Reef Safe Crabs? . .

[ScubaFish802]

Are there any true "reef safe" crabs? Hermit or otherwise?

I would like to diversify my CUC beyond snails and brittle starfish.

Is there such a thing or am I crazy?

 

[John Genmel]

I have some hermits that haven’t touched anything but I don’t trust nothing after that

 

[ReefHomieJon]

Don’t do it..... lol
Try urchins and shrimps

 

[ReefHomieJon]

And hermit crabs are great options too

 

[WV Reefer]

Are there any true "reef safe" crabs? Hermit or otherwise?

I would like to diversify my CUC beyond snails and brittle starfish.

Is there such a thing or am I crazy?

Never trust a crab.

 

[Cole.mormon]

Emerald crabs try a conch an mithtax crab

 

[Privateye]

Scarlet reef hermits are great, as are many other varieties of hermit crab. Zebra hermits, blue legs, and Mexican red legs have good reputations. Hermits do tend to fight with each other though.

 

[Cole.mormon]

Red legs

 

[Mr_Knightley]

Emerald crabs, strawberry crabs, hermits you name it, are all reef safe as long as they have enough food. The second they run out of food they will start eating your snails, and if you leave them long enough they may even go after corals, but I have found they they don't really like the taste.
I personally love crabs, I've got tons of hermits in my tank that live peacefully with the rest of my livestock. I've got an enormous emerald as well who is a model citizen.

If you don't want to take the crab risk, then I would recommend trying some urchins (Personally I would want then anyways nomatter the crabbage). Cleaner shrimp are just about as trustworthy as crabs or less, of course as long as they are well fed they should be model citizens.
Good luck and God bless!

 

[Tired]

Hermit crabs aren't actually crabs! But they're pretty close. Scarlet hermits are the least troublesome.

Porcelain "crabs" are another fake crab (closer to squat lobsters), but can be trusted to be safe. Filter-feeders (though you can give them other foods) whose large claws are mostly for show.

Emerald crabs can be trouble once they get large, don't trust them.

Micro decorator crabs (not regular ones!) may try to wear a zoanthid polyp or two, but will otherwise leave things alone. Regular decorator crabs can work, too, but will definitely snip and wear zoas. Safe for LPS and other corals that are too big to wear.

Mime crabs are too small to cause any trouble, but you'll probably never see them unless it's a pico.

 

[rkpetersen]

I was wondering if anyone was going to mention porcelain anemone crabs (Neopetrolisthes sp).
Beautiful patterns, fun to watch, completely reef safe.
Best if you have some anemones for them to occupy.
Multiples are fine, although they may fight with each other at times.
Not really part of the cleanup crew though.

 

[BloopFish]

Are there any true "reef safe" crabs? Hermit or otherwise?

I would like to diversify my CUC beyond snails and brittle starfish.

Is there such a thing or am I crazy?

Don't buy crabs for long term clean up crews, only buy them if you just enjoy them for what they are.
I guarantee you from my experience of catching many many different inverts, gastropods and echinoderms are much better at cleaning up algae. Nothing will devour nuissance algae like a sea urchin, and nothing will devour hair algae like a sea hare... but they are like mindless eating machines without personality... whereas a hermit crab is like a evil funny demon that may kill eachother or kill some snails or MAYBE eat your nuissance algae. They are fun, but a nuissance. Just like cleaner shrimps they will steal your corals food rather than work hard being your janitor, because they'd rather work smart than hard. I keep crabs just because I find them interesting, I don't treat them like they are my workers lol.
As others have said a porcelain "crab" is a safe option, but they aren't really a clean up crew member since they just eat whatever they catch in the water column.
For detritus and uneaten food, bristleworms, nassarius snails, and micro brittlestars are pretty interesting options. Bristleworms and micro brittlestars will grow in population based on how much you feed your tank, very versatile clean up crew option (though the micro brittlestars seem a bit more appealing to the eye). Stomatella snails and trochus snails are also great in that same way.

 

[terraincognita]

Crabs are scavengers for sure, but they're also higher on the food chain compared to fish IMO. So while we add slower, smaller, peaceful ones like hermits and sometimes people add emeralds for nuisance algae ultimately, they're going to look for food if their hungry, and they eat lots of things.

With that said only truly safe reef crab I know of is Anemone Crabs and Trapezia Pocillopora/Acropora Crabs, as they are "hosters" rather than free agents. However these aren't really CUC material either. They're hobby/interest specific.

Others statistically eventually most of the time start attacking other inhabitants, whether fish, or coral. With the exception of Hermits, But I think it's a size and speed thing.