Vertebrates: birds

Welcome back to evolution of venom, in today’s blog topic, we will be covering birds. Although there is currently no known bird species that produces or actively inject venom, some species of birds that are toxic to eat or even touch. A brief recap: we covered amphibians that use venom.

The Hooded pitohui (Pitohui dichrous) is a species of bird that belongs to the genus Pitohui that is found in New Guinea. The skin and feathers of this bird and others belonging to the same genus contain a neurotoxin called Homobatrachotoxin. Homobatrachotoxin belongs to a group of neurotoxins called neurotoxic steroidal alkaloids or batrachotoxin which stabilize the open form of voltage-gated sodium channels in nerve and muscle membranes (Dumbacher et al, 2000). This toxin was previously found in Central American poison dart frogs. Below is a picture of the Hooded pitohui and the chemical formula of Homobatrachotoxin (Boland, 2001). The Hooded pitohui diet of beetles may have contributed to the toxins in the skin and feathers, but it is still currently being debated.

Formula taken by Boland, W and picture of Hooded pitohui by Unknown.

The Spur-winged Goose (Plectropterus gambensis) is a species of bird that resides in Africa belongs to the Genus Plectropterus. Like the Hooded pitohui, the Spur-winged Goose also has a neurotoxin that is found in the feathers and skin, but their neurotoxin is different from the birds belong to the genus Pitohui. The neurotoxin found in the Spur-winged Goose is called Cantharidian which comes from their diet of blister beetles. Cantharidian is considered to be highly toxic to humans as it causes blistering upon skin contact and when ingested can lead to death (Boland, 2001). Below is the chemical formula for Cantharidian and a picture of a Spur-winged Goose. 

Formula taken by Boland, W and picture of Spur-winged goose by unknown.

For the last post for this blog, we will be covering the medical uses of vemon.

References

Boland, W. 2001, "Chemistry and ecology of toxic birds", ChemBioChem, vol. 2, no. 11, pp. 809-811.

Dumbacher, J.P., Spande, T.F. & Daly, J.W. 2000, "Batrachotoxin Alkaloids from Passerine Birds: A Second Toxic Bird Genus (Ifrita kowaldi) from New Guinea", Proceedings of the National Academy of Sciences of the United States of America, vol. 97, no. 24, pp. 12970-12975.

Picture references

https://wol-prod-cdn-literatumonline-com.elibrary.jcu.edu.au/cms/attachment/e3b2358d-75a7-414f-b310-8a21b1af0dfe/mcontent.jpg

https://upload.wikimedia.org/wikipedia/commons/6/61/Pitohui_dichrous.jpg

https://en.wikipedia.org/wiki/Spur-winged_goose#/media/File:Spur-winged_Goose_RWD4.jpg

https://br9xy4lf5w.search.serialssolutions.com/?ctx_ver=Z39.88-2004&ctx_enc=info%3Aofi%2Fenc%3AUTF-8&rfr_id=info%3Asid%2Fsummon.serialssolutions.com&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.atitle=Chemistry+and+ecology+of+toxic+birds&rft.jtitle=ChemBioChem&rft.au=Boland%2C+Wilhelm&rft.date=2001&rft.issn=1439-4227&rft.eissn=1439-7633&rft.volume=2&rft.issue=11&rft.spage=809&rft.epage=811&rft.externalDBID=n%2Fa&rft.externalDocID=33722672&paramdict=en-AU

Vertebrates: amphibians

Welcome back to evolution of venom, in today’s blog topic, we will be covering amphibians that use venom. Majority of amphibians currently found are poisonous rather than venomous, but there are three amphibians that use venom.

The Iberian ribbed newt or Spanish ribbed newt (Pleurodeles waltl) is a species of newt found in central Iberian, Peninsula and Morocco. It is the largest European newt species found and it is known for its odd defence mechanism. When the Iberian ribbed newt is threatened or agitated, it swings its ribs forward out of its skin so the ribs are outside of its body. If a predator tries to bite or pick up the newt, the ribs act like venomous barbs, injecting a milky substance into the predator causing severe pain or death. This defence mechanism does not hurt the newt as it is able to reconstruct the tissue around the area where the ribs broke through (Rosania, 2014). Below is a picture of an Iberian ribbed newt.

Picture taking by Peter Halasz.

The other two venomous amphibians are a pair of frogs with an unusual defence mechanism. Greening’s frog (Corythomantis greeningi) and Bruno’s casque-headed frog (Aparasphenodon brunoi) both use bony spines located on top of their head to inject venom into predators. Most frog species produce or secret poison to ward off predators which makes these two frogs unique (Carlos Jared et al, 2015). The venom of these frogs has not been studied a lot as venomous amphibians are rarer than amphibians that produce poison. However, study suggest that Greening’s frog venom can provoke effective nociceptive and inflammatory effects (Mendes et al, 2016). Below on the top is a picture of Greening’s frog and on the bottom is Bruno’s casque-headed frog.

