dead snail shells with holes

[draco]

Looking in our tank we noticed our snails died ,we had just bought them 2 weeks ago, seemed it a little strange they were all in a pile had a close look there is holes in the shells. what could have done this .please help it is right by a rock . Two clowns ,citrus goby,2 twin spot (signal) goby,yellow headed jawfish ,fire fish,2 cleaner shrimp,1 fire shrimp, hermit crabs.

[marie]

One culprit could be another snail, like a whelk. Look for snails "hitching" a ride on other snails.Once when I ordered a bunch of ceriths, one of them was a carniverous snail (it actually didn't look much like the other snails I don't know why they included it in a cerith order) it ate 3 other snails before I realized it wasn't in the least bit interested in algae
Another culprit could be a mantis shrimp, I don't know if they leave holes in the shells or not though

[Scavenger]

My first thoughts are mantis. Given the short term demise of lots of snails and the fact the "evidence" is piled in a small area.

Listening for clicking at night and setting up a bottle trap or similar would be my top priority at this point. If it is a mantis, darn near everything in the tank is at risk.

All this is just my opinion, it has no scientific, horrific or other ific evidence or knowledge. <grin>

[draco]

what should we use for bait in the trap?

[Kabong]

If it's a nice clean little hole that looks like its been drilled.
I'd agree with welk or conch.
For that the best way to catch them is just look for a snail piggy backing on another. Or an oddball snail you didnt order.
Some of these are night time predators.
So do a little night time flashlight checking

[Scavenger]

Originally Posted by draco

what should we use for bait in the trap?

Pretty much anything seafood and meaty that isn't going to pollute your water. Ie krill, uncooked shrimp, oyter, clam ect. I'd personally avoid oily meats such as salmon ect. (had my skimmer going nuts)

Do you know how to make a bottle trap??

I wouldn't discount the whelk theory, it just seems strange to me that the shells are in the same area. Sounds to me like a pretator with a burrow and hunting area. Just my one point three cents.

[draco]

yeah i definetly do i catch all my stuff with one.

[justinl]

Try staking out the tank one day and one night. At night don't use any lights, just have enough light that you can see some detail in the tnak. red lights are useless for mantids. Beer helps . Just sit and watch. Search the net for some mantis pics if you don't know what they look like.

The only hard evidence of a mantis imo is a visual, as not all mantids click and not all leave shells in the open. Not all hunt fish either. but anyways describe the holes in the shells. Are they perfect circles/ovals? or jagged like they were smashed in? Mantids would leave the jagged kind of hole.

Did you just add LR or something that the mantis might have just hitched in on? It seems very odd if it is a mantis because your shrimp and hermits survived just fine for this long.

[draco]

our tank is fairley new we just upgraded so we did add some live rock.as for the snail shells it is at the back end, and what ever did it, has sawed the end perfectly off. it almost is right in half. there is only one shell that has a small whole that looks like it has been drilled. all these shells were in a perfect pile at the base of one of my rocks. also i had a yellow headed jaw fish and he has been living in his house he made for a long time. then one day he moved and i wasnt sure why, and now he is gone, but the shells are piled up at the back of his house, so i am wondering if something didnt kick him out. thoughts?

[justinl]

those shells don't sound like a mantis' work. i don't know what might have done it.