The deep sea is one of the most inhospitable environments on the planet and is home to some of its strangest creatures.
The latest specimen to have courted scientists’ attention is the barbeled dragonfish, a terrifying predator with an arsenal of evolutionary quirks.
It’s equipped with two rows of dagger-like teeth, a distensible stomach and a set of bioluminescent chin barbels to attract prey.
But perhaps the strangest feature is one that’s found in just a small number of the deep sea predators: a flexible head joint.
“We suspect that the head joint adaptation helps these fishes engulf their prey items, since the added flexibility allows them to open their mouths up to 120 degrees wide,” said Dave Johnson, a scientist at the Smithsonian.
”The arsenal of specialized traits that barbeled dragonfishes have evolved as deep-sea predators—huge mouths with dagger-like teeth, distensible stomachs, snake like, black bodies with light producing organs and elaborate chin barbels with bioluminescent tissue—make them ferocious and voracious ambush predators, thus the name dragonfishes,” Johnson added.
The head joint is thought to be unique and is made up of the back of the head and a flexible rod running to the top of the vertebral column.
“In most other fishes, the head articulates directly with the first vertebral and thus does not offer a flexible joint between the two,” said Nalani Schnell, co-author of the study. “The functional head joint in those deep-sea fishes greatly reinforces the maneuverability of the head in order to engulf significantly large prey items.”
Fortunately for us, the dragonfish live between 600 and 3,000 feet deep in the ocean, so it’s unlikely we’ll be coming across one any time soon.