Gerlachea was first described as a genus in 1900 by the Belgian palaeontologist Louis Dollo when he was describing the only species in this monotypic genus Gerlachea australis,[1] the type of which had been collected by the Belgian Antarctic Expedition at a depth of 500 fathoms at 71°34'S, 89°10'W off Antarctica.

[3] Gerlachea australis has its body and cheeks covered in cycloid scales and there are no spines or hooks on the naked operculum.

The snout is long and flattened and the mouth extends back as far as the rear pore in the interorbital space.

The operculum and the lower part of the head are light brown, There is a large dark spot at the base of the pectoral fin.

[5] Gerlachea australis breed when they attain a length greater than 200 mm (7.9 in) in the Weddell Sea.