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Types of Carp - Species Identification and Invasive Threats

Written by: John B
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Two general kinds of carp are present in North American waters: the common carp, Cyprinus carpio, and several species of closely-related carp collectively known as Asian carp.

Both the common carp and the species we call Asian carp are invasive species, and though they’re infrequently targeted by rod and reel anglers, bow fishermen find the possibility of skewering a big carp truly exciting.

But there are many other species of carp when we look outside Canada and America, including some interesting hybrids.

In this article, we’ll break down these species and investigate what you need to know about carp.

If you want to know more about carp and carp fishing, keep reading!

Also Read:

North American Carp

Eurasian or “common” carp

Cyprinus carpio is native to the waters of the Danube in Europe and the sluggish waters in Anatolia, Turkey.

eurasian common carp

Known as the “common” carp in America and Canada, the Eurasian carp was introduced in the US in 1831, where it was hoped it would catch on as a food fish. That gamble was backed by the Eurasian carp’s enduring popularity as a meal across Central Europe, and the bet was that immigrants from Germany, Hungary, Poland, and Austria would take the fish in America, too.

Unfortunately, that gamble didn’t pay off.

Instead, American diners hold a strong preference for filets of fish, and the tiny bones of carp necessitate cooking these beasts whole. And since common carp grow quickly, reproduce easily, and prove hardy even in low oxygen, high turbidity environments, they rapidly grew in number.

That’s proven to be something of a problem. Lacking sufficient natural predators or intensive commercial fishing, carp numbers exploded. And their feeding habits, especially their propensity for rooting through the soil on the bottom to eat aquatic plants, can diminish the habitat for native species like canvasback duck by increasing the turbidity of water.

Common carp habitat and diet

The common carp are hardy fish that can survive in a wide variety of habitats. Marine biologists note that while carp generally prefer “lakes, ponds, and the lower sections of rivers” - where water flow is sluggish at best - they can also spread to “brackish-water estuaries, backwaters, and bays.”

Carp don’t particularly enjoy clear water or fast currents.

carp love murky water with vegetation

Still, murky water with plenty of aquatic vegetation is just perfect for carp.

What they love, however, are “manmade [sic] impoundments, lakes, and turbid sluggish streams receiving sewage or agricultural runoff.” There, the agricultural wastes feed aquatic vegetation and encourage the growth of marine invertebrates that common carp love to eat.

And make no mistake about it: the common carp is an omnivore that feeds on vegetation, snails, insects, crawfish, and plankton.

Growing quickly on this rich diet, they reach maturity quickly, measuring 16 to 31 inches and as heavy as 30 pounds or so.

Common carp identification

carp barbels

If you look carefully at this fish, you’ll see those barbels.

The common carp is pretty easy to identify.

It’ll be armored by a shiny, gold- to copper-colored head. Scale color can vary a lot but is usually golden to coppery-brown.

Also look for a long, sickle-shaped dorsal fin with 2 to 3 hard and 17 to 22 soft rays. That first ray is a sharp, serrated spine, so be careful handling this fish!

You’ll also find two pairs of barbels, one on the lower mouth and one on the upper lip.

That makes it pretty easy to tell the difference between a common carp and a bigmouth buffalo, but for bow anglers, the major sign to shoot should be color.

“Asian carp”

asian carp

It’s not hard to figure out where the bighead got its name.

Collectively, the bighead carp, black carp, grass carp, and silver carp make up a family of fish we refer to as the “Asian carp.” 

According to the National Park Service, “These four species of fish were introduced to the U.S. in the 1970's to control algae, weed, and parasite growth in aquatic farms, weeds in canal systems, and as one form of sewage treatment.”

That makes sense - at least on paper- given that two of these species, the grass and black carp, are voracious herbivores that can eat up to 40% of their body weight in aquatic vegetation per day. The other two species, the bighead and silver carp, dine on plankton, including the larval stages of parasites. 

The Invasive Species Centre of Canada observes that “Silver and Bighead Carps have established populations throughout the Mississippi River Basin and are now in the Illinois Waterway and within striking distance of Lake Michigan and the Great Lakes. Black Carp are spreading towards the Illinois River and recent evidence has found natural reproduction of Grass Carp in two U.S. tributaries of Lake Erie, which is an immediate threat to Lake Erie.”

All carp create a problem for local wildlife.

Because they grow and reproduce quickly, and can survive in marginal environments, they can outcompete native species or food and space. That can lead to rapid declines of indigenous species of all kinds.

