New Ghost Shark Species May Have Been Discovered off Costa Rica

Marine biologists from the University of Costa Rica reported a possible new ghost shark species in Pacific waters near Cabo Blanco and Cano Island. The fish, provisionally named *Rhinochimaera costaricana*, shows distinct physical traits separating it from known relatives.

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Ghost sharks (chimaeras) are cartilaginous fish that split from true sharks about 400 million years ago; three species have been documented in the Atlantic (from Greenland to Brazil) and in waters off South Africa, Taiwan, Australia and Japan. The Costa Rican specimen would be the first ghost shark recorded along the Central American coast.

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The study is led by Arturo Angulo Sibaja, professor of biology at the University of Costa Rica, with assistance from student Naidely Vidaurre Quesada, who examined the specimen in San José.

South China Morning Post

The shark has a shorter snout, darker coloration, and an unusually long dorsal-fin spine. Early genetic tests show no reproductive contact with other ghost shark populations, indicating possible isolation. Similar specimens from Peru and Chile display comparable features, prompting further comparison.

The Straits Times

If confirmed, *R. costaricana* would be the first ghost shark species documented along the Central American coast and may have a broader distribution along the Pacific coast of Central and South America. The discovery adds to the diversity of the ancient Rinochimaera lineage, which diverged from sharks nearly 400 million years ago.

The Straits Times

University of Costa Rica researchers, led by Arturo Angulo Sibaja, reported that the specimen exhibits a shorter snout, darker coloration, and an unusually long dorsal-fin spine. Genetic analysis showed no reproductive contact with other ghost shark populations, suggesting reproductive isolation. The team also noted that the species appears to be the only ghost shark known from the Central American coast and may have a broader distribution along the Pacific coast of Central and South America. Researchers indicated that further comparison with similar specimens from Peru and Chile is needed before a formal taxonomic conclusion.

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Sources differ on how closely the Costa Rican shark matches specimens from Peru and Chile. While genetics suggest isolation, morphological overlap creates ambiguity, indicating a need for comparative analysis.

South China Morning Post

• “shorter” snout. — Arturo Angulo Sibaja, Professor, University of Costa Rica

The Straits Times

• “much longer spine on its dorsal fin” — Arturo Angulo Sibaja, Professor, University of Costa Rica

The Straits Times

• “no reproductive contact” with other ghost sharks. — Arturo Angulo Sibaja, Professor, University of Costa Rica

The Straits Times

• “known for the Central American coast” — Arturo Angulo Sibaja, Professor, University of Costa Rica

The Straits Times

Scientists will continue comparing specimens and conducting further genetic and morphological analyses to resolve the species’ status.

South China Morning Post