Scientists rediscover the world's rarest shark, the sailback houndshark, in Papua New Guinea after 50 years.

After 50 years, scientists have rediscovered the sailback houndshark in Papua New Guinea's Astrolabe Bay, where it was last seen in 1973. Six new individuals, including the first male, have been documented since 2020, revealing the shark's likely microendemic nature. The species, considered one of the rarest in the world, faces threats from overfishing and the increasing trade in fish swim bladders. Conservation efforts and DNA analyses are underway to better understand and protect the sailback houndshark.