For instance, bighead carp “are voracious eaters and consume a wide range of zooplankton, detritus and small invertebrates, outcompeting native species for food. Bighead Carp lack a true stomach, which requires them to feed almost continuously.”

Add to this that Silver carp are easily disturbed by vibrations like the prop on an outboard, and you can get a serious issue for anglers and recreational boaters.

Asian carp habitat and diet

silver carp

Silver carp get big and jump high, causing plenty of injuries to boaters.

Each of the four species classified as Asian carp prefer the same slow-moving or still water in temperate climates. Quite adaptable, they can survive in very cold water and are extremely tolerant of low dissolved oxygen levels.

These hardy fish have different habits when it comes to feeding, however.

The bighead consumes zooplankton of all kinds, small marine invertebrates, and detritus. Mature black carp feed on mollusks, shrimp, crawfish, and insects, often decimating these food sources and leaving local wildlife unable to compete. Grass carp have a diet composed primarily of aquatic vegetation, but they’ll switch to invertebrates, worms, detritus, and nearly anything else if they need to. Finally, silver carp are filter feeders specializing in phytoplankton.

Asian carp identification

Four species make up this “family:” the bighead carp, the black car, the grass carp, and the silver carp.

Each has a distinctive appearance.

Bighead carp

bighead carp

Bighead carp get big, with a maximum observed length of 4 feet, 9 inches and a whopping 88 pounds!

Typically, however, they’ll be in the neighborhood of 2 feet or so.

Their eyes can be found very low on their heads, which are distinctively dark - like their fins - and paired with small mottled scales. 

Their dorsal fin will be rounded and small rather than the long sickle-shaped fin the common carp wears.

Black Carp

black carp

Black carp are sometimes huge, reaching lengths of more than 6 feet and weights of 240 pounds. And while more typical specimens will range from 24 to 47 inches, they’ll still be bruisers by anyone’s standards!

Expect brownish-black, overlapping scales that create a cross-hatched appearance.

Grass Carp

grass carp

Growing to as massive as 6 ½ feet and nearly 100 pounds, grass carp are a common target for bow hunters.

Look for large gold-green to copper-orange scales that sport a cross-hatched effect. The grass carp will have a rounded, small dorsal fin.

Silver carp

silver carp

Another big fish, the silver carp reaches a maximum length of 55 inches, tipping the scales at an impressive 110 pounds at that size. Typical specimens will be in the range of 24 to 39 inches, however.

The silver carp is easy to identify. Look for bright silver scales and eyes placed very low on the head. And like all Asian carp, you’ll find a small, rounded dorsal fin on their backs.

Amur carp

amur carp

Cyprinus rubrofuscus was once regarded by scientists as a subspecies of the common carp, but the discovery of significant genetic differences led to it being reclassified as a new species.

Native to China, Vietnam, and Laos, careful breeding of the Amur carp has created a beautiful scale pattern that makes this ornamental fish incredibly popular. Known as the Koi when that spectacular scale pattern is present, the process of producing Koi is simple and effective.

plain amur carp

A plain Amur carp displaying its usual scale color and pattern.

When Amur carp hatch, most will not display the Koi’s distinctive patterns. These fish are culled, leaving only the beautiful Koi that then make their way to garden pools across the world.

Koi have been released into the wild in some places in America, and though their numbers are relatively small, the plain Amur can easily be mistaken for the common carp, making it difficult to assess their total impact.

carp in the united states

Amur carp habitat and diet

Amur carp are bottom-feeding omnivores enjoying a varied diet that ranges from aquatic vegetation to invertebrates such as crawfish, insects, and worms. 

And like all carp, they can thrive in low-oxygen environments, allowing them to outcompete other fish in stagnant water. Sometimes released into the wild, the colorful Koi will quickly revert to the plain Amur carp in a generation or two, with very few of the distinctive fish surviving to maturity.

Preferring temperate climates, Amur carp are nonetheless capable of overwintering under the ice, making them a hardy species that could survive in a wide range of introduced environments.

Amur carp identification

koi

There’s no mistaking the bright colors and vivid patterns of Koi.

But the plain Amur carp can be a bit more tricky.

plain Amur carp tricky to identify

Typically, you’ll find that the Amur carp sports pale golden or yellow scales with a dark head. Two barbels will decorate the mouth on either side, and the dorsal fin will be serrated.

Ghost carp 

ghost carp

Information on the ghost carp isn’t as complete as we’d like, and apparently, this hybrid is quite new. According to the Farnham Angling Society, “Ghost Carp (simply an alternative name for Ghost Koi), are a hybrid, and are usually the result of breeding Mirror or Common Carp with Purachina Koi (Platinum Ogon) to get White Ghost Koi or Yambuki (Yellow Ogon) to obtain Yellow Ghost Koi.”

