J. Richardson, 1845
- The Hypophthalmichthys nobilis or Bighead carp are native to Asia. Bighead carp are a large deep bodied fish with big heads. It has a laterally compressed (relatively flat side to side) body form. The head is longer than the body is high. The mouth slants upwards and the lower jaw extends slightly over upper jaw. Their scales are very small with from 85-100 scales along the length of the fish with 26-28 rows of scales above the lateral line. Larger fish have a heavy, stiff, non-serrate spine at the origin of the dorsal fin and a slightly stiffened spine at the anal fin origin. The dorsal fin has eight and sometimes 9 soft rays. The anal fin has thirteen and occasionally fourteen soft rays. The gill rakers are long, comb like and close-set.
- Life Cycle
- H. nobilis are a synchronous (all spawn at the same time) and gonochoristic (have separate male and female) species that spawns annually for dozens of years during its life span. H. nobilis is a semi-migratory fish. Reproductive adults migrate from lakes and the lower reaches of rivers to the spawning ground in the upper reaches of the major rivers in its native range. Flowing water and changes in water level are essential for natural spawning. Semi-buoyant eggs are laid that suspend in the water column when there is a current.
- H. nobilis have been introduced around the world. They have been found in Africa, Australasia-Pacific, North America, and South America. They may be introduced as a fish for the food industry.
- Control Efforts
- Cooperation is recommended between the states where H. nobilis may spread to ensure consistency in regulation and enforcement.
- Common names
- Bighead carp, Asian carp
- Bighead carp is a large fish (sometimes more than 4 feet and to nearly 100 lbs) with a compressed (relatively flat side to side) body form. Its back is dusky gray-olive in color, fading to darkly mottled sides on a silver-white field and a whitish belly. Its ventral surface features a smooth keel the runs from pelvic to anal fins. The large head is scaleless with a large terminal mouth and a somewhat longer lower jaw (unlike common carp, lacking barbels) and eyes set forward and downturned, below the body’s midline.
Bighead carp are native to China and eastern Asia in latitudes ranging parallel to Florida through the lower Great Lakes. In its native range, bighead carp occurs in large rivers, although the species has been stocked in a variety of habitats, including warmwater lakes, ponds, and reservoirs. Bighead carp actively feed on plankton near the water’s surface, and are relatively opportunistic, sometimes shifting between phyto- and zooplankton as abundances in food sources shift seasonally. Bighead carp spawn in the warm, flowing water of large rivers.
In 1972, bighead carp were introduced to an aquaculture pond in Arkansas as an experiment in water quality control. By 1974, these experiments had been taken up by agencies and universities. These initial stocks accidentally escaped their culture-pond environments via flood waters, and by the early 1980s, wild fish were being collected in the Mississippi and lower Ohio Rivers. They are now found throughout much of the Mississippi system with a handful of genetic detections in the Great Lakes. There have also been five adult individual fish captured in Lake Erie from 1995–2003; these individuals exhibited early growth patterns that seem consistent with origins in southern hatcheries. Bighead carp are prone to bait-bucket transfers because juveniles resemble native shads. They can also be mistakenly included in shipments of catfish from the south for use in stocking. Bighead carp consume large amounts of plankton, competing for food with larvae of native fish, paddlefish, and bigmouth buffalo in the upper Mississippi River system. Bighead carp can also load the nets of commercial fishermen to the point they are forced to abandon the fishing spot.
- The Global Invasive Species Database is managed by the Invasive Species Specialist Group (ISSG) of the IUCN Species Survival Commission.
- USGS Nonindigenous Aquatic Species Database.
- Texas Invasive Plant and Pest Council
Images from Bugwood.org