About Aplodactylus arctidens Richardson, 1839
The body of Aplodactylus arctidens is elongate, with depth equal to between one third and one fifth of its standard length. It has a rounded head, a short snout, and a small, slightly downturned mouth with fleshy lips; the upper lip projects forward. The jaws hold small tricuspid teeth, alongside a small number of sharply pointed teeth, arranged in 3 to 4 rows. The outermost row of teeth is the largest, and two patches of vomerine teeth are present. There are two pairs of nostrils: the front pair has a fleshy flap with small tentacles on both the front and rear margins. A wide, flattened spine sits on the operculum, and this spine does not extend to the operculum's margin. The dorsal fin has a long base, and is nearly divided in two by a deep, wide notch between its spiny and soft-rayed sections. The dorsal fin contains 16 to 19 spines and 16 to 18 soft rays, while the anal fin has 3 spines and 6 to 8 soft rays. This species has large pectoral fins that may be longer than the head; the lowest 5 to 6 pectoral fin rays are unbranched and fleshy. The entire body is covered in small, embedded cycloid scales that extend onto the cheeks and operculum, and form a sheath along the base of the spiny section of the dorsal fin. The maximum recorded total length for this species is 70 cm (28 in). The head, body, and fins are overall olive green or brown, marked with many small, irregular whitish spots, blotches, and lines. Aplodactylus arctidens is native to the southwestern Pacific Ocean. In southern Australia, it occurs from immediately east of Mallacoota, Victoria, westward to Kangaroo Island, South Australia, and is also found in southern Tasmania. Around New Zealand, it can be found from the Three Kings Islands in the north down to the Snares Islands, 200 km (120 mi) south of New Zealand's South Island, and also occurs at the Chatham Islands. It inhabits weedy reefs in shallow water, at depths ranging from 0 to 20 m (0 to 66 ft).
