Scientists have confirmed 57 new deep-sea species and five entirely new genera from Argentina's Mar del Plata canyon.

The discoveries were confirmed on October 1 after expeditions explored the canyon's depths. Among the finds is a sea cucumber from the genus Loki, spotted at 2,577 metres below the surface.

The census adds to one of the most detailed surveys of deep Atlantic life. Researchers used submersibles and cameras to document creatures never seen before.

Deep-sea canyons are among Earth's least explored habitats. Each expedition tends to reveal species unknown to science.

The new genera represent entirely new branches of the tree of life. Taxonomists will now formally describe each species.

Conservationists say the findings underline how much remains to be discovered, and protected, in the deep ocean.

The canyon lies off Argentina's Atlantic coast and drops thousands of metres. Previous expeditions there had already hinted at rich biodiversity.

Researchers will now catalogue each new species in detail.