As we all know,
A lot of sharks are oviparous,
And some of them are oviparous,
In fact
Shark breeding has a lot to be known about
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Spotted bamboo shark embryos swim actively within the egg shell. Image source: NOAA
No need for a husband,
The "old lady" is pregnant by herself
Some female sharks are so self-sufficient that they don't even need male sharks to have children! The researchers looked at females from at least two different species of sharks, who were separated from the male sharks and gave birth to cubs without mating. Genetic testing showed that baby sharks only carry the DNA of females. This suggests that they reproduce asexually.
Inside the egg crate are a bit of a striated bamboo shark embryo.
A dog blood drama of a mother and a father is staged at any time
Like many animals in nature, when sharks breed, females do not choose only one mating partner. Female sharks use sperm from multiple males when breeding, meaning that the baby sharks in a litter may be half-siblings.
The inner volume begins at the embryonic stage
Sharks have no fewer inner rolls than human rectums. While still in the mother's belly, the largest embryo sometimes eats siblings in the womb, which is known as "intrauterine cannibalism." Researchers who study sand tiger sharks point out that a pregnant shark may have 12 embryos in its womb, but the largest will eat the rest. The sharks will then give birth to 1-2 larger and stronger baby sharks, increasing their chances of survival.
A 12-week-old porbeak embryo already has teeth!
What is 10 months pregnant,
Sharks are 24 months pregnant
Pregnancy in October, for human mothers, has been a hard and exhausting period of time, but for some species of sharks, 10 months is not a big deal, such as spiny horn sharks can be pregnant for up to 24 months, which is also the longest gestation period in vertebrates.
135 babies a litter is crazy
Some sharks, the embryos begin to roll inwards, and finally give birth to one or two babies, and some sharks are born endlessly. The sheer number is staggering. For example, the great blue shark can give birth to 135 cubs at a time. Fortunately, they don't need diapers, milk powder and kindergarten, otherwise they wouldn't have been born like this if they had mines at home.