MaraRavenous
Community Member
Hey everyone, my aquarium has been very healthy and happy for some time and shows consistent improvement... For everyone but my Emerald Crabs. They don't ever seem to shed, have been dropping limbs, and their shells no longer appear bright and green. They are some of my longest cared for reef inhabitants and I'm worried they won't last much longer...
Backstory: About a month after I inherited this aquarium from a friend, I picked up 4 Emerald Crabs from a local LFS. Since then I've determined that LFS has bad livestock keeping practices as many of their livestock are sick, so I don't go there anymore. Two of the crabs didn't last very long, but I've had the other two for the 5 months since. They have been model citizens for the most part, except for when they uproot a frag looking for algae once every few months.
Over the last two months their health has been rapidly declining. Both crabs have been losing limbs and although others say they will shed and recover them, I've never seen either crab have a shed the entire time I've kept them (though they have definitely grown in size) and they just keep losing more limbs, and not recovering them. One crab is missing two legs and one pincer, and the other is missing 4 legs (almost all its legs from one side!). Their shells have lost their green and become more pale and mottled in color, and I've noticed little pits in certain areas of their shell.
I've considered a few things as possible causes...
1) Parasites. Both crabs have had tiny, rust-colored mites the entire time I've had them. These tiny mites run all over their bodies but don't exist anywhere else in the aquarium, and seem to only live on the crabs. I've looked around and other threads suggest almost all emeralds have mites of some kind, so I'm wondering if this is really an issue or just par for the course.
2) Iodine deficiency. I know that lacking enough Iodine can cause issues with shedding. But my Skunk Cleaner sheds perfectly fine and has no health issues in the same tank. I feed them a varied diet... They pick for algae, are fed small bits of nori 2-3 times a week (I give it to them directly with tweezers), and scavenge meaty foods off the aquarium floor (brine shrimp, mysis shrimp, occasionally squid). There is definitely plenty of extra food as other members of my CUC have continued to propagate (stomatella, spaghetti worms, bristle worms).
3) Predation? The only fish in the aquarium are my two Ocellaris Clowns, who both give the crabs a fairly wide berth and will immediately swim away if the crabs make an aggressive gesture with their claws. The skunk cleaner likewise mostly avoids them and is quick to move if they seem annoyed by him. My CUC are all small critters that are not capable of hurting him: snails, spaghetti worms, very small bristle worms (1-2" long), conches...
4) Infighting? Perhaps they fight with each other? But the aquarium has lots of space, hiding spots, and food for them both, and they generally hang out on opposite ends of the aquarium. So I doubt it...
Please help. Any suggestions about a next course of action are appreciated! I know they are just cheap $2 crabs but I want to care for them, and being some of my first reef pets I actually really care about them.
Backstory: About a month after I inherited this aquarium from a friend, I picked up 4 Emerald Crabs from a local LFS. Since then I've determined that LFS has bad livestock keeping practices as many of their livestock are sick, so I don't go there anymore. Two of the crabs didn't last very long, but I've had the other two for the 5 months since. They have been model citizens for the most part, except for when they uproot a frag looking for algae once every few months.
Over the last two months their health has been rapidly declining. Both crabs have been losing limbs and although others say they will shed and recover them, I've never seen either crab have a shed the entire time I've kept them (though they have definitely grown in size) and they just keep losing more limbs, and not recovering them. One crab is missing two legs and one pincer, and the other is missing 4 legs (almost all its legs from one side!). Their shells have lost their green and become more pale and mottled in color, and I've noticed little pits in certain areas of their shell.
I've considered a few things as possible causes...
1) Parasites. Both crabs have had tiny, rust-colored mites the entire time I've had them. These tiny mites run all over their bodies but don't exist anywhere else in the aquarium, and seem to only live on the crabs. I've looked around and other threads suggest almost all emeralds have mites of some kind, so I'm wondering if this is really an issue or just par for the course.
2) Iodine deficiency. I know that lacking enough Iodine can cause issues with shedding. But my Skunk Cleaner sheds perfectly fine and has no health issues in the same tank. I feed them a varied diet... They pick for algae, are fed small bits of nori 2-3 times a week (I give it to them directly with tweezers), and scavenge meaty foods off the aquarium floor (brine shrimp, mysis shrimp, occasionally squid). There is definitely plenty of extra food as other members of my CUC have continued to propagate (stomatella, spaghetti worms, bristle worms).
3) Predation? The only fish in the aquarium are my two Ocellaris Clowns, who both give the crabs a fairly wide berth and will immediately swim away if the crabs make an aggressive gesture with their claws. The skunk cleaner likewise mostly avoids them and is quick to move if they seem annoyed by him. My CUC are all small critters that are not capable of hurting him: snails, spaghetti worms, very small bristle worms (1-2" long), conches...
4) Infighting? Perhaps they fight with each other? But the aquarium has lots of space, hiding spots, and food for them both, and they generally hang out on opposite ends of the aquarium. So I doubt it...
Please help. Any suggestions about a next course of action are appreciated! I know they are just cheap $2 crabs but I want to care for them, and being some of my first reef pets I actually really care about them.
I feed them nori and they get plenty of meaty food off the grounds so I swear they shouldn't be starving...
