A new-to-science hammerhead species, the shovelhead shark, has been hiding in plain sight for three centuries due to its close resemblance to a long-lost relative, the bonnethead shark.<\/p>\n
After a decade of research, a breakthrough study published Sept. 24 found that these are two distinct species, challenging the widely accepted 1758 description by biologist Carl Linnaeus, known as the father of modern taxonomy.<\/p>\n
The shovelhead shark (Sphyrna alleni) has a pointier head and 82 vertebrae, compared to 72 for the bonnethead (Sphyrna tiburo). But it was only with DNA analysis that scientists were able to confirm they were entirely different species that diverged 3.5 million to 5 million years ago.<\/p>\n
\u201cSuddenly the species is telling you, \u2018Hey, I\u2019m different!\u2019\u201d study lead author Cindy Gonzalez, a marine biologist at Florida International University, told Mongabay by phone. \u201cIt was such an amazing moment, a once-in-a-lifetime kind of thing. We were thrilled.\u201d<\/p>\n
But the newly described, flat-yet-protruding-headed species, named after the late Microsoft co-founder Paul Allen for his patronage of shark conservation and research, is already facing the threat of extinction.<\/p>\n
In 2019, the bonnethead shark was classified as endangered on the IUCN Red List, facing a global population reduction of up to 79%. Bonnetheads make up to 10% of fishery bycatches in some areas, meaning they\u2019re caught by accident in fishing nets.<\/p>\n
\u201cThe populations have been collapsing over the past few decades, it\u2019s a real crisis,\u201d Gonzalez said. \u201cThey were overfished, and they weren\u2019t even being targeted specifically, which makes their population decline even more concerning.\u201d<\/p>\n
The conservation status of the newly described S. alleni hasn\u2019t yet been evaluated, but it\u2019s likely to be at even greater threat than S. tiburo. That\u2019s because their shared habitat, the western Atlantic coast from Belize to Brazil, lacks strict fishing regulations, so overfishing is a serious threat.<\/p>\n
\u201cWe were even at risk of having a species go extinct before we had a chance to know it,\u201d Rodrigo Domingues, a marine biologist at S\u00e3o Paulo State University who contributed to the DNA analysis of the shark but was not involved in the final findings, told Mongabay by audio message.<\/p>\n
\u201cEven though they may look similar, they can have different behaviors, biology, ecological niches and play distinct roles in the marine environment,\u201d he added. \u201cNow we can implement conservation measures tailored to each species.\u201d<\/p>\n