"Water tiger" appears, this fish is very edible, has no friends and is still single...

Recently in Jiangxi Province, a lucky angler successfully caught a big fish, estimated to be about seven and a half kilograms. From the video, the fish has a huge and pointed head, the upper body is gray, the side of the body is silvery white, and the area near the gill cover is yellow. It should be the bighead carp (Elopichthysbambusa).

Bighead carp, also known as water tiger, is the little bully in freshwater. This predatory freshwater fish belongs to the Cyprinidae family of the order Cypriniformes, and is in the same family as the carp, crucian carp, and the four major carps that we are familiar with.

Note: The latest classification considers it to be an independent family (Xenocyprididae).

Common carp, scientific name Cyprinus rubrofuscus

Photographed at Tianjin Natural History Museum

The “footprints” of bighead carp

The distribution range of the bighead carp is quite wide. In China, it can be found in many rivers from the three northeastern provinces to southern China. Abroad, it is more common in eastern Russia and northern Vietnam. The first discovery of the bighead carp and its Latin scientific name was based on a specimen of the bighead carp found in Guangzhou.

Note: The English name of yellowcheek comes from the yellow color near its gill cover. In English, the Chinese pinyin of the word yellowcheek is sometimes used as its English name.

Some locations in China where yellowcheek Elopichthys bambusa has been recorded. Image source: Microsatellite Diversity and population genetic structure of yellowcheek, Elopichthys bambusa (Cyprinidae) in the Yangtze River

"Super Foodie" and "King of Involution"

As a "super foodie" in the water, a bighead carp can grow to more than one meter long or even two meters, and can weigh more than ten kilograms, or even more than fifty kilograms, which is about the same as a male leopard. In October 2019, a large bighead carp was found in Danjiangkou Reservoir, which was 1.68 meters long and weighed about 50 kilograms.

Juvenile bighead carp, photo source: zoochat

The reddish-brown carp and the four major carps around us are not small in size among fish, so in order to deal with such huge prey, the bighead carp itself has to be "strong enough to make good use of its own strength".

Even when they are still small fish fry, they can already attack other fish fry. In addition to big fish and meat, they also eat some zooplankton as a side dish.

Sometimes they even kill their own kind, and captive populations have reported cannibalism when they are just two centimeters long.

In order to prevent them from "rolling inward", fish farmers also need to separate the larger bighead carp fry from their smaller companions. In a report by Contemporary Aquatic Products magazine, some fish farmers also complained that it is still a bit troublesome to manage bighead carp schools.

Seriously fish found in Guangxi, source: https://www.seriouslyfish.com/

The fierce carnivorous mullet does not have teeth like the bull shark and the great white shark. They rely on the beak on their mouth to inflict damage on their prey. The beak formed by their premaxilla and maxilla is quite similar to the mouth of a giant alligator turtle and an eagle. It has no teeth but is a powerful weapon.

Unlike the ambush hunters common in Chinese rivers, the snakehead fish actively pursues its prey rather than ambushes it, catching up with its prey and attacking directly with its mouth, swallowing the injured fish, causing great damage, and the snakehead fish can even break some fishing nets.

The invincibility of the catfish may be due to its loneliness. They don't gather in large groups. Ancient Chinese people thought that catfish travel alone like men without a partner, so they even called catfish "widower" in ancient Chinese.

Juvenile mullet, source: https://www.inaturalist.org/

From "eyesore" to "dish"

Regardless of how the bighead carp survives, in the eyes of fishermen who used to raise other economic fish, the bighead carp can be said to be a thorn in the eye and a thorn in the flesh. After all, it is a predator with a large appetite. If a young bighead carp mixes into the school of small fish they raise, the bighead carp will eat almost the entire school of small fish.

There are many ways to control bighead carp. Some people have formed a fishing team, but soon, some people also discovered the benefits of bighead carp, that is, it can be eaten. After all, compared with the four major carps, they have fewer bones. In the "China Economic Aquatic Products Original Color Atlas", someone mentioned that they are good fish with good meat taste, so some people raise bighead carp as an economic fish.

Immature bighead carp, recorded near the Yangtze River estuary, source: GBIF

Dried catfish meat, source: GBIF

At the end of the last century, bighead carp faced a major crisis. One of the reasons was the change in hydrological conditions caused by the relevant river and lake barriers in the Yangtze River area, which brought some negative impacts on the survival of bighead carp.

In addition, the bighead carp in the Pearl River and other places also faced a survival crisis. Fortunately, its distribution range is relatively wide, and its reproduction speed is much faster than many rare fish. In this century, the artificial breeding technology of bighead carp has broken through the bottleneck.

