snake. (2017). In Encyclopaedia Britannica, Britannica concise encyclopedia. [Online]. Chicago: Britannica Digital Learning.
Vertebrate. (2017). In P. Lagasse & Columbia University, The Columbia encyclopedia. (7th ed.). [Online]. New York: Columbia University Press.
 

Warrell, D.A. 2015;2016;, "Venomous animals", Medicine, vol. 44, no. 2, pp. 120-124

Picture Reference

http://www.newtonsapple.org.uk/wp-content/uploads/2014/08/venomous-snake-fangs-diagram.jp