Both pictures were taken by Carlos Jared / Butantan Institute.

Next time, we will be covering on some interesting birds that are poisonous (not venomous as there are no known venomous birds).

References

Rosania, K. 2014, "Newts with superpowers", Lab Animal, vol. 43, no. 7, pp. 231-231

Carlos Jared et al. Venomous Frogs Use Heads as Weapons. Current Biology, published online August 06, 2015; doi: 10.1016/j.cub.2015.06.061

Mendes, V.A., Barbaro, K.C., Sciani, J.M., Vassão, R.C., Pimenta, D.C., Jared, C. & Antoniazzi, M.M. 2016, "The cutaneous secretion of the casque-headed tree frog Corythomantis greeningi: Biochemical characterization and some biological effects", Toxicon, vol. 122, pp. 133-141.

Picture references

http://www.sci-news.com/biology/science-venomous-frogs-corythomantis-greeningi-aparasphenodon-brunoi-03105.html

https://en.wikipedia.org/wiki/Iberian_ribbed_newt

Vertebrates: Mammals

Welcome back to evolution of venom, in today’s blog topic, we will be covering mammals that use venom. A brief recap: we covered other venomous lizards and how they use venom.

 

Studies on venomous mammals are rare as many mammals do not use venom or have lost the ability to use or develop venom over the course of their evolution.

Shrews are small mole-like mammals that belong to the family Soricidae, Order Eulipotyphla. Shrews are about the size of a mouse, but are closely related to hedgehogs and moles and are the only mammals (besides vampire bats) to produce venomous saliva. They feed on insects and seed, but some have specialized in hunting in the water, living in snow, climbing trees, and living underground. Some species of shrews have developed venomous saliva from the saliva glands in their body, causing bites from the shrew can cause a paralysing effect on insects, snails and small mammals, but has little effect on humans unless they are allergies to shrew bites (Ligabue-Braun et al, 2012). Below is a picture of a Southern short-tailed shrew (Blarina brevicauda).

By Unknown

 

Platypus (Ornithorhynchus anatinus) is a semi-aquatic egg laying mammal that belongs to the family Ornithorhynchidae, Order Monotremata (sometime called Monotremes). Their appearance of a duck-billed, beaver-tailed, otter-footed mammal is unusual and baffled scientists when they first encountered it. Both female and male platypuses have spurs on their hind legs, but females lose their spurs during development (Whittington et al, 2010). The spurs on the male platypus are connected to venom-producing crural glands, forming a crural system. When attacked by another animal, the hind legs of the platypus are driven towards each other, causing the flesh of the attacking animal to be caught in-between the hind legs and receives venom from the spurs by repeated jabs. Venom from a platypus is not fatal toward humans, but can cause extreme amount to pain (Ligabue-Braun et al, 2012). Below is a picture of a platypus.

 

By Klaus - Flickr: Wild Platypus 4, CC BY-SA 2.0

 

Common vampire bat (Desmodus rotundus) is a small, leaf nose bat that belong to the family Phyllostomidae, Order Chiroptera. The Common vampire bat is a hematophagous specialist which means that they feed of the blood of other animals. They are one of the most social species of bats where males defending groups of females, bringing back food for the ones that miss out on feeding (mostly nursing mothers), and participate in social grooming. The Common vampire bat venomous saliva contains anticoagulant properties that prevent blood from clotting when feeding, a bat will find a host to feed (when they are asleep) and make a small incision with it teeth (causing no pain to the host) allowing the saliva to prevent blood from clotting and allowing the bat to drink until it is full. The saliva is not fatal to most animals, expect for chickens that may die of haemorrhage (Ligabue-Braun et al, 2012). Below is a picture of a common vampire bat.

 

Picture taken at Sangayan Island, Paracas National Reserve, Departamento Ica, Peru, in March 2005

 

In next week’s post, we will be covering amphibians that use venom. Below are the articles that were used in this week’s post.  

 

 

References

 

Ligabue-Braun, R., Verli, H. & Carlini, C.R. 2012, "Venomous mammals: A review", Toxicon, vol. 59, no. 7-8, pp. 680-695.

 

Whittington, C.M., Papenfuss, A.T., Locke, D.P., Mardis, E.R., Wilson, R.K., Abubucker, S., Mitreva, M., Wong, E.S.W., Hsu, A.L., Kuchel, P.W., Belov, K. & Warren, W.C. 2010, "Novel venom gene discovery in the platypus", Genome Biology, vol. 11, no. 9, pp. R95-R95

 

Picture references

https://upload.wikimedia.org/wikipedia/commons/e/e0/Wild_Platypus_4.jpg

https://upload.wikimedia.org/wikipedia/commons/d/d4/Southern_short-tailed_shrew.jpg

https://upload.wikimedia.org/wikipedia/commons/3/3f/Desmodus.jpg

 

 

Vertebrates: Venomous Lizards

Welcome back to evolution of venom, in today’s blog topic, we will be coving other reptiles that use venom. A brief recap: we covered on what vertebrates are, what are snakes and how they use their venom.

 

Venomous lizards are restricted to two species, the Gila Monster (Heloderma suspectum) and the Mexican beaded lizard (Heloderma horridum). The Gila Monster is a heavy, slow moving lizard and is the only venomous lizard in the United States. The Mexican beaded lizard is slightly larger than the Gila Monster and is found in Mexico. Both species are Helodermatids, which are large, stout- bodied lizard with short legs designed for digging and they have a large head with powerful jaws (West et al, 2014).

 

The venom glands are located in the lower jaw with enlarged, grooved teeth located above the glands. Their jaws are designed to bite on to their prey and maintain a vice grip on the prey. Their venom is mainly for defensive purpose and human deaths are rare, the venom mostly causes a drop in blood pressure causing hypotensive shock (West et al, 2014). Below are 2 images on what each lizard looks like.

Gila Monster (Heloderma suspectum)

By I, Blueag9, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2292282

Mexican beaded lizard (Heloderma horridum)

By David Rubin - originally posted to Flickr as 00254-20.07.2007-Zoo, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=8350359

 

Komodo dragons (Varanus komodoensis) are the world’s largest lizard weighing up to 90 kg and a length of 3 m. It is found on five small islands in Eastern Indonesia. Komodo dragon’s saliva contain bacteria that can cause sepsis and infection allowing the Komodo dragon to follow the weaken prey until they collapsed and died from their infection. There is a debate on if the Komodo dragon’s saliva is venomous or not (Bull, 2010).

 

Komodo dragon (Varanus komodoensis)

By Mark Dumont - Flickr: There Be Dragons, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=25935468

 

 

In next week blog, we will be covering mammals that use venom, below are the articles that were used in this week's blog.

 

References

Bull, J.J., Jessop, T.S. & Whiteley, M. 2010, "Deathly drool: evolutionary and ecological basis of septic bacteria in Komodo dragon mouths", PloS one, vol. 5, no. 6, pp. e11097

 

West, G., Heard, D. & Caulkett, N. 2014, "Venomous Reptile Restraint and Handling" in John Wiley & Sons, Inc, Hoboken, NJ, USA, pp. 337-350.

 

Picture references

https://en.wikipedia.org/wiki/Komodo_dragon#/media/File:Komodo_dragon_with_tongue.jpg

https://en.wikipedia.org/wiki/Mexican_beaded_lizard#/media/File:Heloderma_horridum_-Zurich_Zoo-8a.jpg

https://en.wikipedia.org/wiki/Gila_monster#/media/File:Gila_monster2.JPG

 

 

 

 

 

 

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

 

 

Invertebrates:bees, wasps, centipedes and moths

Welcome back to evolution of venom, Today’s blog topic, we will be covering bees, wasps, centipedes and moths and how they use their venom. A brief recap: we covered cone snails, jellyfish, and sea urchins and how they use their venom.

Bees are flying insects that belong to the order Hymenoptera, superfamily Apoidea that produces honey and beeswax, they are known for their role in pollination and live mostly in large colonies (Danforth et al, 2006). Bee venom comes from the poison gland that contains a variety of toxins and chemicals, bee stings are dangerous to both humans and bees as the stinger that introduces the venom into the human’s system is torn from the abdomen causing the death of the bee. Some humans can have a severe reaction to bee venom causing shock and death (Warrell, 2015). Below is a diagram of a honey bee. 

Diagram of honeybee by exploringnature

 

Wasps are another flying insect that belongs to the order Hymenoptera, but belongs to the family Vespoidea. A majority of wasps are carnivores, feeding on grubs, spiders, and other insects. Many species of wasps live in solitary but they can live in social colonies with a queen, workers and drones with the worker wasps been sterile. Unlike bees who died after losing their stinger, wasps can use their stinger repeatedly (Wasps, 2017). Below is a diagram of a sterile worker wasp.

By WikipedianProlific at the English language Wikipedia, CC BY-SA 3.0.

 

Centipedes are arthropods belonging to the class Chilopoda, Phylum Arthropoda. Their body is made up of a flattened head with a trunk composed of segments (somites). The head has long antennas, jaws and two pairs of maxillae used for food handling. The appendages on the trunks first segment has claws that have been modified to allow poison glands to deliver venom to stun or kill prey (Centipedes, 2017). Below is a diagram of a centipede.

