A pear-bottomed, stubby-nosed, big-eyed shark has made its way into the new year as the world’s first newly described shark species of 2019, but good luck actually meeting it in real life. Belonging to the family of whaler sharks, the aptly named “Lost Shark” hasn’t been spotted in the wild for at least 80 years and it’s unlikely – though not impossible – that it will make an appearance again.
To uncover the correct taxonomical information on the new shark, researchers examined the morphological and anatomical features of just three known specimens, one late-term embryo and two juveniles, preserved in ethanol back in the 1930s that were previously believed to belong to the smalltail species. Though the three sharks collected from Borneo, Thailand, and Vietnam more closely resemble the Borneo shark (C. borneensis), the team noticed their sharks differed in tooth morphology and other features around the face.
The historic range of the Lost Shark is under intense fishing pressure, and whaler sharks (family Carcharhinus) are economically important in fisheries around the world. The researchers say their find highlights the importance of understanding how our changing climate may impact vulnerable and undescribed species and how humans interact with their natural world.
Between 2002 and 2012, more than 180 new species of sharks, rays, and chimaeras – broadly known as Chondrichthyan fishes – have been formally described, with another 80 new species described in the last six years. Roughly 20 percent of current living sharks and rays have been described since 2002.
“There is an urgent need to assess its extinction risk status for the IUCN Red List of Threatened Species,” wrote the authors in PLOS One. "With so few known records, there is a possibility that Carcharhinus obsolerus has been lost from the marine environment before any understanding could be gained of its full historic distribution, biology, ecosystem role, and importance in local fisheries.”
Carcharhinus obsolerus (Latin for “extinct”) is a small, slender shark that presumably lived along the coasts of Southeast Asia. Though its distribution is uncertain and getting a better understanding of its past home waters is “unlikely unless archaeological or paleontological records are found,” not all hope is lost. In 2004, the Borneo shark made a reappearance in the wild after not having been spotted since 1937.