Horseshoe crab with shell disease?

[Nemz]

I have an adult female horseshoe crab for about 1.5 year now. She is doing very well. She eats well, unbothered, and very actively digging . The problem is she has developing shell disease . No other horseshoe crabs have this problem. Its only her. Her shell is very rough as she has freckled holes all over her frontal carapace. It is starting to develop every part of the shell. This is problematic as the thick layer is being shredded by algae or fungus. I started dosing calcium/kH thinking she may regenerate faster but it has no effects. She has not molt a single time so I assume she is old.

I am open to any suggestions on ways to treat this disease (I acknowledge that this is a rare discussion case as most threads cover fish related problems)

 

[Jay Hemdal]

I have an adult female horseshoe crab for about 1.5 year now. She is doing very well. She eats well, unbothered, and very actively digging . The problem is she has developing shell disease . No other horseshoe crabs have this problem. Its only her. Her shell is very rough as she has freckled holes all over her frontal carapace. It is starting to develop every part of the shell. This is problematic as the thick layer is being shredded by algae or fungus. I started dosing calcium/kH thinking she may regenerate faster but it has no effects. She has not molt a single time so I assume she is old.

I am open to any suggestions on ways to treat this disease (I acknowledge that this is a rare discussion case as most threads cover fish related problems)

Once produced, their shells have little ability to self-repair. Improvement in shells comes through molting. Broken telson, missing legs, pockmarks n the shell all get repaired through molting.
I think the real issue is why hadn’t this animal molted often enough? I see issues with terminal molt animals, since they have reached final molt, and eventually, their shells just wear out. Your animal likely hasn’t reached that size yet. I’m not sure what else can interfere with molts in horseshoe crabs…..
Jay

 

[Nemz]

Once produced, their shells have little ability to self-repair. Improvement in shells comes through molting. Broken telson, missing legs, pockmarks n the shell all get repaired through molting.
I think the real issue is why hadn’t this animal molted often enough? I see issues with terminal molt animals, since they have reached final molt, and eventually, their shells just wear out. Your animal likely hasn’t reached that size yet. I’m not sure what else can interfere with molts in horseshoe crabs…..
Jay

This is her prior to the shell disease developing on her carapace. The species isn’t the American variant (it’s Tachypleus Gigas from Southeast Asia). I’d assume she is max molt since they molt every year? But I’m not sure as horseshoe crab size varies a lot.

Even if there is no treatment for it, she is living just fine. I just worry as it is shredding patches of layers out of its shell.

Thanks for your input!

 

[Jay Hemdal]

This is her prior to the shell disease developing on her carapace. The species isn’t the American variant (it’s Tachypleus Gigas from Southeast Asia). I’d assume she is max molt since they molt every year? But I’m not sure as horseshoe crab size varies a lot.

Even if there is no treatment for it, she is living just fine. I just worry as it is shredding patches of layers out of its shell.

Thanks for your input!

Cool - I’ve never worked with the Asian species!
They are smaller, right? If so, then it is probably at terminal molt. If so, the shell can’t be fixed, but they can live some time like that (at least Limulus can).
Jay