 The Question: A friend found an egg sack shaped like a donut in Millinocket Lake in central Maine, and we are wondering what laid the eggs. The photo was taken with an underwater camera. The egg sack was in a little more than a meter (4 feet) of water and the blob was about 8 cm (3 inches) in diameter total. The bottom is sandy with some silt sediments. Nearby are lily pads, and a few grassy weeds, but otherwise, not much of anything else.Submitted by: Pamela and Lori-Ann, Maine, USA |
Phryganea caddisfly egg mass
Update, A Possible Answer (December 20, 2014): Charley Eiseman, a naturalist and author (check out Tracks & Sign of Insects and Other Invertebrates), was of enormous help in solving the puzzle of who laid spiral loops of green eggs in lakes in Nova Scotia and Maine. (Click here to read that post.) And when he was checking out AskaNaturalist.com, he came across this mystery of the donut blob. Charley suggested that the source of this blob might be the same as the layer of the spiral loops of green eggs: caddisflies in the genus Phryganea or Agrypnia.
It’s possible that this donut ring is the spent egg mass, after all the larvae have hatched and moved away. This donut is a little bigger than the egg mass shown here, but it’s possible that they swell and stretch as they disintegrate.
This is the most likely explanation I have heard yet.
Here’s what I had written previously …
The Short Answer: This one has me stumped. I sent the photo to an expert on amphibian eggs who insisted it wasn’t anything he’d seen before. I sent it to an expert on bryozoans, the “blob under my dock” that is one of the most common questions for AskaNaturalist.com. The answer was negative. I sent it to an expert on freshwater snails, who nixed that possibility. It has been viewed by at least half a dozen biologists who work with fresh water lakes in Maine all the time. None of them could identify it. So you’ve stumped the experts.
My guess is that it’s some kind of anomaly – a normal object rendered abnormal by strange coincidence. For example, maybe it’s a salamander egg mass that happened to get curled around into a donut shape, and then stayed intact after the eggs hatched and the tadpoles dispersed. Or maybe it’s an Ophrydium blob that formed a donut shape. If you look at the third picture on this page, http://www.bio.umass.edu/biology/conn.river/ophrydiu.html, there is an Ophrydium blob in a roughly similar donut shape. Due to its symbiotic algae, Ophrydium would normally be green, but maybe this one somehow lost its algae so that it appears to be clear. One biologist suggested a shed snake skin that just happened to form a donut shape.
We’re grasping at straws here, maybe. So instead of a good answer, I can only offer two things:
1. If you ever see anything like this in Millinocket Lake again, please take more pictures and send them along and I’ll take another shot at it.
2. If any AskaNaturalist.com reader has an idea about what this is, please add it as a comment to the end of this article. If your suggestion is a good one, I’ll see if I can get an expert confirmation.
Thanks to Pamela and Lori-Ann for the question. Sorry I don’t have a better answer.
Tom,
Thank you for your attempts. This one still has me curious, and all the more eager to get back into the lake and snorkel, but now that winter is upon us, it’ll be a while for sure though if possible, I break the ice and get underwater shots even during the winter months…always curious. I snorkel the shallow waters throughout the lake and will definitely be on the look out for such a thing as this in the future.
Again, thank you for all your help.
Always curious of nature! I can’t get enough of it, esp. the underwater world!
Merry Christmas!
Lori-Ann Willey
Once again, Maine baffles the Nation (smiles). Would it possibly be fresh water jelly fish? One year in Plymouth, Maine there were jelly fish found in Round Pond. It was the talk of the town!
Pamela,
I don’t think it could be fresh water jellyfish (Craspedacusta). They are considerably smaller than this. And they aren’t really donut shaped.
I wrote something about freshwater jellyfish here: http://askanaturalist.com/is-it-safe-to-swim-with-freshwater-jellyfish/
And some time ago, on an earlier website, I wrote something more extensive on freshwater jellies:
http://curiousnature.org/A1-Jellyfish.htm
I saw a very similar thing in Echo Lake located in Calif two weeks ago. It is definately donut shaped and transparent, but the ones I saw were about 1 inch or smaller in diameter. Furthermore I saw quite a few in several different groupings.
Judy, thanks for your comment. If you get a chance to take photos, I’d love to see them.
I also found one of these, i picked it up and something crawled out of it and bit me, dunno if its of any help but i have a short video of it on my instagram “saela_elska” i would sure like to know what it was too!
Interesting. What’s coming out of there is way too big to be hatching from the eggs. It must have just been on the outside or possibly inside. It’s a little hard to tell in your video. Is it a tiny fish? Can you send me the original video? Or any still photos? Send them to tom@askanaturalist.com. Thanks!
I would also love to see the video clip. I did not find any more of these this year, but my snorkeling was short-lived due to the cold summer we’ve had this year (coldest on record). Would LOVE to see the video clip. Is it on YouTube? My email is liberty@damcamp.com Thanks!
We just found the same thing in a small lake in Ontario — I have a 30 second video and photos. We are all curious to find out what this could be!!
Hey! So I found they exactly the same thing as “the donut blob” only these ones are straight and their where about 4 of them on one of the buoys out in the lake.. I would like to send you some pictures of them!
Hi Brittany. Send them to tom@askanaturalist.com.
We have a bunch in our pond in Alberta as well I’ll email photos to the above
That would be great. I’d love to see them. Email them to tom@askanaturalist.com.
I’d like to see the other photos as well. If everyone wouldn’t mind :-).
pgrated13@gmail.com
Advance thanks & appreciation