Callionymus belcheri

Background

Callionymus belcheri has a yellowish to brown head and body with many small white spots on its back. The flanks are marked with white blotches that have dark brown margins, and the underside is white. It has two dorsal fins: the first is brownish with a distal margin often blackish, and in males it has white spots; the second dorsal fin is marked with light and dark streaks or small white spots.

The anal fin of males has a dark streak, while in females it is colourless or has dark spots on its distal portion. The lower two-thirds of the caudal fin has brown spots. The preopercular spine has a concave ventral margin.

This species occurs in Queensland from Moreton Bay north to northern New Guinea and into the Gulf of Carpentaria, and westwards to northern Western Australia. It is a marine, demersal fish found at depths of 18 to 36 metres. Its diet is mainly invertebrates, including polychaete worms, gastropods, bivalves, small crustaceans, and scaphopods; larger fish also ate echinoderms and caprellids.

They feed mainly in the late afternoon between 16:00 and 18:00, spending the rest of the day buried in sand or mud. Spawning occurs once a year in the southern Autumn, from March to May. Both sexes mature at lengths of 70–80 mm, and females become less fertile towards the end of their lives.