About Pteroidichthys amboinensis Bleeker, 1856
Pteroidichthys amboinensis has the elongate, compressed body that is typical of the genus Pteroidichthys. This species has 12 flexible spines and 9 soft rays in its dorsal fin, and 2 spines and 6 soft rays in its anal fin. It has a relatively short snout, which averages around 14% of its standard length. The rear margin of the maxilla extends past a vertical line running through the centre of the pupil. The species has supraorbital tentacles, and its posterior lacrimal spines are well developed, longer than the diameter of the orbit. There are many tentacles across the body and fins. The lateral lacrimal and suborbital spines are indistinct; they are normally very small spines, and frequently take the form of blunt, bony protuberances. There is no distinct black blotch on the soft-rayed portion of the dorsal fin. These fish sometimes show a mottled blackish and reddish colouration, but can make wide changes to their overall colour and pattern. This species reaches a maximum known total length of 12 cm (4.7 in). Pteroidichthys amboinensis occurs in the Red Sea, through the Indian Ocean and into the western Pacific Ocean, reaching as far east as Fiji, north to southern Japan, and south to Australia. It is a demersal fish found at depths between 7 and 43 m (23 and 141 ft), living over soft substrates and among algae.
