What kind of crab is this?

allendehl · 11/20/2018, 10:02 PM

Hello folks.

After a little over a year I have a crab invasion in my tank. I was able to capture 4 gorilla with bottles but then the others have gotten smart. Though I think they not gorillas. Most of them are doing some kind of karate move with their dusters.
Well, I manage to capture one more and before I decide his fate in want to confirm his intentions.
It seems greenish...maybe an emerald?

Sent from my SM-N950U using Tapatalk

Sk8r · 11/20/2018, 11:46 PM

Not mithrax, I think. Claws are outsized and problematic.

cincyjim · 11/21/2018, 04:57 AM

It almost favors a Porcelain Crab. What do you when you say "dusters"? Below is the description of them I got from Live Aquaria site. If it is one these then its a keeper.

The Porcelain Crab is common throughout the tropical oceans of the world, and has a flat, round body with two large front claws. They are brown and orange in coloration with bright blue spots. These crabs have a pair of front arms called maxillipeds, which have ends that are feather-like in appearance. They use these appendages to filter the water for any passing food. They are peaceful and interesting invertebrates for the marine aquarium.

Sugar Magnolia · 11/21/2018, 07:05 AM

Looks like a porcelin crab.

Crooked Reef · 11/21/2018, 07:08 AM

If they are constantly waving their feather duster things in front of their face like they are using them to eat from the water column, they are porcelain crabs and pretty much the only reef safe crab and I actually trust them. The colors kind of match the ones on liveaquaria

Mithrax, hermits, all of the reef safe ones are opportunistic and will attack and kill small sleeping fish if given the chance.

allendehl · 11/21/2018, 07:23 AM

This one in particular doesn't seem to be doing the feather duster move. Maybe because it was scared. Most of the ones I still have in the tank do.

Thank you all!!

Sent from my SM-N950U using Tapatalk

Uncle99 · 11/21/2018, 09:10 AM

It is always prudent and safe to not trust any crab, there is no such thing as a reef safe crab. They are opportunistic, thus if given the chance........

I had one of these, quite resilient and as it grew acted like a predator.

Since going "crab free" over 2 years ago, I have no coral retracts, no missing inhabitants, not even a snail.

allendehl · 11/21/2018, 09:31 AM

Yeah! I pulled it into QT. Hard to capture these karate kids. Bottle traps did it for some gorilla but these folks seem a bit smarter and I have a ton of them...enough for a good stew probably.

Sent from my SM-N950U using Tapatalk

NeonFish · 11/21/2018, 09:54 PM

porcelain crab has 3 pairs or legs instead of 4. more like a filter feeder than a scavenger.

doradosteve · 11/23/2018, 08:38 PM

petrolisthes armatus aka Green Porcelain Crab

11/20/2018, 10:02 PM	#1
allendehl Registered Member Join Date: Aug 2017 Location: Miami, FL Posts: 692	What kind of crab is this? Hello folks. After a little over a year I have a crab invasion in my tank. I was able to capture 4 gorilla with bottles but then the others have gotten smart. Though I think they not gorillas. Most of them are doing some kind of karate move with their dusters. Well, I manage to capture one more and before I decide his fate in want to confirm his intentions. It seems greenish...maybe an emerald? Sent from my SM-N950U using Tapatalk __________________ [Newbie here so please take my opinions carefully] Current Tank Info: Red Sea Reefer 350 (72G) \| Jebao DCT 4000 (1056 GPH Max) \| Reef Octopus 152-S \| 2 X Jebao PP8 (2100 GPH Max)

11/20/2018, 11:46 PM	#2
Sk8r RC Mod Join Date: Feb 2006 Location: Spokane WA Posts: 34,628 Blog Entries: 55	Not mithrax, I think. Claws are outsized and problematic. __________________ Sk8r Salinity 1.024-6; alkalinity 8.3-9.3 on KH scale; calcium 420; magnesium 1300, temp 78-80, nitrate .2. Ammonia 0. No filters: lps tank. Alk and cal won't rise if mg is low. Current Tank Info: 105g AquaVim wedge, yellow tang, sailfin blenny,royal gramma, ocellaris clown pair, yellow watchman, 100 microceriths, 25 tiny hermits, a 4" conch, 1" nassarius, recovering from 2 year hiatus with daily water change of 10%.

