In an extraordinary turn of events, a swell shark egg has hatched at the Shreveport Aquarium—despite the absence of any male sharks in its habitat. The egg, first identified by the aquarium’s husbandry team approximately eight months ago, may have gone unnoticed for an additional one to two months prior. Since its discovery, the egg has been carefully monitored in the aquarium’s quarantine facility. On January 3, 2025, the shark pup successfully hatched with assistance from the aquarium’s team.
The husbandry team confirmed that the two female swell sharks in the tank had not been in contact with a male in over three years. This suggests the possibility of parthenogenesis, a rare form of asexual reproduction, or delayed fertilization, where fertilization occurs long after mating. To determine the exact cause, the team plans to karyotype the pup once it reaches a suitable size for a blood draw, which will likely occur in the coming months. This DNA analysis will reveal whether the hatchling is a product of parthenogenesis or delayed fertilization.
“This situation is incredible and shows the resilience of this species,” said Greg Barrick, the Curator of Live Animals at Shreveport Aquarium. “We are very excited in the coming months to confirm whether this was indeed a case of parthenogenesis or if it was delayed fertilization. It really proves that life… uh… finds a way.”
The new swell shark, affectionately nicknamed Yoko after the Chumash word for shark, “onyoko,” is thriving under the care of the aquarium’s dedicated aquarists. While Yoko is currently healthy, the team remains aware that sharks born through such rare reproductive events often face significant challenges. Regardless of Yoko’s future, its arrival is already making an indelible mark, contributing valuable insights into shark reproduction and conservation.
Yoko is being closely monitored off exhibit to ensure its health and well-being. Although visitors cannot see the pup in person just yet, the aquarium is thrilled to share updates on Yoko’s progress through its social media channels. Once the pup matures, it will eventually transition to a larger tank.
Swell sharks, native to the coastal waters of the eastern Pacific, are known for their unique defense mechanism of inflating their bodies with water or air to deter predators. This rare addition reinforces the Shreveport Aquarium’s mission as a hub for education, conservation, and inspiration, showcasing the wonders of underwater life.