Red Mithrax Crab eating Finger Leather Coral?

bumbus · 04/17/2019, 04:40 AM

Here's the rundown... I have a 32 gal AIO reef tank that has been fighting a battle with GHA and bubble algae lately. I have recently gotten the water parameters back into proper order (only the phosphate was actually a problem) but still have some nuisance bubble algae and a little GHA that I have not been able to get fully under control. (It's very hard to get to with my rock placement.) The other day I decided to chance it and pick up a Mithrax crab to help with this problem. My LFS only had a Red Mithrax crab available at the time, and I had always heard they are for all intents and purposes the same as the Emerald variety, so I picked him up and brought him home with me. He was a little bigger then I had planned on purchasing for my tank, I would say around a quarter in size, but again I decided to chance it. (I also want to point out I am unsure of the sex as I forgot to examine the belly before adding em to the tank, but I believe it to be male as the pincers are quite large!) After acclimation I released him into the tank. He immediately started to scrape the rock work looking for food so I kept an eye on him for a while, but all seemed good and dandy so I thought I'd see what comes of it. The next morning I awake to find he immediately made an impact on a few patches of bubble algae that I had trouble getting to, and needless to say I was thrilled! Although I also noticed my Finger Leather Coral hadn't fully expanded itself throughout the day as it normally does. After observing normal behavior throughout the day I decided to watch him for a while after the lights go out. So after a while of him moving around the rock work he eventually encounters my Finger Leather Coral and climbs right on top of it. Much to my chagrin I watch as he digs his claw into the deflated flesh of the coral and rips a large chunk off to eat! Well, I immediately spring into action and set about trying to wrangle him out of the tank, trying various methods that failed to work. (That's another problem, but patience I know is key to wrangling him up.)

Now the questions... What is the general consensus towards Mithrax crabs, and could it be because it was Red vs Emerald or whatnot? I've read a lot of information on these crabs and have read both the pros and cons that are out there, yet I have never read of them going for leather corals... could there be an explanation on why he would go for that? (The coral was doing EXTREMELY well prior to the addition of the crab.) What would be the general leaning of people here on whether I should chance it again and go with another Mithrax, or just grin and bear it with the manual removal of the small clusters of bubble algae that I can't seem to squash. (I am afraid if I have a lapse of time during which the tank isn't properly maintained it could easily bounce back and take over.) Also, if I do go the route of swapping out this guy for another would you recommend feeding it plenty as to discourage ravenous behavior that could lead to consumption of corals? Oh yeah, and is it also a better idea to go with a known female over a male?

Sorry for the longer post, just wanted to be thorough! Thanks for any and all information you might provide!!

mcgyvr · 04/17/2019, 04:45 AM

It happens.. They may try to supplement their feeding with corals/inverts or whatever if not well fed with algae.. That can basically apply to any crab..
Hermits can go after snails, etc...
I tend to avoid crabs now..

04/17/2019, 04:40 AM	#1
bumbus Registered Member Join Date: Jun 2018 Posts: 11	Red Mithrax Crab eating Finger Leather Coral? Here's the rundown... I have a 32 gal AIO reef tank that has been fighting a battle with GHA and bubble algae lately. I have recently gotten the water parameters back into proper order (only the phosphate was actually a problem) but still have some nuisance bubble algae and a little GHA that I have not been able to get fully under control. (It's very hard to get to with my rock placement.) The other day I decided to chance it and pick up a Mithrax crab to help with this problem. My LFS only had a Red Mithrax crab available at the time, and I had always heard they are for all intents and purposes the same as the Emerald variety, so I picked him up and brought him home with me. He was a little bigger then I had planned on purchasing for my tank, I would say around a quarter in size, but again I decided to chance it. (I also want to point out I am unsure of the sex as I forgot to examine the belly before adding em to the tank, but I believe it to be male as the pincers are quite large!) After acclimation I released him into the tank. He immediately started to scrape the rock work looking for food so I kept an eye on him for a while, but all seemed good and dandy so I thought I'd see what comes of it. The next morning I awake to find he immediately made an impact on a few patches of bubble algae that I had trouble getting to, and needless to say I was thrilled! Although I also noticed my Finger Leather Coral hadn't fully expanded itself throughout the day as it normally does. After observing normal behavior throughout the day I decided to watch him for a while after the lights go out. So after a while of him moving around the rock work he eventually encounters my Finger Leather Coral and climbs right on top of it. Much to my chagrin I watch as he digs his claw into the deflated flesh of the coral and rips a large chunk off to eat! Well, I immediately spring into action and set about trying to wrangle him out of the tank, trying various methods that failed to work. (That's another problem, but patience I know is key to wrangling him up.) Now the questions... What is the general consensus towards Mithrax crabs, and could it be because it was Red vs Emerald or whatnot? I've read a lot of information on these crabs and have read both the pros and cons that are out there, yet I have never read of them going for leather corals... could there be an explanation on why he would go for that? (The coral was doing EXTREMELY well prior to the addition of the crab.) What would be the general leaning of people here on whether I should chance it again and go with another Mithrax, or just grin and bear it with the manual removal of the small clusters of bubble algae that I can't seem to squash. (I am afraid if I have a lapse of time during which the tank isn't properly maintained it could easily bounce back and take over.) Also, if I do go the route of swapping out this guy for another would you recommend feeding it plenty as to discourage ravenous behavior that could lead to consumption of corals? Oh yeah, and is it also a better idea to go with a known female over a male? Sorry for the longer post, just wanted to be thorough! Thanks for any and all information you might provide!!

04/17/2019, 04:45 AM	#2
mcgyvr Registered Member Join Date: Sep 2003 Location: North Carolina Posts: 20,050	It happens.. They may try to supplement their feeding with corals/inverts or whatever if not well fed with algae.. That can basically apply to any crab.. Hermits can go after snails, etc... I tend to avoid crabs now.. __________________ Who me?