Dog fish Esox lucius

The scientific name is Esox lucius, a type of ferocious fish that likes to live in low-flow water, along river banks, with lakes and trees. Dogfish is one of the most adaptable freshwater fishes - they can survive in very cold water, staying well in warm water and muddy water. This type of dog fish is abundant in North America and Northern Europe.

Fish body Esox lucius rounded, about 1.5 m long; big muzzle; big mouth; eyes can move fast and look almost in every direction; weighing about 23kg. They often hide in one place, their gods always form an "S" shape, ready to snatch people out to catch prey. They live alone and protect their territory to find their prey.

Dogfish patiently hide in the water under the grass, they disguise themselves with white and black spots on their bodies and remain silent for a long time, waiting for the prey to float to the right range. When the time comes, the dog comes out, grabs the prey with two strong jaws.Dogfish attack with lightning speed, so it is hard for any prey to escape .

Up to 90% of the dog's fish are small sized fish, but the dogfish also catch any live animals that their jaws have caught. Dogfish eat both insects, snakes, ducklings, frogs, shrimp, waterfowl, rodents and many other small mammals. The best "medium-sized" food size of fish is from 1/3 to 1/2 of their body size. Big dogs also like to eat even smaller dogs. Big dogs (usually females) also eat dead fish, dying fish or sick fish. Many old stories also tell that dog fish live swallowing the dogs, ducks, swans, etc.

The teeth of canine fish Esox lucius cannot bite off the prey but only functions to hold the prey tightly and push the prey to the esophagus thanks to the alternating movement of the upper and lower jaws. The digestive juices of dogfish are very strong, can destroy not only the prey but also the fishhook, steel spoon or metal wire. Therefore, the dog does not hesitate to attack and eat the fish that are being hooked.

In many places, people also call dog fish as water wolves, lake tyrants, or freshwater sharks. These fish are often hunted because they eat a variety of economically valuable fish (like salmon).

Freshwater fish farmers and fishermen often make the mistake of thinking : they think that when catching all of the big dogs it will help to improve the number of other freshwater fish. But in fact, when the big dogs are caught, the smaller dogs will wear out because of eliminating an enemy. In nature, large dogs often eat smaller dog meat, creating an ecological balance.

Currently, it is known that pike fish is a fish used for fishing sport. Dogfish are still active even in the cold winter, they are very gluttonous so they are easily hooked.

Females are bigger than males. In the early spring, when the snow and ice began to melt, it was also when the prawns spawned on the edge of the water, even on the flooded grasslands due to the snow melting. A fish weighing 1.4kg can lay 35,000 eggs, a 13kg weight can produce 300,000 eggs.

Many males swim after females to fertilize eggs. However, the big females after spawning can turn to eat both the freshly caught males for their eggs. Broodstock and mother fish do not take care of eggs and fry. Eggs cling to plants and hatch after 10-15 days, the rate of fertilized eggs is over 50%, eggs and young offspring die a lot. The young still clings to the grass, thanks to the suction in the front of the head until the egg yolk is used up. At this time the young start to eat small invertebrates.

Most newly hatched eggs and juveniles become prey for large dogs , perch, minnow, waterfowl, water animals and some insects. Less than 0.1% of eggs are grown to adulthood. Most of the time young dogs must live hiding, avoiding enemies. Thanks to the habit of eating a lot, young fish grow very fast, within 1 year it is 20cm long.

Big dog fish have two main enemies: Rocky grouper and human. Female females during spawning usually do not appear in shallow water so they can easily become prey of bears, dogs and other predators.

Dogfish Esox lucius is often infected with a variety of parasitic animals including: tapeworm, tapeworm, if not cooked well, it is easy to infect people who eat them.

The average life expectancy of dog fish is about 10-12 years, and there are also children that live up to 20 years.