Purple Crab Hitchhiker

mikeosoft · 09/17/2007, 08:32 PM

One of my tanks is a small 24gal nano cube which houses a young pair of H. Erectus Seahorses. The tank has been setup for over 6 months and everything seems very healthy. Today I was watching the tank and I saw a fairly large purple (about the size of a quarter) crab come out from under a rock, grab a small piece of rubble with a pineapple sponge attached to it, and drag it back to his little cave. He appeared to be eating the sponge as he pulled it back to his cave. The color of the crab was exactly the same as the purple coralline algae in the tank, there were even some lighter / white blotches mixed in to help camouflage it. The body looked similar to the emerald mithrax crabs in the tank and the shell was smooth. I wasn't able to get a very good look at the claws. I've been looking around on some hitchhiker sites and I have not found a crab that looks anything like this guy. Any ideas?

revenant · 09/17/2007, 08:49 PM

http://home2.pacific.net.ph/%7Esweet...itchcrabs.html

mikeosoft · 09/17/2007, 09:10 PM

I have been looking through that site for quite a while with no real success. It's hard just going from memory, now that I know he's there hopefully I will be able to find him and get a picture.

revenant · 09/17/2007, 09:27 PM

yeah - gotcha.. just pay special attention to carapace shape and what the claws look like.. black tips on claws always = bad. If the carapace looks like a Xanthida get it out.. or even a Mithrix it's probably not reef safe.. most Mithrix crabs will be desctructive in the reef setting.. even our somewhat beloved emerald crabs.. they're very hit and miss. sometimes they become a problem, sometimes not.. I have a large one which might be getting too big.. I'm thinking about getting the trap out. I'm not putting emeralds back in any reef tanks. in general crabs in a tank grow up, get very hungry and go after things you don't want them to.

09/17/2007, 08:32 PM	#1
mikeosoft Registered Member Join Date: Sep 2006 Location: SE Michigan Posts: 77	Purple Crab Hitchhiker One of my tanks is a small 24gal nano cube which houses a young pair of H. Erectus Seahorses. The tank has been setup for over 6 months and everything seems very healthy. Today I was watching the tank and I saw a fairly large purple (about the size of a quarter) crab come out from under a rock, grab a small piece of rubble with a pineapple sponge attached to it, and drag it back to his little cave. He appeared to be eating the sponge as he pulled it back to his cave. The color of the crab was exactly the same as the purple coralline algae in the tank, there were even some lighter / white blotches mixed in to help camouflage it. The body looked similar to the emerald mithrax crabs in the tank and the shell was smooth. I wasn't able to get a very good look at the claws. I've been looking around on some hitchhiker sites and I have not found a crab that looks anything like this guy. Any ideas?

09/17/2007, 09:27 PM	#4
revenant Registered Member Join Date: Jun 2006 Location: Thousand Oaks, CA Posts: 200	yeah - gotcha.. just pay special attention to carapace shape and what the claws look like.. black tips on claws always = bad. If the carapace looks like a Xanthida get it out.. or even a Mithrix it's probably not reef safe.. most Mithrix crabs will be desctructive in the reef setting.. even our somewhat beloved emerald crabs.. they're very hit and miss. sometimes they become a problem, sometimes not.. I have a large one which might be getting too big.. I'm thinking about getting the trap out. I'm not putting emeralds back in any reef tanks. in general crabs in a tank grow up, get very hungry and go after things you don't want them to. Last edited by revenant; 09/17/2007 at 09:33 PM.

09/17/2007, 08:49 PM	#2
revenant Registered Member Join Date: Jun 2006 Location: Thousand Oaks, CA Posts: 200	http://home2.pacific.net.ph/%7Esweet...itchcrabs.html

09/17/2007, 09:10 PM	#3
mikeosoft Registered Member Join Date: Sep 2006 Location: SE Michigan Posts: 77	I have been looking through that site for quite a while with no real success. It's hard just going from memory, now that I know he's there hopefully I will be able to find him and get a picture.