Mike Martin, a veteran of more than 20 years of fishing experience, said earlier this month that he had caught an unusually large 'Goldfish' in Lake St. Clair, Michigan, on the border with Ontario, Canada. Originally, Mike and Martin wanted to catch bass. It was obvious that it was definitely not the bass that Martin wanted. As early as 2002, a giant goldfish as long as 15 inches (38 cm) appeared in a fishing and farming market in Dongguan, China. However, the giant goldfish that Martin hooked has similar characteristics, for example, its body length is about 38 cm, and its weight is up to 3 pounds, or 1.4 kg.
Why is a common goldfish so abnormal? In fact, goldfish is an artificial ornamental fish, which comes from the carp family. Almost two thousand years ago, the ancient Chinese began to domesticate the Prussian carp. With the passage of time, under the effect of gene mutation, colorful appearance began to appear, such as orange, red and yellow. The original boring appearance became colorful, and finally was sent to Europe in the 1600's, and introduced to the United States in the 1850's. Although we usually don't have goldfish in the wild environment, it is occasionally found in ponds, lakes and streams. Most researchers think that goldfish may enter the lower channel system in a certain way and finally flow into other water bodies.
To grow in a pond, goldfish need two main factors: Food and temperature (according to the tropical fish database). High protein food intake can increase the weight of goldfish. With the increase of food intake, the weight of goldfish will also increase. In addition, the water temperature will also affect the size of goldfish. For example, warm water can increase the weight of goldfish. Generally, goldfish in outdoor viewing pool will grow rapidly in summer, and their weight will increase abruptly. The largest goldfish in the Guinness Book of records is 47 centimeters long.