Black Sea Urchin

[BantyRooster97]

So got my first shipment of new rocks from TBS & they are awesome, all kinds of life. That being said, I received 2 black sea urchins attached to the rock. I see online these things get pretty big.

How big do they get in an aquarium?
I have 2 should I get rid of 1 or both, as they grow up?
Are they destructive in the tank? Move frags, etc?

thx

 

[geddavis]

I forget their name but I see them all the time when snorkeling. the biggest one I've seen is about 2 - 2 1/2 feet. they also will move stuff around a lot. if they are small they will probably stay fairly small for a few years. also the hurt like *&%@ when touched so be careful

 

[S-t-r-e-t-c-h]

Like this?
https://www.liveaquaria.com/product/591/longspine-urchin-black?pcatid=591&c=530+591

or like this?
https://www.liveaquaria.com/product/3080/shortspine-urchin?pcatid=3080&c=530+3080

If like #1, I'd get them out. They get really big and are venomous, with a really painful sting.
If like #2, I'd leave it in the tank. Usually a good herbivore to have.

 

[geddavis]

I was thinking of the long spine.

 

[S-t-r-e-t-c-h]

I was thinking of the long spine.

Yeah, for sure. They're cool looking but I can't imagine why anyone would want one in their home aquarium...

 

[BantyRooster97]

So I might have 1 of each. Upon closer look, one has all black spines & the other has spines that are more grey/brown color. Both are about the size of a quarter right now. My tank is a 105g - 4' long, so I don't think it will be big enough for these are they get larger.

 

[BantyRooster97]

I don't usually glue my rocks together, sounds like I may need to with these in the tank... or get rid of them

 

[Gregg @ ADP]

The case for long-spined urchins is that will eat just about any algae out there, including GHA. And they’re pretty cool looking and active.

Case against: they knock a lot of stuff over, and if you have a dark background and aren’t careful reaching around, you are going to get nailed and you absolutely will not enjoy it.

I’ve seen them get really big in tanks....diameter w/spines of 12”. For a frame of reference, that’s the same as a basketball.

 

[Coralreefer1]

Black Diadema Urchins are great at removal of algae. They do not knock over corals since they are not clumsy. You wont have a problem, they are unique and fascinating and are yet just another part of the CUC.

 

[A sea K]

So got my first shipment of new rocks from TBS & they are awesome, all kinds of life. That being said, I received 2 black sea urchins attached to the rock. I see online these things get pretty big.

How big do they get in an aquarium?
I have 2 should I get rid of 1 or both, as they grow up?
Are they destructive in the tank? Move frags, etc?

thx

These are coming from the Gulf of Mexico and I know the rock boring urchins are quite prolific in Florida waters. Diadema urchins are from the Indo Pacific. Do a image search on the rock boring urchin and see if that gets a match. IME they have not been overly troublesome but they do eat coralline algae, move rock structure and upset coral so a word of caution is advised.

 

[S-t-r-e-t-c-h]

These are coming from the Gulf of Mexico and I know the rock boring urchins are quite prolific in Florida waters. Diadema urchins are from the Indo Pacific. Do a image search on the rock boring urchin and see if that gets a match. IME they have not been overly troublesome but they do eat coralline algae, move rock structure and upset coral so a word of caution is advised.

FYI, there are long spine (diadema) urchins in the caribbean too...

 

[A sea K]

FYI, there are long spine (diadema) urchins in the caribbean too...

I did not know that, always thought they were a Pacific exclusive. Born and raised on the Atlantic beaches of So Florida, have countless hours of diving and have never seen one before. Learn something new everyday I guess.

 

[cracker]

are the spines long & slender?(black long spine) Sorry if already answered. They are common in Florida waters. The spines are very sharp & will poke you & fester. They do get pretty big .& are algae eating machines. Hear they will eat corals but never saw mine do it.