At the beginning of January, the aquarium of Shreveport en Louisiana welcomed a surprising birth: Yoko, a young holbiche ventrue, a species of shark, was born in a pool housing only two females, without contact with a male for more than three years. But how is this possible?
The phenomenon that explains this is called la parthenogenesis, a mode of asexual reproduction in which an embryo develops without fertilization by a male. Although rare, it has been documented in several animal species, including some reptiles, birds, amphibians, and fish, such as sharks.
In sharks, parthenogenesis occurs when the female's eggs develop into embryos using only her genetic material. This typically results in young that have only one set of chromosomes from the mother (and are therefore genetically similar to her).
This phenomenon has been observed in several shark species, such as the zebra shark or the hammerhead shark. It may be a survival strategy in environments where males are absent, although the limited genetic diversity of the young may pose challenges to their longevity.
Another hypothesis considered: that of a delayed fertilization. To determine the exact origin of this birth, a DNA analysis will be carried out when Yoko is old enough for a blood test, a process that could take several months.
Luffed sharks are benthic sharks, generally harmless to humans, known for their ability to inflate their bodies by taking in water or air when they feel threatened.
