This is a small goby like fish, which can reach a length of 6.5cm. It has two separate dorsal fins and a large fan shaped pectoral (side) fin, pelvic fins that are not fused beneath the body (as would be in a true Goby) and a square tail. The head is smooth and bluntly pointed and has a moderately sized mouth with a protruding lower jaw, with a number of rows of conical teeth. the outer row of teeth is made of enlarged canines and the males have a pair of prominent fanglike teeth halfway back along each side of the lower jaw. there are scales only on the hind part of the body. Small fish are almost transparent with faint vertical bands of yellow, red and black on the bddy and tail and dark pigment on the head. Adult fish have a dark grey head and the body is banded with grey-brown. the eyes are blue-black.

They can be found in relatively large numbers in sheltered bays around the Otago Coast at certain times of year. Occurs in rock pools and subtidal areas down to 50 m. Found in areas of sand or mud, associated with rocks, shells, or other partially buried objects.

Predator.

They are named after David Graham, a notable biologist from Portobello Marine Station.
Often taken in marine whitebait hauls but can be distinguished from whitebait by having two dorsal fins.

Collins Guide to the Sea fishes of NZ: Ayling & Cox