Good Crab / Bad Crab?

[Giraffe0621]

Good crab or Bad Crab? Temporarily in Sump Limbo, but help me determine what's next?

I think good? Not hairy, no black claws, says please & thank you...

 

[Gweeds1980]

Looks like a Tetralia coral crab of some description... if it is, it's a good one... Will make home in sps and eat stuff that lands on it, keep it clean, eat predators etc. If I'm wrong... and I may be, crabs are notoriously difficult to ID, then it'll no doubt eat all your SPS in twenty minutes

 

[DSC reef]

I don't like pointy claws but I'm no expert on crab Id's.

 

[Lovemyreef2015]

+1 on the Tetralia coral crab. It has a lot of similarities. Crabs are very tough to identify sometimes.

 

[Giraffe0621]

Eek, forgot to add he's from TBS live rock -- so Gulf of Mexico -- if that helps either support or contradict the Tetralia coral crab ID?

 

[Gweeds1980]

Eek, forgot to add he's from TBS live rock -- so Gulf of Mexico -- if that helps either support or contradict the Tetralia coral crab ID?

Oh... I think they're all indo-pacific... again, may be wrong on that.

 

[Giraffe0621]

back at maybe good, maybe bad, maybe my first official Sump Creature?

There's no coral in the tank yet, but wouldn't want to chance it over one 1/2" crab from hell who could demolish it all before I could catch him again

 

[Lovemyreef2015]

back at maybe good, maybe bad, maybe my first official Sump Creature?

There's no coral in the tank yet, but wouldn't want to chance it over one 1/2" crab from hell who could demolish it all before I could catch him again

Until you can be 100% sure I would keep it in your sump. Not worth risking any coral for a crab IMO

 

[mtfish]

It is a porcelain crab. It should not give you any problems.

 

[Giraffe0621]

Well he's king of the chaeto & live rock rubble for now. Not putting him back unless the consensus is keeper

 

[xjiang7]

Agree with porcelain, it has 6 legs

 

[Gweeds1980]

It is a porcelain crab. It should not give you any problems.

Not convinced by that... the porcelain crabs we see in the hobby normally either have a white outline on each part of the body, or are striped or with clear, defined spots. This has none of those. Additionally porcelain crabs are flattened, with claws having a wide, flat lateral profile. Again this doesn't appear to have either of those features. Below is a pic of a porcelain crab vs a Tetralia crab for reference.

 

[Gweeds1980]

Agree with porcelain, it has 6 legs

Er... as do most crabs... 8 limbs, with two being pincers...

 

[xjiang7]

Not convinced by that... the porcelain crabs we see in the hobby normally either have a white outline on each part of the body, or are striped or with clear, defined spots. This has none of those. Additionally porcelain crabs are flattened, with claws having a wide, flat lateral profile. Again this doesn't appear to have either of those features. Below is a pic of a porcelain crab vs a Tetralia crab for reference.

The porcelain carbs offered to sell are often of the two patterns as you describe, but there are “uglier” varieties. Also the shape of carapace is a good indication, true crabs are wider than porcelain crabs. However your crab looks a juvenile so hard to tell. If you see it regenerates more legs in the future we know it’s not a porcelain

 

[DSC reef]

Er... as do most crabs... 8 limbs, with two being pincers...

This threw me off too. Not convinced it's porcelain.

 

[DSC reef]

The porcelain carbs offered to sell are often of the two patterns as you describe, but there are “uglier” varieties. Also the shape of carapace is a good indication, true crabs are wider than porcelain crabs. However your crab looks a juvenile so hard to tell. If you see it regenerates more legs in the future we know it’s not a porcelain

More the reason to tell the OP it might be a porcelain and keep in the sump.

 

[Maritimer]

Crabs are "decapods" ... four pairs of walking legs and two pincers. Some, such as hermits and king crabs, have reduced the last pair to insignificance.

Everything about this crab says "Porcelain" to me; the rounded body, number of legs, the sharp angle at his "elbow" and the way the front surface of his claws faces up - and those are common hitchhikers in Gulf of Mexico liverock. The usual Gulf variety is more grey than white with little red dots.

~Bruce

 

[mtfish]

I am sticking with green porcelain crab. Attached is a list of inverts from Florida. The crab is number 102 on this list. It does not list the Genus Tetralia. Remember, this was a hitchhiker in live rock, not something bought in the "trade".
https://www2.fgcu.edu/CWI/files/SW_Florida_Inverts.pdf

 

[themcnertney]

All crabs are bad crabs!

 

[Forsaken77]

All crabs are bad crabs!

I agree! They attack your sleeping fish. But it kinda looks like a cousin of the Sally Light Foot crab with those markings.