Pseudomugil mellis - photo© Neil Armstrong

Pseudomugil mellis

Species Summary
Pseudomugil mellis is a small species; usually not exceeding 4 cm. Males are honey-coloured with the first two rays of the dorsal and anal fins black with creamy-brown centres and outer white margins. The female is plain amber with clear fins. The body scales are lightly edged with black. Two dorsal fins, separated by a small gap, the first much smaller than the second. Males are easily distinguished from females by their brighter colours and longer and more elongated dorsal fins. Pseudomugil mellis was formally described by Allen and Ivantsoff in 1982. Before then it was considered to be a colour variety of the Pacific Blue-eye (Pseudomugil signifer). Although, it was always recognised by native fish hobbyists as being different.

Kangaroo Creek, Tin Can Bay - photo© Bruce Hansen

Distribution & Habitat
Pseudomugil mellis has a restricted range in southern Queensland, extending northwards from Caboolture to Maryborough, including Fraser Island. It has also been collected in a lake at the northern end of Dismal Swamp, south of Shoalwater Bay. Pseudomugil mellis has been reported from about 18 locations on both the mainland and Fraser Island, although their range had been severely reduced in recent times. It is still relatively abundant in the Noosa River catchment and Fraser Island localities. Most populations are totally isolated from one another. Lacustrine populations occur in seven lakes (six on Fraser Island and one at Cooloola). Pseudomugil mellis is known to co-occur with Pseudomugil signifer at Lake Wabby and Bool Creek on Fraser Island, and Schnapper Creek and Big Tuan Creek on the mainland. Big Tuan Creek is a small coastal creek about 5 km south from the mouth of the Mary River. Although this species is reasonably secure in some areas of its restricted range, its continued existence is being threatened by urban development and the spread of the introduced mosquitofish (Gambusia holbrooki).

Pseudomugil mellis are usually associated with dystrophic waterbodies of pH 4.4 to 6.8. They can tolerate wide fluctuations in stream temperature, from 14°C in winter to 38°C in summer. Pseudomugil mellis are typically found in the coastal lowland "wallum" country inhabiting freshwater lakes, creeks and wetlands. They are found in both clear and tannin-stained waters with sandy or muddy bottoms. They usually occurs where there is little or no flow and the fish can find shelter within or near to emergent and submerged aquatic macrophytes. Pseudomugil mellis are often found with Rhadinocentrus ornatus, Nannoperca oxleyana, several gudgeons and other small sized native fishes.

Remarks
Pseudomugil mellis currently has a conservation status listing as vulnerable. You can do your part in helping to preserve this species and their natural habitat by breeding and maintaining captive populations. Collecting wild specimens for the hobby can have a direct impact on their population numbers to the extent that they could become locally extinct. It is becoming increasingly difficult to find them at the popular spots in Tin Can Bay. We know that their populations undergo large fluctuations associated with seasonal recruitment and if they are over-collected during a period of low population numbers, they may never recover and we could well see them disappear from that location. Habitat destruction or alteration in some areas has also favoured the spread of the aquatic terrorist, Gambusia holbrooki.

The secret in maintaining long-term captive populations of Pseudomugil mellis is to constantly breed them. There is a reduction in the frequency and intensity of spawning activity in fish over one year of age. If you fail to notice the change they become too old and then you just lose them. Try to obtain young specimens and breed them early and regularly and you will always have some around to enjoy. Because each female only lays a few eggs each day, it can take a while before you have significant numbers. If possible, start with 6-10 juveniles rather than adults pairs. They are easy to maintain under standard aquarium conditions and will develop on standard commercial fish foods. Mature fish can be easily set up and induced to spawn by manipulation of water temperature and photoperiod throughout the year. When maintained under appropriate aquarium conditions, survival rates above 90% can be attained.

Pseudomugil mellis [Male - Female]

Literature
Allen, G.R. and Ivantsoff, W. (1982). Pseudomugil mellis, Le Honey Blue-eye, une nouvelle espece de Poisson Arc-en-ciel (Melanotaeniidae) d'Australie orientale. Revue francaise Aquariologie 9(3): 83-86.

Arthington, A.H. and Marshall, C.J. (1993). Volume 1: Distribution, ecology and conservation of the Honey Blue-eye, Pseudomugil mellis, in south-eastern Queensland. Final Report to the Australian Nature Conservation Agency, Canberra. 100 pp.

Arthington, A.H. Marshall, C.J. (1995). Threatened fishes of the world: Pseudomugil mellis Allen & Ivantsoff, 1982 (Pseudomugilidae). Environmental Biology of Fishes 43: 268.

Burnett Mary Natural Resource Management Plan (2005). Country to Coast - A Healthy Sustainable Future. Burnett Mary Regional Group.

Howe, E. (1987). Breeding behaviour, egg surface morphology and embryonic development in four Australian species of the genus Pseudomugil (Pisces: Melanotaenidae) in Australian Journal of Marine and Freshwater Research 38: 885-895

Howe, E., C. Howe & S. Doyle (1988). The surface of the egg in blue eyes in Fishes of Sahul 5(2): 205-211.

Saeed, B., Ivantsoff, W., and Allen, G.R. (1989). Taxonomic revision of the family Pseudomugilidae (Order Atheriniformes). Australian Journal of Marine and Freshwater Research 40: 719-787.

Semple, G.P. (1991), Reproductive Behaviour and early Development of the Honey Blue-eye, Pseudomugil mellis Allen and Ivantsoff 1982 (Pisces: Pseudomugilidae), from the North-east Coast Division, South-eastern Queensland, Australia. Australian Journal of Marine and Freshwater Research 42: 277-286.

Tappin, A.R. (1984) In search of the Honey Blue eye, Pseudomugil mellis. Fishes of Sahul 1(4): 37-39.

Trnski, T., D.J. Bray, J.M. Leis, M.A. McGrouther & S.E. Reader (1993) Survey of Fishes of Shoalwater Bay Training Area, Queensland.

Wager, R. and Jackson, P. (1993). The Action Plan for Australian Freshwater Fishes. Australian Nature Conservation Agency, Canberra.

© Copyright Adrian R. Tappin
Updated December, 2008.