In the past two decades, the population of catfish has continued to grow, and the breeding technology has also developed a lot compared to the past. Today, they are rated as Least Concern (LC) by the IUCN.

The threat level of bighead carp is Least Concern. Image source: IUCN

Note: Least Concern is one of the risk assessment levels for the threat level of wild species populations. Different species have different threat levels. For example, the giant panda is vulnerable (VU) and the Asian elephant is endangered (EN). The highest threat level is extinction, and Least Concern is the lowest. In addition, livestock populations have not been assessed, and some species lack relevant research data.

The life of a misunderstood catfish

Nowadays, as the number of bighead carp increases, some people have demonized it. Some people say that bighead carp is a devil that destroys the ecology and eats fish crazily, while others look for fishing.

A bighead carp weighing more than 12 kilograms. Image source: china.com.cn

However, although the bighead carp is fierce, it is not a problem for it to prey on other fish in the ecosystem. It is a natural law, just like wolves eat sheep and tigers catch deer. Their role in clearing wild fish and sick and weak fish in the water and maintaining the ecological balance is self-evident.

In some places in the Yangtze River Basin, people have discovered a large number of bighead carps in the Three Gorges area through aerial photography, and each of them is more than one meter long. Some people began to suspect that the number of bighead carps is "excessive" and "may harm nature."

But in fact, with the local fishery control and the "reproduction and release" of many farmed fish populations into the wild ecosystem, the number of fish here can be said to be much greater than in previous years, and the food for bighead carp is also guaranteed.

The increase in the number of bighead carp is essentially a sign of ecological improvement . Compared with introduced species such as alligator gar (Atractosteus spatula) and largemouth bass (Micropterus salmoides), bighead carp is a native species and requires a certain degree of protection.

Moreover, they contribute greatly to the natural control of the number of other local fish species, and their distribution in the local area is also restricted by hydrological conditions and food conditions. In addition, the bighead carp is not in a survival crisis like the Chinese sturgeon, so moderate fishing is fine.

Of course, as a native species, the bighead carp cannot be released at will. In an artificial lake in Guangdong Province, a bighead carp over one meter long and weighing more than 20 kilograms was found. It is indeed unsafe to keep such a large bighead carp in a relatively scarce food environment.

In large lakes and rivers with relatively good water ecology, bighead carp can survive and recuperate easily. They may even exclude and capture alien species such as tilapia and largemouth bass.

References

http://www.zoology.csdb.cn/taxon/%7BFBB27075-AF9B-491F-B4D4-B4BCC757469A%7D

Shen Zhigang, Guan Hehe, Ding Yunmin, He Yan, Gao Zexia, Fan Qixue. Research progress on artificial propagation and seed cultivation of bighead carp[J]. Acta Hydrobiologica Sinica, 2024, 48(7): 1258-1266. DOI: 10.7541/2024.2023.0322

Kottelat, M., 2013 - RafflesBulletin of Zoology Supplement 27: 1-663 The fishes of the inlandwaters of southeast Asia: a catalog and core bibiography of the fishes known to occur in freshwaters, mangroves and estuaries.

Liang Zhishen, Yi Bolu, Yu Zhitang. Reproductive habits and embryonic development of bighead carp in the Yangtze River mainstream and Han River [J]. Journal of Hydrobiology, 1984, 8(4): 389-403.

Wu Xianwen, Yang Ganrong, Le Peiqi, Huang Hongjin. 1979. Chinese Economic Animals, Freshwater Fishes, 2nd Edition

Zhang Feiyou, Zhang Hua. Danjiangkou bighead carp was approved as a geographical indication protected product by the General Administration of Quality Supervision, Inspection and Quarantine of the People’s Republic of China [J]. Guide to Getting Rich in Fisheries, 2012(05): 7.

Qi Xirong. Investigation of fishery resources in the upper reaches of the Han River[J]. Fisheries Research, 2022,44(1): 21-32.

Xu Hui, Chinese characters read ancient people: the character "鳏" in "鳏夫" originally represented a fish with tears[M], China in Chinese Characters: Ancient Natural History Hidden in Chinese Characters, 2020

Wan Songliang, Wang Liang, Li Jianbin, et al. Preliminary study on artificial propagation technology of bighead carp[J]. Journal of Fisheries of China, 2008, 21(1): 15-20.

GBIF official website

IUCN related records

Author: Great Qing Dragon

Editor: Dong Xiaoxian

Reviewer: Liu Kun and Li Peiyuan