their nutrients from filtering silt and detritus. As a bottom-feeder, it does not have very much competition, so its main worry is predation. It is typically preyed on by larger carnivorous fish such as northern pike, muskellunge, walleye, and largemouth bass, but only in its juvenile stage. Their largest predators are humans, although some larger birds, such as great blue herons, have been known to eat them. They can be found in large rivers and reservoirs, with sand or silt bottoms in slower-moving currents. The young typically are found in small streams, or tributaries. They are more abundant in areas with slower water velocity and moderate temperatures. Lifecycle During breeding season, small tubercles can be observed on the body of the male. Reproduction typically occurs during late spring, in large spawning groups. The female can spawn more than once per year, and usually releases more than 100,000 eggs. The eggs are typically adhesive and demersal with a diameter of about , and they typically hatch within eight to 15 days. To spawn, the temperature of the water must be , and spawning ends around the beginning of summer when water temperatures begin to rise. They exhibit no parental care; instead, they broadcast their eggs onto the sand and then leave them. The lifespan of river carpsucker can span decades, much like other long-lived catostomids; longevity more than 45 years has been documented. They are schooling fish and will often be found in large groups. Relationship with people The river carpsucker currently has no established management plans, but is frequently caught by commercial fisherman for food, though they are not officially considered a game species. However, they are in large abundance in a few areas in their range. They are very plentiful in Elephant Butte Reservoir and Caballo Lake in New Mexico. They also can be affected by humans; their population begins reducing rapidly with the introduction of toxins into their habitat. The world record for the species stands at 13lb 4 oz caught in Cass County Nebraska in 1999. References river carpsucker Freshwater fish of the United States river carpsucker river carpsucker