Spawning and Early Life History of the Freshwater Drum in Lewis and Clark Lake, Missouri River

Abstract

The early life history of freshwater drum, Aplodinotus grunniens, was studied in 1965–67 to determine factors influencing year‐class strength in a main stem Missouri River reservoir. Fish spawning occurred over a period of 6–7 weeks in June and July when water temperatures reached 18 C. Fecundity of fish 307 to 386 mm long and 6–9 years old ranged from 34,000 to 66,500 ova. Ova reared in the laboratory at a water temperature of 23 C hatched in 27 hr and the prolarvae averaged 3.2 mm long. The prolarval stage was complete 45 hr after hatching and postlarvae averaged 4.4 mm long. Adult characters developed at an approximate length of 15 mm. Diet of fish 6–15 mm long was Daphnia and Cyclops. Bottom fauna became important in the diet of fish longer than 20 mm. Fish movement between channel and floodplain was related to changes in diet. Growth, year‐class strength, and mortality varied among years. Strong year classes were associated with warm summer (June‐August) water temperatures in the spawning and nursery area and weak year classes with cold temperatures. Size of year class was determined before fish attained a length of 25 mm.

Effects of historic flooding on fishes and aquatic habitats in a Missouri River delta

“…It has been hypothesized that flood-induced egg drift causes hatching to occur primarily in productive backwaters located downstream from spawning areas (Koel & Sparks 2002). Freshwater drum spawn in the Delta from June to July (Swedberg & Walburg 1970), a time period overlapped by the 2011 flood, thus egg drift may have been a mechanism for low juvenile CPUE during the disturbance. Alternatively, the flood may have directly impaired reproduction and/or recruitment (Bednarski et al 2008).…”

Seasonal Composition and Abundance of Ichthyoplankton Entrained through Big Bend Dam, South Dakota

“…Freshwater drum under 10 mm were common in samples collected from June 16 to July 20 indicating that drum in Lake Sharpe likely have an extended spawning period. Other studies also found evidence of protracted spawning season for freshwater drum (Hergenrader et al 1982, Swedberg andWalburg 1970).…”

“…Swedburg and Walburg (1970) reported that in Lewis and Clark Lake, freshwater drum began to spawn when water temperatures reached 18.0 "C and Lake Sharpe drum appear to follow the same pattern. Freshwater drum were not present in Big Bend tailrace samples until June 16 when Lake Sharpe surface temperatures were around 19°C.…”

Evaluating the Effects of Discharge Rates, Water Levels, and Peaking on Fish Populations in Missouri River Main Stem Impoundments

“…The estimated mortality rates for freshwater drum were directly related to the flushing rate in Lewis and Clark Lake from 1965 to 1969 (Figure 2). Freshwater drum are pelagic spawners, and the 18-34 mm size group is most abundant in the old river channel area [Swedberg and Walburg, 1970]. Currents in this area of the reservoir are higher than those in the floodplain, and freshwater drum would be extremely vulnerable to being flushed out of the reservoir.…”