Venomous Knowledge: A Beginner's Guide to Venom

What exactly is venom? Fry et al. define venom as a secretion produced by a specialised gland, which is delivered to a target animal through the infliction of a wound. They also state that the secretion must contain molecules that disrupt normal physiological processes (Fry et al., 2009). Different species have evolved different types of venoms, whether it is for defence, predation, or competition. However, all venoms have high levels of proteins and peptides (Casewell, et al., 2013).

A New Guinea Bird-eating Spider (Selenocosmia crassipe) in defensive position (Image 1).

A Russell’s viper (Daboia russelii) which uses venom to immobilise prey (Image 2).

A Slow Loris (Nycticebus), which wards off other Slow Lorises during the mating season with its venom (Nekaris et al., 2013) (Image 3).

Organisms have evolved specific venom based on what they use it for. Many predators use venom to paralyse their prey. The venom toxins disturb the activity of enzymes, cell receptors or ion channels, thus disarranging the central and peripheral nervous system and neuromuscular systems. Other venoms are used to coagulate blood and interrupt the cardiovascular system by disturbing different enzymes or receptors. These toxins are now being studied to help advance pharmaceutical products (Calvete, et al., 2009).

Russell's viper's (Daboia russelii) venom added to blood, causing coagulation (Image 4).

References

Calvete, J. J., Sanz, L., Angulo, Y., Lomonte, B., & Gutierrez, J. M. (2009). Venoms, venomics, antivenomics. FEBS Letters , 583 (11), 1736-1743.

Casewell, N. R., Wüster, W., Vonk, F. J., Harrison, R. A. & Fry, B. G. 2013. Complex cocktails: the evolutionary novelty of venoms. Trends in Ecology and Evolution 28: 219-229.

Fry, B.G., Roelants, K., Champagne, D.E., Scheib, H., Tyndall, J.D., King, G.F., Nevalainen, T.J., Norman, J.A., Lewis, R.J., Norton, R.S., Renjifo, C., de la Vega, R.C., 2009. The toxicogenomic multiverse: convergent recruitment of proteins into animal venoms. Annu. Rev. Genomics Hum. Genet. 10, 483–511.

Nekaris et al.: Mad, bad and dangerous to know: the biochemistry, ecology and evolution of slow

loris venom. Journal of Venomous Animals and Toxins including Tropical Diseases 2013 19:21.