In 2019, American angler Jason Fugate caught a giant goldfish weighing 37 pounds (about 17 kilograms) in the wild waters of Minnesota, USA, breaking the world record for the world's largest goldfish. But just three years later, just a few days ago, Andy Hackett, a 42-year-old British, broke the record while fishing in a French fishing ground.
It took Hackett 25 minutes to catch the giant goldfish ashore, and after weighing it, the goldfish weighed 67 pounds and 4 ounces (about 61 pounds), which broke the 2019 data and was called the largest goldfish ever found.
This isn't the first time a large goldfish has been spotted in France, as early as September 2010, a French angler, Rafael Biagini, caught a 30-pound goldfish (about 13.6 kilograms) in a lake in southern France, which at the time was considered the largest goldfish in the world.
However, goldfish as our most common ornamental fish, in our impression, goldfish are relatively small, and this is precisely why it can become the most popular ornamental fish, why are there such large goldfish abroad? In fact, there is a misunderstanding, because this goldfish is not another goldfish.
This goldfish is not another goldfish
Goldfish is an ornamental fish that originated from the mainland, from the documentary records: Jinhuan Chong saw red scale fish in the lake when swimming in Lushan, of which red scale fish is actually the earliest ancestor of goldfish, it can be seen that goldfish is a natural variant, but this variant is difficult to be retained in nature, because the bright body color is the easiest to be found by natural enemies such as water birds.
However, fortunately, the ancient people on the mainland saw these fish of different colors and then farmed them artificially, which allowed the genes of goldfish to continue.
The earliest ancestor of goldfish is actually golden crucian carp (also known as grass goldfish), which is a natural variant of wild crucian carp, caused by genetic mutations, which was concluded as early as the 50s of the 20th century, scientists have reached a conclusion through hybrid experiments on goldfish and crucian carp, and then with the development of science and the advancement of genetics, this is more confirmed.
Because animals are more prone to genetic mutations in captivity, and protected by humans, those mutations that are not conducive to animal survival in the wild will be preserved, so today's goldfish are diverse and varied, with more than 300 different species.
Dragon Eye Goldfish - One of the dragon species strains of goldfish
After figuring out the real goldfish, we can see the problem when we look back at the largest "goldfish" caught this time, and from the picture above, we can obviously see that the "big goldfish" have beards in their mouths, and combined with their overall size, this is obviously like a carp.
That's right, whether it is the American "giant goldfish" we mentioned above, or the two "giant goldfish" in France, are not real goldfish, but a variant of carp - koi, that is, red carp, but koi and goldfish are artificially hybridized and bred under the emergence of many different varieties, so, let's briefly understand what kind of koi found in France this time?
Giant koi
Koi actually have an earliest origin like goldfish, that is, the mainland, we have used the way of breeding goldfish to breed koi at least before the Ming Dynasty, of course, strictly speaking, there are natural varieties first, and then artificially selected, to the Ming Dynasty, koi has become an ornamental fish as common as goldfish on the mainland.
However, the largest koi caught in France this time is not from the mainland, but from Germany, this is a German koi, the so-called German koi refers to a koi species (non-species) bred in Germany, it is very popular in Europe, as an ornamental fish introduced into many ornamental water bodies in France, and the German koi caught this time was put in an ornamental fish by the owner in a fishing lake.
Although the German koi does not come directly from the mainland, but there is the credit of the mainland koi, why say so? First of all, the German koi was bred from the cross of German koi and leather carp.
Leather carp, also known as patterned light carp, in the world, there are many strains of leather carp, of which the German strain is mainly Tifen, Kikushui, and its production is produced by the use of European wild carp and golden carp hybridization.
And the origin of German koi is more complicated, it is a hybrid of German leather carp and Japanese koi, of which German leather carp is a natural variant of European wild carp loose scale mirror carp, which is caused by a pair of genetic mutations that control the growth of European wild carp scales, under normal circumstances, the scale gene expression of European wild carp is SSnn, where S is a recessive gene, when it becomes dominant "s", there will be a local phenomenon of scales on the body.
Loose scale mirror carp
Of course, in the genetic mutation of the scale, not only the S gene will change, but also the n gene, once there is an n gene mutation, there is another mirror carp-line scale mirror carp (gene expression is SsNn), the two mirror carp hybridized, if the gene expression is SSNn individual, then it is a German leather carp.
The Japanese koi was actually introduced to Japan from the mainland in ancient times, and was further cultivated in Japan, and the German leather carp was crossed with the Japanese koi to obtain the German koi. Finally, the German koi was crossed with the leather carp, and we have the protagonist of today.
The biggest goldfish?
Obviously, the recent uproar of the "largest goldfish" incident is a "Zhang Guan Li Dai", because it is not a goldfish at all, but a koi, although they are all fish under the carp family, but one is essentially crucian carp, the other is carp, the difference is too big, and the carp itself can grow very large, on October 15, 2020, the British "Daily Mail" said that in Cambridgeshire, England, maintenance worker Wayne Mansford caught a 68-pound (75-pound) large carp while fishing in a fishing ground, This is the largest carp ever discovered.
Therefore, it is not surprising that this time I caught 61 pounds of koi, after all, they could have grown so large, and in essence, this koi can only be regarded as the largest koi, not the largest carp.
The goldfish is different, it is domesticated from wild crucian carp, and the crucian carp itself is relatively small under the carp family, in addition to the artificially bred engineering crucian carp, the real wild crucian carp usually weighs up to 3 kg, such as the largest Yunnan Dianchi high-backed crucian carp.
In addition to wild crucian carp, its variant goldfish has also grown into a behemoth in the United States, and in the wild water body of Minnesota in 2021, a group of goldfish was found, and through fishing measurements, it was found that these goldfish are each as large as a rugby ball, with an average body length of 30 cm and a weight of up to 2 kg.
The reason why goldfish can grow so big in the United States, on the one hand, is because it is an invasive species for the United States, there is no threat of natural enemies, on the other hand, goldfish are omnivorous fish, they are not picky about food, and the most important thing is that their lifespan can reach 20 years, which makes them in the United States like no man's land, becoming a real "giant goldfish".
summary
Recently, the "largest goldfish" has attracted much attention, but in fact, the "goldfish" is a German koi, you must know that the carp itself is much larger than the predecessor of the goldfish, crucian carp, in addition, their life expectancy is on average between 20-25 years, put into farmed lakes, food is sufficient, no natural enemies, it is not surprising to grow so large.
And the real largest goldfish weighs about 2 kilograms, after all, it was domesticated from crucian carp, and its body size is constrained by the ancestor's largest body size gene.