1. The metabolic rates of four Antarctic fish have been measured, including the haemoglobin-less Chaenocephalus aceratus.
2. The respiratory rates of the fish are discussed in relation to body weights.
3. C. aceratus has a respiratory rate as high as other Antarctic fish despite its lack of a respiratory pigment. The calculated rate for a 1 kg fish was 45·6 mg O2/hr.