Identification Troubleshoot

Boy with Eggcase © Sophie Benaiges.If you’re having problems identifying your eggcase, there may be several reasons for this...

It’s broken - Eggcases aren’t always washed up on the beach intact, horns are delicate and break easily, therefore it’s likely you will have to identify the eggcase with missing elements. 

Hairs and other attachments - You may notice patches of velvety, fawn coloured hairs or other items growing from, or attached to, the eggcase. Please ignore these as they are not useful in identifying the eggcase once it has been washed up on to the beach.

Misshapen capsules - Eggcases that have been dry for a long time will take longer to rehydrate and may not fully recover their original shape.

Short horns - Look closely at the horns, they may have snapped and therefore look a lot shorter than they should. Species, such as the Small-eyed Ray and Cuckoo Ray, which have long, fine, filamentous endings to the horns are unlikely to survive the surf with these delicate appendages intact.

Beware eggcase imposters - Don’t be fooled into thinking that the large air bladders of some species of seaweed are eggcases. 

Colour - Do not use colour as an identifying factor – individual animals have unique charateristics which make their eggcases slightly different to other animals of the same species. Also, eggcases will change their colour with increased exposure to sunlight and oxygen.
Size - There is much variation in the sizes of eggcases from individual species. This means that when identifying, size is a good way of discounting some eggcases but is not a reliable way of determining exactly which species you have. Use the individual characteristics for each species listed on the Species Pages to make a definitive identification.  

Verification - We always love to receive photos of your eggcases, especially if you’re having trouble identifying your eggcase or want reassurance that what you think is correct. It's also important for our records to verify identifications. Please email us a picture of the eggcase, along with details of when and where you found it. Alternatively you can send us your eggcase in the post; however we won’t be able to return this to you.

So we can correctly identify the eggcase from your picture, please follow the steps below.

  • Place the soaked eggcase on a pale background, so it stands out.
  • Include a ruler or a 2p coin to give it scale.
  • Take a well-lit photo of the eggcase from above and from the side.
  • Write clear notes on: capsule size (length and breadth); horns; fields and keels.
  • Include your name and address so we can record the species, as well as when and where you found the eggcase. We can then identify and record it on your behalf.