Pristis perotteti swordfish

Vietnamese people often call Pristis perotteti fish "swordfish" or "swordfish"; and Westerners are called "fish saws". Pristis perotteti fish has a long striped muzzle that looks like a saw with jagged teeth. The teeth on the saw are not real teeth, but dermal denticles that are broken and lost will not grow any more.

This fish is abundant in tropical waters of the Atlantic and Indian Ocean, in some rivers and some large lakes through the sea. They can survive in saltwater, freshwater and brackish water. Despite the strange and frightening shape of the sword, Pristis perotteti is a stingray.

Swordfish catch crabs, shrimps and a variety of live animals snuggling under the water. Their swords were used to chase prey from the bottom of the water: They stirred their swords to the bottom, chasing the prey that were hiding under them to climb up.

In addition, sawfish catch prey by attacking the crowded fish. When you have plunged into the crowded fish, the swordfish will hit hard on the sword on your head. A few moments later there will be many unfortunate prey to be hit, rolling out unconscious. After a scary "sword dance" , swordfish began to swim slowly to collect the spoils.

Swordfish also use "swordplay" to defend themselves whenever an enemy attacks. Very strong back and forth attacks, enough to cause serious damage to the enemy.

Although the swordfish only defends itself when it feels threatened, there are also cases where they attack and cut down the swimmer's leg. Fishermen often meet them at the mouth of the river, the sword on the head or entangled with the net, each time they are removed they are often torn mesh and the hands of vulnerable people.

The average length is about 5.5m, but sometimes there are also longer than 6.1m. Average weight is about 320kg.

Swordfish is a type of insemination: The egg hatches in the uterus, the embryo continues to grow in the uterus without the supply of nutrients across the placenta (embryos independent of the mother in terms of nutrition). The embryo is nourished by yolk (yolk is located in the yolk sac, connected to the embryo by a stem of the ovule). Before the young fish were born, the entire yolk structure was absorbed.

Each litter, mother breeds about 20 young, each about 0.5-0.8m long. When the young fish is still in the womb, the upper teeth of the sword have not protruded, forever after the birth of new teeth developed. The size of the teeth on the young fish's sword will quickly reach proportional proportions after the young fish are born. Juveniles reach adulthood at about 10 years of age.

The life of the fish Pristis perotteti can reach 30 years or more.