Have you ever seen a mermaid's purse?
By Clint Perry
@cperry2 (5608)
Newport, Oregon
June 10, 2020 12:30pm CST
That is what the thing in the picture is often called, these wash up on the beach and can be found on the "Wrack Line" ( a wrack line is the debris field that is left by the high tide ). These are fairly common but what are they?
These are egg cases for sharks and or skates. This is how they reproduce. They have sex like other animals but the embryos are shed inside these cases which form inside the animal. Both sharks and skates produce them,. One might find them that are two inches across (the square or rectangular portion) or up to five or six inches across. They should be anchored to rocks or something on the ocean bottom but our turbulent tides often break them free.
A scientist at Hatfield Science Center found one of them early one morning and it turned out to still be viable (alive). They took it into a lab and cut a square out of the case cover and glued a plastic sheet on the hole so they could observe embryo development. The experiment was successful and the skates that were born from that case are still on view at the science center. (Well they will be when it reopens)
Just one more wonder of the beauty of nature, mermaid purses, who would have believed it?
Edit #2: It turns out that the vast majority of sharks do not give off egg cases as I have described above, they instead give live birth. However there are exceptions, and some of the ones here are evidently among those that do not. These sharks are considered oviparous, meaning they lay eggs.
Thank you @rebelann for bringing this to my attention!! I am always learning and love the opportunity to learn something new.
Edit: Photo borrowed from Google.
11 people like this
8 responses
@cperry2 (5608)
• Newport, Oregon
11 Jun 20
Some might, I am not 100 percent certain, the ones here do not have a live birth. --- I just did a quick check and have learned that our sharks are the exception. The vast majority of the 500 plus species of sharks do have live birth. Good catch on that and thank you. I"ll edit tihe entry to reflect this.
1 person likes this
@cperry2 (5608)
• Newport, Oregon
11 Jun 20
@rebelann Well, it reminds me I have to fact check my beliefs before posting. I actually love being corrected when I step out of line. It keeps me learning, and it helps make sure what I say is accurate.
Understand, that six years ago before I began volunteering, I knew next to nothing about the ocean or marine biology. I've had some very good teachers, but we did not go over things that did not directly affect our area. And we did not discuss sharks at all that I can remember. Later I learned that there are only six or seven species that live here. We do get an occasional great white come through, usually around september. But they do not remain here.
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@crossbones27 (48417)
• Mojave, California
10 Jun 20
How interesting, thanks for sharing because I would never know that. Do you work in the field or just stuff you just learned the hard way?
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@cperry2 (5608)
• Newport, Oregon
10 Jun 20
I guess I would have to respond --- both. I volunteer as an interpretive host. I am retired and spend several hours a week at the Hatfield Science Museum each week (I should say, I used to) As a volunteer, I answer visitor questions about the ocean or the critters we had on display. I have had some informal training by a couple of marine biologists but a lot of what I talk about I have learned outside that training. I am also a certified naturalist in the field of Cetaceans (whales & dolphins). I have given tours of tide pools and done programs on them for campers at the State Parks on occasion.
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@crossbones27 (48417)
• Mojave, California
10 Jun 20
@cperry2 Nice brother. I always wanted to do some stuff like that here but to far a drive and as much as they preach volunteer they never want it unless manual labor. They have qualifications now just to volunteer. It really makes me mad because reality is so different than what they preach,but at least you out there teaching us.
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@cperry2 (5608)
• Newport, Oregon
10 Jun 20
@crossbones27 Well, when things are open again. But I teach here too, that's why I put up all these creatures and stuff I run across. Most people do not get to visit the ocean and explore it the way we (my wife and I) do. I enjoy sharing what little bit I know.
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@GreatMartin (23677)
• Ft. Lauderdale, Florida
11 Jun 20
I almost gave a wise triple rated word answer to that!!
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@DaddyEvil (137145)
• United States
7 Jul 20
No, I've never seen one of those...
I did have, for about three years, a pair of walking sharks, though. (Epaulette sharks) Mine were shipped to me by an Australian friend. They were about five inches long when they arrived and a little over 14 inches long when they escaped their tank and passed away.
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@DaddyEvil (137145)
• United States
7 Jul 20
@cperry2 I called them my babies...
When Pretty and I were forced to move this past November I set up their tank at the new house. The friends who were helping us move wanted to go get something to eat so kept telling me to hurry up because they were hungry. I did something stupid. My babies were always able to climb out of their tank whenever they wanted so I had made a wire top for it to keep them from climbing out. I didn't attach the top securely enough before we left the house.
Our friends took their time eating and talking before we returned with the next loads of stuff for the house. When I opened the door my babies were there by the door like they were waiting for me to come in and play with them like I usually did. (I got them out of their tank every day and played with them on the floor. If I moved away from them they would squeak, like they were calling for me to wait for them, and follow me.)
I really miss them.
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@DaddyEvil (137145)
• United States
7 Jul 20
@cperry2 At least he wasn't someone's pet.
I actually thought my babies were in shock from the move so didn't hook the top on their tank. I just placed it over the tank and left it at that, thinking I would get them out when we got back from eating and reassure them about the move.
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@dgobucks226 (34365)
•
11 Jun 20
Interesting facts there. Just learned something new which is always fun.. Sea life does some amazing things!
