Episode · Southern Ocean · 18 September 2026

Antarctic Icefish: The Fish With Clear Blood, and a Colony of 60 Million Nests Under the Ice

Name: Antarctic Icefish: The Fish With Clear Blood, and a Colony of 60 Million Nests Under the Ice
Uploaded: 2026-09-18
Duration: 3 min 4 s
Description: The only animals with a backbone known to live without haemoglobin: their blood is as clear as water, in a sea that sits below zero.

The only animals with a backbone known to live without haemoglobin: their blood is as clear as water, in a sea that sits below zero.

The footnote on the shirt

¹ Crocodile icefish are the only vertebrates known to live without haemoglobin or red blood cells; their blood is colourless.

Sidell and O’Brien, J. Exp. Biol., 2006

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Antarctic Icefish: The Fish With Clear Blood, and a Colony of 60 Million Nests Under the Ice

More from Ice and cold

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New episode, new design.