why exactly are gorilla crabs bad?

ckovach333 · 05/28/2011, 04:19 AM

I've seen about five hairy crabs in my live rock. I only saw one fully. He has a head that comes to a point and long arms with small claws that are not black. The others I have only seen fuzzy legs. I haven't seen them come out even with the moonlight on. I'm just curious what is it these guys do to a tank? They seem like they would be tough to catch.

Cozmo4 · 05/28/2011, 06:04 AM

They can eat coral, your clean up crew and as they grow bigger, they can kill fish. I had quite a number of Xanthid crabs come in on the rock for my 185g that I set up a couple of years ago. I leaned a glass against the rocks at about a 45 degree angle where I saw them and put a raw regular table shrimp in the bottom of the glass (rubberbanded to a small rock to weight it down). I caught them all that way. They go in the glass to get the shrimp, but can't climb back out the smooth sides.

Gary Majchrzak · 05/28/2011, 06:34 AM

Crabs can be difficult to ID properly....what species are "gorilla crabs"?

Common names should be avoided since all types of crabs are often called "gorilla crabs".

certain Xanthids can be "good guys"!

since all crabs are omnivores and proper ID can be a challenge: caveat emptor!

Angel*Fish · 05/28/2011, 09:11 AM

Are you saying that somewhere in that article Ron Shimek says some crabs are good guys? I saw where he was talking about commensals, but other than that, I missed it

Gary Majchrzak · 05/28/2011, 09:22 AM

I believe Ron's opinion of crabs is clearly stated in that article

I don't think I've ever heard him call any crab a "good guy". I merely linked to that article to aid with crab identification for the OP.

In my OWN humble opinion/experience:

many commensal coral crabs, (such as the various species that are often found nestled among the branches of some corals) cause no lasting damage and are (IMO) desirable. (They protect my acros from my butterflyfish).

I agree with Ron's suggestion of a case by case evaluation of each crab.

Angel*Fish · 05/28/2011, 09:37 AM

Lol - I was just poking fun

Sorry if it didn't come off that way. On a side note, I used to have a very cool little crabby thing that lived grasping tightly on his gorgonian. Cool little thing.

Gary Majchrzak · 05/28/2011, 10:26 AM

I love fun

I love poking fun, too!

I just don't want to mislead anybody so most of the time I keep my posts fairly serious

Bigcefa · 05/28/2011, 10:57 AM

the one with a pointy head kinda sounds like a decorator crab try to get pics

ckovach333 · 05/28/2011, 11:57 AM

I'm going to try to get some pics I've got all kinds of crazy stuff in there.

05/28/2011, 04:19 AM	#1
ckovach333 Registered Member Join Date: Apr 2011 Posts: 60	why exactly are gorilla crabs bad? I've seen about five hairy crabs in my live rock. I only saw one fully. He has a head that comes to a point and long arms with small claws that are not black. The others I have only seen fuzzy legs. I haven't seen them come out even with the moonlight on. I'm just curious what is it these guys do to a tank? They seem like they would be tough to catch. Last edited by ckovach333; 05/28/2011 at 04:29 AM.

05/28/2011, 06:34 AM	#3
Gary Majchrzak Team RC Member Join Date: Nov 2001 Location: Rochester, NY Posts: 41,560	big stumbling block here! Crabs can be difficult to ID properly....what species are "gorilla crabs"? Common names should be avoided since all types of crabs are often called "gorilla crabs". certain Xanthids can be "good guys"! since all crabs are omnivores and proper ID can be a challenge: caveat emptor! __________________ over 24 years experience with multiple types of marine aquarium systems see Upstate Reef Society Forum on RC and FB GOOGLE JUNIOR'S REEF Current Tank Info: 84x24x30 265g reef past TOTM honors

05/28/2011, 09:11 AM	#4
Angel*Fish cats and large squashes Join Date: Aug 2001 Location: Houston Posts: 5,951 Blog Entries: 1	Are you saying that somewhere in that article Ron Shimek says some crabs are good guys? I saw where he was talking about commensals, but other than that, I missed it __________________ Marie So long, & thanks for all the fish! __________________________ Current Tank Info: Pairs: flame angels, cherub angels, Red Sea mimic blennies, yellow fin fairy wrasses, clowns, mandarins, blackcap basslets, shrimp gobies, damsels, dispar anthias, yellow clown gobies, threadfin cardinals --- Tanks: 100g reef, 2 x 30g refugiums

05/28/2011, 09:22 AM	#5
Gary Majchrzak Team RC Member Join Date: Nov 2001 Location: Rochester, NY Posts: 41,560	I believe Ron's opinion of crabs is clearly stated in that article I don't think I've ever heard him call any crab a "good guy". I merely linked to that article to aid with crab identification for the OP. In my OWN humble opinion/experience: many commensal coral crabs, (such as the various species that are often found nestled among the branches of some corals) cause no lasting damage and are (IMO) desirable. (They protect my acros from my butterflyfish). I agree with Ron's suggestion of a case by case evaluation of each crab. __________________ over 24 years experience with multiple types of marine aquarium systems see Upstate Reef Society Forum on RC and FB GOOGLE JUNIOR'S REEF Current Tank Info: 84x24x30 265g reef past TOTM honors

05/28/2011, 09:37 AM	#6
Angel*Fish cats and large squashes Join Date: Aug 2001 Location: Houston Posts: 5,951 Blog Entries: 1	Lol - I was just poking fun Sorry if it didn't come off that way. On a side note, I used to have a very cool little crabby thing that lived grasping tightly on his gorgonian. Cool little thing. __________________ Marie So long, & thanks for all the fish! __________________________ Current Tank Info: Pairs: flame angels, cherub angels, Red Sea mimic blennies, yellow fin fairy wrasses, clowns, mandarins, blackcap basslets, shrimp gobies, damsels, dispar anthias, yellow clown gobies, threadfin cardinals --- Tanks: 100g reef, 2 x 30g refugiums

05/28/2011, 06:04 AM	#2
Cozmo4 Registered Member Join Date: Feb 2009 Location: Fort Worth, TX Posts: 583	They can eat coral, your clean up crew and as they grow bigger, they can kill fish. I had quite a number of Xanthid crabs come in on the rock for my 185g that I set up a couple of years ago. I leaned a glass against the rocks at about a 45 degree angle where I saw them and put a raw regular table shrimp in the bottom of the glass (rubberbanded to a small rock to weight it down). I caught them all that way. They go in the glass to get the shrimp, but can't climb back out the smooth sides.

05/28/2011, 10:26 AM	#7
Gary Majchrzak Team RC Member Join Date: Nov 2001 Location: Rochester, NY Posts: 41,560	I love fun I love poking fun, too! I just don't want to mislead anybody so most of the time I keep my posts fairly serious __________________ over 24 years experience with multiple types of marine aquarium systems see Upstate Reef Society Forum on RC and FB GOOGLE JUNIOR'S REEF Current Tank Info: 84x24x30 265g reef past TOTM honors

05/28/2011, 10:57 AM	#8
Bigcefa Registered Member Join Date: Apr 2010 Posts: 843	the one with a pointy head kinda sounds like a decorator crab try to get pics

05/28/2011, 11:57 AM	#9
ckovach333 Registered Member Join Date: Apr 2011 Posts: 60	I'm going to try to get some pics I've got all kinds of crazy stuff in there.

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