The Bighead carp is a freshwater fish, one of several Asian carps, Tongsan, also known as big
head, silver big head, black big head, bighead carp, noble fish, speckled armur, lake fish,
tongsan, Chinese fish. Bighead carp are native to the large rivers and associated floodplain lakes
of Eastern Asia. Their range extends from southern China to the Amur River system, which forms the
northern border of China and the southern border of Russia. Today Bighead carp are reproducing in
populations all along the Mississippi, Missouri and Ohio Rivers. Specimens have been reported in
states
as far reaching as California, Minnesota, and Florida.
Description
The body of a bighead carp is deep and laterally compressed with the top being a dark gray
color which grades down to off white on its belly. It has many dark gray to black blotches on its sides,
which gives them a speckled appearance. Adults usually have a mottled silver-gray coloration. Its head
is comparatively large with no scales and a large terminal mouth. The bighead has no teeth and its lower
jaw protrudes out farther than its upper jaw. The eyes are situated low on its head and are positioned
downward. The scales of a bighead carp are small and resemble the scales of a trout. This species is
very similar to another exotic Asian carp found in the United States, the silver carp. The bighead carp
has a keeled belly from approximately its pelvic fins to the anal fin, whereas the silver carp has a
sharp keel from the anal fin to the throat. They can also be distinguished by the fact that the Bighead
carp has many dark blotches on its sides and the silver carp does not. The Bighead is aptly named, as
this fish has a large head with a protruding lower jaw.
There are approximately 85-100 scales in the lateral line, and 26-28 scale rows above the
lateral line. The fins of small specimens lack spines. Large specimens 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 8 - 9 soft rays, the anal fin has 13 - 14 soft rays. They possess gill rakers that are long,
comblike and close-set allowing the species to strain plankton from the water for food. Bighead grow
rapidly. After reaching 1 to 11/2 pounds they can gain 1 pound or more per month. Growth is largely
dependent on the fertility of the water and the stocking density. Market size fish (6 to 12 pounds) are
usually 2 to 3 years old.
Habitats
The Bigheaded Carp lives in large rivers and lakes. They can occasionally tolerate
salinities in the range of 6-12 parts per thousand. The preferred temperature for reproduction is about
25°C, the maximum temperature in which Bighead carp can survive is 38°C. Bighead carp can survive
temperatures down to nearly freezing, on the order of 1°C. Typically found in large rivers, they can
also be found in smaller rivers and streams, as well as lakes and ponds. Bighead carp are known to only
spawn in moving water. Bighead can survive in a wide range of temperatures, but their preferred
temperature is 78°F and the thermal death point was 100 to 102°F.
The natural food of the bighead is zooplankton, along with larger phytoplankton. Bighead
are filter feeders and use their fine, comblike gill rakers to strain tiny animals and large algae from
the water. If zooplankton are scarce, bighead may feed on detritus (organic matter and associated
bacteria that accumulate on the pond bottom). Pond bottom organisms are not a normal food item; in one
study, Bighead were not found to have a significant impact on the benthic (pond bottom) community.
Spawning
Bighead prefer large rivers and will not spawn in still waters or small streams but do
inhabit lakes and ponds. Although fish do mature in ponds and can be induced to spawn with hormone
injections, they do not spawn naturally in still water. In large rivers, spawning typically occurs when
spring rains flood the river and water temperature reaches 77 to 86°F. Spawning grounds are usually
located in river reaches characterized by turbulent or whirlpool-like flow, often in the vicinity of
islands or stream junctions. Female carp may produce over one million eggs in one season. Eggs are
slightly heavier than water and settle out in still water. In rivers, after fertilization eggs are
suspended by turbulence and carried downsteam.
Bighead Carp spawn in flowing water with a heavy mixing of current, such as lake outlets,
behind sandbars, stone beds or islands. It is believed that spawning is initiated by heavy rains. The
eggs are released in heavy current and a given no parental care. These fish grow slowly to start with
but once over 2 years old they grow at fantastic rates.
Bighead carp grow rapidly and once they reach maturity they are able to gain a pound or
more per month. They feed on zooplankton but they are opportunistic feeders, meaning if zooplankton
levels are low they will eat phytoplankton and detritus. They filter the water through their comb-like
gill rakers so they only consume those organisms small enough to penetrate their filter feeding
apparatus.
Fishing Methods.
Although bighead carp reach large size, they are difficult to capture with a rod and reel
because of their filter-feeding habits. They may be captured by the "suspension method" used to catch
silver carp, or, where legal, by snagging them by jerking a weighted treble hook through the water. They
are also popular targets for bowfishers. Bighead carp cannot be shot from the air like silver carp,
because, unlike the silver carp, they do not jump from the water in response to moving boats. However,
they often feed near the surface where they can be shot by bowfishers.
