Sunday, 16 February 2014

Blind Snake

Image: Jonathan Hakim
Desert Blind Snake (Leptotyphlops humilis cahuilae)
There are two kinds of snake in the world: Blind Snakes and "other".

"Other" is all the ones who belong to the superfamily Alethinophidia, which means "true snake". It contains all your fangs and venom, your spitting and constricting, your swimming and climbing... you know, snakes! The ones who encircle the world, flee from naked men and were on a plane that time. Snakey snakes.

The other superfamily is Scolecophidia, which means "worm snake". These are the Blind Snakes. It's not sounding good for them, being a snake that's blind, a bit like a worm and, as it happens, completely non-venomous. Then again, they're still here while a whole assortment of other Ophidians have long died out. Also, actual blind worms seem to do alright for themselves so let's not underestimate them.

Image: Tarique Sani
Beaked Blind Snake (Rhinotyphlops acutus)
Like some others, it has pointy scale to help with burrowing
Blind Snakes live life more like an earthworm than your usual snake. They spend the majority of their time underground, worming their way through soft soil. Smooth, shiny scales minimise friction, while transparent scales cover and protect their eyes as they seek out termites and ants to feed on.

They're not totally and completely blind, but they can only tell light from dark. Since they're burrowers, darkness is safe and homely while light is dangerous and foreign (controversy!). This humble lifestyle has garnered them great success. There are over 300 species of Blind Snake in the world, and they can be found all over the tropics.

Image: Arno Meintjes
Schlegel's Beaked Blind Snake (Rhinotyphlops schlegelii), a giant at 1 metre long!
In terms of size, Blind Snakes are no match for the true snakes or even true (earth)worms. The biggest Blind Snakes, like Schlegel's Beaked Blind Snake, reach up to 1 metre long (3.3 feet). And that's three times longer than most others.

Image: Smithsonian Institution, National Museum of Natural History
Barbados Threadsnake (Tetracheilostoma carlae), a tiddler at 10 cm long!
They win gold on the other side of the scale, though. The smallest known snake in the world is the Barbados Threadsnake at 10 cm (4 inches) long!

Wait a minute... thread? They've gone from blind worms to a bit of thread? I snap thread! I twist and twirl thread! I am extremely cruel to thread. It's one of the reasons I'm not allowed political power; first they snap thread then they snap people.


I've always been denied the opportunity to starve my thread to death because they never seem to be hungry. Blind Snakes on the other hand, have a much bigger appetite. They also have really weird jaws, which I find difficult to fully understand since I don't know much about the medial process of the palatine or the posterolateral edge of the vomer.

Still, I do know that what they do has been called "maxilliary (or mandibular) raking", but there are two very different ways of doing it.

Image: Bill & Mark Bell
Long-beaked Blind Snake (Ramphotyphlops grypus) an (exceptionally snuggly) Tylophid
So! You have your Tylophids or Long-tailed Blind Snakes, a family of over 200 species found all over the tropical world. They have no teeth in their lower jaw. The teeth in their upper jaw are attached to two separate bones, the maxillae, and these maxillae are attached to the rest of the skull by flexible joints.

The teeth are arranged across the skull, more like our front teeth than our back teeth. So when the maxillae are kind of flapped forward and back, the teeth on the end rake in ants, termites and grubs.

Image: Instituto Nacional de Biodiversidad
Helminthophis frontalis, an Anomalepid and redhead!
A much smaller group of Blind Snakes have a very similar system. These are the Anomalepids, or Dawn Blind Snakes. There are only 15 species, all in tropical America, but what they do have which the Tylophids don't is a single tooth on their lower jaw. Take that!

Image: Omid Mozaffari
Myriopholis macrorhyncha, a Leptotyphlopid, demonstrates why they're called Threadsnakes
The other big group is Leptotyphlopidae or Slender Blind Snakes, with 87 species found all over the place. They have no teeth in their upper jaw. This time it's a pair of dentary bones on the lower jaw that has all the teeth but while our lower jaw is one giant bone, for Blind Snakes the dentary bone is only the tip of the lower jaw. So again, they can be rapidly flapped forward and back like an exceptionally dangerous limp wrist to pull in their subterranean prey.

Blind Snakes have done well with their weird, flappy jaws, but one in particular is in the process of TAKING OVER THE WORLD.

Image: Vivek Sharma
Brahminy Blind Snake (Ramphotyphlops braminus), world's most widespread snake!
It's the Brahminy Blind Snake. Thought to have originated in India or Southeast Asia, this most intrepid of serpents now has a patchy distribution across all the warmer parts of the globe! Two things are helping them in their domination of the world...

One, no males. Things are so much easier with no males! No fighting, no courting, no sexual tension, no sex... Ah! Bliss! Every Brahminy Blind Snake that has ever been discovered has been a female, and wherever she goes she can always lay a clutch of eggs that will hatch into tiny snakes about half a centimetre long each. A unisex population like this is very rare among vertebrates, and there's only one other snake which may be in the same situation.


Video: globalzoo
It has no teeth in its lower jaw!

The other help is their habit of nestling underground among the roots of plants. If that plant happens to be bound for someone's garden on the other side of the world, they'll go right along with it. And lay some eggs! This is why it's also known as the Flowerpot Snake. Such a whimsical name for a conqueror!

What would've happened if Genghis Khan was called Geoffrey Flowerpot? Would the word "flowerpot" acquire an exciting aura of menace and violence?

Finally... those "true snakes"... just how "true" are they?

Image: Bill & Mark Bell
Handle the truth!
We've already seen how there are many lizards who are even now losing their legs like so much annoyingly sticky-out dead weight as they take to a life burrowing underground. It has long been thought that this could be exactly what happened to snakes during the Cretaceous Period.

Another idea suggests it happened as an adaptation to life swimming in the sea, but recent fossil discoveries lend weight to the burrowing lizard hypothesis.

Perhaps after all it's your vipers and cobras and pythons who are the oddities, the strange, devious rebels who disregard the ways of their ancestors. Perhaps it's the Blind Snakes who continue in the tradition of their elders. Maybe they're the true snakes.

3 comments:

TexWisGirl said...

one sex sure eliminates a lot of issues! :) they sure are cute, too!

Crunchy said...

All glory to Myriopholi, lord of earthworms!

Joseph Jameson-Gould said...

@TexWisGirl: Down with sex!

@Crunchy: There must be a whole royal family of earthworms by now!

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