Featured Image Credit: Javontae Murphy via Facebook / Wikipedia
By Eva Gruber
Most people, when they think about sharks, conjure up images of the more famous and distinct species – white sharks, tiger sharks, hammerheads. However, the shark order contains over 600 species of shocking diversity, from the petite tropical wobbegongs to the giant, primitive sleeper sharks lumbering the depths below the sea ice of the far north.
With advances in our ability to not only explore the depths, but also to unravel the genetic relationships between specimens, our understanding of shark diversity has burgeoned. One family of sharks in particular has gained a few “new” species in recent years – the Etmopteridae, also known as lanternsharks. Of the 31 recognized species in the genus, about half have been described within the last twenty years. Unique species are consistently documented from specimens recovered during deepwater trawls, suggesting that the Etmopterids contain numerous sister species.
Some of you may remember the ninja lanternshark (Etmopterus benchleyii) whose discovery was announced just last year, and whose species name benchleyii is in homage to Peter Benchley, the author of the 1974 novel Jaws.
After seventeen years of study, the new species is now described as Etmopterus lailae, by Dr. Stephen Kajiura, a professor of biology at Florida Atlantic University. The specimens were collected in about 1,000 feet of water off the shore of the Northwestern Hawaiian Islands while Dr. Kajiura was still in graduate school at the University of Hawaii.
“There are only about 450 known species of sharks worldwide and you don’t come across a new species all that often,” said Kajiura. “A large part of biodiversity is still unknown, so for us to stumble upon a tiny, new species of shark in a gigantic ocean is really thrilling. This species is very understudied because of its size and the fact that it lives in very deep water. They are not easily visible or accessible like so many other sharks.”
Dr. Kajiura did not realize that the species he was describing was new, until he submitted his findings to a research journal. The reviewer informed him that it might be a new species, after which Kajiura collaborated with David A. Ebert – program director of the Pacific Shark Research Center at Moss Landing Marine Laboratories in California.
Identifying and documenting the new lanternshark involved description of specific measurements along with thorough comparisons to other museum specimens.
The specimen’s unique features allowed Kajiura and Ebert to set it apart from previously described Etmopterus species. A major unique feature of this species is its strange head shape, with an unusually bulging and large snout. Kajiura believes that this “big sniffer” enables it to find food (and possibly mates) in the deep sea environment where there is almost no light.
This species also has a distinctive patch on the underside of its snout lacking scales, as well as unique flank markings. Like other lanternshark species, Etmopterus lailae is bioluminescent with glow-in-the-dark markings on its belly, although the pattern of these markings are specific to this species.
With each new species discovery, we are reminded of how little we truly know about our natural world, and how much more there is left to explore.