Short spine urchin gone missing

[peterat33rpm]

I got a short spine urchin 3 days ago and put him in my 32 gallon tank. I saw him the next morning but haven’t seen him since. It’s obviously not a very big tank so I’d be surprised if he’s just hiding really well, but is that possible? Will they burrow under the sand? There are no spines around the tank to suggest he was killed but is that possible? Stock is two clowns, bengai, firefish, flame tail blenny, emerald crab, turbo snail, handful of other snails and hermits, and a conch. If he’s dead, would that cause a big spike and crash the rank like a dead nem?

 

[ISpeakForTheSeas]

I got a short spine urchin 3 days ago and put him in my 32 gallon tank. I saw him the next morning but haven’t seen him since. It’s obviously not a very big tank so I’d be surprised if he’s just hiding really well, but is that possible? Will they burrow under the sand? There are no spines around the tank to suggest he was killed but is that possible? Stock is two clowns, bengai, firefish, flame tail blenny, emerald crab, turbo snail, handful of other snails and hermits, and a conch. If he’s dead, would that cause a big spike and crash the rank like a dead nem?

Just from a quick glance, that looks like a rock-boring urchin of some variety rather than a standard short-spine/pincushion (pincushions have tiny, needle-like spines; pencil urchins have thick, rounded spines; rock-borers have more of a middle-ground spine where it's kind of thick, but not as thick as the pencil urchin spines). I'd check around the rockwork of the tank, and I'd probably expect it to pop up within the next few days.

None of your livestock should bother the urchin at all. I personally wouldn't expect it to cause a meaningful ammonia spike if it dies/is dead.

 

[peterat33rpm]

Ok I thought short spine = rock boring urchin. I’ll just keep an eye out I guess. I’d see spines around the tank if it died surely? I also haven’t seen it on the floor around the tank but the only other possibility is it got out and a dog got to it

 

[ISpeakForTheSeas]

I’d see spines around the tank if it died surely?

Unless it dies somewhere very sheltered/out of view, I would expect to see some dropped spines, yes.

 

[peterat33rpm]

Update - daughter demanded a bottle at 2:30 am last night and on my way I took a peak in the tank and guess who was sitting there on the rocks plain as day. I’m just glad I’m not going crazy and he didn’t vanish into thin air. Couldn’t find him again this morning so he has a very good hiding spot somewhere