Underwater robot explores Antarctic seafloor

An underwater robot named Lassie captured footage of 1,036 fish nests hidden beneath the ice of Antarctica, as reported in a study published in Frontiers in Marine Science on October 29, 2025. This discovery was made possible by the movement of a giant iceberg that broke off the Larsen C ice shelf in 2017, revealing an area of the ocean floor that had been hidden for centuries.

Research mission in 2019

Lassie conducted five dives in January 2019 from the research vessel SA Agulhas II, capturing 27 hours of video footage off the Antarctic Peninsula. Scientists identified 1,036 nests, spread across 277 groups, resting between 290 and 411 meters in depth. The footage also revealed 72 depressions containing larvae as the camera passed by.

Fish species identified

The fish species found in these nests is Lindbergichthys nudifrons, a small species that rarely exceeds 19.5 centimeters in length. The male of the species is responsible for guarding the eggs and chasing away predators, playing a crucial role in the survival of the offspring.

Nest characteristics and behavior

Each nest measures approximately 12 centimeters in diameter. The adult fish continuously clean the plankton debris covering the rest of the seafloor, a behavior that helps scientists identify active nests and understand the fish’s habitat and reproductive patterns.