Help! Emerald/Mithrax crabs legs fallen off!

[FishmanJosh]

I came down yesterday only to find that every single one of my emerald crabs legs had called off! It's defianatley not and empty shell after molting because I can see it's little mouth flicky things moving and he is dragging himself around the tank! I feel quite sorry for him, and all my water parameters are perfect. Water absolutely fine, no nitrates,ammonia, phosphates nothing. Calcium levels fine as are kh and ph. At the same time my sand sifting starfish has also died and gradually been eaten. Don't know what's wrong!!!!! All I have are some turbos, red legs, commn clown, and a royal gramma. None of my tank mates have ever been aggressive towards each other so I really don't know what's wrong! Tank is 20g/90litres (approx) nano. Please help! I will shut up now.

 

[ryshark]

I came down yesterday only to find that every single one of my emerald crabs legs had called off! It's defianatley not and empty shell after molting because I can see it's little mouth flicky things moving and he is dragging himself around the tank! I feel quite sorry for him, and all my water parameters are perfect. Water absolutely fine, no nitrates,ammonia, phosphates nothing. Calcium levels fine as are kh and ph. At the same time my sand sifting starfish has also died and gradually been eaten. Don't know what's wrong!!!!! All I have are some turbos, red legs, commn clown, and a royal gramma. None of my tank mates have ever been aggressive towards each other so I really don't know what's wrong! Tank is 20g/90litres (approx) nano. Please help! I will shut up now.

Maybe you have some sort of hitchhiker predator. At night when all the lights are out observe the tank. If possible use red light to see. What I have done to get red light is take a weak flashlight and put it inside a clear red plastic cup. Typically the creatures can't see the red light waves as well.
As far as saving the emerald crab, I don't think there is anything you can do.

 

[FishmanJosh]

Thanks for the reply but the tank has been set up for almost a year now and I havent had any sign of any hitchhikers or introdcued anything new to the tank lately. I will certainly try the red light thing I never new they couldent see it. Thanks.

 

[milhous3er]

If the crab were to molt, wouldn't his new legs come with his new shell ??

 

[harmy4993]

If it survives to its molt i belive so

 

[FishmanJosh]

Yeah I read some stuff and if he does survive then he should get new legs. Still doesn't explain why they've fallen off though. Thanks for replying.