 

Diagram of a centipede by enchantedlearning.

 

Moths belong to the order Lepidoptera (same as butterflies), although most moths are not venomous, two families (Megalopygidae and Saturniidae) have had human deaths by these moths. The Lonomia obliqua (Giant silkworm moth) larval form has spines with venom that when broken, the venom enters the bloodstream causing mild nausea, burning pain and headache, then progresses to haematuria, bleeding from scars, and severe haemorrhagic syndrome (Spadacci-Morena, 2006). Below is a diagram of a Lonomia obliqua larval.

By Centro de Informações Toxicológicas de Santa Catarina

 

In next weeks’ blog, we be covering vertebrates that use venom. Below are the articles used in this week’s blog for more reading about these animals.

 

References 

Centipede. (2017). In P. Lagasse, & Columbia University, The Columbia encyclopedia (7th ed.). New York, NY: Columbia University Press.

Danforth, B.N., Sipes, S., Fang, J. & Brady, S.G. 2006, "The History of Early Bee Diversification Based on Five Genes Plus Morphology", Proceedings of the National Academy of Sciences of the United States of America, vol. 103, no. 41, pp. 15118-15123.

Spadacci-Morena, D.D., Soares, M.A.M., Moraes, R.H.P., Sano-Martins, I.S. & Sciani, J.M. 2016, "The urticating apparatus in the caterpillar of Lonomia obliqua (Lepidoptera: Saturniidae)", Toxicon : official journal of the International Society on Toxinology, vol. 119, pp. 218-224.

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

Wasp. (2017). In P. Lagasse & Columbia University, The Columbia encyclopedia. (7th ed.).

Picture references

https://www.exploringnature.org/db/view/Honeybee

https://upload.wikimedia.org/wikipedia/commons/b/bd/Wasp_morphology.png

http://www.enchantedlearning.com/subjects/invertebrates/arthropod/Centipede.shtml

https://en.wikipedia.org/wiki/Lonomia_obliqua#/media/File:Lonomia-obliqua-citsc-1.jpg

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Invertebrates: cone snails, jellyfish, and sea urchins

Welcome back to evolution of venom, Today’s blog topic, we will be covering the cone snail, jellyfish and sea urchins and how they use their venom.

Cone snails are marine gastropods belong to the family Conidae that prey on worms, molluscs and fish. Cone snails hunt by using their siphon to track prey, they use their proboscis to shoot a radula tooth to inject venom in the prey. They prey is immediate paralysed, allowing the snail to swallow the prey whole (Dutertre et al, 2014). Below is a diagram of a cone snail and how they hunt fish.

Anatomy of a cone snail and their hunting strategy by Ocean’s treasure  

Jellyfish are soft-bodied invertebrates that belong to the phylum Cnidaria, they mostly feed on small fish and prawns. Jellyfish float in the water and rely on their venomous tentacles to catch prey or defend themselves from other predators (Warrell, 2015). The tentacles have over a million sting capsules that when they come into contact with prey, they release small harpoons into the prey and bring it closer to them to eat (Junghanss & Bodio, 2006). Below is a diagram of a box sea jelly.

Anatomy of a box sea jelly by Ocean’s treasure 

Sea urchins are spiny echinoderms that belong to the class Echinoidea. Their shells are round and spiny, with the spines and tube feet helping them move across the ocean floor. Sea urchins mostly feed on algae, but will feed on slow moving animals. Their venom comes from their spines that when threatened or step on, the spines become embedded in the skin, causing extreme pain (Warrell, 2015). Below is a diagram of a sea urchin.

Anatomy of a sea urchin by Ocean’s treasure 

 

Next week blog, we will be covering bee’s, wasps, centipedes and moths that use venom. Below the articles used in this week blog for more reading at their venom.

 

Article references

Dutertre, S., Jin, A., Alewood, P. & Lewis, R. 2014, "Intraspecific variations in Conus geographus defence-evoked venom and estimation of the human lethal dose", TOXICON, vol. 91, pp. 135-144

 

Dutertre, S., Jin, A., Vetter, I., Hamilton, B., Sunagar, K., Lavergne, V., Dutertre, V., Fry, B., Antunes, A., Venter, D., Alewood, P. & Lewis, R. 2014, "Evolution of separate predation- and defence-evoked venoms in carnivorous cone snails", NATURE COMMUNICATIONS, vol. 5, no. 3521, pp. 3521-9

 

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

 

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

 

Picture references

http://otlibrary.com/conus-snail/

http://otlibrary.com/box-sea-jelly/

http://otlibrary.com/sea-urchin/