You are here: Home Blog What's stranger than a fish with no eyes?

What's stranger than a fish with no eyes?

By Leonard Ho - Posted Jun 16, 2014 09:00 AM
How about a blind fish that still has the gene responsible for perceiving light? How about a fish that broods its eggs in its gills?! Not weird enough? Then how about one with an anus located right behind its head?!! Combine all these attributes and you have Amblyopsis hoosieri, a newly discovered cave fish from Indiana.
What's stranger than a fish with no eyes?

Amblyopsis hoosieri

Amblyopsis hoosieri (named after the Indiana Hoosiers) is the only other cave fish in its genus, and it really ratchets up the weirdness factor.  While it lacks pigments and eyes like many cave fish, A.hoosieri retains its rhodopsin gene, the gene responsible for the perception of light. The presence of this "visual" gene in an eyeless fish living in pitch darkness would suggest that some of A.hoosieri's DNA has yet to catch up with the rest of its morphological evolution.

What's more, this cave fish broods its eggs in its gills ... an extremely unusual breeding habit but also a behavior that makes practical sense when coping with the extreme cave environment where visual tending of eggs is impossible.

To facilitate the transfer of eggs to its gills, this fish may have evolved its strangest feature yet: an anus located right behind its head far away from the usual spot next to the anal fin!  We have all sorts of low-brow comments we'd love to make (but we'll restrain ourselves).  Suffice it to say, Amblyopsis hoosieri is a certifiable oddball.

Journal Reference: via Monga Bay News


Author: Leonard Ho
Location: Southern California

I'm a passionate aquarist of over 30 years, a coral reef lover, and the blog editor for Advanced Aquarist. While aquarium gadgets interest me, it's really livestock (especially fish), artistry of aquariums, and "method behind the madness" processes that captivate my attention.


Document Actions
Filed under:
blog comments powered by Disqus


Contribute to our blogs!

Do you have news or discussion topics you want to see blogged?  Let us know!