pin cushion urchin

1 diamond goby (stays low in my tank) and 2 purple pincushion urchins, free to good home -- Pasadena 91105 almost Free ($1) to a good home. The diamond goby is a good citizen and stays close to the bottom without creating sand storm. His burrow though is getting larger and he's burying the...

Urchin decided to put down the empty shells and put on something a bit more colorful! Let’s see those cool urchin hats!

My pincushion sea urchin has been going strong for a month. Carrying hats moving all over the tank. today I found him upside down. His feeler things are still there. He won’t stick to the glass. see video - https://youtube.com/shorts/slbrkj58fYE?feature=share

I've heard that pincushion and tuxedo urchins will starfish. Has anyone experienced that, or is it safe to keep both in the tank at the same time?

I have a maroon hermit crab (I believe that is what he is) and a pincushion urchin in the same tank. My urchin is very dear to me and the crab is killing the urchin. He will go up to the urchin and rip his small tentacles and lots of spines off. I stop this whenever I see it, but my urchin has...

I live in an apartment in a city and manager lady told me I could only have a small fish tank... I think she meant something more like a 2 gal betta tank... *awkward laugh* Anyways, after a lot of research online I decided to go with a Fluval Evo 13.5 tank. There was a lot of debate in my head...

My LFS had a sale on purple pincushion urchins and said they are the same as my tuxedo urchin so could share a tank? Is this correct or am I being given bad information, wouldn't be the first time, I really like urchins so I would like to have both but is it possible?

They would be unstoppable and the perfect algae control. Unfortunately, one of mine spends entirely too much time lost on the glass... The time it is "working" on the rocks, it has made a amazing difference! Just a week ago ALL of my rocks were covered in this...whatever collection of algae...

Hello! I have two urchins, a pincushion and a tuxedo. Recently, one of them started getting these white balloon like balls coming out of it. Can anyone identify what they are? Pictures attached

I have an urchin that came in as a hitchhiker which might be a pin cushion urchin. She's been increasingly active lately and I'm concerned she might not be getting enough food. I offered her some Nori but she doesn't want it. I found an estimate that they can reach eight inches but the same site...