What shade of red is the red of the mullet?

In 2020, an illegal fishing case occurred in Kaizhou City. The person involved, Yu, was caught illegally fishing during the fishing ban period, and a 0.1 kg Chinese redfin mullet, a national second-level protected animal, was found in his catch. According to the national ecological compensation system, Yu was ordered to purchase more than 50,000 yuan of fish fry for ecological restoration compensation. At the same time, he faced corresponding criminal penalties for suspected illegal hunting of endangered wild animals.

Crimes caused by mullet are not isolated cases. In recent years, many people have been sentenced or punished for catching "jail fish" (a term used by anglers to refer to fish that are protected by the state). What is the origin of this mullet?

Redfin Fish| Young Hero Little Yellow Chicken

Rouge Mermaid

Myxocyprinus asiaticus, commonly known as pink ribs, yellow ribs, and smooth sailing, belongs to the Catostomidae family. Most species of Catostomidae are distributed in North America and Central America, with only a few distributed in Asia. Myxocyprinus lives in the Yangtze River and Minjiang River basins (wild Myxocyprinus in the Minjiang River basin are now almost extinct). It is a large freshwater fish unique to my country and the only monotypic genus and species of Catostomidae distributed in the Asian continent.

As the name suggests, the important feature of an adult male fish is that there is a crimson band on the side of the body that runs almost horizontally. The band is very wide, from the gill cover of the rosy fish to the tail, just like a layer of rouge. The rosy fish is not only famous for its rouge band, but also has a very distinctive appearance. The towering back has a very high dorsal fin that stands upright, and even has a bit of the momentum of a shark's dorsal fin. Its English name, Chinese high-fin banded shark, comes from this. The rosy fish is also called the "Asian mermaid".

Artificially bred mullet, the adult male fish is bright red | Shaoxia Little Yellow Chicken

The life span of Chinese mullet is quite long, but it takes a long time for sexual maturity to occur, with males taking 6 years and females taking 9 years to reach sexual maturity. Juvenile Chinese mullet live in the upper waters of the Yangtze River system, where the water flow is relatively still. Sexually mature adult fish then move to live in the middle and lower water layers, and swim upstream to the turbulent waters of the upper Yangtze River during the breeding season to reproduce.

This cute little fish can grow into a huge monster. In 2008, people caught a 1.3-meter-long and 29-kilogram redfin bream in the Jialing River. It was estimated that the fish was about 25 years old.

A long history of transformation

The rosy bar with crimson stripes is very beautiful, but only adult male rosy bar has bright color stripes, while adult female rosy bar is relatively inferior, with only a slightly reddish color stripe under the main gray-brown color.

Whether male or female, juvenile mullets do not have this color band, instead they have three vertical stripes running up and down. After entering adolescence, it gradually changes to three vertical stripes and one horizontal stripe. By adulthood, the three vertical stripes are almost completely faded, leaving only one horizontal stripe.

Black and white mullet fry | Leon sculpin

In addition to the changes in body color with age, rosy barbs can also show different color characteristics in different living environments. Young rosy barbs living in clear waters are mainly black and white, while young rosy barbs living in turbid (low transparency) waters have obvious faded black stripes and the body shows the unique light red color of rosy barbs. This is mainly because in turbid water bodies, rosy barbs have a high sense of security and thus show their original color; while in clear water, rosy barbs show a color similar to the bottom of the water in order to defend against potential predators. The rest of the body of rosy barbs is generally white, but can also become almost black to enhance concealment.

The ever-changing appearance of the Chinese mullet has caused confusion among people, and some even recognize the juvenile fish but not the adult fish, or see the adult fish but not the juvenile fish. Historically, the older generation of fishermen in the Yangtze River were familiar with this strange fish whose appearance changes over time, and gave different names to the Chinese mullet at different stages, such as "green body, yellow ribs, pink ribs, and blood ribs."

Edible fish and ornamental fish

The mullet has a unique appearance, with a towering dorsal fin, three unique vertical stripes on juvenile and young mullets, and a cute downward-pointing mouth, which is very ornamental. Juvenile mullets are not only cute in appearance, but also eat algae and fish tank food debris, and have some cleaning ability, which makes them popular among ornamental fish enthusiasts in my country and around the world.

Fish mouth pointing downwards, isn't that cute? | 5snake5 / Wikimedia Commons

Wait, isn't it a "fish that will be in jail for life"? How can it be bought and sold? Chinese mullet is a national second-level aquatic wild protected animal, and is listed in Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), and is listed as a vulnerable species by the International Union for Conservation of Nature (IUCN). The Chinese mullet that can be legally traded are all artificially bred second-generation Chinese mullet. Units that have obtained approval from provincial industry authorities and are qualified to domesticate and breed wild animals can trade the second-generation Chinese mullet they breed normally.

With the breakthrough in artificial breeding technology of rosy barb and the expansion of its application, the artificial breeding of rosy barb in my country now not only has the traditional purpose of continuing resources and replenishing the over-consumed wild resources in the natural environment; many regions have also begun to experiment with breeding rosy barb for the purpose of selling it as edible fish.

Juvenile mullet | Jörn / Wikimedia Commons

After about 2 years of breeding cycle, the edible Chinese mullet reaches the market specifications. The market price is slightly higher, up to 40-50 yuan per catty, but it is still very popular. Chinese mullet not only has fewer bones, but also is different from the relatively tough meat of the four major carps. It is very tender and sweet, which is inseparable from the high proportion of umami amino acids in its meat (up to 31.3%). Whether it is steamed or braised, Chinese mullet is a good ingredient. But everyone must remember that you can only buy artificially bred Chinese mullet with clear and legal sources. Do not catch or buy any wild Chinese mullet, which is a clear violation of the law.

Resource protection is your and my responsibility

Speaking of Chinese mullet, recall that before the 1970s, the resources of Chinese mullet in the Yangtze River were still good (for example, in Yibin, Sichuan, the annual catch of Chinese mullet accounted for about 13% of the total catch). Since the 1980s, due to the construction of various new hydropower stations, the increasing fishing efforts in the Yangtze River, frequent river transportation, and various pollutant emissions caused by the development of cities on both sides of the strait, the number of Chinese mullet populations in the wild has been continuously reduced, and its suitable habitats and spawning grounds have become fewer, and the food sources needed for survival have become increasingly difficult to find.

In addition, due to the late sexual maturity, long reproduction cycle and long egg development cycle of Chinese mullet, the resources of Chinese mullet continue to decline in the wild. Although Chinese mullet has been listed as a national second-level key protected wild animal decades ago, the frequent illegal trading and fishing of wild Chinese mullet in recent years reminds us that there may still be high-intensity human activities in the limited living space of Chinese mullet in the Yangtze River, thus affecting its survival.

Specimens of Chinese mullet in Wuhan Institute of Hydrobiology | Black-scaled crested snake

At the same time, relevant studies in recent years have also shown that the situation of wild Chinese mullet populations is not optimistic, and the population is still showing a downward trend. In 2020, the Ministry of Agriculture and Rural Affairs of the People's Republic of China issued a ten-year fishing ban plan in the Yangtze River. This ban has given many species inhabiting the Yangtze River basin a real chance to breathe.

Many fishery resources in the world, once the population of the target species is reduced to a very small number, even if the fishery management measures are very good, it will take a long time for the species to recover to the original level. In short, it is easy to destroy, but difficult to restore. In addition to Chinese redfin bream, the Yangtze River, my country's mother river, also has many unique and rare aquatic organisms in my country. Ensuring the survival and reproduction of these species in our lifetime is a precious natural wealth we leave to future generations.