What kind of hermit crab?

[markc212]

We've had this hermit crab for a few months now. Everything was just fine as he's very active, not shy, and has brilliant colors. But recently, we introduced some zoos into the tank and he started picking on them like cinnabons! We relegated him to the refugium for the time-being. Now the question is what kind of hermit is he, and is there any doubt he's not reef-safe? We've scoured many books but can't find a good ID. The legs have brilliant purple, red, and blue markings, and you can see lots of hair on those legs.

 

[flower]

Quote:
Originally Posted by markc212 http:///t/387737/what-kind-of-hermit-crab#post_3413708
We've had this hermit crab for a few months now. Everything was just fine as he's very active, not shy, and has brilliant colors. But recently, we introduced some zoos into the tank and he started picking on them like cinnabons! We relegated him to the refugium for the time-being. Now the question is what kind of hermit is he, and is there any doubt he's not reef-safe? We've scoured many books but can't find a good ID. The legs have brilliant purple, red, and blue markings, and you can see lots of hair on those legs.

LOL...he is a reef safe hermit crab and he most likely was picking at algae on the zoa, doing the coral a favor...let him out of prison. Oh and they call them blue legs, scarlet legs, red legs...just to identify them for all I can tell. LOL..they do have hairy legs....what a great camera you have, and you took an awesome close up picture.

 

[markc212]

Unfortunately, I'm pretty sure he was eating the zoos. Big chunks were coming off and floating into the water. You could definitely see the coral torn up and flailing. Very disturbing. I really wanted to make the same assumption too, but the evidence was all going in the wrong direction.
I feel horribly that I put him into the refugium. It's not even a sump one, it's a HOB refugium. It's gotta be cramped in there!
I showed the same pic to my local excellent LFS, and they said that practically all hermits are reef safe..... until they get to be a certain size. Then, it's possible that all bets are off. This guy is the biggest hermit in my tank, but I wouldn't consider him to be huge.

 

[flower]

Quote:
Originally Posted by markc212 http:///t/387737/what-kind-of-hermit-crab#post_3413713
Unfortunately, I'm pretty sure he was eating the zoos. Big chunks were coming off and floating into the water. You could definitely see the coral torn up and flailing. Very disturbing. I really wanted to make the same assumption too, but the evidence was all going in the wrong direction.
I feel horribly that I put him into the refugium. It's not even a sump one, it's a HOB refugium. It's gotta be cramped in there!
I showed the same pic to my local excellent LFS, and they said that practically all hermits are reef safe..... until they get to be a certain size. Then, it's possible that all bets are off. This guy is the biggest hermit in my tank, but I wouldn't consider him to be huge.
Well, in this hobby there are always exceptions....I had a Hippo tang once that literally ate the Xenia tops off of them. The LFS owner didn't believe me, but took him back. Next visit, he confirmed that it did eat coral, because it tore into his.....and said he sold it to a guy with a fish only tank.

 

[saxman]

That hermit is NOT reef safe. It's similar to Dardanus sp., and may actually be from that genus. FWIW, most of the "hairy" hermits aren't reef safe. That being said, ALL hermits are opportunistic omnivores, and they will pretty much eat whatever comes along and is easy to grab.

 

[1guydude]

+1 hairy hermits and hairy crabs are a no go in the reef tanks!
Not sure of proper id but he looks rather large, almost bigger than ur emerald! I had a strawberry hermit the size of a golfball when i 1st started. I found out that he had eatin $40 in feather dusters....cuz i caught him in the act! He went back the lfs as a donation!

 

[saxman]

OK...so curiousity got the better of me, so I researched it. Your crab is Dardanus sanguinocarpus (AKA the bloody hermit crab) which is quite destructive, as is the entire genus. I'm not sure of its entire range, but it is endemic to the HI and Marshall Islands and Marquesas.

 

[markc212]

Thanks for the insight. I didn't know about the hairy-legs clause. Unfortunately, while I love this guy because of his striking colors, I might have to trade him back to the LFS. Last time, they gave me $12 store credit for trading in a gigantic emerald crab that was feasting on my torch coral. Fluorescent bits floating everywhere! And I thought emeralds were reef-safe too.
The funny thing is that everyone tells me that my Halloween Hermit isn't reef safe, but I'm 90% sure he hasn't touched a single coral..... yet.

 

[1guydude]

ya mine was a dardanus magnifica or something similar...i dont trust any of the bigger hermits...even the smaller ones can get to be to big eventually!

 

[saxman]

Your "Hallowe'en hermit" is Ciliopagurus strigatus (AKA Cone shell hermit), which as the common name suggests, typically inhabits empty cone shells. It's a 1" species that is endemic to HI and the Indo-Pacific.
The hermit most folks refer to as the "Hallowe'en hermit" is a 3/4" crab (Calcinus elegans) and is also referred to as the elegant hermit. It is also a HI/Indo-Pacific denizen.
The most commonly offered Dardanus species is D. megistos (AKA white-spotted hermit) and can reach 12" in length!
HTH

 

[1guydude]

Thats the one i had saxman! Awsome creature just no good for a reef tank...maybe a FOWLR tank! Deff not a reef! LOL

 

[markc212]

Saxman,
How is it possible that you know this much about hermit crabs? Is it just hermits, or everything aquarium? The specificity of your responses is incredible!

 

[1guydude]

some people have been doing this a loooonnngggg time!

j/p saxman!

 

[saxman]

Quote:
Originally Posted by 1guyDude http:///t/387737/what-kind-of-hermit-crab#post_3414208
some people have been doing this a loooonnngggg time!

j/p saxman!
Actually, I HAVE been doing this a LONG time...over 50 years of FW (which I now know little about), and over 20 years of SW. I shudder to think how many tanx I've set up and torn down, and each time, I learn something new.
Renee (Cranberry) and I have a penchant for the obscure/oddball fish and critters that most peeps don't generally keep, or that there is little info about (you've seen some of our fish!). A good part of the "fun" is "the hunt", either for specimens, or information. I used to be one of those "I don't tell my wife how much I just spent on the hobby" people, but Renee and I just got lucky when we realized that both of us are SW junkies. The only problem with that is now there isn't anyone to say "NO"...

 

[markc212]

Well, I traded Harry the Bloodly Hermit Crab back to the LFS for $12 worth of chaetomorpha. While not an exciting trade, at least I got some cash value from the transaction as well as a few month of enjoying his distinctive colors and interesting personality. I'm was very sad to see him go, and hope he finds a good home.
Thanks to everyone on the board, especially Saxman, for helping with the ID and the in-depth details.
Mark.