Scientists have discovered a species of ghost shark lurking deep in waters off the coast of Costa Rica.
The discovery of the new species, called Rhinochimaera costaricana, was highlighted in a study published in the peer-reviewed journal Zootaxa.
What happened?
In research led by Costa Rica's Fisheries and Aquaculture Institute and the University of Costa Rica, alongside Brazil's Federal University of Pará, the team determined that the fish was separate from its nearest relatives by combining historical specimen records with contemporary genetic analysis.
The identification was based on three male specimens collected between 2000 and 2023 at depths of 1,280 to 2,583 feet, far below recreational diving ranges.
The species is part of the long-nosed chimera group, and ghost sharks are cartilaginous deep-sea fish related to sharks and rays.
Researchers compared 49 body measurements from the Costa Rican specimens with data from more than 90 individuals spanning the three previously recognized Rhinochimaera species.
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Alongside those anatomical comparisons, DNA testing found a 3.9% to 4.7% genetic divergence from other known species. The Costa Rican fish also differed in having a shorter snout and fewer tail tubercles, supporting its recognition as a separate species.
Why does it matter?
In the study, the researchers explained the importance of the finding, saying: "This discovery improves our knowledge of deep-sea fish diversity in the region and underscores the importance of integrative approaches in species identification, delimitation, and characterization."
Scientists now say the deep Pacific off Costa Rica may contain far more biodiversity than current records show.
Because the region beyond the continental shelf is still not well understood, some species may remain unidentified for years, and some could vanish before they are ever formally recorded.
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Better maps of ocean life can help inform fishing policies, marine protections, and decisions by coastal communities that depend on healthy seas for food, jobs, and long-term stability.
The finding also reflects the growing role of genetic sequencing in conservation. New tools are helping researchers revisit animals that may have been misidentified for decades, giving communities and policymakers a clearer picture of what is actually at stake in the deep ocean.
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