Aquarium surprised by ‘virgin birth’ of swell shark in all-female tank

Yoko the swell shark was born to a female that had not had contact with male sharks for three years. Photograph: Shreveport Aquarium

Birds do it, bees do it. Even educated fleas do it, according to Cole Porter’s classic song on the universal nature of sex.

But a baby swell shark born in a Louisiana aquarium that houses only females has flummoxed marine experts and raised the possibility that the species may not require such earthly pleasures to produce offspring.