
The discovery of the fish nests, made distinct from the muddy seabed by a circle of stones, was a surprise to the researchers.

The fish were observed by using an Ocean Floor Observation and Bathymetry System, a camera sledge built to survey the seafloor of extreme environments -- like ice-covered seas.

Deep sea biologist Autun Purser monitors images taken by the camera system, which is attached to the stern of the ship. It transmits pictures up to the deck as it's being towed.

The nests were evenly spaced and typically guarded by one adult icefish.

The research team was on board the German polar research vessel Polarstern.

A sketch of one of the icefish by the lead author of the study, Autun Purser.

The researchers on board the Polarstern visited the Weddell Sea in February 2021.

The icebreaker Polarstern has been exploring the Weddell Sea in Antarctica since the early 1980s.

The Weddell Sea is home to some 2,000 seals, which may feast on the icefish.