By Victoria Bell For Mailonline
Published: 12:13 GMT, 11 February 2019 | Updated: 15:16 GMT, 11 February 2019
Fascinating footage shows an unhatched baby shark wriggling around in its egg sac after it had washed up on a beach.
Mother Karissa Otero made the discovery while searching for 'mermaid's purses', empty shark egg cases, with her two-year-old son Bodhi in California.
Ms Otero was stunned when she stumbled upon the baby swell shark, still alive in its case, having become beached after the region experienced a period of high tide.
The tiny creature can be seen wriggling about inside the sac with its stalk still connected to its yolk for nutrients.
Swell sharks lay rubbery egg cases with wiry tendrils at the corners which catch on rocks and seaweed, anchoring them to prevent being washed to shore.
After capturing the video the 34-year-old waded waist-deep into the sea to release it so it would survive when it finally hatched.
Ms Otero posted the footage on social media, where it racked up more than 845,000 views.
'We came across a lot of sea debris, including seaweed, driftwood, rocks, and shells and along with the debris we found this swell shark egg,' she said.
'You can see from the background of the footage in the video that there was no way this egg would have made it back out to sea on time if at all.'
It's very common to find mostly empty mermaid purses like these along the beach in this region but this was the first time Ms Otero found a live shark in one.
'I look because I knew it was possible to one day find one as the tide is constantly washing all kinds of stuff on the beach,' she added.
Fascinating footage shows an unhatched baby shark embryo wriggling around in its egg after it had washed up on a beach. Mother Karissa Otero made the discovery while combing a beach for 'mermaid's purses', empty shark egg cases, with her