The big egg case hunt

What does a mermaid keep in her bag? Baby sharks and baby rays obviously!


There are more than 600 shark and rays in the world and at least 15 species are found in Dutch coastal waters. Some of these are also found in the Eastern Scheldt. Curious what they look like? You will find them all on this nice overview.


Some of them breed by laying tough, leathery egg cases, sometimes called mermaid bags. These egg cases of about eight rays and two shark species can be found on the beaches.


Each species will lay egg cases of different sizes and shapes. They remain lying on the sand bottom for months on a sandy floor or hang on to seaweed for months, while the embryo in it grows into a tiny ray or shark. When empty, the egg cases often wash up on the beach. Around the entire Eastern Scheldt there are several beaches (icon strandjes) where you can search for them.


With the determination guide you can find out which species it is. You can help researchers to map out the distribution of the different species by registering your find at