The baby shark eats its own kind before it is born, and what happens to the last one?

survived. Shark reproduction is so fierce that the young shark will survive in the last and its strength is not weak, so that it can survive.

After the last baby shark fetus has devoured its other siblings, it will "break out of the cocoon" and become the king of life.

The last one to enjoy the mother's nutrition alone, and the contribution of its siblings makes the baby shark very powerful from birth.

Some smaller sharks, such as horned sharks or tiger sharks, are usually oviparous. The total number of oviparous sharks accounts for about 30% of the total number of sharks. Speaking of fish, most of their eggs are thousands of eggs that are fertilized and hatched in vitro.

But the eggs of oviparous sharks are fertilized in the body, and the number is much smaller than that of the average fish.

The eggs of a tiger shark. The eggs of a cat shark.

In general, sharks lay 18 20 eggs with a diameter of 5 to 11 cm at a time. After a few months or even a year, these eggs hatch into baby sharks. Mother sharks usually wrap their eggs in seaweed or between sponges.

Some of them are spiral-shaped, and some are pocket-shaped. The eggs are as hard as leather, and there are tendrils on them that help them stay in place and not drift with the current.

People gave the shark eggs a beautiful name, "Mermaid's Pocket".

Viviparous sharks.

Viviparous sharks are usually larger, such as the sand shark family, the true shark family, and the hammerhead shark family. Like mammals, their young grow up in their mother's womb and depend on the umbilical cord for nourishment.

Ovoviviparous most of the sharks are ovoviviparous. The eggs hatch in the body and then are laid. Baby sharks are not connected to their mothers by the umbilical cord, but by the nutrients in the eggs.

There are three breeding strategies for sharks

1. Oviparous: Generally used by large sharks. Shark eggs are large and nutritious.

The discharged egg is packed in a flat, cushion-shaped sheath that is added around the egg as it passes through the fallopian tubes, the outer skin of the sheath hardens when it enters the water, and each corner of the sheath has a short, hollow horn that allows seawater to enter and give the egg oxygen.

2. Ovoviviparity (non-placental viviparity): The fertilized egg is born in the uterus, and the yolk sac or the egg discharged into the uterus by the ovary is the nutrition**, and the placenta is not formed in the uterus. Except for whale sharks, which can produce more than 300 at a time, the rest can produce dozens at most each time, and the least is the fox shark (thresher shark), which only produces two at a time.

3. Viviparity (placental viviparity): The fertilized eggs covered by the horny shell develop in the uterus, and the nutrients required for growth are obtained from the yolk sac placenta, until the young sharks are almost completely formed, and dozens of fish are produced each time. Most of the sharks in the ocean are viviparous.

Mode of reproduction:

Sharks are fertilized in vivo, and males have finned feet for mating organs.

Oviparous type. The egg shell is peculiar, the size and shape vary with different species, the largest is 30cm, 14cm wide, 9cm high, it is the largest egg of living fish, the smallest egg is 63mm long and 37mm wide, most of the egg shells are rectangular, and there are extended tendrils at the four corners to be wound on seaweed, stones and other objects for incubation.

Ovoviviparous. Most shark fertilized eggs develop into fetuses in the mother's womb and eventually give birth to larvae. The number of fetuses produced varies from dozens to 2-3.

The above content reference: Encyclopedia - Shark.

Because that's the fins of baby sharks. Every shark is born with such a thing, its function is to be able to speed up swimming in the water, to be able to reduce its own resistance, is a very important thing. If the shark loses this thing, it will slowly lose its balance in the sea.

Habits. Sharks mostly feed on marine animals such as fish. Sharks feed on injured marine mammals, fish, and carrion, culling weaker members of the animal. Sharks also eat litter and other waste left behind by boats.

In addition, some sharks also hunt a variety of marine mammals, fish, and animals such as turtles and crabs. Some sharks can go months without feeding, and the great white shark is one of them. It is reported that the great white shark is going to be separated.

Eat only once in a month or two.

I'm so brain-dead, I'm also drunk. That's a nursery bag, okay.

Ovophytic, viviparous, oviparous.

Ovoviviparity: Most shark fertilized eggs develop into fetuses in the mother's womb and eventually give birth to larvae. The number of fetuses produced varies from dozens to 2-3.

Viviparous type: the fetus has a close relationship with the mother, the maternal uterine wall and the fetal yolk sac are connected to form the yolk sac placenta, and the mother's nutrients and oxygen enter the human fetus through the yolk sac placenta.

Oviparous type: the egg shell is peculiar, the size and shape vary with the different species of invocation, the largest is 30cm, 14cm wide, 9cm high, the largest egg of the living fish, the smallest egg is 63mm long, 37mm wide, most of the egg shells are rectangular, and there are extended tendrils at the four corners to be wound on seaweed, stones and other objects for hatching.

What are the parts of a shark's teeth?

Shark teeth are made up of dentin, osteodontic, enamel-like and tremors, which evolved from shield scales.

The morphology of the tooth is one of the classification criteria, there are many styles of shark teeth, there are comb-shaped teeth, special-shaped teeth with different front and rear teeth, three-peaked teeth with 3 tooth tips, multi-peak teeth with more than 5-7 tooth tips, single-peak teeth with 1 large side flattening, stone-paved teeth with many small number of teeth, granular teeth with many fine and small number and incisors with wide and flat teeth, a total of 8 styles.