Is it normal for a Brittle Star to have more than 5 limbs?

[chammergren]

I had a red fancy brittle star climb out of a coral frag I picked up a couple of weeks ago. He survived the dip unseen and didn't come out of the coral on the frag until the next day when I was feeding my tank. When it did come out he had only one and a half limbs left but the central body was fully in tact.

Over the past couple of weeks I noticed it had been sticking a limb out from a crack in the rock every time I was feeding the tank so I would put a tiny fragment of mysis near the crack for it to grab and pull in. A few days ago it finally emerged fully from the crack and has 7 limbs. Is that normal when they are regenerating limbs for there to be a couple of extra by mistake?

I am very new to the saltwater aquarium hobby so I apologize if this is a dumb question.

 

[Betta132]

It's not exactly normal, but it can happen, it's not too rare, and it's not harmful. He'll be perfectly fine like that, although the limbs may not quite develop to full size.
Occasionally happens to lizards, too. They can grow back a forked tail accidentally.
Cool little brittle, either way. How large is it? Has it grown at all?

 

[chammergren]

He is pretty small, I would say 2 inches across tops if his limbs are fully stretched out. His central body is a little smaller circumference wise than an eraser on a #2 pencil.

Having said that, he has definitely grown since I first saw him. Not only has he added the extra limbs but the three longer limbs he has are all wider and longer than both of the limbs he had when I first saw him.

 

[pagojoe]

Some species (almost) always have six arms.

http://calphotos.berkeley.edu/cgi/img_query?enlarge=4444+4444+0113+2498