emerald crab ate zoa's

Ssteve

New member
My tank is new and only had two polyps of zoas that were hitchhikers from the rock I got from a friends tank. After my cycle I added a few snails and a emerald crab. All was well for about 4-5 days and then last night the crab ate the two polyps. Or I would assume its the crab but maybe the snail? They were both very small polyps so no biggie, but Im about to start stocking a few corals, and the first thing in will be a small colony of zoas. Should I evict the crab?
 

JRR1285

New member
I have heard they can eat zoa polyps but I believe they typically go after damaged or dying ones. They will usually leave healthy coral alone.

They are opportunistic feeders though, and if they are not kept well fed there's no telling what they may go after. I took them out of my display due to paranoia but now I really miss them. Very interesting to watch.
 

Ssteve

New member
What can I supplement/feed them to make sure they dont get to my corals? I just got my first fish(true perc) and will be feeding him newlife spectrum small pellets for now. Can I slightly over feed the pellets and help keep the crab happy? Its a 14g cube and Im doing 2g wc once a week so Im not real concerned with water quality going south this early.
 

Ssteve

New member
And your right, he is fun to watch, and very opportunistic as he trys to catch the clown every time he swims by. Which sometimes the clown will toy with him and just repeatedly dive bomb him. Entertaining stuff.
 

Meanmike

New member
And your right, he is fun to watch, and very opportunistic as he trys to catch the clown every time he swims by. Which sometimes the clown will toy with him and just repeatedly dive bomb him. Entertaining stuff.

I think what your seeing is the crab keeping the clown away.
 

Ssteve

New member
Yeah it could be. I acclimated the clown last night with just moonlights on, and he wasn't a fan of the flow in the tank so he stuck to a corner. Happened to be where the crab was also, but then the crab headed towards the clown. Maybe a Territorial thing or something like that, but now they seem to be fine until the crab is ontop of the rock, then the clown toys with him.
 

Guygettnby

New member
all crabs are not really reef safe IMHO... they all will eat what ever they can get there claws on if given the chance and hungry enough. usually if you keep them well fed you have a better chance of them never bothering anything but thru all of my years keeping reef tanks, I can honestly say that as of right now I will no longer keep any kind of crabs in my tanks besides hermits.

I have sat back and seen first hand them eat perfectly healthy corals, attack fish and even tear apart my anemones.

if you must keep them for some reason or another, make sure they are well fed.
 

Ssteve

New member
just dropped a few pellets in and the crab went nuts for them. My nassarius snail popped right out of the sand for them too... The clown however wasnt crazy about them. Took a couple pellets in and just spit them back out.
 

chain

New member
I have one emerald in my 29 gal nano and he doesn't seem to mess with anything. Generally he sticks the hanging upside down on the bottom of rocks. Never see him on top messing with stuff. I like him and plan on getting a couple more once I have my 120 running. The hermits are the ones that drive me nuts. They just crawl right over corals like the aren't even there. They act like stupid little bulldozers.
 

cloak

New member
I don't trust those big claws they have. They didn't eat the valonia I had at the time, so there was really no reason to keep them in the tank then. JMO. GL.
 

zoafarm

New member
It's more likely that the zoas were not healthy after the cycle, and the crab was cleaning and the polyps came loose. I've had them in all my tanks, and I have seen them picking around the base of my zoas every once in awhile. But I have not seen them eat them...not to say they won't.
 

Cancros Amo

New member
My emerald crab is the main pet in my aquarium. I adore her, and feed her 2-3 sinking crab pellets per diem. I also add tisbe pod phytoplankton green water.

In my 6 weeks with an emerald crab, I find that she ate all obvious green algae growing in the tank. After her daily pellets, she hangs upside down on the rocks and continuously moves the two brush-like feelers between her eyes, apparently feeding on microbes in the water.

She is not aggressive, but will literally backhand the hermit crabs if they try to take a pellet. Obviously, I solved that by feeding her first, then dropping pellets to the two hermits at a distance. After feeding time, the three congregate close together, or wander the tank, with no conflict or damage.

I have a stomatella snail (hitchhiker from initial live rock), and the crabs totally ignore him when he's nearby.

To me, they're delightful pets on their own.
 
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