11/21/2018, 04:57 AM	#3
cincyjim Registered Member Join Date: Sep 2011 Location: Northern Virginia Posts: 1,147	It almost favors a Porcelain Crab. What do you when you say "dusters"? Below is the description of them I got from Live Aquaria site. If it is one these then its a keeper. The Porcelain Crab is common throughout the tropical oceans of the world, and has a flat, round body with two large front claws. They are brown and orange in coloration with bright blue spots. These crabs have a pair of front arms called maxillipeds, which have ends that are feather-like in appearance. They use these appendages to filter the water for any passing food. They are peaceful and interesting invertebrates for the marine aquarium. __________________ Jim Current Tank Info: SCA 150G, 5 inch sand bed, 2 Tunze 6095s, ReefBreeders v2+ 50" with 2 all Blue Reefbrites, and Continuous Water Change System

11/21/2018, 07:05 AM	#4
Sugar Magnolia Registered Member Join Date: Feb 2003 Location: Northern VA Posts: 17,691	Looks like a porcelin crab. __________________ Adrienne The only thing to fear is fear itself....and spiders.

11/21/2018, 07:08 AM	#5
Crooked Reef Registered Member Join Date: Feb 2014 Posts: 1,765	If they are constantly waving their feather duster things in front of their face like they are using them to eat from the water column, they are porcelain crabs and pretty much the only reef safe crab and I actually trust them. The colors kind of match the ones on liveaquaria Mithrax, hermits, all of the reef safe ones are opportunistic and will attack and kill small sleeping fish if given the chance. __________________ “In wine there is wisdom; in beer there is freedom, in water there is bacteria.” - Benjamin Franklin Current Tank Info: 90 gallon reef. Biocube 29 lionfish tank. Mantis tank.

11/21/2018, 07:23 AM	#6
allendehl Registered Member Join Date: Aug 2017 Location: Miami, FL Posts: 692	This one in particular doesn't seem to be doing the feather duster move. Maybe because it was scared. Most of the ones I still have in the tank do. Thank you all!! Sent from my SM-N950U using Tapatalk __________________ [Newbie here so please take my opinions carefully] Current Tank Info: Red Sea Reefer 350 (72G) \| Jebao DCT 4000 (1056 GPH Max) \| Reef Octopus 152-S \| 2 X Jebao PP8 (2100 GPH Max)

11/21/2018, 09:10 AM	#7
Uncle99 Crab Free Zone Join Date: Sep 2017 Location: Ontario, Canada Posts: 2,906	It is always prudent and safe to not trust any crab, there is no such thing as a reef safe crab. They are opportunistic, thus if given the chance........ I had one of these, quite resilient and as it grew acted like a predator. Since going "crab free" over 2 years ago, I have no coral retracts, no missing inhabitants, not even a snail.

11/21/2018, 09:31 AM	#8
allendehl Registered Member Join Date: Aug 2017 Location: Miami, FL Posts: 692	Yeah! I pulled it into QT. Hard to capture these karate kids. Bottle traps did it for some gorilla but these folks seem a bit smarter and I have a ton of them...enough for a good stew probably. Sent from my SM-N950U using Tapatalk __________________ [Newbie here so please take my opinions carefully] Current Tank Info: Red Sea Reefer 350 (72G) \| Jebao DCT 4000 (1056 GPH Max) \| Reef Octopus 152-S \| 2 X Jebao PP8 (2100 GPH Max)

11/21/2018, 09:54 PM	#9
NeonFish Registered Member Join Date: May 2007 Location: Petaluma Posts: 370	porcelain crab has 3 pairs or legs instead of 4. more like a filter feeder than a scavenger.

11/23/2018, 08:38 PM	#10
doradosteve Registered Member Join Date: Jan 2016 Location: Palm Beach Posts: 145	petrolisthes armatus aka Green Porcelain Crab