'Alien' Catfish Features Baffle Scientists

The skeletal features of a small, toothy fish, which researchers say resemble the terrifying creature from the movie "Alien," are highly unusual and baffling scientists.

Kryptoglanis shajii is a tiny, subterranean catfish, whose mindboggling skeletal features include a bulging lower jaw similar to a bulldog's. So far scientists have been unable to classify the strange species.

The unclassifiable catfish is native to the Western Ghats mountain region of Kerala, India, and is rarely ever seen. It is so elusive that scientists didn't categorize it as a new species until 2011.

"The more we looked at the skeleton, the stranger it got," John Lundberg, Drexel University's resident fish zoologist, said in a statement. "The characteristics of this animal are just so different that we have a hard time fitting it into the family tree of catfishes."

Kryptoglanis may look like a normal catfish from the outside, but digital radiography and high-definition CAT scans revealed anomalies in its bones.

Lundberg and his colleagues found that Kryptoglanis was missing several bony elements - a characteristic fairly common for subterranean fish. And changes in the shapes of certain bones were so strange that Lundberg described them as "completely unique among catfishes and all fishes as far as I know."

Researchers believe that these unusual features serve some unknown purpose.

"In Kryptoglanis, we don't know yet what in their natural evolution would have led to this modified shape," Lundberg added.

Based solely on its teeth and subterranean home, Lundberg speculates that this species eats meat, such as small invertebrates and insect larvae.

Lundberg's team, along with researchers at the Natural History Museum of London, still cannot determine which other catfishes Kryptoglanis is most closely related to.

"It continues to be a puzzle," Lundberg said.

This research was published in the 2014 issue of the Proceedings of the Academy of Natural Sciences of Philadelphia.