Twenty-seven years after the birth of the world's first test-tube baby, Australian scientists are ready to use the test tube nursery program on gray nurse sharks to save this endangered object.
In this 10-year research plan, the Australian government will spend US$ 189,400 on artificially inseminating nurse sharks and incubating shark embryos in vitro.
The Grey Nurse Shark is a fierce looking but shameful shark. Although Australia has declared it an endangered species since 1984, and has taken protective measures for its habitat, scientists say that in the next 20 years, the nurse shark will be exterminated on the east coast of Australia.
The nurse shark species are endangered, which is related to the reproductive process of the "fragile" of the embryo in the uterus. According to Nick Kobe, director of the Melbourne Aquarium, Nurse Shark’s baby has developed jaw and razor-sharp teeth in the early stages of development to bite the sibling brothers and sisters in the womb to develop faster. Each nurse shark has two uterus. The result of "kill each other" between young children is that in the end, only the most ferocious baby in each womb survives.
Of course, over-capture is also an important reason why nurse sharks are on the verge of extinction.
Because of its docile character, the nurse shark is known as "The Labrador Dog in the Sea." Unfortunately, because of its fierce appearance, it was backed by a "sweeping swimmer" and was killed by humans. As a result, the number of people was reduced. Until the 1960s, public sentiment was only able to be washed.
The key to incubating artificially cultivated gray nurse sharks in vitro is to avoid the "fragmentation in the womb" process. As the
Fish marine biologist Nick Otway put it: “As soon as a young child reaches 10 centimeters in length, he has a full-featured jaw and teeth and begins to bite the same kind. So we must bypass the fratricidal phase. â€
To this end, scientists from the Fisheries Department of NSW have come up with a bold idea: Shark embryos are individually cultivated in separate test tubes. Scientists plan to obtain embryos from pregnant female sharks, and then raise them in the artificial uterus in the laboratory.
However, before cultivating test tube sharks, scientists must first create artificial shark uterus and artificial uterine fluid, and then create artificial eggs. This is because when female nurse sharks only have a dominant baby in their womb, the female shark will produce fish eggs to feed it. Until young child grows to about 1 meter long, then it is born.
To ensure that everything is safe, scientists say that once an artificial uterus has been created, it will be tested first with non-aggressive sharks and will be applied to wild grey nurse sharks after successful trials.
Obtaining an Embryo In fact, while building an artificial uterus, the Melbourne Aquarium has conducted artificial insemination tests on the shark “Lonnie†in the museum this month. However, "Lonnie" is not a nurse shark, but a seven-inch shark that is 2
.6 meters long. Compared to nurse sharks, the shark sharks are less aggressive.
If Lonnie succeeds in pregnancy, artificial insemination technology will gradually be applied to gray nurse sharks.
If artificial uterus can be created and artificial insemination is successful, the remaining problem is to obtain shark baby.
Otway believes that Nurse Shark embryos can be obtained using current tracking techniques. The identity tag can help scientists identify which female sharks may become pregnant, and then capture the pregnant female sharks in a plastic float and perform an ultrasound to confirm that they are pregnant.
If you are really pregnant, put them in the water tank on the boat, then flick their backs with your fingers to make them restless or even faint. Finally, flush out the shark embryos or carefully remove them with tweezers.
Most sharks must continue to move forward in the water to ensure that the oxygen-rich seawater enters the orbit. Fortunately, gray nurse sharks can pump seawater directly into the cockroach, so when the scientists take the fertilized eggs, the shark can be in a fixed position. Of course, you can also give them a sedative if needed.
Once the artificial uterus is implanted, the scientists will use artificial eggs to feed the baby until they are born. Then they will put them back into nature.
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