The Antarctic butterfish or Deep sea trevally, Hyperoglyphe antarctica, is a medusafish of the family Centrolophidae found in all the southern oceans, at depths of between 40 and 1,500 m. Its length is up to about 140 cm, with a maximum published weight of 60 kg.
The Antarctic butterfish is similar to the Hapuku – it is completely unrelated but the confusion has given rise to another common name, Blue-nose grouper, in New Zealand.
The Antarctic butterfish has an abruptly blunt snout, long dorsal and anal fins, and a forked caudal fin. They are blue-black on the back, sometimes with a brownish tinge, and have silver-blue flanks and bellies. There are a number of small cream colored dots around the mouth and lower jaw and the eyes are golden with an inner black ring. The mouth is large with a single row of small teeth in each jaw and it is a voracious carnivore, feeding on squid, crabs, Lantern fish, and small ling.
Illustration by Dr Tony Ayling