Sea urchin?

[KSum89]

What kind of urchin is this? I thought all they did was eat algae.




I recently had a fish die... Got the memo to not buy a fish from PetCo a little to late. Looked like it had a swim bladder issue when i bought him and i felt sorry for it and wanted to nurse it.

$25 down the drain.. But live and learn i guess. Back to the urchin.. This morning i see the urchin all over the dead fish body.. Same spot all day/all night eating it.

I tried to get the dead fish body out but the urchin had a nice hold to it and i didnt want to hurt him so i let it be. So he seems to be a carnivore?

[KSum89]

I have about 6 hermits, 2 of them are huge and 2 nassarius Snails too.

the urchin is eating the head part of the fish. I guess the clean up crew demolished the rest, along with my tiger shrimp probably. Even seen my cleaner shrimp pick at it.

-so i know a fish dying could crash a tank, so i know to be careful with that.

[MacDracor]

Did some digging, and I cannot identify your urchin to species with certainty, but I have some likely culprits. Go ahead and google these to find pictures.
Slate pencil Sea Urchin (Heterocentrotus mammillatus)
Red sea urchin (Strongylocentrotus franciscanus)
Spiny Sea Urchin (Centrostephanus rodgersii)
Anyway, urchins can do much more than just eat algae. Some are predatory and will eat corals. Some will carry small objects around on their backs. Some are venomous. Some are known to strip Live Rock of all algae, even coralline, leaving it white and barren.
Hope this at least gives you a starting point!

[KSum89]

Thanks!

But it is weird, i googled all those species you wrote out and none of them exactly match my urchin.

I still cant get the remaining body parts of the dead fish out, he is sitting on it.. Usually the urchin is climbing up and down rocks or the glass.

[kdpuffer]

Personally not a fan of urchins, great looking and a good conversation pieces but destructive (unintentionally). They eat coralline which I like the looks of and tend to knock stuff down, the later reason cost me a beautiful metallic green torch coral.

[Jlsardina]

Looks like a longspine urchin. I've seen em go after coralline, gsp, and a couple other things. But just like fish it depends on the personality of the creature. Since its going after dead fish there may be some concern tho

[Rosesrblu1]

I believe that is a rock boring or common urchin. Pencil urchins have very thick spikes and long spines are just that, with very long needle like spikes. I have had or have all of them. They will graze on algae and if a pc of mysis or meaty food gets caught in the spikes, it will eat that too. All of mine did.

[MacDracor]

Most likely, the fish died and the urchin smelled it.

[KSum89]

Thanks guys, I got this from liveaquaria.

Thank you for contacting Drs. Foster and Smith's LiveAquaria. We are sorry to hear about the loss of your Angel fish. Comparing photos, the Urchin you have may be a Pincushion Urchin. These urchins are not known to attack live specimens. However, they are known to eat the bodies of deceased specimens. We apologize for any inconvenience this may have caused. If you have any further comments or concerns, please feel free to contact us back

[crister13]

A dead fish won't nuke a tank. A lot of people leave the fish for the cuc.

[Newfiereefer]

Originally Posted by crister13

A dead fish won't nuke a tank. A lot of people leave the fish for the cuc.

It won't nuke a tank that that is a lot of nutrients going in the tank that otherwise was not there . Usually the CUC are good for taking care before its a issue , Arrow crabs are awesome for eating dead things. I've lost one fish so far and I never once saw the body *_*

Not all urchins are that bad. I have a Blue Gobular Urchin and he only grazes on the algae on the rock ..... Yes it will eat coraline , but it's constantly moving so all I see is a light purple streak on the rock rater that a solid color ....if you rock has a lot of coraline in it already then chances are it will grow back in pretty quick. The only other thing is dose is pick up rubble from the bottom :-/ .
But that nice cobalt blue color he has is worth the munched on algae !

[carey]

I have a purple urchin and really like him. He has super cool with all the shells he picks up from the sandbed all embedded in his spines. lol

The only downside is like mentioned, they eat coralline. I started my tank and was getting a nice amount of it growing really fast in just a few weeks due to the purple rocks I added. Within a week of the urchin going in all of it was gone. :-( Now it is kinda growing on the back overflow alittle but not a spot gets a foothold on the rocks now.

[Newfiereefer]

Nice urchin Carrie !
This is my lil guy , it's a older pic since he is the worse spot ever for a pic right now, I personally done see the loss of coraline a bad thing mine is starting to get in the pest side of the spectrum since it's everywhere 0_I

[Rosesrblu1]

Does anyone ever worry that the spines from the urchins will pierce a soft coral? I would love a tuxedo urchin in my 54g reef, but have a fox coral near a rock and am planning to pick up a green cats eye bubble very soon.

Any suggestions?

[MacDracor]

Personally, I wouldn't be concerned about that unless you got a longspine urchin. Real easy for things to get poked with those. My tuxedo urchin crawls right over zooanthids, kenya tree, blastomussa, etc, and never hurts anything.

[mr_X]

Originally Posted by Rosesrblu1

Does anyone ever worry that the spines from the urchins will pierce a soft coral? I would love a tuxedo urchin in my 54g reef, but have a fox coral near a rock and am planning to pick up a green cats eye bubble very soon.

Any suggestions?

You can slice and dice a soft coral with a knife to frag it. It's not going to hurt a soft coral to get punctured.
I've never seen an urchin eat coral and they are way too slow to capture live prey. besides knocking over frags and eating coralline (nuisance algae to some) I don't see any problems with them.