Baby shark was born in an aquarium that houses only two females

At first glance, Ispera looks like an ordinary shark. Of the species of smooth emissoles, this shark born in August in Acquario di Cala Gonone in Sardinia (Italy) is nevertheless a scientific curiosity: the female who gave birth to it did not rub shoulders with a shark. male for years.

Indeed, the young mother shares her aquarium with another shark, but it is also a female. Thus, the birth of Ispera, whose name means “hope” in Sardinian, is identified as a case of parthenogenesis, one of the first observed and documented in sharks.

‘Miracle’ baby shark born in tank of females living together for decade https://t.co/S7MXrVQTmc pic.twitter.com/CB4hFlnEg5

– New York Post (@nypost) August 19, 2021

This phenomenon, which remains rare, is akin to a form of “self-reproduction” or asexual reproduction. It occurs outside of all sexuality and allows the development of an individual from an unfertilized egg. Researcher at the University of Queensland, Australia, Christine Dudgeon gives more explanations to Live Science.

According to her, during parthenogenesis, the ovum merges with “a polar body, which is another cell produced at the same time” as itself, rather than with a sperm. This polar body “possesses the complementary DNA” necessary for the formation of an embryo. Ispera is not strictly speaking a clone of his mother, since the genes of the latter have been “mixed” to give birth to another individual.

Potentially reduced chances of survival

Still, the genomes of the two sharks are very close to each other. On this point, Christine Dudgeon is categorical: “Parthenogenesis is essentially a form of consanguinity, because the genetic diversity of the offspring is considerably reduced”. For Ispera, this can mean reduced chances of survival.

Even if the mother’s living conditions leave little room for doubt, the Sardinian aquarium teams have sent DNA samples from the small shark to confirm that it is indeed the result of parthenogenesis. His case excites the scientific community because the phenomenon is not only rare, but also very difficult to observe in nature.