Crab ID?

[pccharity]

We would appreciate any info on this crab. We have seen him in our tank before, he was a hitchhiker in our LR, we finally caught him tonight and would like to know if he is dangerous. If he is can we just keep him in the filter system since there are already snails down there and he seems completely nocturnal? Also how big will he get?

 

[1journeyman]

Looks like an emerald crab to me.

 

[jafrench]

An emerald crab. I have two and would recommend to anyone looking for algae cleanup. My two are awesome eaters. Definitely keep him. What luck, being a hitchhiker.

 

[viper_930]

Doesn't look like an emerald to me.
By the pic, the claws look sharp, which is a bad sign.

 

[1journeyman]

Viper, look again closely... those claws are blunted.. either that or I've encountered some dang "sharp" clawed crabs..

 

[fishmamma]

Certainly no expert on the subject but that doesn't look like any emerald crab I have ever had.

 

[viper_930]

I'm looking, and the claws look pretty sharp.
They don't look the same to me. :thinking:

 

[jdragunas]

i agree, not an emerald crab.
But i disagree, i think the claws are pretty blunted. Look at how they round out at the tip. The pic of the emerald crab you posted has pointed claws.
This one looks pretty safe to me, but that's JMO...

 

[viper_930]

Anybody else think they're sharp or blunt? Or if PCcharity could just confirm it. I swear on my comp the claws look sharp and the emeralds' are dull.

All emerald crabs' claws are not sharp. They're not predators and have no use for sharper claws.

 

[symon]

they look small and blunted to me, Rip one off and take a side view pic !!!!!!! :thinking:
Actually look at the 2nd pic, they do seem more sharp then i saw before, also seem to open more then i 1st thought!

 

[fishmamma]

Emeralds have disc shaped pincers, this other crab does not appear to have discs. There, now we can debate 'sharp' and 'blunt'. ***)

 

[celacanthr]

I agree, that it isn't an emerald, or at least not Mithrax sculptus, the claws do look different to me, not sure I would say it is blunt, but I don't think it is sharp either. Also the legs look different, also we need to remember that water refraction could change how we see them....

 

[dogstar]

Could be Cancer antennarius...... I hate crabs. Dont trust any of em.

 

[kimc]

Claws look sharp to me. Don't think it's an emerald crab.

 

[oceanists]

they look blunt to me , i was thinking sally light foot with midget claws

 

[bang guy]

Look on the inside of the left "elbow". If there's a red dot then it's an Emerald Crab.

 

[1journeyman]

Dang taxonomy....
Viper, you are absolutely correct, those are definitely 2 different looking crabs. My mistake.
Now, on to the subject at hand... I've got 6 "Emeralds" in my tank. 5 look like the pic on the left, 1 (the biggest of course) looks more ike the one on the right.
I always assumed "emerald" was a Genus name, not a specific species.
Anyway, so far my crabs are all peaceful.

 

[vejomatic]

the backside of a bread knife is "rounded" yet the actual cutting side is quite sharp.

~mc

 

[st.george]

Look like a mud crab to me and by the way what do you all think this is? =PIC

 

[jdragunas]

my bad. They do look sharp... in the first pic they look small and blunted, but in the 2nd picture, they do look sharp.
and, st. george, i can't decipher your pic. I can see the general shape of a crab, but everything is green, so i can't really tell what kind of crab it is...