Pacific Blue Eye, Pseudomugil signifer Click to enlarge image
A Pacific Blue Eye from Dawson Creek near Taree, northern New South Wales. Image: Andrew Lo
© Andrew Lo

Fast Facts

  • Classification
  • Size Range
    Males grow to 88 mm in length and females grow to 63 mm.
  • Habitats

The Pacific Blue Eye is an Australian native fish that, as its common name suggests, has blue eyes.


The Pacific Blue Eye has a semi-transparent body that can vary in colour from pale olive, yellow to bluish. As the common name suggests, the iris of the Pacific Blue Eye is blue. The operculum and belly region are silvery. There is often a series of pearly spots along the side of the body.

The fins of males and females are different shapes. The dorsal, anal and pelvic fins of males are extended into filaments. The fins can also differ in colouration, particularly during breeding when the fins of the male can become brilliantly coloured.


The Pacific Blue Eye lives in clear, fast flowing streams and also in mangrove regions of estuaries.


It is an Australian native species that occurs in coastal streams along the eastern coast of Australia from northern Queensland to southern New South Wales.

The map below shows the Australian distribution of the species based on public sightings and specimens in Australian Museums.

Feeding and diet

The species feeds on mosquito larvae and other insects.

Life history cycle

Females lay one or two eggs at each spawning with up to nine spawnings a day over the spawning period, which may last over a week. The 1.8 mm diameter eggs attach to vegetation by adhesive filaments. At 22-24ºC the eggs take 18 to 21 days to develop. Well developed young hatch and can feed immediately. In an aquarium, the newly hatched young can reach maturity in six months.

Breeding behaviours

At courtship a male will dart backwards and forwards in front of the female, while fluttering the pectoral fins and holding the dorsal, anal and pelvic fins erect. At spawning, the two fish swim into vegetation and their bodies shake violently.


  1. Allen, G.R. 1989. Freshwater Fishes of Australia. T.F.H. Publications. Pp. 240.
  2. Ivantsoff, W & L.E.L.M. Crowley in McDowall, R.M. 1996. Freshwater Fishes of South-Eastern Australia. Reed Books. Pp. 247.
  3. Merrick, J.R. & G.E. Schmida. 1984. Australian Freshwater Fishes. Biology and Management. John R. Merrick. Pp. 409.