You don't give sizes in your post, but this looks ostensibly similar:
http://glashistoriskselskab.dk.server871186721.internet-server.dk/index.php?option=com_ponygallery&Itemid=65&func=detail&id=3016
These designs may also hold some significance in Denmark - certainly three identical herrings make up the town of Rønne's coat of arms, famously used as a logo by Bornholm ceramics factory Michael Andersen.
(http://upload.wikimedia.org/wikipedia/commons/f/fb/R%C3%B8nnes_v%C3%A5ben.png)