What is this blob?

Mbossy · Sep 16, 2023

Came in on some feather caulerpa. Can anyone id this blob? It is very small but moves around the tank.

blaxsun · Sep 16, 2023

My best guess would be some kind of nudibranch.

Alexraptor · Sep 16, 2023

Hard to say from those pictures, but maybe some sort of Sea Hare?

Mbossy · Sep 16, 2023

Ok I think it's a brittle star that has had a very bad day. By the way it's moving in the video I got tonight it no l longer looks like it has symmetrical sides.

JoJosReef · Sep 16, 2023

Following. Super interesting. @ISpeakForTheSeas @EeyoreIsMySpiritAnimal seen this one yet?

EeyoreIsMySpiritAnimal · Sep 17, 2023

Mbossy said:
Ok I think it's a brittle star that has had a very bad day. By the way it's moving in the video I got tonight it no l longer looks like it has symmetrical sides.

Do you mean Asterina? That definitely not a brittle star. Doesn't resemble any asterina I've ever seen either...

Hopefully @ISpeakForTheSeas will have a better idea.

Shon · Sep 17, 2023

That's neat. Looks like a Frankenstein project of a sea pansy crossed with sea cucumber.

Alexraptor · Sep 17, 2023

Mbossy said:
Ok I think it's a brittle star that has had a very bad day. By the way it's moving in the video I got tonight it no l longer looks like it has symmetrical sides.

Ok now that it's in motion I'm pretty certain that is an arm from an asterina. They are able to reproduce asexually by splitting off. And from the looks of it, it's already regenerating a new body.

ISpeakForTheSeas · Sep 17, 2023

EeyoreIsMySpiritAnimal said:
Do you mean Asterina? That definitely not a brittle star. Doesn't resemble any asterina I've ever seen either...

Hopefully @ISpeakForTheSeas will have a better idea.

Honestly, I'm inclined to think it's an Aquilonastra ("Asterina") species too, though I don't think it'll be possible to tell which one until it's regrown some more.

It's definitely a very small starfish (Asteroid) - you can see the tube feet in the video there at the tip of that leg by the bottom/left side of the video - and it's clearly regenerating into a new starfish; so, while it's possible that it's another kind of tiny, fissiparous starfish, my guess would be Aquilonastra at this point.