Thursday 5 April 2018

Invertebrate: spiders


Hello again. Welcome back to Evolution of venom. Today blog topic, we will be covering more about invertebrates that use venom. A recap from the last blog: we covered what an invertebrate is and scorpions and their venom.
 
Spiders belong to the order Araneae that is a part of the arachnid’s family, that includes scorpions and ticks. Below is a diagram of the internal anatomy of a female two-lunged spider with the venom gland located just below the simple eye.

Internal anatomy of a female two-lunged spider by John Henry (1996)
 

Spider venom is introduced to the body by the fangs connected to the venom gland, some species of spider fangs are too small to penetrate human skin or their venom is too weak to produce any effects (Junghanss & Bodio, 2006). Brown/black widows, wandering spiders and funnel web spiders have neurotoxic venom that cause vomiting, fever, muscle spasms, sweating, cramping pains and alteration in blood pressure and heart rate (Warrell, 2015-2016). Spider venom is used to make anti-venom that is used for extreme cases depending on which spider species caused the bite (Hardy, Cochrane & Allavena, 2014).

In next weeks’ blog, we be covering the cone snail, jellyfish and sea urchins that use venom. Below are three articles about spider venom used for this post.

 References
Hardy, M.C., Cochrane, J. & Allavena, R.E. 2014, "Venomous and Poisonous Australian Animals of Veterinary Importance: A Rich Source of Novel Therapeutics", BioMed Research International, vol. 2014, pp. 1-12.
Junghanss, T. & Bodio, M. 2006, "Medically Important Venomous Animals: Biology, Prevention, First Aid, and Clinical Management", Clinical Infectious Diseases, vol. 43, no. 10, pp. 1309-1317
Warrell, D.A. 2015;2016;, "Venomous animals", Medicine, vol. 44, no. 2, pp. 120-124.

Picture reference
Spider_internal_anatomy.png: John Henry Comstock Conversion to SVG: Pbroks13 (Ryan Wilson) (talk)  -  Anatomical information and original diagram from The Spider Book (1912, 1920) by John Henry Comstock Additional anatomical information from Biology of Spiders (1996) by Rainer F. Foelix
 

 
 

 
 
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2 comments:

  1. Tasmin7 April 2018 at 22:14

    Do you know what the evolutionary relationship between the venom of spiders and scorpions is? Did they evolution from a single common ancestor, or were there separate evolutionary events?

    ReplyDelete
  2. sherazabbasi14 June 2021 at 03:37

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    ReplyDelete

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