exceed two pounds in weight, with a current International Game Fish Association world record of . Life cycle and reproduction Brown bullheads typically live between six and eight years, but have been recorded as old as fifteen in captivity. The species spawns between April and June. For the duration of each breeding season, females will be monogamous. There are no consistent behaviors of mate attraction. The females lay eggs in dark locations such as under rocks and inside logs, where they are externally fertilized by the male. The fish face opposite one another during the fertilization process. Nests are primarily created by females, but the eggs are protected by both sexes. An egg cluster in a nest may contain between 50 and 10,000 eggs. The eggs usually take six days to hatch, but may take up to 13 days. Both parents generally care for their offspring for an additional five days after the eggs hatch. The young are kept in a school by a parent for up to one month. They will remain in schools as juveniles. Brown bullheads, both male and female, will reach sexual maturity around age three. Brown bullheads have occasionally been recorded eating their own eggs. As an invasive species The fish has been introduced into many European countries, such as Poland, Germany, Sweden, Norway, Finland, Romania, Estonia, Hungary, Serbia, and Croatia. Brown bullheads have also been introduced to western North America, Chile, Puerto Rico and New Zealand. Countries who have reported adverse effects from the introduction of the brown bullhead species include Iran and Turkey. Diet Brown bullheads are omnivorous benthic bottom feeders. Their diet consists of algae, leeches, worms, mollusks, crustaceans, insects, crayfish, other smaller fish species and fish eggs. Brown bullheads are typically nocturnal feeders, but have been reported to feed diurnally. Bullheads have poor eyesight and are heavily reliant on their sensitive barbels to locate their food. The fish are omnivorous and will reportedly eat almost anything that fits in their mouth. Predation Brown bullheads are the most susceptible to predators in their developmental stages, primarily as eggs. They are prey to the following species: northern pike, muskellunge, walleye, snapping turtles, water snakes, green herons, yellow perch, and sunfish. Additionally, brown bullheads are used for small-scale commercial fishing, recreational fishing, and more specifically for consumption and research. Predation by other fish and coexisting species is only a realistic threat to bullheads under