Black carp (Mylopharyngodon piceus)

Common Names: Snail carp, Chinese black carp, black amur, Chinese roach, black Chinese roach, Asian carp

Description:

Black carp (Mylopharyngodon piceus) is a large invasive fish native to rivers and lakes across eastern Asia, first brought to the United States in the 1970s for use on catfish farms [1]. Adults can exceed five feet in length and 150 pounds, making black carp the largest of the four non-native carp species now present in North American waters [2]. The species is confirmed to be naturally reproducing in the Mississippi River basin, where its powerful crushing teeth and appetite for native snails and mussels pose a serious threat to already-imperiled freshwater species [4][5].

Identification:

Black carp have a long, sturdy body covered in large scales whose dark edges create a bold crosshatch pattern. Their color runs dark brownish-black on the back and sides, grading to blue-grey or white on the belly, with dusky brownish-black fins [2]. The head tapers to a small, slightly downturned mouth with no barbels ? the fleshy whisker-like projections visible at the lip corners of common carp [1]. Adults stay near the bottom in the deepest parts of large rivers and do not leap from the water like silver carp [2]. In the field, adults are most likely encountered by anglers or commercial fishers hauling nets in large, deep Midwest rivers during summer months, when fish concentrate in outside river bends and side channels [1].

Juveniles are nearly impossible to tell from young grass carp in the field ? definitive identification requires laboratory examination of the throat teeth or a genetic analysis [3].

At-a-glance cues:

1. Very large scales with dark edges, giving a chainlink-fence appearance when viewed close-up [2]
2. Dark brownish-black body with a blue-grey to white belly ? distinctly darker overall than grass carp [2]
3. Small, slightly downturned mouth ? no barbels (whiskers) at the lip corners [1]
4. Stays near the riverbed in deep water; rarely visible at the surface [2]

Habitat:

Black carp are native to large rivers, lakes, and connected ponds across eastern Asia ? from the Amur River basin on the China-Russia border south through the Yangtze and Pearl rivers [1]. In North America, established populations have been documented in the Mississippi River and its major tributaries, including the Missouri, Ohio, Illinois, Cumberland, and Tennessee rivers [1][2]. Adults prefer the deepest, slowest parts of large rivers: deep pools in outside bends and wide side channels [1]. They can survive for many years in connected oxbow lakes and large reservoirs, but successful spawning requires long stretches of fast, turbulent river where the current can carry semi-buoyant eggs downstream while they develop [1].

Reproduction:

Black carp mature slowly, typically reaching breeding age between 4 and 6 years [1]. Once mature, they spawn every spring and early summer. When water temperatures climb above roughly 64?F (18?C) and river levels rise, adults migrate upstream to turbulent stretches of river ? rapids, river confluences, and outside bends with strong current [1][8]. There, males and females release eggs and sperm directly into the water. The fertilized eggs are semi-buoyant and drift downstream for tens of miles while they develop, hatching in roughly 24 to 48 hours under warm conditions [1]. Young fish seek calm backwaters and floodplain shallows as nursery habitat before moving into deeper river channels as they grow [1][8].

Each female can produce 1 to 3 million eggs per year [1]. Black carp also live long ? more than 15 years ? giving a single fish many seasons to reproduce [1]. Multiple wild year classes have been confirmed in the Mississippi River basin, showing that natural reproduction is now established [5].

Impact and Damage:

Black carp are built to eat freshwater mussels and snails. Powerful molar-like teeth set deep in the throat ? not the jaw ? work like millstones, crushing the hard shells of mollusks that most other fish cannot handle [2]. A study of wild-caught black carp in U.S. rivers found shell fragments from seven species of native freshwater mussels in their stomach contents, confirming that predation on native species is already occurring [4]. Separate laboratory research found that juvenile black carp are more effective at consuming native freshwater mussels than non-native species such as Asian clam ? suggesting that the mollusks least able to cope with this new predator are the ones most at risk [9].

This threat matters because the Mississippi River basin holds some of the most diverse freshwater mussel communities on Earth, and many of these species are already in steep decline from habitat loss, pollution, and competition with invasive zebra mussels [6]. Aquaculture records document that black carp can eliminate all snails from an enclosed pond ? the effectiveness that originally made them attractive as a biocontrol agent ? raising serious concern about what a free-ranging wild population could do to native mussel beds [1].

Black carp were listed as injurious wildlife under the Lacey Act in 2007, prohibiting the import of live fish, eggs, or gametes into the United States and their transport across state lines without a federal permit [7]. This was the first federal injurious-wildlife listing to explicitly cover both fertile and sterilized forms of a fish species.

