In addition to the "sea knife" and "lake knife", it is also easy to confuse with the "river knife" there are also the "anchovies" abundant by the sea, and the short-jawed fish living in the Yangtze River lake, so what is the connection between so many similar-looking fish, how to define the "river knife", and how to examine the "river knife"?
Text/ A man is wandering
*This article is an exclusive draft of the Seafood Guide and unauthorized reproduction is prohibited.
"Shoulders are thundering, blush is new out of the water", spring is getting stronger, the legend of the most expensive river fresh - Yangtze River knifefish is about to start to occupy the front page of the media, this humble small fish, with the deep love of scholars, has occupied the throne of Chinese delicacies for more than a thousand years. In recent decades, due to the cliff-like decline in production, it has continued to create jaw-dropping sky-high prices, continuing its legend in another way.
However, for a long time, some of the yangtze river knifefish have long been widely known - the top Yangtze River knifefish is the "river knife" salvaged in the Nantong to Yangzhou section before the Qingming Dynasty; the one that is entrenched in the mouth of the Yangtze River and no longer continues to migrate is the lower product, which is the "sea knife"; and the one that lives in the lakes of the Yangtze River system all year round and does not migrate between the ocean and the Yangtze River is the "lake knife".
Picky diners believe that the "river knife" in February and March is from the mouth of the Yangtze River to migrate up to spawn, the body fat is the most fat and moist mouth, swimming to Jiangyin, Jingjiang area, the body salt is just right off, the gonads have also matured, the most "plump but not greasy, delicious and delicious", and wandering in the mouth of the sea no longer migrating "sea knife", there is a bitter sea, is not elegant, all year round living in the lake "lake knife", is more thorny and hard, can not sell at a price.
Friends who are interested in taxonomy may understand the principles of taxonomy, and the system created by Swedish biologist Carl Linnaeus determines whether they belong to the same species by analyzing the common characteristics of individual organisms.
Under Linnaeus' taxonomic system, what we often call the river knife, known as Coilia nasus, Chinese scientific name is knife squid, this fish was defined by 2 unique characteristics when it was discovered and demarcated by Western taxonomists, first, its maxilla end exceeded the base of the pectoral fin, and second, it had the nature to hatch in fresh water, grow in seawater, and migrate to fresh water to reproduce.
According to these two definitions, in 1903, the German Kreyenberg defined a fish with shorter maxillas and no migratory jaws that he found in Dongting Lake as another new species, the Coilia brachygnathus.
But then, people found that some knife fish also adapted to freshwater life, giving up the migratory nature, which is what we call the lake knife, and some knife fish, adapted to seawater life without returning to fresh water, which is what we call the sea knife.
What is even more difficult is that after in-depth research, it was found that even in the traditional group of fish that are considered to be knife fish, not all of them meet the criterion of "the end of the maxilla exceeds the base of the pectoral fin", which gives rise to three questions: Are the lake knife and sea knife real knife fish? Are the shorter mandibles in the knife squid really knife squid? Since there are also short jaws in the knife fish, what is the difference between the short jawed fish and the knife fish?
In recent years, some new taxonomic methods have gradually become practical, and we can now determine that whether it is the river knife that is flocked to by the gourmets, or the sea knife and lake knife that are regarded as inferior products, or even the short-jawed fish that was once regarded as another species, they are just different populations of the same species living in different waters, in essence, they are actually knife fish (Coilia nasus), the difference between them is at best the difference between Shandong red Fuji apple and Shanxi red Fuji apple, in the end, It's all Red Fuji.
Further research has found that the expensive river knife is inextricably linked to the low-priced anchovy coilia mystus that is abundant on the southeast coast.
The origin of the fish is likely to be in today's Indonesia, and the anchovy is the first fish out of Indonesia, and it is in the process of their evolution all the way north that they gradually differentiate into the coilia nasus adapted to the colder climate, and the coilia grayii, which is only distributed in Fujian to Hainan in China, and the coilia grayii, which is adapted to the warmer climate.
anchovy
Of course, when trying to analyze the difference and origin of the river knife and other knife fish, my intention is not to depreciate the value of the river knife, and it is not advisable to simply think that "the river knife and the lake knife are the same thing, and spending a lot of money to buy the river knife is the wrongdoer".
For our Chinese, "wind object" is the most wonderful word, and I also believe that the subtle differences in water and soil and seasons may really have an unpredictable impact on the quality of ingredients. What's more, for us, the river knife is no longer an ordinary ingredient, and the historical memory it carries, the elegant affairs of the literati, and even the solemnity of the sense of ceremony when the fish bones are carefully removed, have long surpassed the ingredients themselves and become the real factors of great value.
However, the past is no longer mentionable, and the deteriorating water quality and the overfishing of the past have pushed this ingredient farther and farther away from our tables. The purpose of writing this article is to hope that in the midst of the legend of Jiangdao's sky-high price, you can take everyone to a different perspective and understand another story of Jiangdao, which is comforting.