LongSpine Blue Dot & Blue Dot Fire Urchin

[reefwisher]

I like to know if anyone has any expierence with these 2 urchins that Live Aquaria sell? They are the Blue Dot Long Spine (astropyga radiata) and the Blue Dot Fire urchin on Diver Den. I believe they call it that, can't remember the first part of the name but the second part is Varium. Thanks

[sacremon]

Asthenosoma varium. I have one, which I got from Diver's Den. I also had an astropyga radiata that grew rather quickly then died. I wasn't keeping a close eye on the Mg levels in the tank, and they had gotten too low for it, I think.

The A. radiata is out during the day and quite active, which is rare for urchins. It would monopolize the rock I tied nori to for the tangs/rabbit that I had to add a second rock for them.

The A. varium is a typical nocturnal urchin. The interesting thing about them is that the plates of their test are not fused, so they are flatter and can bend to get into spaces.

[reefwisher]

Thanks for the info. I did'nt know Mg plays a role in keeping urchins. What should the Mg levels be? I am kind of leaning on getting the Asthenosoma Varium, look like they are more colorful ,is this true? Then again I would like to get both of them.

[sacremon]

Keep Mg at 1300 or so. Urchins are very sensitive to water conditions.

They are both colorful in their own ways, but I do prefer the A. varium for their color. I just wish it wouldn't keep eating all the sponges that grow in the tank.

[reefwisher]

I have a pencil urchin and a blue tuxedo. Both are in a 75 gal fowlr tank. Did'nt realize the pencil was a carnivore until i read up on it. Tried feeding it krill one night, he would'nt eat it but will eat algae sheets. He did lose around 4-5 spines, but grew up new ones. Been reading up on sea urchins. I knew they were sensitive to water conditions but not that sensitive.