Barnacle eggs

Charles Krebs · Post by **Charles Krebs** » Wed Dec 12, 2007 12:00 am

I had gathered some salt water samples for study under the microscope. While collecting some algae off a dock a couple small barnacles broke off into my collecting jar. Later, while examining the sample with a stereo scope I found a small, dense cluster of eggs. It was about the size and shape of a grain of rice. I isolated the eggs and within day a few barnacle nauplius hatched out. In order to photograph the eggs I made a mini-aquarium using microscope cover glass. The images were taken with my tabletop setup using a Nikon D200 and bellows.

The individual eggs measure .25mm x .16mm.
The field size shown in the upper photo is 2.5mm x 1.6mm.
The field size in the lower image is 1.3mm x .8mm.

If you are curious what a barnacle larva looks like, I'll be posting some photos over in the microscope section.

Nikon 5X M Plan objective on bellows, Nikon D200

Minolta 12.5mm macro lens on bellows, Nikon D200

tpe · Post by **tpe** » Wed Dec 12, 2007 4:09 am

They are very nice, but possibly just on the limit of your resolution? Very small though, is it entirely reflected light? Fantastic to actually see these things though, æast time i tried it was under a microscope and we could only see a transverse section because of the DOF, we never really got to see the whole thing at onece, and here so many clear examples.

Just wondering if you could give me a couple of hints. I have to take some pictures of nemetode worms soon, about 1mm long as adults, would your method be a good place to start or should I be looking at transmitted light?

Just a passing note, did you know barnicles have the longest penis to body size ratio of any animal, as once they have made their home they can only mate with other barnicles within the length of their outstretched memebers? I guess thats what makes marine biology so facinating, especially trying to do barnicle impersonations in the bar after work?!.

tim

Ken Ramos · Post by **Ken Ramos** » Wed Dec 12, 2007 4:13 am

tpe wrote:

Just a passing note, did you know barnicles have the longest penis to body size ratio of any animal, as once they have made their home they can only mate with other barnicles within the length of their outstretched memebers? I guess thats what makes marine biology so facinating, especially trying to do barnicle impersonations in the bar after work?!.

Dang! Here after all this time, I thought I was the only one who could do that.

rjlittlefield · Post by **rjlittlefield** » Wed Dec 12, 2007 9:18 am

Now now, guys, let's keep it clinical. This here's a family-oriented public forum.

Of course this discussion did send me off to Google to research this bit of biology about which I was (blissfully?) unaware. Fascinating stuff -- and danged if the #3 hit didn't turn out to be an article by forum member Wim van Egmond.

Despite having lived around barnacles for a number of years, I really don't know anything about them. Always more stuff to learn...fortunately...

--Rik

jmlphoto · Post by **jmlphoto** » Wed Dec 12, 2007 9:42 am

never seen anything like that. great shot and discovery.

Charles Krebs · Post by **Charles Krebs** » Wed Dec 12, 2007 10:53 am

Tim,

It's not really at the limit of what can be done in this manner. One problem is that the eggs are rounded and smooth with no real detail on their surface. The substance that binds them into a semi-solid mass tends to obscure whatever detail or edges do exist.

Cover slip glass is good window because it is so thin, but you need to be cautious that it is not "flexed" when gluing things together. Otherwise you turn it into a weak "lens" instead of a "window".

I had photographed the eggs a day earlier on the microscope with transmitted light. The results were just OK, but not great. The mass is so dense that little light gets through, making darkfield and DIC difficult. Brightfield has shadows and coloration from the cells below the surface.
This is a subject that would really benefit from a 3D rendition.

cactuspic · Post by **cactuspic** » Wed Dec 12, 2007 12:34 pm

Fascinating shots. Charles . I agree with Rik that the learning adventure about these unusual creatures is enjoyable.

Irwin

Wim van Egmond · Post by **Wim van Egmond** » Sat Dec 15, 2007 11:01 am

Super stuff! You can see little diatoms between the eggs. I am looking forward to see more images of the subject, Charlie!

Rik, I wrote that Micscape article a long time ago and over the years I have received many e-mails from people who wanted to know how they could get rid of the barnacles that were growing on their boat. It ois a real problem for ships! I also received many e-mails about the misspellings in my article and I see they are still there.

Yes that 'thingy' is huge, it is a weird sight! Barnacles are fun to watch. If you submerge them (take a small stone with barnacles that are closed and look fresh) they will open pretty soon. Amazing how they can survive in the harsh conditions of the tidal zone.

Wim