From The Australian Museum:
Hairtail Blenny, Xiphasia setifer Swainston, 1839
The Hairtail Blenny is a burrow-dwelling species that has an enormous fang on either side of the lower jaw.
Alternative Name/s
Eel Blenny
Identification
The Hairtail Blenny has a long eel-like body with a high dorsal fin originating in front of the eyes. It has large eyes and two enormous curved fangs, one on either side near the front of the lower jaw.
This species is brownish-yellow with a series of brown bars. There is a blue-edged black ocellus anteriorly on the dorsal fin.
Size range
The species grows to 53 cm in length.
Distribution
The Hairtail Blenny is found in tropical and warm temperate marine waters of the Indo-West Pacific. In Australia it is recorded from the central coast of Western Australia, around the tropical north and south to southern New South Wales.
Distribution by collection data
What does this mean?
Habitat
The Hairtail Blenny occurs on sandy or muddy substrates.
Behaviour and adaptations
Other behaviours and adaptations
The Hairtail Blenny lives in the burrows of other fishes. It enters burrows tail first. Divers usually see just the head of this fish projecting from the sand.