Researchers in Italy specialising in sharks say they may have recorded a miraculous 'virgin birth' after a baby shark was born in a tank filled entirely with females.
The smooth-hound shark was born at the Acquario di Cala Gonone in Sardinia, Italy, to a mother shark who had been living in the tank for 10 years. All of the other female sharks had also been living in the tank for an extended period of time.
The scientists say that this may be a case of parthenogenesis, in which an egg develops without ever being fertilised by the sperm of a male shark.
The phenomenon is not unheard of in sharks. Demian Chapman, director of the sharks and rays conservation program at Mote Marine Laboratory & Aquarium in Florida, told LiveScience:
"About 15 species of sharks and rays are known to do this."
This will, however, be the first time such an event has been recorded in smooth-hound sharks. Another 80 vertebrate species have been documented undergoing parthenogenesis.
While the event may just be a freak of nature, other scientists have postulated that such events may occur as an evolutionary trick for when there are no males in an area for an extended period of time.
Christine Dudgeon from the University of Queensland in Australia explained parthenogenesis to LiveScience, saying:
"Rather than combining with a sperm cell to make an embryo, [the egg cell] combines with a polar body, which is essentially another cell that is produced at the same time that the egg cell is produced and has the complementary DNA. Parthenogenesis is essentially a form of inbreeding, as the genetic diversity of the offspring is greatly reduced."
Sharks have also been known to undergo automixis in which the female creates sharks similar to herself without direct male fertilisation.
Many creatures have breeding systems in which no mating ever takes place, most famously certain types of worms. The events in Italy show that evolution will almost always find a way to overcome any obstacle put in the way by nature.
[h/t: Science Alert]
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