Tuesday, August 31, 2010

Slime star


This is Pteraster tesselatus, commonly known as a slime star. As its name implies, when disturbed this star can produce copious amounts of slime, which may protect it from predators [1]. It eats sponges and the like and lives in the colder waters off the west coast of the US.

It also has an interesting feature common to many members of its family. It has a 'brood pouch'. The surface that you see is actually a soft covering which covers the true surface of the sea star. In other members of the family, females will release their eggs from their gonopores (like all other sea stars), but retain them under that covering until they develop into juvenile sea stars and crawl out. In this particular species, they do not brood their young, and instead send them shooting out of the osculum, an opening in the covering. The osculum is generally used for exchanging water from the water vascular system to the outside, and can be seen opening and closing even in individuals who are not spawning.

4 comments:

Limey said...

I suppose it's non-scientific to say this star is so cute!

Von said...

Well that is amazing!!I always thought these were starfish.We have them here in South Australia..please correct me if I'm wrongI haven't been up close and personal with one for a while.
I'm posting a link, hope that's ok as I enjouyed it so much! Love this blog.

jabblog said...

Some creature have no maternal instinct whatsoever ;-)

Brine Queen said...

@Von:

Sea star is the new 'PC' term for starfish. It was thought that since sea stars were not fish it would be incorrect to say starfish. Personally, I use whichever term takes my fancy that day.