Emerald Crab Concerns..

[aspen1990]

Hi there! I'm a newbie, just got my first saltwater tank up and running. Was finally able to introduce my clean up crew and a Royal Gramma to my tank last night. Immediately upon entering the tank, (within the first 15 seconds) my Emerald Crab attempted to eat one of my bumblebee snails.. I shooed him away and moved the snail before he could finish attacking it and threw in some crab pellets (which he ate). My concern now is for the safety of my fish.. I was under the impression that Emerald Crabs were typically peaceful with their tank mates. Since my Royal Gramma sleeps and spends a lot of time in the rock work, I'm now worried the crab will take advantage of this.. Thoughts? Am I paranoid over nothing?

 

[cloak]

:thumbdown

http://www.advancedaquarist.com/2010/12/inverts

JMO, GL

 

[aspen1990]

So he should leave my fish alone even if they're in the rock work together?

 

[justthewife]

In my experience they either have opportunistic personalities or not. I have two very peaceful ones in my tank right now but I had one a while back that went Rambo on my corals. He just started ripping everything apart. They can be very hard to catch if you have a lot of rocks and other things in your tank. If you can get him easily, return him to the store and get another. He may also just have been really hungry. If you feed him enough he may be ok but why risk it?

 

[150Ron]

I have a half a dozen of them with never an issue. That's what they do when you get them from an lfs and they are starving

 

[Dkuhlmann]

I lost two royal gramma's to my emerald crab. He caught them while they were sleeping and ate them. The first one disappeared and I just chalked it up to a fish dying. The second one, was doing wonderfully, then the third morning after lights on there is my emerald crab eating my royal gramma where it slept. :hammer: So I grabbed the emerald and put him in the sump.

It seems that the male emeralds go rogue after the get over an inch in width from shell point to point. After that size they'll be pretty much opportunistic and eat whatever they can get, including fish and corals. Most crabs Mithrax included will eat anything available if there is no algae for them to eat, even the females.

Now the only crabs allowed in my DT are scarlet legged hermits. They won't kill anything and do a great job of cleaning the rocks. Which reminds me I need to get one or two more.

 

[fairl80z]

I got rid of my emerald crabs( put them in the sump ) and bought two Sally light foot crabs . They seem to be a whole lot more peaceful

 

[Dkuhlmann]

Sally light foot crabs will go ballistic on your tank as well. There is no good crab for a reef tank accept the scarlet legged hermit IMO and IME.

Here is one thread about them eating fish, Do a Google search and you can read horror stories about them too.

http://www.reefcentral.com/forums/showthread.php?t=1654754

 

[Calappidae]

I got rid of my emerald crabs( put them in the sump ) and bought two Sally light foot crabs . They seem to be a whole lot more peaceful

That is very surpisingly actually as sallys are some of the most aggressive crabs you can get.

 

[fairl80z]

They are super happy in my tank , prolly because I over feed like crazy . Hahah

 

[aspen1990]

My lfs is 2.5hours away :\ here's hoping he doesn't eat my fish before I can rehome him..

 

[ruiny]

It seems my emerald is killing fish and nipping fins.
To the sump he went.

 

[Dkuhlmann]

Aspen, you need to catch it first it's not as easy as you think

 

[aspen1990]

I'm finding that out haha. I had a new home lined up for him, but literally haven't seen him out once since posting this. My fish is still alive though, so I guess the crab is content with eating other things thankfully!

 

[SteveVai9708]

You will not regret having an emerald crab. They have awesome personalities and excellent clean up crew members. Oh, and since their opportunistic, you can hand feed them ^-^ . I was shaky with mine to, but I do not regret having him. If you want him to be a cute, cocky emerald crab you have to look at him as a pet not a janitor, but there's always one on the crowd that will just hide all day. ... Inverts are more interesting than people think. Sorry your emerald hides all day... Reminds me of my serprent star

 

[kcinnick]

Just say no to crabs!

Female emerald crabs are a better bet, but still not 100% safe.

I agree that Scarlet Hermits are the only safe clean up crew crabs out there. Some small anemone crabs and porcelain crabs should be fine also. All crustaceans are opportunistic...

 

[Calappidae]

Pom Poms are safe as well. Just don't touch their anems, I've heard nasty things about those guys they hold, but can't confirm myself.... I mean maybe i can... nah.

 

[DLreef]

I lost two royal gramma's to my emerald crab. He caught them while they were sleeping and ate them. The first one disappeared and I just chalked it up to a fish dying. The second one, was doing wonderfully, then the third morning after lights on there is my emerald crab eating my royal gramma where it slept. :hammer: So I grabbed the emerald and put him in the sump.

It seems that the male emeralds go rogue after the get over an inch in width from shell point to point. After that size they'll be pretty much opportunistic and eat whatever they can get, including fish and corals. Most crabs Mithrax included will eat anything available if there is no algae for them to eat, even the females.

Now the only crabs allowed in my DT are scarlet legged hermits. They won't kill anything and do a great job of cleaning the rocks. Which reminds me I need to get one or two more.

I honestly didn't think anything could kill a Royal gramma, seeing as how aggressive they are.

I always have loved emerald crabs, never bothered a thing. just keep it well fed :spin1:



EDIT: Oops this thread is a little old