1. History:

In the family Osteoglossum, the silver band is like an elephant fish They are all representative species of ancient fish in the Amazon River. According to Vandeli's record in 1829, the silver band was the earliest disclosed species of the bony tongue. Since it was first introduced to Germany in 1935, it has maintained its place in the world. Written by Nobuji Makino in 1956, there is a one-page color page introduction in the "Picture Book of Primary Colors" published in the first edition of Japan. At that time, this beautiful fish really amazed everyone. The first boom, which coincided with the 1964 Tokyo Olympics, was also performed by large fish such as silver belts and exotic fish raised in a fish tank with a stainless steel outer frame. Until the period of high economic growth after the Sui Dynasty, and even after the collapse of the bubble economy, fish from all over the world continued to flow in, and a large number of wild individuals were collected. At this time, the price of silver belts gradually fell and became an entry point for ancient fish. fish species. Although the price slide has its positive side, the handling of the "living body" that has lost the value of the commodity has undergone great changes. Isn't this also a big drawback of market economicism? Almost all of them are collected from Brazil and Peru in South America. After being dug out from the mouth of the broodstock (male), it is temporarily stored and cultured before being exported to all over the world. The collection starts from October to March of the following year, because the silver belt will start spawning when the rainy season comes one or two months before this time. At this time, all individuals will have a yolk sac (YorkSack) as large as an orange projectile in the abdomen. During this period, there is no need to eat at all, and self-nutrients alone are sufficient. Soon, after its digestive system is healthy, it can be fed to red worms. However, at this time, juveniles are still in the training period to learn feeding methods and enemy avoidance skills in the mouth of the broodstock. For the bony tongue fish with very low production volume, adopting the method of mouth hatching is the limit to improve the survival rate of larvae and juveniles. A good side failed. If you raise dozens of juveniles in this period, you will often find that they will gather in groups, resting for a while near the surface of the water where the current is still or in the corner of the tank, with their heads up as if they are about to die.

Behaviors like this lack of biological "imprinting" (the inheritance of a biological instinctive behavior) are rare in fish. As the fish grow older, this behavior gradually disappears. The eyes of fish in this period were very large, and the length of the head was very disproportionate to the diameter of the eyes. About 4 cm larvae (individuals with yolk sac) have a thick black longitudinal band on the body and head, which will gradually disappear with the absorption of the yolk sac. In the juvenile stage, the fins are very large compared to the body, especially the anal fins. The first soft fin of the pelvic fin is significantly elongated, and the tentacles at the snout are also large. In the picture above, let it absorb the yolk sac while feeding the crickets with a real length of 6cm and staring at the crickets on the leaves. The real length of the photo is 10cm. It can be dragged for such a long photo, the real length is 18cm, and the real length of the photo is 12cm at the moment of jumping out of the water and fighting for food.

Caused by long-term feeding of bottom food, it will recover if put back into the pond. Cover the fish tank with opaque black paper, add a white light to the upper part of the fish tank, feed the top food or place an object on the top of the fish tank to attract the attention of the arowana, and remove the black paper after 3 months.

Caused by unclean water, insufficient space, insufficient dissolved oxygen, and sudden changes in water temperature. Irregular movement of the gills, shortness of breath, the pia on the operculum outward instead of inward, and the red color of the gills can be seen at the onset of the disease. Change the water quality as soon as possible to provide more oxygen, the gills will turn from soft to hard, and there is no choice but to perform surgery. Surgery needs: scissors, gloves, disinfectant alcohol, clean and damp cloth, anesthesia. Find a clean plastic bag, put water in the pocket, put the arowana in the pocket, add anesthesia to the water in the pocket, wait for the anesthetic to work, take the arowana out of the pocket and put it on a clean and damp cloth Trim with scissors (guaranteed to be sterilized), then put the silver arowana back in the tank to increase the amount of dissolved oxygen. When the arowana regains consciousness, let the silver arowana rest and rest in dim conditions. If the arowana does not have any interest in food, change 20%-30% of the water every day, change the quality of the water for 6 days, and increase the salt to reduce the risk of parasite attack.

Caused by the parasite protozoa, a part or most of the body of Arowana is covered with small white spots. Mainly affects the fins and reduces the appetite of the dragon fish, and the silver dragon fish can often be seen rubbing the body. Raise the temperature to 30 or even 34 degrees Celsius and add a 3% concentration of small table salt. If it still does not work, it will be treated in a medicine tank alone. The main symptom is that there are white spots all over the body, like sprinkled with white powder, and in severe cases, it is like covering a layer of milky white film on the fish. The cause of the disease is caused by the parasitic worms on the fish. Main control measures: 1. Sprinkle 0.1-0.2ppm mercurous nitrate all over the pool; 2. Sprinkle 500ppm copper sulfate and 500ppm magnesium sulfate all over the pool.