13 — Deep-sea skate egg case

A mermaid's purse (skate egg case).
Challenger Plateau, 1012m, May 07.

This is the egg case of a skate; they often get called ‘mermaid’s purses’. Skates are related to sharks and also have a cartilaginous skeleton. They're often confused with rays, but are a separate family (Rajidae) within the super-order Batoidea, which contains both.

Mermaid’s purses can wash up on beaches and sometimes they can be seen in shallow water attached to the bottom. If you find one and put it into an aquarium, you can often watch the baby skate develop and grow. The shape of the egg case is species specific, so with the right guides it should be possible to work out what species of skate produced the egg case.

The egg case pictured came from deep-water (1012m), on the Challenger Plateau in 2007, which means that this egg case likely came from a deep-sea species. It is about 60mm long. It could be one of a few species of deep-sea skate found in New Zealand waters.


More info: 

https://www.sharktrust.org/en/skate_ray_morphology

http://www.teara.govt.nz/en/sharks-and-rays/page-8

http://fs.fish.govt.nz/Doc/22895/AEBR_68.pdf.ashx