_Lepomis humilis_ (Girard). Orangespotted sunfish. KU 6, 9, 11, 14, 15; UMMZ 1, 2, 4, 5; DM 4, 6, 16, 17, 21, 23, 24, 25, 26, 32, 33, 34, 37, 38, 39, 40, 41, 42. _Lepomis megalotis breviceps_ (Rafinesque). Longear sunfish. KU 8 (one individual taken in Rock Creek, 1951). _Pomoxis annularis_ (Rafinesque). KU 9, 15; UMMZ 2. White crappie occur in Lone Star Lake and in farm ponds in the basin. _Pomoxis nigromaculatus_ (LeSueur). Specimens of black crappie were obtained from Lone Star Lake and in farm ponds in the basin. _Aplodinotus grunniens_ Rafinesque. Drum. KU 12. _Discussion_ Our data show that the present fish-fauna of the Wakarusa River has three major components: (1) A group of species that are mainly restricted to the lower mainstream; all of them are common in the Kansas River (_Lepisosteus osseus_, _Carpiodes carpio carpio_, _Ictiobus cyprinella_, _Moxostoma aureolum_, _Cyprinus carpio_, _Hybopsis storeriana_, _Hybopsis aestivalis_, _Notropis percobromus_, _Hybognathus nuchalis_ and _Pylodictis olivaris)_. (2) A group of species that are ubiquitous; they comprised the entire fauna in some tributaries, despite the existence of habitats that seemed suitable for other species (_Notropis lutrensis_, _Pimephales promelas_, _Ictalurus melas_, and _Lepomis cyanellus_). (3) A group of species having distributions centered in Rock Creek, Washington Creek, Deer Creek, and some nearby tributaries (_Catostomus commersonnii_, _Semotilus atromaculatus_, _Hybopsis biguttata_, _Notropis cornutus_, _Notropis topeka_, _Notropis umbratilis_, _Phenacobius mirabilis_, _Pimephales notatus_, _Campostoma anomalum_, _Noturus exilis_, _Percina caprodes_, _Etheostoma nigrum_ and _Etheostoma spectabile_). The distributions of groups (2) and (3) provide clues to the effect of drought on the fish-population, and on the relative ability of various species to repopulate areas where they have been extirpated. Larimore _et al._ (1959) studied the re-establishment of stream-fish following drought in Smiths Branch, a small warmwater stream in Illinois. They found that 21 of the 29 species regularly occurring there reinvaded most of the stream-course within two weeks after the resumption of normal flow, and that all but three species were present by the end of the first summer. Our study indicates a much slower rate of dispersal by many of the same species. This is presumably attributable to the ecological barrier presented by the Wakarusa mainstream.