Shark egg cases (IMAGE) Field Museum Caption Egg cases (aka "mermaid's purses") laid by bamboo sharks and fertilized via artificial insemination. Credit Photo by Jay Harvey, Aquarium of the Pacific Usage Restrictions Please include credit License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.