12-04-13 Huanchaco Beach Peru Beach Finds

by David & Lin
(Huanchaco, La Libertad, Peru)

Mermaids Purses - actually shark or skate egg cases. These were fresh and nice. Nice? Hmmm...

Mermaids Purses - actually shark or skate egg cases. These were fresh and nice. Nice? Hmmm...

~ submitted by David and Lin of OdysseySeaGlass.com in Huanchaco, Peru

Lin and I have come across these interesting finds off an on while beachcombing. They are tough and leathery. I did some research to try to figure out exactly what these were.

Commonly called Mermaid's Purse, you may have run across one of these tangled up in seaweed at the wrack line.

It turns out that young sharks of some species, like the dogfish (shark) and the catshark, lay these things and leave them to float in the sea.

The young sharks, "pups," are nourished by yolk in the egg case. Later, one side splits and the young sharks come out to grow up and scare people like you and me.

On the other hand, all skates lay their eggs in these pouches and it can be hard to tell if the egg case is from a shark or a skate.

Wikipedia shows the following photos of shark and skate casings:

Egg Casing of a Skate

Egg Casing of a shark
Egg Casings of a Small-Spotted Catshark

The British Marine Life Study Society describes the Dogfish (shark) common on England's coasts and includes photos of egg casings similar to ours. 

Jim Hall, the author of the page on Dogfish egg casings states that he has successfully raised sharks from the "pups" he has released from shark egg casings.

On his page, Jim Hall shows photos of several different shark egg casings as well as those from skates. These casings are very similar to the photos above.

For more information, here is an excellent 2-page brochure by the NOAA

mermaids purse

It is titled Where do Baby Skates Come From? It is detailed but offers graphics that are easy to understand.

Our conclusion?

We've reached the definite and non-controversial conclusion that what we found today is... either the egg casing from a skate or the egg casing from shark.

Perhaps one of our readers can add some information to help us determine which it is.

Happy hunting,

David and Lin Sea Glass

~ submitted by David and Lin Schneider

PS -

If this information has been interesting, entertaining, and/or helpful, please remember to click the "Like" or other buttons at the top of this page to share this with your friends.

Smiley  Thanks!

Comments for 12-04-13 Huanchaco Beach Peru Beach Finds

Click here to add your own comments

Mar 17, 2014
Treatment of skate egg-cases
by: Martin C. Cadee

The egg cases are empty, so there is no problem to collect them. Only very rare a baby skate is in the egg, in that case you can put it back to the sea (but I think it will beach again), or put it in e seawater aquarium to observe the young raja if it appears.

The empty egg cases can be dried, just in a dry [place , not in the sun, The egg-case will shrink to about 70% of its wet domensions.

The only problem is tha the egg case becomes more brittle.

Therefore I treat the egg case with a 50%-50% mixture of ethanol and glycerol.

It will dry again but is somewhat less brittle. I have egg cases that were foud in 1960 and are good preserved.

If you want to see the original dimensions you simply put the egg-=cae in fresh-water for 24 hours, and it gets almost its original dimensions.

Dry egg-cases can be sent by post, they are not very haevy.

I hope you like the information,

Yours Martin


~ David from OdysseySeaGlass says:

Thanks, Martin, that's good information to know on preserving these egg sacs.

However, I really think that there are babies in there. The sacs are not open. They are bulging and have liquid inside.

I tried to rip open one with my fingers but it was tough like leather and I couldn't do it, so threw it back.

Next time, I am going to take one home and see if I can cut it open.

Thanks again,

David and Lin

Mar 15, 2014
Martin - Mermaid Purses specimen
by: David at OdysseySeaGlass

Hi Martin,

We don't know how to preserve and ship specimens, although it sounds fascinating.

Also, we put those back in the ocean after taking the photos.

We'll try to find some more and then take a series of closer photos for possible identification.

See also:

Mar 15, 2014
Mermaid Purses
by: Martin C. Cadée

Quite interesting, that mermaid purses.

Can you collect some specimens for me. I can send you some Dutch mermaid purses back.

I'll try to find literature about the mermaid purses from Peru, so that J can determine from which species they are.

From the Dutch ones this is already known.


Martin C. Cadée [mc.cadee (at) casema (dot) nl]

Dec 05, 2013
by: Kay Carruth

I've never seen Mermaid purses....don't know if they are common on the Gulf coast??

Very interesting...

Click here to add your own comments

Join in and write your own page! It's easy to do. How? Simply click here to return to Photos General.

Enjoy this page? Please pay it forward. Here's how...

Would you prefer to share this page with others by linking to it?

  1. Click on the HTML link code below.
  2. Copy and paste it, adding a note of your own, into your blog, a Web page, forums, a blog comment, your Facebook account, or anywhere that someone would find this page valuable.