Emerald Crab too big?

[mikemathis555]

I have had an emerald crab in my tank for almost 3 months now. He is generally a good tank mate, and has good personality. He does great on the algae on my rocks, and even solved a Bryopsis outbreak I had. The problem…he is molting about one a month, and is approximately 2-3 times larger than when I got him. I’d say he’s now over three inches in diameter. He’s big enough now that he’s able to dislodge corals from my rocks even when glued and epoxied, as he get under them and, while farming for algae, plucks the coral off the rocks. He’s done this about 10 times now…never eating them, just causing a mess. Attached is latest picture where he popped my favorite mushroom of its home on the rock.

I have a 13.5G Fluval and have plenty of rocks, but I’m wondering if a lawnmower blenny is a better solution for me at this time.

Anyone share this same experience?

 

[aws2266]

I have one like that. He turned into a bully and made me nervous around my shrimp. He liked to mess with my coral as well. Ended up temporarily putting him in my small aggressive tank and he's done well there. The trigger goes after him from time to time but the crab is quick to find cover. I'm going to end up selling/giving him away as I'm going to get a puffer and don't think he'll survive that.

 

[mikemathis555]

I have one like that. He turned into a bully and made me nervous around my shrimp. He liked to mess with my coral as well. Ended up temporarily putting him in my small aggressive tank and he's done well there. The trigger goes after him from time to time but the crab is quick to find cover. I'm going to end up selling/giving him away as I'm going to get a puffer and don't think he'll survive that.

His only bad habit is this coral thing and being to big for the tank maybe. He plays nice with the fish and the actual corals themselves, never see him nipping. I don’t have any shrimp, my CUC is all snails. He gets along with the and calmly cleans their shells of algae too.

 

[LiveFreeAndReef]

If you think the crab is too big for the tank, a lawnmower blenny definitely will be. There are some great smaller blennies though, tail-spots are great and don't bother coral, bi-colors are good too as long as you don't have SPS. My bi-color loved the taste of pocillopora polyps

 

[mikemathis555]

If you think the crab is too big for the tank, a lawnmower blenny definitely will be. There are some great smaller blennies though, tail-spots are great and don't bother coral, bi-colors are good too as long as you don't have SPS. My bi-color loved the taste of pocillopora polyps

thanks for the comments. I’m looking for algae control and guess I need to research the smaller blenny types. When I say my crab is too big, I mean he’s grow large enough now his pincers are powerful enough to get under coral and dislodge them from the rock. He isn’t knocking them over just by bumping into them.

 

[moz71]

I had one grow that big quickly too and then proceeded to eat a large piece of my clams mantle. So of course out he came. Clam recovered nicely!

 

[youcallmenny1]

I've repeatedly tried mithrix thinking I was getting rogue ones. The trend is always the same. They come, they grow, they grow some more and then they become a threat. I've just given up on crabs of any kind at this point including hermits. Now I have a thriving host of snails in my CUC instead of a graveyard of shells.

 

[LiveFreeAndReef]

What kind of algae are you dealing with?
This is one of my current favorite blennies, the linear blenny. Great for turf and hair algaes, and he tries to munch film algae off the glass too (I'm sure he gets a little lol) Same story as the bi-color blenny though, will definitely nip at SPS coral. The tail-spot blenny leaves SPS alone, which is nice. They have such awesome personalities that I feel like they're an "every tank" fish just like clowns

 

[mikemathis555]

What kind of algae are you dealing with?
This is one of my current favorite blennies, the linear blenny. Great for turf and hair algaes, and he tries to munch film algae off the glass too (I'm sure he gets a little lol) Same story as the bi-color blenny though, will definitely nip at SPS coral. The tail-spot blenny leaves SPS alone, which is nice. They have such awesome personalities that I feel like they're an "every tank" fish just like clowns

Correct - general algae types, mainly turf and GHA. I’ll do some research on the blenny. I do have a second smaller tank with some live rock rubble I could probably move the crab to and feed him herbivore diet things.

Edit; also I have almost exclusively softies and LPS coral. Was going to try a montipora on my rock arch, but think I’m having second thoughts on that.