Hey, just got an update on my July Post "Glowing Eggs on Myrtle Beach" from the Assistant Interpretive Ranger at Myrtle Beach State Park.
I had sent her a letter asking if she might know what this was now that I had photos posted. She contacted the Interpretive Ranger at the Huntington Beach State Park who forwarded this suggestion...
"They look like juvenile jellyfish to me, but that doesn’t explain the bioluminescence. I wonder if they could be juvenile comb jellies; they are certainly bioluminescent. I think the air bubble is just a bubble trapped inside them."
I then did a bit of research on comb jellies (Mnemiopsis) and found this article at http://jrscience.wcp.muohio.edu (you can go to the link to read the full article)Scrolling down, I found this segment:
"Bioluminescence
What really created an interest in comb jellies for me was their bioluminescence. When I worked on the coast of Georgia, students and I would catch comb jellies during dock study. When we got back to the classroom to look at what we caught, the comb jellies would usually steal the show (only skeleton shrimp created more of a stir). The students would watch the comb jellies' cilia on the video cam, but the best part came when the lights were turned off. If it was dark enough and someone disturbed the comb jelly it would glow! The best was if the students saw comb jellies bioluminescence in shallow pools during their night walk.
The bioluminescence (cold light) on comb jellies comes from the gastrodermis cells in the walls of the meridional canals. This makes it look like the light is coming from the comb rows and giving an overall appearance of a pulse or blob of light. When disturbed, the comb jellies as well as many other marine organisms (jellyfish, siphonophores, deep sea squid, etc), glow with bioluminescence. Some of those mentioned (unclear if comb jellies do) lose their glowing tentacles or release a glowing cloud to distract predators (Waller, 1996)."
The way the glow occurs when disturbed and along it's outer layer makes me believe it's the best answer so far. I've found a PDF online that mentioned these characteristics, too...
If you want to see what they look like, check out Chai's Marine Life Blog: "Comb Jellies on the Cottesloe Reef". He's got geat pics and descriptions.
So this could be it. They're still doing a bit of research just to verify it. Many thanks to the Assistant Interpretive Ranger at Myrtle Beach State Park and the Interpretive Ranger at the Huntington Beach State Park for taking the time to look into this for me. I was at Myrtle Beach State Park Nature Center in July and they're wonderful people and they have interesting displays there, and there's lots to do at the park.
So next summer, when you're strolling along Myrtle Beach at night, watch your footsteps for those glowing eggs. They're really fascinating to see.
3 comments:
Hi Dale,
Nice to know that you like my photos. And thanks for the link to my blog.
I have just read both your posts about the comb jelly. Your first encounter with them on the beach and the effort you made to find out further info about them are interesting to read.
Good work, mate.
Hi Dale,
This is a follow-up to the email I sent you about a month ago regarding those glowing egg-things you found at Myrtle Beach. I was not convinced they were the comb jellies the rangers suggested after I found the same thing at Carolina Beach near Wilmington NC. Like you, to me they looked more like fish eggs. I was back at the beach this weekend and found them again! Not nearly as numerous as before but it didn't take to long to find some. This time I collected a few and brought them back to the college in Raleigh.
Small tentacles and other jellyfish-like structures were clearly visible under the microscope. Unfortunately my microscope camera is not working so I couldn't take any pictures. It looks to me like they are in the subclass Hydromedusae. These are closely related to typical or "true" jellyfish. Hydromedusae are small creatures with a few short tentacles, a spherical bell (as opposed to the umbrella shaped bell found on true jellyfish) and there are many that bioluminesce. They are in the same phylum as Jellyfish (Cnidaria) but in a different class. True jellyfish are in the class Scyphozoa while Hydromedusae are in the class Hydrozoa.
Comb jellies also bioluminesce but have no tentacles, no bell, and are in a different phylum (Ctenophora).
Anyway, I hope this settles that long standing puzzle.
Brandon Foster
Awesome, Brandon! Thanks for sharing your research. I googled them and they're gorgeous creatures. If I knew how to keep them alive I would have brought some home with me. If you ever get a photo of them, please feel free to share it.
Post a Comment