Photo credit: U.S. Geological Survey, Bugwood.org
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Species at a Glance
The bighead carp is a member of the Asian carp complex, which includes silver, black, and grass carp. As of 2016, there are no established populations in the Mid-Atlantic Region; however, its large size and voracious appetite make it an enormous threat to the area. Any potential sightings should be reported immediately.
The body of the bighead carp is large, reaching 1-1.5 m (3.3-4.9 ft) in length and weighing over 100 pounds. It is broad, fusiform, and laterally compressed with a solid dark gray top blending to white underneath. It has many irregular gray-black blotches on its sides. Its large head lacks scales and its big terminal mouth lacks barbels and teeth. The lower jaw also protrudes out farther than the upper jaw. The eyes are situated low on the head and are positioned downward. The short dorsal fin lacks spines, and contains 7-10 rays. Scales are very small and resemble those of a trout.
The bighead carp most closely resembles the invasive silver carp (Hypophthalmichthys molitrix). The keel of the bighead carp runs from the pelvic fins to the anal fins, while the silver carp has a mid-ventral keel that is more extensive and runs from the anal fins up to the base of the gills. Silver carp also lack the dark blotches characteristic of the bighead carp. The bighead carp may also resemble the common carp (Cyprinus carpio), which has barbels on either side of the mouth, or species of suckers (Catostomidae), which have thick lips containing small nipple-like bumps.
The bighead carp lives exclusively in freshwater and prefers large river systems with flowing water that is needed for spawning. It will also inhabit lakes and ponds.
Once introduced to open waters, the bighead carp can readily spawn and disperse itself. Because juveniles of this species can resemble common baitfish species, it may be unintentionally spread through the use of live bait. Spread can also occur as it is sold through the live Asian food market.
Native to eastern Asia, the bighead carp was intentionally introduced into the United States to control algae in aquaculture ponds. During flooding in the early 1980s, it escaped into the Mississippi River and has since moved upstream towards the Great Lakes. There is evidence of reproducing populations in the middle and lower Mississippi and Missouri Rivers and in the Ohio River. The bighead carp is also in the Illinois River, which is connected to the Great Lakes via the Chicago Sanitary and Ship Canal. In the Mid-Atlantic region, bighead carp were successfully eradicated from a private fish culture facility in Hunterdon County, New Jersey, and an isolated bighead carp individual was caught by an angler in the Raritan River in New Jersey in the late 1990s. However, there are currently no established populations in the Mid-Atlantic region.
Note: Distribution data for this species may have changed since the publication of the Mid-Atlantic Field Guide to Aquatic Invasive Species (2016), the source of information for this description.
The bighead carp can consume up to 40 percent of its body weight in plankton and detritus per day, competing with native filter feeders and juvenile fish for food. This impact on the food web and trophic structure of an ecosystem could result in large population declines, impacting biodiversity as well as commercial and recreational fishing.
Information for this species profile comes from the Mid-Atlantic Field Guide to Aquatic Invasive Species (2016).