Other sources disagree, stating, “A ghost carp is a freshwater fish that was artificially bred in Germany in the early 2000s. They are a cross between a common carp and a wels catfish, which is why they sometimes get mistaken for other species. Ghost carp’s official name is Cyprinus Carpio Albino and their coloring can vary depending on their breeding stock. They are a pale, almost translucent white and can have gray markings.”

It seems far more likely to us that the Cyprinus carpio albino is the result of hybridization between species of carp.

Growing to as long as 48 inches and almost 70 pounds, the ghost carp is far more likely to be encountered at a length of 18 to 26 inches.

Ghost carp habitat and diet

Omnivorous like the common carp, the ghost carp enjoyed a diet of aquatic invertebrates like mollusks and snails, as well as insects of all kinds and plant material.

It prefers slow-moving, torpid water and can be found in lakes, ponds, and sluggish rivers.

Ghost carp identification

The ghost-like white scales of this fish are a dead giveaway, and it’s hard to mistake this fish for anything else but perhaps a Koi.

European and Asian Carp

Mirror carp: Cyprinus carpio carpio

Mirror carp

The mirror carp, so called due to its large, shiny scales, is native to the Danube and Volga rivers, as well as other waterways in Europe.

Probably the result of selective breeding to create a fish that was easier to clean and prepare than the common carp, this subspecies has taken on a role of its own in European ecosystems, becoming a prized catch for anglers across the pond.

Its history of selective breeding results in a wide variety of scale patterns, making many of these fish immediately identifiable as individuals. Anglers have given these fish nicknames like “Nutsey Mirror,” “Toadless Leather,” and “Big Plated,” and these individuals are highly-sought after catch-and-release trophies.

linear carp

A “linear” carp, displaying the mirrored carp’s single-line-of-scales variation.

You’ll run into carp “species” such as the fully-scaled mirror carp, linear carp, or leather carp - but in truth, these are just scale pattern varieties of the mirror carp when the different genes that govern scale size and number are expressed.

This means that there are genetic differences between these subspecies, though information on the taxonomy of these fish is scarce.

leather carp

A “leather carp,” a scaleless mirror carp.

Mirror carp habitat and diet

Mirror carp can be found in sluggish water, typically in ponds or lakes, but also in very slow-moving rivers. As you would expect, they don’t mind turbid water.

Tough and adaptable, they can survive cold winters and hot summers, allowing them to thrive pretty much anywhere they’re introduced or manage to move on their own.

That said, the leather carp variety is less cold tolerant and not as capable of surviving in water with a low dissolved oxygen content.

Mirror carp identification

Mirror carp can be tricky to identify, at least in the sense that they express a variety of unique scale patterns.

According to Daniel Hughes, “These carp will have large and small irregular scales scattered across their flank, some of these patterns can form known formations such as a Linear of fully scaled pattern. A mirror carp with a linear pattern would have one single row of scales running down the entire flank along their lateral line. The fully scaled pattern speaks for itself, the carp will usually have its [sic] entire flank covered in scales, sometimes all similar in size or varied. Most other mirror carp will have an irregular scale pattern, making each carp very different in looks.”

Crucian carp

Crucian carp

Carassius carassius, as wildlife biologists and scientists call the Crucian carp, is a native of Northern Europe, being quite common from Scandinavia to Russia, Germany to England. Despite some debate, it is now understood that Carassius carassius is native to Great Britain and not an introduced species.

Smaller than other carp species, the Crucian carp rarely exceeds 4.4 pounds, typically growing to lengths of about 6 inches. Closely related to the goldfish, sterile hybrids can occur in the wild.

Crucian carp habitat and diet

Slow-moving streams and rivers and quiet ponds and lakes are the favorite habitats for Crucian carp. 

A notable feature of this fish’s biology is its ability to carry on anaerobic respiration for long periods, allowing it to live below the winter ice with little to no dissolved oxygen in the water. This makes it extremely cold tolerant, explaining its wide distribution in colder climates.

Crucian carp identification

Because crucian carp are related to goldfish and capable of interbreeding, strict identification is necessary.

Look for golden-bronze scales that are richly colored, and count the scales covering the lateral line: there should be 33 or more.

That will help you separate a true Crucian from a goldfish hybrid.

