Herpetology: The First Amphibian With A Venomous Bite Discovered

Amphibians, Any living creature that lives one part of its life in water and another part on the surface. Frogs are among the most known poisonous amphibians, but there never once was a discovered venomous amphibian. Until now. The first amphibian with a venomous bite. A member of the Caecilian family. Caecilians are an amphibious creature with no arms or legs but are mistaken for snakes a lot of times. They live mostly in South America and Central Africa. However, before we start dissecting a Caecilian, we must address an extremely common but relatively unknown terminology.

Venomous or Poisonous? People assume that the two terms are similar, but in fact, they are completely different. If something is venomous then it is inflicted by a bite or a slash. An example: a snake is venomous because it has to bite you in order to fill your bloodstream with toxins. If something is poisonous then your body has to absorb it in. This could happen by touching, breathing, or eating the substance.

An example: A Golden poison frog excretes a poisonous substance on its skin, if one touches it then the toxin would be absorbed into the person’s skin. [ Fun fact: A single Golden poison frog measuring two inches has enough venom to kill ten grown men.]

As noted, Don’t touch anything pretty in nature, or anything unknown. Actually, don’t touch anything without knowing what it is.

Scientists like Pedro Mailho-Fontana, who have been researching caecilians, stumbled across this discovery and studied it even more. They had found out that there were large glands in the creature’s upper jaw connecting to the teeth using ducts. This pattern usually occurs in venomous animals like snakes. Unlike the only known venomous frog, this amphibian could actually inject their toxin by biting. When Mailho-Fortana and his team of researchers looked more closely at the amphibian, they realized that there were no grooves or tubes in the teeth that could hold the venom and deduced that the Cecilian worked more like a Gila Monster than a snake. 

A snake has grooves and tubes in its teeth to hold venom from its glands. This means that the tooth itself could act as a way to store venom and a good hunting device. However, the Caecilian and the Gila monster excrete the venom around the tooth, kind of like when we gargle some of the water stays on our teeth for a bit and then leaves. Using this, we could say that Caecilians, when about to bite, excrete their venom around the tooth, so that when they bite the venom gets washed away into the victim’s or prey’s bloodstream/body. 

Kartik Sunagar, an evolutionary scientist from the Indian Institute of Bangalore says that cross-referencing and tracking the genes that turn on and turn off the oral glands with the tail poison and other tissues can give a better sense of what the oral secretions contain and whether they are unique to those glands. Soon, scientists will find out what makes this amphibian so special.

Original Blog here: https://www.sciencenews.org/article/caecilians-amphibians-venomous-bites

Good paper: https://www.cell.com/iscience/pdf/S2589-0042(20)30419-3.pdf