about 50 percent of the freshwater drum's diet. In August through November, they tend to eat fish (which are primarily young-of-the-year gizzard shad). The percentage of fish in their diet at this time ranges from 52 to 94 percent. Other items in the drum's diet are mollusks and crayfish. The freshwater drum competes with several organisms. During its early stages in Lake Erie, it has been shown to compete with yellow perch, the trout-perch, and the emerald shiner. During its adult lifetime, it competes with yellow perch and silver chub in deep water, and competes with black bass in the shoal areas. Predators on drum include humans and other fish. During its first year, the freshwater drum serves as a forage fish for many species of predatory fish. These include smallmouth bass, walleye, and many other piscivores. After its first year, the primary predators on freshwater drum are humans. The drum is an important commercial crop on the Mississippi River, but in other areas it constitutes only a small portion of the commercial catch. Consistent with other sciaenids, freshwater drum are strongly nocturnal with the bulk of most catches being derived from night angling/sampling. Commercial fisheries are present for this species, although market price tends to be quite low. Thus, many freshwater drum are harvested as bycatch from targeted higher-value species. There has been some research on the freshwater drum's impact on the invasive zebra mussel in northern lakes and rivers. Zebra mussels are consumed by freshwater drum once they reach a length of , but drum under in length only eat small mussels and reject the larger ones. The fish larger than exhibit less selectivity and consume mussels relative to their availability in lakes. These larger fish are not restricted by their ability to crush zebra mussels, but they are restricted by the size of the clumps that they can remove. The drums' eating of zebra mussels contributes to a high mussel mortality, but not enough to have an impact on their spread, or control the population. Life history During the summer, freshwater drums move into warm, shallow water that is less than deep. The freshwater drum then spawn during a six to seven-week period from June through July when the water reaches a temperature of about . During the spawn, females release their eggs into the water column and males release their sperm. Fertilization is random. Males generally