what is eating my snails???

[reef tank 2.0]

I recently added a clean up crew to my tank, which consisted of

57 Dwarf Cerith
5 Nassarius vibex
23 Florida Ceriths
44 Astraeas
6 Indo Turbo Snail
3 Limpets

shortly after adding them to my tank, I noticed a few things.

limpets - these were shipped on a sea shell. day after getting them, two of them moved off the shell and made their way around. the next day, their mantle/foot was detached from the shell, obviously they were dead. that was quick. the third one is still attached to the shell he was shipped on. so I am closely monitoring him.

one of my indo turbo snails were killed. just like the limpets, mantle laying n the sand and the snail was gone.

astraea - this is where twilight zone things are happening. every day I look at the tank, everyone of these snails are upside down. only ones that are normal, are the ones stuck to the glass/rockwork. last night, I pulled one off the top of my gyre pump to clean the algae off its shell. I pulled the algae off and sat him back on top of the gyre where I found him. didn't think much of it after the fact. came back to the tank today, he's still on the gyre, upside down, shell completely empty. the gyre one boggles my mind. what could have gotten to the top of the gyre to eat him??? once the lights came on, I noticed all these guys were again, upside down. most still had a snail in the shell, some not. I turned that upright and i'll continue to monitor.

I don't have any hermits, but these snails are being eaten by "something". the only snails that I had prior to this addition that wern't one of the same species, are my bumble bee snails. I've had them since the beginning of my tank. (1+ year). they've never messed with any of the tank mates. I haven't had any of my snails eaten before, except when I used to have hermits. I have none now.

a lot of my snails are now deceased, within 2 weeks.

 

[aftrout]

The main culprit I can think of is the large number of snails introduced at once and the possibility of lack of food for them. When I introduced cleanup crews I did it in stages, small numbers over a period of months as my tank matured. This allowed me to fine tune the numbers and replace any of those past away. Remember also, these critters are usually housed in tanks with no food from the time they are harvested to when you receive them so they may be behind their calorie need when you get them. I would get some nori and rubber band it on a rock and supplement them until your tank gets enough load to support.

 

[Fish Fan]

One possibility is that some species of Dinoflagellate algae can be toxic to inverts, and if you have Dinos and your CUC is feeding on them, you might have one of the toxic varieties. I don't know for sure, I'm just offering this as a possibility

Good luck!

 

[Tripod1404]

Do you find the shells covered up by clear slime? If so you likely have a predatory worm, likely a species in Oenone that specializes in hunting molluscs.

 

[BonnieB]

I was also thinking a worm/worms as the shells wouldn’t be knocked over if they just died, unless of course they all fell off the rockwork. Take a look at night after lights out with a red light (or light with a red filter) and see if any guilty culprit emerged from the rocks!