An Only Female Shark Tank Produced a Pup

 On February 3, 2025, CNNScience published an article discussing how a baby swell shark was born in an all female shark tank at the Shreveport Aquarium in Louisiana. The aquarium explains that there are two possible reasons that this could have happened. One is delayed fertilization, where sperm is stored in the female's body and fertilizes at a later time. One species of shark was found to have stored sperm for at least 4 years. Another reason this could have happened is through parthenogenesis. Pathogenesis is a form of asexual reproduction that is found in many species around the world and has been observed in other sharks including zebra sharks and bamboo sharks. An expert in mating systems and population biology of sharks explains that parthenogenesis can happen when females are isolated from males as a way to still pass on her genes, but it is not entirely known how or when parthenogenesis would “kick in”. Once the pup has grown bigger, a genetic test will be conducted to help determine what mode of reproduction was used. 

Yoko, the pup born at the Shreveport Aquarium in Louisiana

I find it so interesting as someone studying marine biology that this is possible. I’m curious to see what the genetic test shows when it happens, if the pup is 100% the mothers DNA or if there was a male involved in its conception. This information will add more to the knowledge of sharks and genetics in general. Discovering methods of reproduction used by different species and how one species can possibly use different methods will help build on the knowledge of reproduction as a whole.