Movement, Reproduction and Ecological Relationship of Channel Catfish, Ictalurus Punctatus (Rafinesque), in the Little Missouri River, North Dakota, 1972-1973

The biology and ecology of the channel catfish population in the Little Missouri River was investigated during the summers of 1972-1973. A total of 3142 catfish were caught; 3097 were marked and released. The 1972 catch exceeded the 1973 catch be approximately three and one-half times and was attributed to higher average stream discharge in 1972. There have been 257 recaptures to date. Over half (55.25 percent) of the recaptured fish showed no movement and were recovered within a short time; the abundance of local recoveries reflected activity within a limited area rather than a sedentary cohort of the population. Upstream movements were recorded less frequently (8.95 percent), but occurred over longer periods of elapsed time and covered greater distances than did downstream movements (35.8 percent); ascent occurred in the spring, descent in the fall. Stream discharge is the dominant axiotic limiting factor influencing population stability. Seasonal increases expedite catfish migration for reproduction, foraging, and recruitment. Spring runoff generally facilitates ascent. Reproductive success is dependent upon discharge and temperature constancy during incubation; increased flow is again imperative for autumnal descent and recruitment. Rocky spawning areas shield developing embryos from suspended sediment scouring; however, a paucity of such habitat limits production