Photographer: Corey Clouse Source: TPWD
Silver carp (Hypophthalmichthys molitrix) are heavy bodied fish from the family Cyprinidae and can weigh up to 60 pounds. Silver carp can be identified by having a stout, silver body, low-set, slightly downturned eyes, an upturned mouth lacking barbels, and a keel along the belly that runs from the pelvic fins all the way to the throat. They have tiny scales on the body but lack scales on the head. The silver carp looks very similar to another invasive species, the bighead carp (Hypophthalmichthys nobilis), which is grayer in color and has a keel that only extends from the anal fins to pelvic fins. Young silver carp are similar in appearance to shad but can be identified by their low-set eyes—shad’s eyes are located near the top of their heads—and the lack of a long, whip-like segment on the dorsal fin. Silver carp grow to approximately 3 feet in length and can weigh up to nearly 60 pounds. Silver carp are also known and recognizable for their ability to jump several feet out of the water when disturbed by noise from boats, sometimes jumping into boats and injuring boaters.
Silver carp are voracious filter feeders that consume up to half their body weight in plankton and detritus. They are able to outcompete native filter feeding fish, larval fish, and native mussels for resources, negatively impacting aquatic food webs and fish populations.
Silver carp reach maturity as early as 2 years old in North America and are capable of reproducing until 10 years of age. Temperatures must reach 18o C for silver carp to spawn. Spawning occurs from May to September, when they can be witnessed migrating upstream in groups of 15 to 20 adults. Each female may lay as many as 5 million eggs per year. Eggs require enough river current to transport eggs downstream and a minimum spawning river length of 62 miles for the eggs to survive.
Silver carp were first introduced to the United States in 1973 as an import to stock fish farms in Arkansas for control of phytoplankton. Popularity of stocking the silver carp increased by the mid 1970's with records of six state, federal, and private facilities importing the fish. The silver carp was ideal for phytoplankton control and a food source. By the 1980's there were occurrences of silver carp in natural waters due to accidental escapes from stocked ponds and aquaculture facilities.
The silver carp is native to the major drainages in Eastern Asia, Southern Russia, Eastern half of China, and possibly part of Vietnam.
U.S. Habitat: Silver carp are primarily found in large rivers. Their diet consists primarily of phytoplankton, but they are also known to feed on zooplankton, bacteria, and detritus.
Distribution
U.S. Present: Occurrences have been documented in AL, AR, AZ, CO, FL, HI, IL, IN, IA, KS, KY, LA, MN, MS, MO, NE, NV, ND, OH, OK, PR, SD, TN, TX, WI
Texas: Silver carp were recently reported from Texas tributaries of the Red River in 2021, but were already known to be present in the waters of the Red River which borders Texas and Oklahoma, where they have been reported as far upstream as the area just below Lake Texoma in 2019.
Click here to view range map provided by USGS, NAS
Management of silver carp in Texas primarily focuses on preventing their spread. It is prohibited to possess, transport, or introduce silver carp in Texas. If a silver carp is caught, it is permitted to immediately release it back into the water body from which it was taken or to keep it provided it is immediately killed or placed on ice upon possession. Silver carp have tasty, white flesh and are excellent for consumption, but filets have numerous bones. To help prevent the spread of silver carp as live bait, regulations prohibit the transport of live non-game fish from the Red River in Texas where silver carp have been found. Juvenile silver carp are difficult to distinguish from other native species of bait fish (i.e. gizzard shad) and can contaminate live bait. If you believe you have caught a silver carp in a new area, please email location and photographs to Texas Parks and Wildlife Department at AquaticInvasives@tpwd.texas.gov.
Aquatic Invasive Species Fact Sheet -- provided by Indiana Department of Natural Resources
Berg, L. S. 1948-1949. Freshwater fishes of the U.S.S.R. and adjacent countries, 4th edition. Three volumes. Translated from Russian, 1962-1965, for the Smithsonian Institution and the National Science Foundation, by Israel Program for Scientific Translations, Jerusalem, Israel. Volume 1:504 pp.; volume 2:496 pp.; volume 3:510 pp.
Carter, F. A., and J. K. Beadles. 1983. Range extension of the silver carp, Hypophthalmichthys molitrix. Proceedings of the Arkansas Academy of Science 37:80.
Laird, C. A., and L. M. Page. 1996. Non-native fishes inhabiting the streams and lakes of Illinois. Illinois Natural History Survey Bulletin 35(1):1-51.
Li, S., and F. Fang. 1990. On the geographical distribution of the four kinds of pond-cultured carps in China. Acta Zoologica Sinica 36(3):244-250.
Rinne, J. N. 1995. The effects of introduced fishes on native fishes: Arizona, southwestern United States. Pages 149-159 in D. P. Philipp, J. M. Epifanio, J. E. Marsden, and J. E. Claussen, editors. Protection of Aquatic Biodiversity. Proceedings of the World Fisheries Congress, Theme 3. Science Publishers Inc., Lebanon, NH.
Internet Sources
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