The scientific name of the sunfish is Mola mola, which belongs to the family Sunfish. Large, tall and flattened, with small eyes, located on the upper side of the body, the eye septum protrudes; the tail is short, without the caudal stalk; the nostrils are two on each side, but small, located directly in front of the eye; the mouth is also small, in the front position of the body; each gill cap is buried under the skin, the gill foramen are relatively small, located in front of the base of the pectoral fin; the body and fins are rough, with thorny or granular protrusions; there is no lateral line; the dorsal side of the body is gray-brown, the ventral surface is silvery-gray, and each fin is gray-brown.
Sunfish are large oceanic fish that inhabit tropical and subtropical oceans and are also found in temperate or boreal oceans. Swimming alone or in pairs, sometimes more than ten tails in groups, small individual fish are more active, often jump out of the water, large individual fish slow movement, often lying on the water, or dorsal fin exposed to the water, can also dive into more than 100 meters deep water. Feeds on seaweeds, molluscs, jellyfish, planktonic crustaceans and small fish.
The sunfish has a very large number of eggs and is the creator of the Guinness Book of Records, reaching 300 million grains, which is the largest number of eggs in fish. Although the spawning number of sunfish is high, the survival rate of larvae is extremely low, only one in 10 million. A storm or an attack by a predator can kill and injure the larvae. The sunfish have a wonderful way of breeding. The male will first dig a pit in the sand, and then the female will release her eggs into it, and then the male will immediately come to the pit, drain his sperm, and begin to take care of the fertilized eggs.
From the day of its birth, the sunfish has faced various dangers. When they were still baby fish, they were too weak to resist the enemy, and when they grew up, they were often bullied by other animals because of their swimming ability. The adult sunfish, although unusually large, is actually a "big and brainless" guy. How brainless are the sunfish? In general, escape is the instinct of living things on Earth, and the first instinct of all animals in the face of danger is to escape, but the sunfish is an exception. Many of its deaths are very peculiar, for example, dying of excessive tension, being sunburned alive, and so on. What's even more outrageous is that some sunfish are chased and nibbled by predators all the way without reacting to their imminent death, and still leisurely swim in the ocean. This is because the skin of the sunfish is very thick compared to other animals, and there is no nerve ending distribution in it, so it does not feel pain at all when it is eaten, and the thick fish meat is eaten in vain.
Sunfish also has a serious identity as a marine doctor. It has been shown that sunfish secrete a substance that helps treat injuries in other fish. However, the skin of the sunfish is covered with parasites, as many as 50 species, and even parasites have parasites on their bodies. When it floats on the surface of the sea to bask in the sun, some birds will stand on it and peck at these parasites for it.
bibliography:
[1] Turning over. Taiwan Fish Database
【2】Mola mola． Animal world
[3] ZHOU Tongxuan. The Most Bizarre Shape of the Sunfish[J].Extracurricular Life, 2019, (Issue C3): 86-89
Source: Aquatic Animal Health Assessment