bogleech:

malformalady:

Frog with eyes in its mouth as a result of macromutation.
A macromutation is a mutation that has made a significant impact on an
organism, caused by a change in a regulatory gene that’s responsible for
the expression of an array of structural genes.

It’s been suggested that the cause of the mutation was the result of a parasitic infection by a trematode worm (Ribeiroia ondatrae).
Trematode infections have reportedly been linked to an increasing
number of amphibian limb mutations, particularly missing, malformed, and
extra hind legs.

Photo via
pipistrellus

on Reddit

OH MAN this happened again!?! I guess it might happen quite often in the wild and we just don’t often catch it. This is the semi-famous prior example in a toad:

After I talked about this one on my website a bit, I was actually emailed by its original discoverer. They said they named him Gollum and he lived for a long time on a diet of earthworms.

I love how frogs and toads never normally hold their mouths open until they eat but you can tell these weirdos have learned to do so all the time so they can see.

It’s not too far fetched a “defect” for them, of course, because an anuran’s eyeballs already protrude into its mouth when it swallows or yawns:

It seems sad, but the only thing they’re really suffering from is a narrowed field of vision, and maybe a mouth that gets annoyingly dry. In captivity, they’re fine. In the wild, they likely get eaten by the first predator to approach them from behind, which would explain why we find them so rarely.

I’m not sure this would be caused by those parasitic trematodes, though. They specifically attack the arms and legs as the host develops from a tadpole, damaging them so that they end up branching into extra limbs. Then again, maybe sometimes the flukes get confused and damage something that determines which side of the skull the eyes develop on. Hard to say.