3 – Fish distribution, status and threats 33 Biodiversity Conservation Act 1999) and also on the Red List of Threatened Species (International Union for the Conservation of Nature 2016). Widespread fish species Despite the comparative paucity of studies of fish within Queensland’s western rivers, some general patterns have been observed. Some species occur across all catchments, from the Bulloo River in the east to the highly temporary Mulligan River on the edge of the Simpson Desert, in permanent and ephemeral waterholes and across a wide range of habitats (Table 3.1). This group includes the algivore/detritivore bony bream, the carnivore spangled perch, two species of catfish, the silver tandan and the larger Hyrtl’s tandan, and two small-bodied species, the desert rainbowfish and glassfish (Table 3.1). Most can move at least 300 km into ephemeral habitats following flooding. Many also continuously recruit, maintaining populations in both dry and wet periods. Large-bodied species such as Barcoo grunter, Welch’s grunter and yellowbelly possess similar adaptations to living in the Australian arid zone, but tend not to move as far into temporary desert habitats, probably due to their longevity (around 10 years) and adult size (at least 300 mm). Fish species confined to particular rivers The waterholes and reaches of the Cooper catchment (the Barcoo, Thomson and Wilson Rivers, Kyabra Creek and many more headwater subcatchments Fig. 3.1) provide habitat for three species that do not live in the western rivers of the Lake Eyre Basin: carp gudgeon, Australian smelt and the endemic Cooper Creek catfish (Table 3.1). Carp gudgeon are widespread in all catchments east of and including the Cooper, although their origin remains unclear (P. Unmack, pers. comm.). The similarly located Australian smelt reflects a more traceable story. It is more closely related to southern cousins in the South Australian Murray–Darling Basin than to eastern populations in Queensland and New South Wales (Hammer et al. 2007), suggesting it may have colonised the Lake Eyre Basin from the south, when the continent was wetter. The Lake Eyre Basin’s most curious aquatic inhabitant is arguably the Cooper Creek catfish (Fig. 3.2). This large bottom-dwelling species is probably older or more ancestral than the other widespread catfish species (P. Unmack, pers. comm.). It is the only endemic riverine fish species from the Cooper, found in the Thomson and Barcoo Rivers and downstream in Cooper Creek, but nowhere else. Cooper Creek catfish produce relatively few large eggs (~1000, 3–4 mm diameter Unmack 1996). It is possible that they may guard their eggs, or make shallow nests in the substrate in a similar fashion to freshwater catfish from southern Australia (e.g. Tandanus tandanus from the Murray–Darling Basin). However, the life history of Cooper Creek catfish is yet to be studied in detail. The Diamantina and Georgina River catchments also provide habitat for species that have not been able to cross the catchment divide into the Cooper Creek catchment, or successfully colonise via Kati Thanda-Lake Eyre during wet periods. For example, the banded or barred grunter is widespread across northern Australia (Allen et al. 2002), with either an advance or ancient population living only in the Diamantina and Georgina River