For a full listing of Central Australian fish click here
There appear to be two reasons fish have been able to persist in Central Australia despite the lack of permanent water. First, it is generally rare for all the waterholes in a particular system to go dry at the same time. Second, the permanency of some waterholes is affected by floods. Most species are effective at migrating long distances. Within each river system, fish distribution is fairly uniform, most waterholes will typically contain 80-100% of the total fauna. This is assisted by the enormous floods which occur. When a flood occurs, virtually every water body above the point where flow ceases will be connected albeit briefly. This is assisted by very low gradient, thereby allowing flood water to persist for longer periods.
Most Central Australian fish species have very broad environmental tolerances. All species can tolerate temperatures between 15 and 35°C (59-95°F); most would tolerate 7 to 37°C (45-98°F); a few will survive from 4 to 42°C (39-104°F), for short periods. An example of the last extreme would be, desert goby and spangled perch. Virtually every Australian fish examined can tolerate direct transfer into 50% sea water. However, few can tolerate 100% sea water. Most can generally survive in relatively low oxygen concentrations, although specific data is lacking. The recruitment of most species is linked to flooding. Several species can spawn independently of flooding, but significant juvenile recruitment only occurs after floods. Most species generally spawn at temperatures above 20 to 26°C (68-79°F). The upper spawning temperatures are not known for any Australian species. Most of the smaller species, especially hardyheads, rainbowfish, smelts, and glassperches, tend to lay a few eggs daily during the warmer months, ie 20-60 eggs per day. Larger species, such as catfish, grunters, and perches tend to spawn large numbers of small eggs during floods. All of the gobies and gudgeons tend to attach eggs onto hard surfaces. The male guards the eggs until hatching, after which no further parental cre occurs.
Search these web pages
This file was last modified: 18 March 2003