Similar species:

Grass carp (Ctenopharyngodon idella) is the species most commonly confused with black carp ? both are large, big-scaled fish of similar body shape and fin arrangement. Grass carp are lighter in color (olive to brassy green on the back, silvery-white on the belly) with a broader, rounder snout and the mouth positioned at the very tip of the snout, while black carp are distinctly darker brownish-black with a narrower, more pointed snout and a slightly downturned mouth [3]. The throat (pharyngeal) teeth are completely different ? grass carp teeth are serrated and grooved for shearing vegetation, while black carp teeth are smooth and flat for crushing shells ? but checking the teeth requires sacrificing or X-raying the fish [2][3].

Common carp (Cyprinus carpio), another large, dark fish common throughout Midwest lakes and rivers, is readily distinguished from black carp by two pairs of fleshy barbels at the mouth corners and a stiff serrated spine at the front of both the dorsal and anal fins [2]. Black carp have neither barbels nor fin spines on any fin.

Bighead carp (Hypophthalmichthys nobilis), another invasive Asian carp present in the Mississippi River basin, has a massive head relative to its body ? with eyes set well below the midline of the head ? and a very wide gaping mouth [2]. Black carp have a proportionate, pointed head with normally placed eyes and a small, subterminal mouth. Bighead carp also feed by filtering microscopic plankton near the surface rather than hunting mollusks along the river bottom.

Monitoring and rapid response:

Signs to watch for:

1. Any large, unfamiliar dark fish in a major river ? adults routinely reach 3?5 feet and 30 or more pounds, with a dark brownish-black body, large crosshatch-patterned scales, and no barbels or serrated spines at the front of the dorsal or anal fins [1][2]
2. If you catch an unusual fish, photograph all sides and record the exact location (GPS coordinates or nearest landmark) before releasing ? a single photograph is enough to start an expert review [10]
3. Summer is the peak detection season; adults concentrate in the deepest pools of large rivers during warm months [1]

What you can do:

1. Black carp live in large rivers and are not currently established in Michigan ? no action is needed on home ponds, lakes, or small waterways at this time [10]
2. Never buy, move, or release live fish you cannot positively identify; importing or transporting black carp across state lines is a federal violation under the Lacey Act [7]
3. Clean, drain, and dry your boat, trailer, and gear between waterways to avoid spreading any invasive aquatic species
4. Natural area stewards and river monitoring volunteers can support early detection by learning black carp field cues and photographing any unusual large carp during river surveys

When to call a professional:

1. If you catch or observe a fish you believe may be a black carp, keep it on ice and contact the Michigan DNR Invasive Species Hotline (1-800-292-7800) or your state fisheries agency immediately ? do not release it [10]
2. Whole specimens retained for expert examination or genetic testing are among the most valuable data sources for tracking the range of wild populations [5]
3. For chemical control options, contact a licensed applicator or your local cooperative extension office.

Report sightings to MISIN. Help track this species' spread by submitting observations through the MISIN web site or the MISIN mobile app (Android, iOS, Windows, and macOS). Photos at multiple angles paired with a precise GPS location are the most valuable data for confirming new occurrences and triggering rapid-response review.

Credits:

1. USGS Nonindigenous Aquatic Species. Mylopharyngodon piceus ? Black Carp. U.S. Geological Survey. nas.er.usgs.gov
2. U.S. Fish & Wildlife Service. Black Carp (Mylopharyngodon piceus) Species Profile. fws.gov
3. Kroboth, P., Chapman, D.C., Hrabik, R.A., & Neely, D.A. (2019). Characteristics for the external identification of Black Carp from Grass Carp. Journal of Fish and Wildlife Management. semanticscholar.org
4. Poulton, B.C., Kroboth, P., Aiken, G., Chapman, D., Bailey, J., McMurray, S.E., & Faiman, J.S. (2019). First examination of diet items consumed by wild-caught black carp (Mylopharyngodon piceus) in the U.S. The American Midland Naturalist, 182(1):89?108. doi.org/10.1674/0003-0031-182.1.89
5. Whitledge, G.W., Kroboth, P.T., Chapman, D., Phelps, Q.E., Sleeper, W., Bailey, J., & Jenkins, J. (2022). Establishment of invasive Black Carp (Mylopharyngodon piceus) in the Mississippi River Basin. Biological Invasions. semanticscholar.org
6. U.S. Fish & Wildlife Service. Ecological Risk Screening Summary ? Black Carp (Mylopharyngodon piceus): Uncertain Risk. fws.gov ? ERSS Black Carp
7. Federal Register. (2007). Injurious Wildlife Species; Black Carp. Final Rule. 72 FR 59019 (Oct. 18, 2007). federalregister.gov
8. Invasive Carp Regional Coordinating Committee. Black Carp. icrcc.fws.gov
9. Porreca, A.P., et al. (2021). Differential Vulnerability of Native and Non-Native Mollusks to Predation by Juvenile Black Carp. Biological Invasions. semanticscholar.org
10. Michigan Department of Natural Resources. Black Carp ? Michigan Invasive Species. michigan.gov/invasives

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