Colourful crab hitchhiker

mattybecks · Oct 10, 2019

Hello.

Hoping someone could help me ID this hitchhiker who has been in my tank for a few weeks now.
He is quite small, so the video and pics wont be all that clear, my apologies for that.

Legs are yellow, which turn into a light red pinky/orange colour. The body of the crab is purple, peppered with little white spots. The claws are white, and rather slim.

flsalty · Oct 10, 2019

Try lookingg up Sally Lightfoot crab to see if it looks like that. Hard to tell from those pics but that's what came to mind.

Bbfishb81 · Oct 10, 2019

I agree, looks like it might he a Sally.

KJ · Oct 10, 2019

Hard to tell from those pics.

reef lover · Oct 11, 2019

Seems to be picking at detritus in rhe vid...thats a good sign.

mattybecks · Oct 12, 2019

I had rearrange my rock work a little this weekend. One of the rocks I picked up he was hiding in, I almost got a photo be he scuttled off and disappeared again in the water after pinching me surprisingly hard. He walks around seemingly picking up invisible things on the surface of the rock. I assume it's detritus and tiny algaes.
He changed coloured very quickly when I first pulled him out the tank. Went more purple and his legs seemed more yellow (it might have just been because he was out the water) I had a closer look at the Sally light foot crabs and the colours don't seem the same as them. Maybe the juveniles are just different coloured?
I'll see as he grows if I can get a better picture. He must only be about 2 - 3cm now

mattybecks · Nov 7, 2019

Got a better video. Getting more friendly now.

Lovemyreef2015 · Nov 7, 2019

mattybecks said:
Got a better video. Getting more friendly now.

Looks like a Perisesarma bidens ( Red-clawed crab)

Malifry97 · Nov 7, 2019

Lovemyreef2015 said:
Looks like a Perisesarma bidens ( Red-clawed crab)

He would be dead by now then. Red claw crabs are brackish crabs and are semi aquatic. They have to be able to leave the water.

DSC reef · Nov 7, 2019

Malifry97 said:
He would be dead by now then. Red claw crabs are brackish crabs and are semi aquatic. They have to be able to leave the water.

Semi aquatic means they can tolerate both so no, it wouldn't be dead by now. Do you have a guess with ID as to help the OP??

BeardedMcG · Nov 7, 2019

No idea but it's a good looking crab.

Lovemyreef2015 · Nov 7, 2019

Malifry97 said:
He would be dead by now then. Red claw crabs are brackish crabs and are semi aquatic. They have to be able to leave the water.

They can be housed in freshwater or saltwater but live a longer heather life in brackish. And like said above they can handle being fully submerged or having a paludarium to live in. I've done my research on this specific species of crab before I made any attempt to make a ID.

Malifry97 · Nov 7, 2019

DSC reef said:
Semi aquatic means they can tolerate both so no, it wouldn't be dead by now. Do you have a guess with ID as to help the OP??

no I do not have another suggestion, but everything I have read about them has said that they need a paladarium. Sorry, I could be wrong.

Malifry97 · Nov 7, 2019

DSC reef said:
Semi aquatic means they can tolerate both so no, it wouldn't be dead by now. Do you have a guess with ID as to help the OP??

Also, semi aquatic means that they live partly on land partly in water.

DSC reef · Nov 7, 2019

Malifry97 said:
Also, semi aquatic means that they live partly on land partly in water.

Thanks for the education,lol. Feel free to help the OP if you get a chance

I wonder where it says, will die if completely under water....

Malifry97 · Nov 7, 2019

DSC reef said:
Thanks for the education. Feel to help the OP if you get a chance

Yep no problem. Im looking now.

Malifry97 · Nov 7, 2019

DSC reef said:
Thanks for the education,lol. Feel free to help the OP if you get a chance I wonder where it says, will die if completely under water....

Whenever I see something that states that red clawed crabs can live submerged I'll come back and admit I was wrong.

Lovemyreef2015 · Nov 7, 2019

To the OP this is one of the things I found by researching this species of crab. I could be wrong with my ID as crabs are not easy to identify correctly. Regardless it's definitely a cool looking crab.
"They don't NEED air to survive, but they really like being able to get out of the water every once in awhile. If you don't have any land they will simply leave and go somewhere else. There is no amount of sealing a tank that can stop a red claw crab that wants to leave."

stanleo · Nov 7, 2019

Crabs are weird too when researching them. I have a freshwater panther crab that is huge in a planted tank. I researched the crap out of them and found conflicting articles stating that they need a land structure AND that they don't. I have had this guy for almost two years fully submerged and he seems perfectly at home. He does like going into the floating wysteria and searching around the rim of the tank. I have even found him crawling on the floor. That's when I sealed the lid good and tight so it never happened again. I think a lot of "research" that we find when looking for information is anecdotal from aquarists like us and not from experts on crabs so you have to take the source of information into consideration.

Side note, that crab you have is awesome.

mattybecks · Nov 10, 2019

Thank you everyone for the replies and insight, it is much appreciated.
I think he is really cool looking! He is starting to come out now when I feed the other fish.

Maybe this could help us ID him, I collected him from rocks in the ocean about waist/shoulder height, near the bottom. The ocean/beach I was at has no estuaries or rivers nearby. Dubai is a desert so I actually don't know of any rivers here. Just plain old saltwater. Just from the area I have collected him it seems he is a full marine crab.

As he continues to grow and come out more Ill keep you all updated.