Bighead Carp

Bighead Carp

　　The Bighead Carp closely resembles the common carp in body shape but has a notably wider and larger head, hence its name "Bighead Carp." In traditional Chinese medicine, it can also be used as an herbal remedy, known for its nourishing and wind-dispelling effects. In recent years, its population has been declining rapidly and is in urgent need of protection. The Bighead Carp is endemic to China and is found only in Xingyun Lake and Qilu Lake in Yunnan Province. It is popular among people for its tender meat, high fat content, delicious taste, and rich nutrition.

　　It has a slender caudal peduncle. The body length ranges from 9–12 cm, and the maximum body weight can reach 2 kg. The head is particularly large and wide, with a head length greater than both the body height and the base length of the dorsal fin; the dorsal surface of the head is broad and flat. The mouth is wide and large, subterminal, arched, with a distinctly oblique mouth cleft, and the mouth width is greater than the snout length. It lacks barbels. The second tooth in the main row of pharyngeal teeth has a crown with 2–5 grooves. The gill rakers are very densely arranged, numbering over 48, and their length exceeds that of the gill filaments. The scales are large, with 34–37 lateral line scales. The dorsal fin...

　　Both the dorsal and anal fins have hard spines with fine serrations. The starting points of the dorsal and ventral fins are opposite to each other or the dorsal fin is slightly longer, with a long fin base and short fin rays, and the outer edge is deeply indented. The pectoral, ventral, and anal fins are all large; the pectoral fin extends to the ventral fin. The lower lobe of the caudal fin is orange-red. The starting point of the dorsal fin is roughly opposite to the ventral fin, and it is slightly closer to the base of the caudal fin than to the tip of the snout. The posterior edges of the hard spines of both the dorsal and anal fins are serrated. The caudal fin is deeply forked. The swim bladder has two chambers.

　　Habits

　　　　It prefers to live in the upper-middle layers of clear and deep waters, but has poor tolerance to harsh environments. It is prone to death if the water becomes turbid or if it is removed from the water. It is active and swims swiftly. Its diet is relatively simple, with little difference between individuals of different sizes. It almost exclusively feeds on large zooplankton such as cladocerans and copepods. Occasionally, it also consumes some diatoms, filamentous algae, and cyclopoid copepods, but in very small amounts.

　　Breeding habits

　　　　Generally, females reach sexual maturity at around 50 grams. The spawning period is long, starting from early April until September, peaking from May to June. The eggs are attached to aquatic plants to hatch.

　　The growth rate is relatively slow, but it is steady, with an average annual growth of about 60 mm for fish of all ages. The maximum individual weight is 2 kg. Usually, 50% of the one-year-old fish are sexually mature, weighing 52 grams, while males are only 117 mm in length and 32 grams in weight. The Bighead Carp has a high fecundity, with 3–4-year-old fish producing up to 130,000 eggs. Spawning occurs in batches, typically divided into two groups, with a 7-day interval between them. Each batch spawns over three days, then after 7 days, the second batch is produced. The spawning season is from May to June. Eggs are usually laid at dawn (between 3–5 am) on sunny days, at depths of 1–2 meters underwater. They are adhesive eggs that attach to aquatic vascular plants. The fish feed mainly on zooplankton, particularly cladocerans and copepods, which dominate, followed by rotifers. They also consume small amounts of diatoms, filamentous algae, and aquatic vascular plants.

　　Bighead Carp (15 images).

　　Threats

　　　　In the 1950s and 1960s, it was the main economic fish in the region and dominated the fish catch in both lakes, accounting for about 70% of total production. Since the 1970s, the introduction of silver carp and bighead carp created competition for food with the Bighead Carp. Additionally, during these introductions, small wild fish such as gobies, bitterlings, and topmouth culter were also brought in. These species are highly resilient and consume large quantities of fish eggs. Furthermore, the decline in lake water levels and reduction in aquatic plants destroyed spawning grounds. Long-term overfishing, combined with the Bighead Carp’s own weaknesses—such as low disease resistance, slow growth, and poor adaptability—led to a sharp decline in its population.

　　Population status

　　　　Currently, the Bighead Carp accounts for only about 0.5% of the fish yield in Xingyun Lake and Qilu Lake.

　　Statistics from 1963 show that the Bighead Carp made up 70% of the total fish production in Xingyun Lake and 30% in Qilu Lake. Starting from the 1970s, due to overfishing, the introduction of similar fish like bighead carp, and environmental changes, the Bighead Carp resources have been increasingly depleted. In 1979, the Jiangchuan Fish Farm successfully bred them artificially in ponds. After 1988, larger fingerlings were released into the lakes, gradually increasing fish production.