Wednesday 25 April 2012

Basket Star

Image: Nick Hobgood
What on Earth is going on here? There must be a million creatures in there! Or at least one of those crazy corals that are actually composed of millions of creatures.

Nope. This is one, solitary Basket Star. She looks hungry!

Image: Derek Keats via Flickr
Basket Stars are a group of exceedingly peculiar Brittle Stars. If you thought Brittle Stars were like strange starfish, well... it only gets stranger.

Image: NOAA
You get your colours where you can in the deep sea
They're found all over the world, but most of them live in the deep sea. The world's biggest Brittle Star is actually a Basket Star. It reaches 70 cm across when you include the arms, 14 cm if you only count the central disc.

They're in the order Euryalida, same as the Snake Stars we saw before. It's up to you whether Snakes are simplified Baskets or Baskets are complicated Snakes. Either way it all looks pretty complicated, so what's actually going on here?

Image: Ria Tan,
Basket Star have 5 arms sprouting from their central disc, same as any Brittle Star. But madness immediately ensues. Each arm branches out over and over and over again until you end up with a kind of mesh, the basket. These are incredibly flexible tendrils, just like the Snake Star's unbranched arms.

One interesting thing is that Basket Stars have a covering of leathery skin on their arms. If you happen to be a heartless monster, you could tear it off and expose the vertebrae-like ossicles beneath.

Image: NOAA
Hanging out on a good ol' Sea Fan
So they crawl up a sponge or coral, or maybe just rest on the ground. Whatever they need to get an adequate current.

Image: Derek Keats via Flickr
Unfurling that ridiculous kerfuffle of arms forms the basket so they can catch their prey. Some of them eat plankton, others will grab hold of small crustaceans and coil their tendrils around them in a horror movie sort of way.

Image: Ed Bierman via Flickr
Look closely and you can see the tiny hooks
The arms are... armed... with spines and hooks which look seriously nasty close up. Along with the tube feet and mucus (nature's WD-40), they ferry food along to the mouth in the central disc. Still a horror movie.

If the current is too much for them they'll curl up to avoid getting swept away. The ones that live in shallower depths also do that during the day, because they only come out at night. Just like a horror movie. Also...

Image: prilfish via Flickr
Sometimes they look like a pile of unwanted viscera as they snooze their coiled and curled days away. It's just like a horror movie!

Image: owenwangensteen via Flickr
Searching for the stars
But then you see them in a different light and leathery skin turns to silk and the arms become ivy and ferns in the darkness of night. These creatures are an amazing mixture of delicate beauty and obnoxious fleshiness. Just like humans, it all depends on what time of day you find them.


TexWisGirl said...

like a mass of roots on a vegetable. :)

Emily said...

I love Ernst Haeckel's illustration of a basket star-- it really captures both their beauty and their grotesquery:

Joseph JG said...

@TexWisGirl: They're amazing! It's true they don't look like something from the sea. Until you see them properly and then they couldn't come from anywhere else.

@Emily: That's fantastic! With Haekel's stuff around, surely monster concept artists have half their work done for them. Also I shall have to start using the word "grotesquery"!

Crunchy said...

What a mess! Looks like you ought to store these guys in a basket CASE! Eh? Eh?

Joseph JG said...

Hahaha! You're worse than me!

Keiki4Kupuna said...

The wonders of our beautiful oceans...

Joseph JG said...

So true!

Unknown said...

this is so cool most people just over look the star fish but when you look at them up close there amazing. and i love your pun lol.

Joseph JG said...

A lot of things are amazing when you look up close! Even amazing things are even more amazing when you really look!

Unknown said...

They are amazing. When I had my saltwater tank I would talk the pet shops into giving me the tenticles that would fall off. They thought they would die but they grew.