A tiny, rare species of catfish that lives underground continues to baffle scientists since it was finally classified as a species in 2011.
Nicknamed "Alien" because it resembles the beast in the movie, the catfish Kryptoglanis shajii is found only in the Western Ghats mountain range of Kerala, India, Live Science reported. The catfish lives in subterranean waters, but has been spotted in the area's springs and wells.
Researchers conducted a study of the catfish in the hopes of understanding more about it. But the results, recently published, tuned up questions as well as answers.
What stumped researchers the most about the "alien" catfish- which is only 4 inches long- was its bone structure. With a protruding lower jaw line and face full of sharp teeth, the fish has several bones missing from its body that are present in other catfish.
"The more we looked at the skeleton, the stranger it got," John Lundberg, a researcher from the Academy of Natural Sciences of Drexel University who studied the catfish, told Live Science. "The characteristics of this animal are just so different that we have a hard time fitting it into the family tree of catfishes."
Scientists already know it is not unusual for subterranean fish to have bones missing. But the structure of the "alien" catfish's bones was specific to only that type of fish.
CAT scans revealed the tiny bones in the fish's face were developed in such a way as to make its lower jaw jut out like that of a bulldog's mouth, Live Science reported. Researchers also learned the fish has four rows of pointy, cone-shaped teeth.
"In dogs, that was the result of selective breeding," Lundberg told Live Science. "In Kryptoglanis, we don't know yet what in their natural evolution would have led to this modified shape."
Until the next time the "alien" catfish is studied, its skeleton and its origins will remain a mystery.
