As an experiment I bred two related throdama, and the result is this creature:

http://beastkeeper.com/pet/192342

She seems to have grown bones. Really terrible bones.
I appreciate that negative mutations are to be expected from inbreeding, but since throdama do not have genes for bones (since they are insect-based) I feel like this should not happen. Especially since if I used a mutagen and was fortunate enough to change them into strong/steel bones, I would have a unique and incredibly valuable pet.

Also do you know what will happen to her offspring - are they guaranteed to inherit her thin bones? That would be unfortunate since she has fairly good genes otherwise. If that's the case I guess I'll just send her to the portal service. 

Anyway, thank you for reading.

That is quite odd o.0 YOu have a truly weird critter there... Throdama don't have any "bone" related genes.... Which makes sense as they are an insect....

This is a bug... ahh... no pun intended...

I also noticed that the list of genes are not the same as on other pets. The "teeth/mandibles" should be first on the list.

Thank you for reporting.

This is a bug, you're right to post it here. We're working to remove this issue.

You don't need to get rid of this of this pet, we will fix it in a while.

Sorry for the inconvenience.

Update: the bug is fixed. Thank you for your patience.