sea urchins, good or bad for reef tank?

[fungia]

my lfs recommends me to buy some sea urchins to attack my algae. are they good for reef tanks? what are the pluses and minuses? any urchin i should get or avoid? thanks.

 

[Anonymous]

What sort of algae problems are you having?

 

[fungia]

i have all sorts of algae right now. it isnt too bad but it is always around so i want something to eat it. i have some short furry algae and some long ones that look almost see-thru green.

 

[fyrefysh]

I've heard that the algae eating urchins usually prefer the coralline algae over hair or macro. I would recommend some turbo snails or maybe a conch of some kind.

 

[Anonymous]

I have a Diadema (aka black longspine) urchin. It definitely attacks turf and hair algae over coralline. Every tank I move it into with algae problems gets nice purple rocks after a few weeks.

 

[Anonymous]

How big is that guy matt? I was going to get one of those but was thrown off by the bulldozing and potential large size of them. As a result went with tuxedos, still got algae, less coraline, but I do have some cool urchins who like to carry algae around on their backs... amongst other things

 

[Anonymous]

When I got it its test was about the size of a maraschino cherry. That was around a year and a half ago. It is now probably about 15" across from spine to spine, and its test is about, oh, roughly the size of a racquetball or so. It's in a 100 gallon. Most of the day it just hides in the rocks. They are actually fairly nimble around frags, although it is is wise to glue them down anyhow.

YMMV.

 

[Anonymous]

Yikes, that's what originally scared me off to the long spine. While they are nimble, I hardly notice a large one in at LFS in the coral tanks, the fact they can get almost as wide as the tank scares me.

 

[Anonymous]

Here's a shot of the 100 gallon tank my urchin is in. You can see it doesn't make much of a dent in the coralline algae. :lol: The rock towards the bottom of the pic is the last little patch of a green turf algae issue I've been battling in this tank for the last year or so. The owner had been using tap water for water changes. 8O The urchin and a tomini bristletooth tang have helped a lot. Most of the rocks look like this wall now.

 

[Anonymous]

Here's a better looking (camera phone) shot of the tank....

 

[Anonymous]

Yikes, that's what originally scared me off to the long spine. While they are nimble, I hardly notice a large one in at LFS in the coral tanks, the fact they can get almost as wide as the tank scares me.

They only come out and spread their wings at night and right before lights out IMLE. Rest of the time mine is tucked in a hole in the rockwork with its spines all folded up. In fact I usually have to search the tank a bit to find it when the lights are on.

 

[Anonymous]

Hmmm interesting. My downstairs tank doesn't have much in the way of "holes" to hide in, I wanted a more open look, and to separate three distinct types of corals (mushrooms in the middle under the brace), SPS and other stuff over on one side under a 250w MH bulb (although they'll hopefully make their way to a dedicated tank), and misc, stuff on the other side (zoos, and such) all the softer stuff. There's not much in the way of algae in that tank... my tank upstairs on the other hand.. whew boy, I think every strain of algae is in that tank, hair, turf, feather, (even have some halimeda growing!) but as soon as I setup my other tank I'm yanking everything out so don't think I'll worry about a long spine.

 

[bleedingthought]

How big of a hole does it usually need? In your urchin's case.

 

[das75]

Had some lobophora so tried both the Longspine and Tuxedo, neither one would touch the lobo but both loved the coraline. Ended up returning both, was really too bad as both rather neat animals.

 

[MartinE]

You could try a tuxedo urchin (Mespilla) they only get about 2-3" and like algae too.

 

[fungia]

thank you guys. i might try the longspine.

is the tuxedo the pincushion type? my lfs has a pink one from the atlantic.

 

[Anonymous]

The tuxedo is the "furry" kind.. they look like a fuzzy ball, occasionally you see sweeper "spines" coming out, they do like to pick things up and use it as decoration (including algae!). Don't think there is a pink version of it, I've seen red & blue.

 

[MartinE]

I was talking about the blue, or purplish one and yes it does look "furry" and the picking things up in its spines is supposed to indicate a healthy speciman.

 

[Anonymous]

I had a longspine / diadema - absolute machine for grazing algae but they grow fast! Went from golf ball to soccer ball size in 2 years and I ended up trading him off after getting jabbed one too many times (even being careful it's easy to get stabbed by the spines and they really hurt).

would love to do a tank someday just lots of mangroves with prop roots, a few diademas, some live rock and a bunch of bangaii cardinals.

 

[Anonymous]

I had a longspine / diadema - absolute machine for grazing algae but they grow fast! Went from golf ball to soccer ball size in 2 years and I ended up trading him off after getting jabbed one too many times (even being careful it's easy to get stabbed by the spines and they really hurt).

would love to do a tank someday just lots of mangroves with prop roots, a few diademas, some live rock and a bunch of bangaii cardinals.

The spines do hurt good. I think they're venomous. I found it easy to avoid them though, and they have a little give to them. They're not very sharp either. YMMV.......