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FAQs about Emerald Green, Mithrax/Mithraculus Crabs 2

Related Articles: Mithrax Crabs, Arrow Crabs, Crabs

FAQs on: Emerald Green Crabs 1,
FAQs on: Mithrax ID, Mithrax Behavior, Mithrax Compatibility, Mithrax Stocking/Selection, Mithrax Systems, Mithrax Feeding, Mithrax Disease, Mithrax Reproduction,

Related FAQs: Marine Crabs 1, Marine Crabs 2Marine Crabs 3, Marine Crabs 4, Marine Crab Identification, Marine Crab Selection, Marine Crab Compatibility, Marine Crab Systems, Marine Crab Feeding, Marine Crab Reproduction, Marine Crab Disease, Micro-Crustaceans, Amphipods, Copepods, Mysids, Hermit Crabs, Shrimps, Cleaner Shrimps, Banded Coral Shrimp, Mantis Shrimp, Anemone Eating Shrimp Crustacean Identification, Crustacean Selection, Crustacean Behavior, Crustacean Compatibility, Crustacean Systems, Crustacean Feeding, Crustacean Disease, Crustacean Reproduction,


white powdery look... On Mithraculus, snail...         2/5/16
I have had 2 emerald crabs die. Both developed a white powdery looking substance on their bodies.
<Precipitation? From... supplement use likely>
I have 6 snails and a few have the same substance, 1 extreme. I have a pajama cardinal, a banded coral shrimp and a cleaner shrimp with no apparent issues. Any ideas?
<Stenopids will eat all other small crustaceans, snails.... were the bodies intact? Are you sure these weren't/aren't simply molted exoskeletons (the Mithraculus hiding?). Bob Fenner>
Thanks, Greg
Re: white powdery look         2/5/16

Thanks for the reply. No supplement use. Watched the crabs slowly die.
<Slowly? How much time; please describe their behavior. What do you feed?
Have you read on WWM re this species?
The one snail is covered with this. Would a picture help?
<Yes! As close up, highly resolved image as you can provide. B>
Thanks, Greg

Red Emerald Crab; ID, comp.      9/15/15
So I will begin with the disclosure that I know emerald (Mithrax) crabs have a dubious reputation as reef tank inhabitants.
<Mithraculus are opportunistic; like other Decapods>

I don't hold opportunistic behavior against them but one of them is heading for a new home. My inquiry is in regards to your opinion of the traditional emerald crab versus the, sold by online vendors and my lfs, red emerald crab. He(big red)is described as being identical to a traditional emerald crab save for coloration. Do you have any knowledge of this crab variation or his possible variation in behavior?
<.... some folks purport this is also Mithraculus sculptus>
There are three Mithrax crabs in my 65 gallon reef, one is to tiny to be the culprit, and one each of a large red and large green Mithrax. Just trying to make the best decision, without hard evidence, as to who is tearing my green star polyps off from the base. I did consider the health of the coral and definitely seems to be some clawed species is clipping the polyps off leaving the purple base intact. Any input as to the potential difference in culpability. I did search for these red Mithrax variants and found little evidence of them on your site. Hence the email and appreciation of your opinion.
<Both, all are suspect. I'd remove them. Bob Fenner>

Emerald crab issue.   4/18/11
Hello, thank you for taking time with this issue!
<Welcome Boo>
My system is a 125 gallon system with one Clarkii species clown, Condylactis Anemone (saved from horrible treatment at the LFS), and two damsels. I also have one Mithrax species crab.
<Mmm, some members of this genus (Mithraculus for some now) do get quite large, predaceous>
My issue is that the crab seems to have a tentacle growing from one of its lower legs!
It's known to fight my anemone for the occasional fresh piece of seafood, so I know it's come into contact with the Condylactis on occasion.
<Evidently so>
My obvious idea is that he got a tiny piece of the foot stuck in a joint of that leg and that piece is regenerating a new anemone.
However, I'm wondering if it could be an illness or parasite,
hence writing you today. In lieu of a picture (which I don't have access to) I can describe it.
It's *exactly* like a smaller version of the pink tentacles of my anemone.
It grows a few millimeters per week, and doesn't seem to be affecting the Mithrax at all.
Water parameters for nitrogen compounds are perfect, pH is 8.3, and I dose the tank with PurpleUp weekly.
Thank you!
<I either wouldn't worry, or remove the crab/tentacle together or separately... Let's see, that about covers all contingencies. Oh, yeah, read here: http://wetwebmedia.com/mithraxfaqs.htm
Bob Fenner>

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