The Emerald Devil

[AXO]

I figured I'd share my experience with the emerald devil because during my reefing life I have met many people who refuse to believe that crabs can be extremely destructive.

It all started when I found this emerald crab who I did not put into my tank. How do I know this? Because I never bought emeralds until about a week before I found him. Once I added 3 little guys to help with some bubble algae I noticed this big fella come out of the woodwork.

Fast forward a bit- He had become become more powerful, killing all the other emeralds/ snails until we get to where i'm at now. I have almost no snails left, he killed all the turbos, shells everywhere, even caught him picking on acans.

Now to the climax. In the past week he has taken chunks off of my Battle stag, but this morning which was the last straw, I woke up to find that my ReefRaft Wolverine had chunks taken out of it. I struggled to catch him and finally later this night I got him. During my chase with him I even caught him trying to snatch a sapphire damsel mid swim with his claws.


Not all emeralds will be bad but I just urge you to be careful, (especially if they run out of algae to graze on) This one crab has caused big damage, and my wolverine is in critical condition, this is a $500 coral if you're looking at Reef Raft's pricing, I paid $250.

The only reason he is alive is the fact that he is big, and I'd like to see him grow from the safety of my frag tank sump.

 

[tankstudy]

I found out first hand myself during my first days of reefing.

I don't deal with crabs/hermits anymore.

They are cool and all but not several hundred dollars cool enough.

 

[ChiCity]

IMO, it's the males that cause the most damage!
I think there are 2 to maybe 5 different types of emerald crabs that are being collected, varying by region of course....

 

[McMullen]

But they're are great for bubble algae!

 

[AXO]

IMO, it's the males that cause the most damage!
I think there are 2 to maybe 5 different types of emerald crabs that are being collected, varying by region of course....

Yeah definitely the males.

 

[LetItReef]

That's a big size EC.
I have a small size but no luck yet helping to control bubble algae.

 

[ChiCity]

In my experience, the hairy females that are super cryptic are the best ones to have.
Talking full bush

 

[Lowstorm]

I used to have a huge one too, a few years ago. I kept him in my sump and when reefers came over, they wanted to see the huge guy. Every time! Fun pet not fun for the tank

 

[AcanSkywalker]

I figured I'd share my experience with the emerald devil because during my reefing life I have met many people who refuse to believe that crabs can be extremely destructive.

It all started when I found this emerald crab who I did not put into my tank. How do I know this? Because I never bought emeralds until about a week before I found him. Once I added 3 little guys to help with some bubble algae I noticed this big fella come out of the woodwork.

Fast forward a bit- He had become become more powerful, killing all the other emeralds/ snails until we get to where i'm at now. I have almost no snails left, he killed all the turbos, shells everywhere, even caught him picking on acans.

Now to the climax. In the past week he has taken chunks off of my Battle stag, but this morning which was the last straw, I woke up to find that my ReefRaft Wolverine had chunks taken out of it. I struggled to catch him and finally later this night I got him. During my chase with him I even caught him trying to snatch a sapphire damsel mid swim with his claws.


Not all emeralds will be bad but I just urge you to be careful, (especially if they run out of algae to graze on) This one crab has caused big damage, and my wolverine is in critical condition, this is a $500 coral if you're looking at Reef Raft's pricing, I paid $250.

The only reason he is alive is the fact that he is big, and I'd like to see him grow from the safety of my frag tank sump.

Wow! How big is your display tank? Seeing that guy went unnoticed I have to imagine it's huge!

 

[mookinpie]

That's how big mine is in my display I've notice some of my snails [emoji222] died off I thought it was to natural cause then I've seen him steeling silver sides from my Seabae now I wonder is he really targeting my coral I've seen them shriveled up from time to time [emoji33]

 

[mookinpie]

Ty for sharing I'm going hunting for crabs [emoji886]

 

[Mike_J]

This is exactly why I no longer use crabs in my reef and only snails and my cucumber

 

[Psiber_Syn]

I have had several emeralds over the course of a year ...... Not one ate bubble algae I think it's a myth lol

Although I am positive I watched one crab on two occasions destroy a birdsnest colony I mean like beach ball sized over night long story short no more emeralds for me

 

[blkhwkz]

I bought an emerald 2 weeks ago for a small bubble algae problem. It ate it all within 2 days, I saw it at night finding it between polyps and eating it. Strong crab though, had a fish die the other day and had to fight the emerald to remove it from the tank. Had the fish picked up in it's claws and tried walking away with it. Also likes to hang out during the day where one damsel sleeps at night so during the day they get into it a bit every so often.

Had another emerald in another tank last year and he decided he liked the taste of SPS, so had to be removed. Saw it one night just tearing chunks out of corals. Few weeks after removing it they all healed.

 

[AXO]

Wow! How big is your display tank? Seeing that guy went unnoticed I have to imagine it's huge!

Worst thing is that its only a Reefer 250. The thing was It was hiding and I never checked the tank at night, and I only noticed him when the other emeralds got put in there and it made him mad haha.

 

[McMullen]

They absolutely will eat bubble algae and eventually be a nusance.

 

[rock_lobster]

I think as long as you have some sort of algae they will not eat anything else. They are omnivores and when starvation kicks in probably they will eat just about anything. If you have a large emerald and lots of algae your probably fine like me. Large emerald plus no algae most likely going to have problems.

 

[Rick.45cal]

I've heard SO many horror stories over the years of Emerald crabs and Sally lightfoots going rogue that I have never trusted any crab. I honestly am not the biggest fan of hermits either, though I do keep blue legs. There are quite a few marine animals that depending on the individual can just up and decide to go rogue on you and change their behavior completely overnight. Some individuals just don't play by the same rules as the rest of their species (especially in captivity).

Marine aquaria and reef aquaria especially are dynamic environments, the inhabitants sometimes must alter their behaviors to survive. (Sometimes to the aquarist's dismay.)

Glad you caught him! He would probably be nearly impossible to get out of my display.