Long-thought extinct shark species rediscovered after 5 decades

A rare shark species once thought to be extinct due to overfishing has been rediscovered in Papua New Guinea for the first time after 50 years.

The sailback houndshark (Gogolia filewoodi) is one of the rarest species of sharks. It was described for the first time in 1973 by scientists based on a single specimen caught in New Guinea’s Astrolabe Bay near the Gogol River.

Now after five decades, the scientists have found 6 new species of G. filewoodi, exhibiting the first record of documentation after decades.

According to findings published in the Journal of Fish Biology, “The five females and one male G. filewoodi recorded in 2020 and 2022 near the Gogol River mouth are the first verified records of this species since its description from a single specimen in the 1970s.”

The latest findings are based on specimens recorded in 2020 and 2022 during surveys by fishers at Madang in Papua New Guinea.

Scientists wrote, “Two individuals measuring 61 and 60 cm were caught on 18 March 2020, and three individuals measuring 75.5, 76.1 and 59 cm LT were caught on 19 March 2020. One of the individuals is the first male recorded for G. filewoodi.”

According to researchers, shark species endemic to Papua New Guinea have unique and unprecedented evolutionary lineage along with a long first dorsal-fin base.

The International Union for Conservation of Nature (IUCN) lists the species as “data deficient” due to scarcity of records that document its existence.