I hate Emerald crabs

[Tab28]

I had one eat my new clam I put in my tank, the next day my clam was mostly gone.

An emerald crab can not do that it is physically impossible for an emerald crab to pull a clams mantle open. The most it would be able to do is pick a few pieces of mantle. The clam would have closed. End of story. If the clam likely died on its own. The crab took advantage of the free meal. Clams are not open at night unless they are not well. Light controls the clam opening and closing. The closes at night for safety reasons.

 

[GHill762]

An emerald crab can not do that it is physically impossible for an emerald crab to pull a clams mantle open. The most it would be able to do is pick a few pieces of mantle. The clam would have closed. End of story. If the clam likely died on its own. The crab took advantage of the free meal. Clams are not open at night unless they are not well. Light controls the clam opening and closing. The closes at night for safety reasons.

mine was holding on to the mantle and tearing pieces off within 5 minutes of putting the clam in the tank. this was nearly 2 years ago, the clam was perfectly healthy and is still alive and doing well today.

as far as opening the clam up, I would agree with that, but it easily could do enough damage to stress the clam to near death in a short period of time.

 

[rjcranor]

Tab28 well, all I know is I got the clam and put it in my tank the next day it was mostly gone. I got rid of the crab. That was several years ago. Over a year ago I picked up another clam. Of the evening when my lights go down it's still open. So if there was stress from the move and the crab I don't know? The crab was eating it when I got up.

 

[Tab28]

mine was holding on to the mantle and tearing pieces off within 5 minutes of putting the clam in the tank. this was nearly 2 years ago, the clam was perfectly healthy and is still alive and doing well today.

as far as opening the clam up, I would agree with that, but it easily could do enough damage to stress the clam to near death in a short period of time.

A few seconds yes possible. And you separated them. The clam would close its shell lightning fast. The crab would not get more than a few picks. A male may get to hold onto the shell allowing the smaller claw to grab a piece. But that would still be limited. The claw would only be able to enter a few millimeters to maybe a centimeter. The clam would not open its shell with a crab holding it. The crab can try this a few days to get a piece or two. But would normally try for something easier. The clam would stay closed until the crab left. A healthy clam is lighting fast and an emerald grab can get nothing more than a nibble of mantle. I had clams kill fish if it tried to grab a piece of mantle.

 

[erk]

Emerald crabs are no different than any other living creature. If they are hungry they will eat. If they are eating your corals you are not providing them with enough food. They will rather grab a piece if food on the sand bed than rip it off something that gives more resistance. Even a reef safe fish will resort to eating at coral if it is hungry. If you do not have enough food on sand bed. Do not get any invertebrates. There is a reason many tanks that are low nutrient do not have fish or most types of invertebrates. They require food. Uneaten food and digested food byproducts means higher nutrients.

A fox face will get too big for a 90 gallon and knock over things. They scare easily and freak out. They will also nip at LPS if not given enough food. What the fish believes is enough food not what you think is enough food.

I don't think the problem is I'm not providing enough food. I feed twice a day because I have a scooter blenny. All fish are fat and healthy. I also feed a filter/coral food for my NPS gorg. As I said in the original post, the crab only ripped the mouth off of my nickel sized chalice frag. It did not eat any of it. Kind of a strange thing to do IMO. I realize that its a crab and will do whatever it wants. My main question was if anyone has had a chalice frag come back from such an injury. So far the frag seems to be responding well. It extended a few of its remaining tentacles.

Your statement that they will go for food on the sand bed before things that resist is somewhat true, but I have plenty algae, sponges, and detritus for them to consume. Instead they climbed up and swam or whatever/however they did it to my frag rack and started grazing amongst the corals there. I moved one to my refugium which should make it happy because its filled with all sorts of stuff.

I'm not sure if you were saying that I should reduce nutrients to reduce the amount of bubble algae I have or not. Either way, bubble algae is not really nutrient dependent in the same way that most other nuisance algae are. Bubble algae is a macro algae and can grow at reduced nutrient levels. Manual removal is the only real way to control it. Kinda like trimming caulerpa to keep it controlled.

I agree that a foxface gets too big, which is my main reason for going with emerald crabs. Just wish there were more options of animals that consume bubble algae. Not that I want to get them just to consume the bubble algae, but that I like keeping animals that I have their natural food growing in my tank. Its a lot of fun seeing these animals exhibit their natural instincts and such as they search the water column or substrate for food.

 

[Stephanie11]

I had one in my 90g he was awesome. I decided to put 2 more in my frag tank and they were not good. They would eat new frags, so they went into the sump. I think they need a bigger tank to possibly live in peace. Also I believe they can tell damaged or dying flesh and eat it, then what happens is they turn the good flesh near the injured into more damaged flesh creating more food.

 

[Baldguy]

Always amazing at the amount of blame people place on the things they put in their tank.

Not so much blaming the crabs as a comment on the sites that always list them as "reef safe". They are not.

 

[Krypt1979]

I have 3 Emeralds in my 75 and 1 in my 30g frag tank. They have been great additions, in fact the one in my frag tank has been alot of fun. My daughters and I brought home one of those little cocktail swords once, and we got him to grab the handle with his claw. For about a week he was walking around the tank with this big red sword, lol

 

[ahmed.boomer]

Mine was a model citizen. No issues at all. Just kept to itself as long as it was fed properly. Died three months ago after two good years. The only thing it did that would be "not reef safe" was that it ate my monti cap and hollywood stunner chalice from underneath a couple time. I didn't care as it wasn't enough to affect growth. I mean I imagine it looked like liverock from under his rock.

 

[Lbyrne]

I have never had a problem with emerald crabs before in my smaller tanks in the 10 years I have been keeping reef tanks, but I got 3 for my DT about 3 weeks ago & decided to pull them tomorrow! Though I have not seen them picking at fish or eating corals, every time I target feed they come out, climb on top of & are taking the food from the corals! Idk what the difference is but it may be because these guys are a lot larger than any I have had in the smaller tanks, but these 3 are super aggressive. As far as catching them, not sure how others are behaving, but when I put any meaty food in the tank mine come out of hiding right away even when the lights are on & have even grab onto the tool I am target feeding with..... Good luck all

 

[IdahoFledgling]

Bought a large colony of pulsing xenia couple years back on the cheap. Only full on colony I've ever bought... started dying within the first day, took me the days to figure out my emerald crab was treating it like an all you can eat buffet. Crab was banished to the dark sump, he was the only resident for about a year before he went missing. The xenia didn't survive.