Seasonal venom
A study found that in certain venomous species there is a correlation with the season and venom yield. There was no effect of food consumption, molting, and pregnancy on the yield of the venom, which excluded these as factors for the increase in yield. It is believed that the temperature is the main factor for this correlation. During summer the venom yield is highest and during winter the venom yield is lower. The Northern Mojave rattlesnake (Crotalus scutulatus scutulatus) was found to have the highest venom yield in spring/summer conditions and the maximum venom yield during the hottest summer conditions. Another study done on the Southern Pacific rattlesnake (Crotalus oreganus helleri) found higher venom yield from July to October. I have not covered venomous mammals in my blog yet, but one venomous mammal only produces its venom during mating season. This mammal is the Platypus (Ornithorhynchus anatinus) and will only use its venom in the Spring while breeding. The Platypus possesses a spur on their hind leg that is connected to glands in the pelvic region and is believed to be used to fight off other males.
Belov, K. Gombert, S. King, G. Mofiz, E. Morgenstern, D. Morris, K. Papenfuss, A. Renfree, M. Temple-Smith, P. Warren, W. Whittington, C. Wong, E. (2012), 'Proteomics and Deep Sequencing Comparison of Seasonally Active Venom Glands in the Platypus Reveals Novel Venom Peptides and Distinct Expression Profiles', Molecular & Cellular Proteomics, Vol. 11, Iss. 11, Pgs. 1354-1364.
Bosisio, A. Egen, N. Gregory-Dwyer, V. Righetti, P. Russell, F. (1986), 'An isoelectric focusing study of seasonal variation in rattlesnake venom proteins', Toxicon, Vol. 24, Iss. 10, Pgs. 995-1000.
An interesting idea about the original function of fangs and great information on the different types of fangs found. I also found it very interesting that season and temperature can play a role in venom yield. On the subject of venom yield and fang type – I assume that yield is estimated through “milking”, but how would you go about milking a rear-fanged or Opisthoglyphous snake? Are there some species that do not demonstrate variation in venom yield with season/temperature? Interesting information!
ReplyDeleteRear fanged snakes are very hard to milk!! You can milk them though by putting them under anesthetics and giving them a shot of pilocarpine, which is a stimulant. Then you use a pipette and gather the venom that you receive. This is very hard to do and needs to be done properly by an expert! The venom in mammals is not effected by the temperature/season as much as cold blooded venomous reptiles are. The platypus is an exception due to its venom used only for breeding situations. Reptiles in warmer months can produce higher quantities and are more active.
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