About Gymnapistes marmoratus (Cuvier, 1829)
Gymnapistes marmoratus, commonly called the South Australian cobbler, has a long-based dorsal fin containing 12 or 13 spines, with each spine separated by an incision in the connecting membrane; the fin also has between 7 and 10 soft rays, and the spiny and soft-rayed parts of the dorsal fin are separated by an incision. The species has 3 spines and 4 to 6 soft rays in its anal fin. Its eye does not bulge above the dorsal profile of the head. The intraorbital space is slightly concave, and there are several obvious spines on the head. The lacrimal bone is mobile; it bears a large, curved, erectile spine on its posterior side, and a smaller spine on its anterior side. The only scales this fish has are located on the lateral line. The South Australian cobbler has a mottled color pattern: the upper body is covered in brown to dark brown blotches that fade to a pale color on the ventral side. These blotches are less distinct in larger individuals. There is a clearly visible dark blotch on the dorsal fin between the 4th and 7th spines. A dark, oblong spot sits near the base of the pectoral fin, while the other fins often display vermiculations or faint, unclear spotting. This species reaches a maximum total length of 22.5 cm (8.9 in). This fish is endemic to the temperate southern coasts of Australia. Its range extends from the central coast of New South Wales to Perth, Western Australia. It inhabits shallow inshore waters, tidal pools, and estuaries at depths between 0.25 m (9.8 in) and 35 m (114 ft 10.0 in), and lives in seagrass beds.