Mrigal carp

Mrigal carp

Mrigal carp, Cirrhinus cirrhosus, is native to India, where the only surviving populations still make a home in the Cauvery River. It has been introduced elsewhere for sport, especially in Southeast Asia, and is a popular catch for anglers headed to fishing resorts.

It can grow to almost 4 feet in ideal conditions, weighing as much as 43 pounds at this size.

Mrigal carp habitat and diet

The Mrigal carp is unusual in that it prefers a lively current. Look for it in fast-moving streams and rivers, even where salinity is high.

In impoundments, lakes, and ponds, it cannot breed successfully and must be artificially spawned.

Mrigal carp feed on plankton, growing rapidly to maturity.

Mrigal carp identification

Expect dark gray scales on the dorsal side, shading toward silvery white on the sides and belly. Their dorsal and tail fins are dark gray, but the fins along their belly have an orange color.

Catla carp

Catla carp

Labeo catla is native to Southeast Asia, including Bangladesh, India, Myanmar, Nepal, and Pakistan, though its popularity as a sport fish has led to its introduction in other areas, most notably Thailand.

Reaching lengths of 6 feet and weights of 85 pounds, this is a large species of carp that attracts a lot of attention from anglers.

Catla carp habitat and diet

Catla carp prefer slow-moving water, using their gill rakers to filter plankton. Preferring to feed near the surface, these large fish grow rapidly, reaching maturity in about two years.

Catla carp identification

Catla carp are known for their very large heads relative to body size. Look for a protruding lower jaw and large gray scales shading paler toward the belly.

Mud carp

mud carp

Cirrhinus molitorella is native to the Mekong River, the Chao Phraya River, the Mae Klong River, and the Tapee River Basin of Thailand but is also found in the Pearl River in southern China. It has also been introduced to other parts of east Asia, including Japan.

Long revered as a replacement for the common carp in Chinese cuisine, the mud carp is actively farmed and intensively fished, leading to some concern about its conservation status.

Not large by carp standards, the mud carp reaches a maximum length of about 21 inches, but it’s far more commonly caught at about 6 inches.

Mud carp habitat and diet

Mud carp prefer light to medium currents in warm water, where they consume aquatic vegetation, insects, and aquatic invertebrates. They don’t thrive in impoundments, preferring a nomadic lifestyle that includes migrations into flooded forests.

Mud carp identification

Look for 37 to 43 scales covering the lateral line, and no dorsal spine, but 11 to 15 soft rays along the dorsal fin.

Small-scale Mud carp - Cirrhinus microlepis

small scale mud carp

Not to be confused with the similarly-named mud carp, the small-scaled mud carp, Cirrhinus microlepis is an entirely different species.

Native to the Chao Phraya and Mekong basins in Thailand, Laos, Cambodia, and Vietnam, this fish can grow to as long as 3 feet and as heavy as 22 pounds.

Known for its habit of leaping clear of the water, it is sought after for its sweet flavor in steamed or stewed dishes.

Small-scale mud carp habitat and diet

Cirrhinus microlepis prefers shallow flood plains, and like the mud carp, migrates into flooded forests when it can.

There, it eats everything from detritus to insects and aquatic invertebrates to plants.

Migratory by nature, it does not survive or thrive in impoundments.

Small-scaled mud carp identification

Larger small-scale mud carp will present with distinctive blue scales along the dorsal side, fading to white at the belly. 

Positive identification can be confirmed by a scale count: look for 53 to 60 scales along the lateral line.

Final Thoughts

Many species of carp are invasive in North America, and we all need to do our part to help tackle this problem.

We leave you with this list of best practices compiled by the National Park Service:

  • Minimize use of Mississippi locks for watercraft travel (carp can swim upriver when the locks are opened). Consider trailering your watercraft around locks whenever possible.
  • Don't harvest bait or transport water from infested areas.
  • Dispose of unwanted bait in the trash, NOT in water bodies.
  • NEVER release fish from one water body into another
  • Report catches of invasive carp to the Minnesota Department of Natural Resources.
  • Drain and rinse your boat when you are done boating.
  • Spread the word! The more people who know about the problems Asian carp cause and how they can help keep them out of the Great Lakes and from further moving up the Mississippi River, the easier it will be to stop these fish.

We hope you learned as much from this article as we did while researching for it, and as always, we’d love to hear from you if you have any questions.

Please leave a comment below!

About The Author
John B
If it has fins, John has probably tried to catch it from a kayak. A native of Louisiana, he now lives in Sarajevo, where he's adjusting to life in the mountains. From the rivers of Bosnia to the coast of Croatia, you can find him fishing when he's not camping, hiking, or hunting.
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