Dragonfly and passengers

[Steve Maxson]

This image perhaps has more biological than artistic appeal, but I wanted to show what the dragonfly nymph from my previous post looked like before it molted its exoskeleton. It is not uncommon for these nymphs to be covered by what I think are colonial protozoans (I'm not an authority on those). These organisms do not harm the dragonfly - they are simply using it as a substrate for attachment. They feed by filtering microscopic particles out of the water. You might also note how the nymph's wings have increased in length following the molt (see my previous post). 40D, 100 mm macro, 1/250, f/16, ISO 100, MT-24EX twin flash (diffused), tripod, cable release. RAW file PP in CS3 - curves, vibrance. I cloned some bits of debris in the water and toned down some flash-generated spectral highlights. All comments are welcome and appreciated.

[Brendan Dozier]

Very, very cool, Steve! Love the image detail, and learning new things about these creatures. Would you say that the protozoans and the nymph have a symbiotic relationship - like pilot fish have with the sharks?

[bhavya joshi]

This is the best image in Dragonfly series.. great details.. Thanks for sharing Steve.. you gave us good information about this mysterious creature..:cheers:

[Mitch Haimov]

Another fantastic image, Steve! I do find the protozoan hitchhikers interesting, as well as educational. Their structures, presumably for filtering lunch from the water, are quite compelling. Once again the detail in amazing, and couldn't ask for a cleaner BG. I'm glad you posted this one. Very well done.


Would you say that the protozoans and the nymph have a symbiotic relationship - like pilot fish have with the sharks? Brendan: This relationship would qualify as commensalism--a relationship in which one party benefits and the other is neither helped nor harmed. Commensal relationships are one of three categories of symbiotic relationships. The other two mutualism (both parties benefit) and parasitism (one party benefits and the other is harmed). Symbiosis is often used synonymously with mutualism.

[Steve Maxson]

Thanks for the comments folks.

Mitch has done a good job of explaining the basics of symbiotic relationships and I think he is correct in calling this a commensal relationship. This raises other interesting (to me, at least :S3:) questions as well. How many species are attached? - there appear to be several. Are these species associated specifically with this species of dragonfly? - or are they also found on other aquatic inverts or plants stems, etc. Hmmm, sounds like a thesis topic - if someone hasn't already looked at this. :S3:

[Roman Kurywczak]

Hey Steve,
Agree with your self assesment that this one is cooler for bio reasons that artistic......but still a fantastic shot nevertheless! I have no answers for you on any of the questions......as a matter of fact......I have to google a few of the words even with the explanations:e3!

[OvidiuCavasdan]

Well... another biology lesson a and amazing image. Cool details and wery good job on using light. Thanks for sharing! I would clean up the green line at bottom:w3

[Ken Childs]

Steve, you've outdone yourself with this one! The extra life attached to the bug adds a lot of interest.


Are these species associated specifically with this species of dragonfly? - or are they also found on other aquatic inverts or plants stems, etc. Hmmm, sounds like a thesis topic - if someone hasn't already looked at this. :S3:

I would bet that these hitchhikers are found attached to all sorts of things, not just dragonfly larvae. I think you could compare them to saltwater barnacles.

[Steve Maxson]

Thanks for the comments Roman, Ovidiu, and Ken.

Ken - You may be right. There are certainly lots of protozoans, algae, etc. attached to all sorts of things in these freshwater pond systems. What I was wondering is whether certain species attach "preferentially" to certain substrates (e.g., a dragonfly nymph vs a water scorpion vs a plant stem, etc.). There's probably no way to really get at this without doing an in-depth study. I know very little about protozoans so I don't have any answers, but stranger things than this are being documented all the time in nature. :S3: