Someone killed my urchin, and I can't figure out who.

[HotManwich]

About two weeks ago I put a blue tux urchin in the tank. It was active, constantly crawling and exploring until about three days ago when it started acting a lot more lethargic and sitting in the same place for a few days. This morning I wake up and its aristotles lantern has been ripped out and laying next to it, with nothing having eaten its insides either.
The only fish in the tank are two banggai cardinals, a percula clown, a royal gramma, a lubbocks fairy wrasse, and a neon goby. In the days leading up to its death I never saw a single fish take notice of it, let along peck at or annoy it. What do you think could have killed it? I'm heartbroken since it was such an adorable creature and a loss of life.

 

[nereefpat]

Bummer.

My guess is that it wasn't a 'someone,' but that it's death was caused by something other than a fish.

 

[El_Guapo13]

You sure it was killed by one of the other tank inhabitants? How are your water parameters?

 

[HotManwich]

You sure it was killed by one of the other tank inhabitants? How are your water parameters?

No ammonia or nitrites, low nitrates (5), 1.025 salinity, temp 78

I don't know how it would be eviscerated like that without having something pull its mouth out. Also I forgot to mention two skunk cleaner shrimps, and I just added one last night.

 

[Jesterrace]

The only thing on that list I could see is the Percula clown might have taken exception to it venturing into it's staked out turf. I have heard of clowns murdering hermit crabs that venture into their set turf. The next question would be what inverts do you have in there and are you using actual live rock or dry rock?

 

[Greg P]

It's possible it just died and you're seeing the aftermath.
Fish, shrimps and crabs will quickly pull apart dead critters

 

[HotManwich]

The only thing on that list I could see is the Percula clown might have taken exception to it venturing into it's staked out turf. I have heard of clowns murdering hermit crabs that venture into their set turf. The next question would be what inverts do you have in there and are you using actual live rock or dry rock?

The clown is totally nonterritorial and doesn't have anywhere to defend.
I am using live rock, and other than a billion stomatella snails and a couple aptaisia that I'm dealing with I haven't seen anything at all out of the ordinary at night.

 

[Tahoe61]

The Urchin may have been compromised pior to purchase. If you do not have sufficient coralline algae or supplement feedings starvation can set in.

 

[HotManwich]

The Urchin may have been compromised pior to purchase. If you do not have sufficient coralline algae or supplement feedings starvation can set in.

I have a ton of macro and coralline algae in the tank, he didn't even make a dent in it.

 

[nereefpat]

Inverts can be touchy. It could have been doomed before it even went to your tank. Capture, shipping to wholesaler, acclimation to wholesaler, shipping to fish store, acclimation at fish store, acclimation to your tank.

Don't sweat it too much.

 

[HotManwich]

Inverts can be touchy. It could have been doomed before it even went to your tank. Capture, shipping to wholesaler, acclimation to wholesaler, shipping to fish store, acclimation at fish store, acclimation to your tank.

Don't sweat it too much.

Yeah true. I just find it such an odd way to die with its guts pulled out.
This is my only real loss other than my firefish who swam into the rock flower and got devoured so I'd like to know what happened!

 

[jda]

I don't know how, but the urchin probably died and then the fish and invert were there for a free meal.

It was not likely old age since I once read that they can live for 100 to 200 years, but they are very sensitive to nitrate, phosphate and ammonia. They also need a lot to eat, but they can eat coralline if you run out of "soft" algae.