Fin's Fish Guide
The Castelnau's jawfish (Opistognathus castelnaui) is a saltwater fish of the family Opistognathidae that grows up to 25 cm.
Asia: Australia, Taiwan/Ch Taipei, Indonesia, Japan, Ryukyu Is., Malaysia and others
Description
The Castelnau's jawfish is a jawfish (Opistognathidae) from coastal waters of northern Australia. The species grows to about 25 cm and has a stocky forebody with a very large mouth and large eyes. As a bottom-dweller it digs and lines a vertical burrow with pebbles, from which it protrudes its forebody to snap at passing zooplankton; when threatened it withdraws backwards into the burrow. The male broods the eggs in his mouth. The fish is harmless to humans.
Frequently asked questions
How do you recognise the Castelnau's jawfish?
The Castelnau's jawfish has an elongate, eel-like body and is mainly brown.
Where does the Castelnau's jawfish live?
The Castelnau's jawfish lives in the sea (marine waters) and is mostly found around sand or mud bottom. Asia: Australia, Taiwan/Ch Taipei, Indonesia, Japan, Ryukyu Is., Malaysia and others
How big does the Castelnau's jawfish get?
The Castelnau's jawfish grows to a maximum of about 25 cm.
Is the Castelnau's jawfish dangerous to humans?
No, the Castelnau's jawfish is harmless to humans. This species is harmless to humans. No specific first aid is needed. Still handle the fish with care: mind the fin rays and the sharp edges of the gill cover, and rinse any scratch with clean water and cover it. For a dirty or deep wound check tetanus status.
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All data
Identification
Appearance
Habitat & distribution
Behaviour & biology
For anglers
Safety
Status & sources
Same genus Opistognathus
More from the family Opistognathidae
Want the complete picture on the Castelnau's jawfish?
Point your camera at the fish and Fin names the species in seconds. Free, and the Castelnau's jawfish is one of 12,519 species in the app.