FISH DIVERSITY IN AN ISOLATED ARTIFICIAL WETLAND

Adult, juvenile and larval fishes were sampled in a managed isolated w etland in the Red Chute Bayou floodplain, LA from December 1994 to Jul y 1995. Nineteen species were captured. Principal components analysis of adult fishes showed little difference between sites, but a gradient of habitats and seasons reflecting variable richness was observed. Bo wfin (Amia calva), black bullhead (Ameiurus melas), spotted gar (Lepis osteus oculatus), bluegill (Lepomis macrochirus), warmouth (Lepomis gu losus), black crappie (Pomoxis nigromaculatus) and fliers (Centrarchus macropterus) were the dominant adult fishes. Juvenile and post-larval fishes had low catch-per-unit-effort and were dominated by fliers. Pr incipal components analysis distinguished three habitat groups and sig nificant seasonal variation in the juvenile/post-larval fish community . The ichthyofauna resembled that described for irregularly inundated isolated floodplain ponds of the lower Mississippi River valley. The r elatively low diversity of this system is probably due to the isolatio n of the backwaters from active river cycles. The problem may be furth er compounded by the timing of water drawdown in late spring.