Genus Cyttus

A genus with three species, all found in Australian waters.

Characteristics: very compressed, deep-bodied fishes with a large head, moderately large eyes and a large highly protrusible mouth; caudal peduncle narrow; minute conical teeth in jaws and on vomer; scales small; lateral line arched anteriorly; ventral body margin with enlarged overlapping “zipper-like” row of scales; bases of dorsal and anal fins with low scaly sheath; dorsal fin in 2 parts with short-based spinous fin followed closely by long-based, low soft fin; some species with elongate dorsal and pelvic fins.

Key to species of Cyttus.

1a. Row of zipper-like scutes present along ventral midline between origins of ventral and anal fins; dorsal fin with 9 or 10 spines and 34–36 segmented rays; anal fin with 2 spines and 35–38 segmented rays; pectoral fins with 17–18rays; 1st anal-fin spine fused and immovable ………….......................................................................Cyttus traversi

1b. Scutes absent from midline of abdomen between origins of ventral and anal fins; dorsal fin 7–9 spines and 27–30 segmented rays; anal fin with 2 spines and 27–31 segmented rays; pectoral fins with 10–12 rays; 1st anal-fin spine movable ….............................................................................................................................................................................2

2a. Body scales ctenoid, rough to touch; spinous dorsal fin elongate, longest spine equal to or greater than head length; 15–17 scales between lateral line and 1st dorsal fin .........................................................Cyttus australis

2b. Body scales cycloid, smooth to touch; spinous dorsal fin short, longest spine about equal to eye diameter; 9–11 scales between lateral line and 1st dorsal fin .............................................................................Cyttus novaezealandiae.