Something is eating my sps

[PrettyBoy]

I have been having this issue for some a month or so now. The only new addition to the tank is Cross Hatch trigger and I highly doubt it is that. Usually when I wake up in the morning for the past few weeks I see tons of SPS with snapped off tips and I dont just mean the very tip, ive seen whole frags 1-2" completely gone over night. At first it was only affecting some crappy frags or very large colonies. Now its starting to happen to some very expensive slow growing sps and Im getting annoyed. My fish stock consists of Blue devil damsels, purple tang, orange shoulder tang, copperband butterfly, black clowns, cross hatch trigger and a lawn mower blenny. Normal snails and hermit crabs, sand sifting stars and a pretty large black sea urchin (not sure what kind, just black very pointy and with an orange dot/mouth/eye on the top.

I am yet to see a culrpit actually eating the sps, I feed seaweed numerous times a week and an array of different frozen foods. The corals look like someone just snapped a frag actually very roughly, not actually even cut.

 

[ReeferNets]

Dude im pretty sure the only one out of the bunch with jaws that can grind coral is the crosshatch.

Butterflys just suck out the polyps like angels do.

 

[Gecko]

I agree easy answer here.

 

[PrettyBoy]

I really dont think it is that easy. There has been pieces missing that were clearly 1-2" long. Why I trigger would want to shove a big piece of SPS down its throat I dont really know. It isnt even eating them, most of the time I can find the pieces laying in the sand bed

 

[dnov99]

It isnt even eating them, most of the time I can find the pieces laying in the sand bed

Sounds like the urchin could be snapping them off when it is moving around at night.

 

[PrettyBoy]

It isnt even eating them, most of the time I can find the pieces laying in the sand bed

Sounds like the urchin could be snapping them off when it is moving around at night.
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ive had a few people tell me they feel this is the cause of it as well. The urchin is the only one really active at night, and the damage seems to come during the night time as well.

 

[Jcurry@wesketch]

When I worked at an LFS many years ago I watched the triggers pickup large pieces of rubble and carry it around the tank just drop it after a few laps. They would even break off pieces of live rock and carry them around. I thought it was strange bahaviour but many of the triggers did the same thing and it wasn't limited to a certain species or size trigger.
My guess is the crosshatch. Urchins usually bulldoze frags over so they fall and break, not snap off a branch here or there.

 

[harlequinreef]

large black sea urchin (not sure what kind, just black very pointy and with an orange dot/mouth/eye on the top.

I dont mean to bust your chops, but this cracks me up whenever I hear it. Thats its anus. I love when I hear a customer say "Woah something just came out of its eye!"

 

[reefsandrotts]

Well heres my input,
my purple tang took care of every SPS in my tank.....
He would bite them and brake them apart just your describing.

 

[Dave]

Can you put the cross hatch in a QT for a little while and see if it is still occuring?

I know nothing about cross hatch triggers, but if the breakage started after the trigger was added, it has to be considered the "primary suspect".

And the urchin, sounds like the <a href="http://www.liveaquaria.com/product/prod_display.cfm?c=497+530+591&pcatid=591"> Black Longspine Urchin </a>, based on your description.