Silver Carp:Hypophthalmichthys molitrix: Hypophthalmichthys - Greek, means underneath eye; molitrix- Latin, means molar-like.
The angler never knew what hit her….at least she didn’t 5 years ago when I first started hearing about these ‘jumping carp’. Today there are many videos on the internet of anglers along the Mississippi River, having their greatest prayers answered as the fish jump into their boats. Or is it? The silver carp and its look-a-like cousin, bighead carp are expanding their geographical range and increasing their population size by leaps and bounds, literally.
Silver carp (Hypophthalmichthys molitrix) was imported from China in the 1970s for use in aquaculture ponds to control plankton. By the early 1980s, both silver and bighead carp had escaped into open waters in the southern United States and began expanding their range up the main channel and tributaries of the Mississippi River watershed.
This species is naturally found in eastern Asia from the Amur River of far eastern Russia south through much of eastern half of China. It is highly prized for its food quality in that part of the world.
The silver carp is a deep-bodied fish that is laterally compressed. They are a very silvery in color when young and when they get older they fade from a greenish color on the back to silver on the belly. They have very tiny scales on their body and the head and gill covers are scale-less. They have a large mouth without any teeth in the jaw. The eyes are situated far forward near the middle of their head and are slightly turned down. I often refer to them as the Picasso Fish, since they look like they might be swimming upside-down.
The silver carp has a sharply keeled belly from the anal fin to the throat,
whereas the bighead carp has a keeled belly from approximately its pelvic fins to the anal fin.
Silver and bighead carp are large filter feeding fish that can weigh up to 110 pounds for bighead carp and 60 pounds for silver carp.
No established populations are known to be in Minnesota. A bighead was caught in the St. Croix River in 1996 and another was caught by a commercial fisherman in Lake Pepin in 2003. Populations of bigheads are in the Mississippi River and its tributaries downstream of pool 12 in Iowa. Silver carp populations are further downstream in the Mississippi and its tributaries.
The primary habitat for these fish is open water, where they can effectively find and feed on large schools of plankton.
At 3 years of age, silver carp are mature enough to breed and will breed until their maximum age of 10 years old. Spawning occurs anytime between April and September when the temperature is between 18-20 degrees Celsius. They migrate up stream to breed in groups of 15 to 20. They need water with some current so the eggs and larvae can float downstream.
Not much is yet known about species that eat silver carp. It is presumed that small silver carp are eaten by predators such as the walleye, northern pike, and flathead and channel catfish. Once they reach the 2-3 pound range it is likely that their primarily predator are not other fish. Mammals and birds may also feed on these fish opportunistically. Humans are becoming more interested in eating these fish and world-wide their flesh is considered desirable.
Silver and bighead carp eat huge amounts of plankton and detritus. Because they feed on plankton, these fish compete for food with native organisms including mussels, larval fishes, and some adult fish such as paddlefish. This competition for food could result in fewer and smaller sport fish.
Silver carp can jump up to 10 feet out of the water when disturbed by sounds of watercraft. They often jump into boats and can injure boaters, personal watercraft operators, and water skiers.
We are often asked: Can you eat them? Is it safe?
Silver Carp (and Bighead Carp) are both edible. In fact, their diet may be their best selling point. A study done on the Mississippi River by researchers at Southern Illinois University determined that silver carp fed primarily on phytoplankton (algae/plants) and zooplankton (crustaceans/animals). These carp are filter feeders (think baleen whales) and capture algae and crustaceans that are floating in the water, not on the bottom. Phytoplankton and zooplankton occur much lower in the food chain and so have many fewer associated contaminants (mercury/PCB’s), so biomagnification is less of a problem. The primary challenge to eating these fish are the numerous bones, but because of their large size this issue can be alleviated with careful filleting techniques.