Fish associations within the different inland habitats of lower south - western Australia

In order to determine whether certain fish species or groups of species are associated with the different habitat types occurring in the inland waterbodies of south-western Australia, 239 sites sampled between Margaret River and Broke Inlet were assigned to appropriate Ramsar wetland categories and their fish assemblages then subjected to classification, Each of the sample sites fell into one of the following categories, pools (ephemeral or permanent), riverine (fresh or salt affected), reservoirs, lacustrine (fresh or saline) or estuarine, One-way analysis using ANOSIM in the PRIMER package suggested that the fish communities of the ephemeral pools were significantly different to those of the rivers and lakes, Thus, the ephemeral pools were characterised by the presence of the endemic and restricted species, Lepidogalaxias salamandroides and!or Galaxiella nigrostriata, whereas the permanent rivers and lakes of the region were characterised by a fauna dominated by the other small endemic freshwater teleosts, Le, Galaxias occidentalis, Galaxiella 1111mda, Bostockia porosa, Edelia vittata and Nannatherina balstoni and in many cases the lamprey Geotria allstralis. ANOSIM also showed that there were significant differences between the fish faunas in each of the freshwater habitats in the study region when compared to the estuarine and salt affected waterbodies of the region, The species most commonly encountered in the estuarine and salt affected sites included the estuarine affiliated Leptatherina wallacei and Pseudogobills olorum, the endemic G, occidentalis and also the introduced Gambusia holbrooki.