Tropical Black Bream 

The name black bream has also been applied to Acanthopagrus berda , which is also called pikey bream, and sooty grunter Hephaestus jenkinsi . A. berda is very abundant in tropical estuaries in Queensland NT and WA, and is a valued recreational fishing species. Its reproductive and dietary biology and growth characteristics have been investigated (see Sheaves & Molony, submitted, & Molony and Sheaves, in prep. a,b).

Sooty grunter, Hephaestus jenkinsi , is a common freshwater species in the Kimberley, extending west to the Fitzroy River (Allen, 1982) and is closely related to the sooty grunter from the Northern Territory and Queensland, H. fuliginosus, which has been bred and used for stocking farm dams by Queensland Department of Primary Industries for a number of years (C. Lee, pers. comm.). Useful information on the spawning and stocking of H. fuliginosus in farm dams is given in Hogan (1994). As with barramundi (Fowler, 1999), fingerlings can be produced in ponds stocked with larvae or by intensive hatchery techniques through to fingerling stage (Hogan, 1994; Langton & Graham, 1996). Several batches of juveniles of H. jenkinsi have been produced by Fisheries

WA in Broome and a private farmer in Kununurra and are being grown out in commercial ponds near Kununurra and in recirculating land-based tank systems by Aboriginal groups in the Kimberley on a pilot-scale training basis (C. Lee, pers. comm.).

Recently, a major research project was undertaken to assess appropriate feeds for sooty grunte, also called Argyle bream, (Smith, 1999). He found that black bream were omnivorous (consume plants and animals), have a tendency to accumulate body fat if feed intake is inappropriate, and required formulated feeds containing mineral and vitamin premixes to avoid low Manganese and Vitamin A content in the fish when farmed. They could grow very well on a high quality feed designed for silver perch, yielding an excellent food conversion ratio of 1.2 kg of feed for each kg of fish production.

Use of feed ingredients produced in WA can decrease feed costs and maximise the benefits of an aquaculture industry to the state. Although further research may be necessary to assess how well the fish digests individual feed ingredients, it was apparent that sooty grunter can consume large amounts of lupin or cottonseed meals without sign of adverse effects or toxicity. In contrast, inclusion of large amounts of soybean meal may have affected immune response and use of leucaena meal, which contains a relatively severe anti-nutritional factor, should be avoided.

As well as accepting a range of differing composition, sooty grunter will adapt to autofeeders at least under aquarium conditions. Such feeders also allow characterisation of feeding behaviour and Smith (1999) concluded that these fish feed most actively around dusk and early morning. The fish behave in a manner consistent with their tropical distribution in that feed consumption increases as temperature is increased progressively from 25 o C to 34 o C but is depressed at 36 o C. A strong link was established between abnormalities or diseases and the diet provided. An example is the problem of 'fatty infiltration' of the liver. In general, Smith's publication is a useful introduction to disease problems with tropical freshwater fish.

 Informtation courtesy of the WA Department of Fisheries