trouble molting?

[cosmo49au]

Hello there,
hope someone can offer advise.
We obtained our mantis by accident about a year ago and on discovery set him up in an 80L tank with live rock. His previous molt saw him disappear for about 4-5 weeks but he appeared looking bigger and healthy. He went missing again recently but only for 2 weeks, this time one front leg is missing and the other looks odd. He is only comming out of his cave to eat a small piece of prawn every day or so.
Will this deformity mend itself?
The salinity is a little high and I need to fix that otherwise his tank seems fine.
We would hate to lose him!
Cheers, Meg

 

[fras]

I'm far from an expert, but here's a quote from http://www.blueboard.com/mantis/ that might be of some use.

"Why do some mantis shrimps' raptorial appendages "fall off"? (Dr. R. Caldwell)

First, stomatopods have ways of dealing with this. If they are missing a single raptorial appendage (2cd maxilliped), there is no modification of the molt cycle and they molt at a normal rate. They usually have no problem feeding, although smashing shells may take a bit longer. If the entire appendage is lost, after one molt there will be a small, poorly colored appendage. It will not be functional. After a second molt, it will be a little more than half size and will move, but not strike very well. After a third molt, it will be 3/4 size and functional (but weaker). After a fourth molt, you won't know the difference. Given that it may be a couple of months or more between molts, it can take up to a year to regenerate the appendage. Juveniles can do it in a couple of months.

If both appendages are lost, the animal has to eat prey that it can chew - worms, soft meat, etc. However, it will put all of the energy it can into molting resorbing the ovaries or testes, etc. It will molt up to 50% faster and if it is fed well, can grow the appendages back to full size in about 2/3 the time it takes to grow back one. Obviously, however, this is at a cost. It does not reproduce and energy reserves are dangerously low.

As to why the animal lost both rapts, I would guess some sort of stress. Heat, cold, salinity, organic solvents, etc. can all cause the muscles in the raptorial appendages to be permanently damaged. The rapts don't fall off, the stomatopod literally breaks them off. Stomatopods can't autotomize its claw the way a lobster or crab does, so it grabs the appendage with the other maxillipeds and twists it back and forth until it breaks free.

The other common cause of rapt loss is during the molt, but often this involves just a single rapt. Also, loss during molting is not as common in Gonodactylids as it is in O. sycllarus."

 

[cosmo49au]

Thankyou

Thankyou

Thanks for the reply, I've now been to the site, a lot to learn. It's good to know he might survive and eventually be his old self, as I said we have become fond of him despite his evil ways!