VFT, like a deep-sea predator

[Guest]

When I went to shoot this venus fly trap under UV I didn't actually expect to see much of anything. As it turns out though, it looks like this meat eater might just be using a trick to lure victims into its mouth/leaves. The reflective spots and dark stripes along the rim of the leaves almost remind me of a deep-sea predatory fish which uses little light lures to attract its meals. Or it could be coincidence. Either way it was surprisingly cool to find this.

 

This makes me wonder how many other plants may have some kind of UV signature in parts other than the flowers. I did try also imaging a Sundew, Pitcher Plant, and Bladderwort - none of which showed anything particular under UV.

[OlDoinyo]

Interesting..

 

You might check out http://onlinelibrary.wiley.com/doi/10.1111/j.1469-8137.1985.tb02864.x/pdf; it seems that this has been noticed before.

[Guest]

Well, how about that. Thirty one years later (almost to the day) and I just made the same old discovery. I guess I'm going to have to step it up a notch!

[Andy Perrin]

Your photos are better, though! :P

[colinbm]

Excellent Mark

[OlDoinyo]

Your photo is definitely better. It looks as though some pitcher plants might be good subject matter--maybe you didn't happen to get the right species.

[enricosavazzi]

That's interesting. The UV signature might be just a consequence of thickening/stiffening of the epithelia along the edge of the leaves and the spines, which is necessary to prevent the escape of trapped insects. Or it might have started evolving this way and then taken an additional function of providing UV visual cues similar to those of flowers, which might increase the attractiveness to insects. We won't really know until someone starts exposing artificially altered specimens versus controls to insects, and logging the number and length of insect visits.

[Andrea B.]

Well that is just totally cool, Mark !!!! Very interesting to see.

 

Enrico has suggested a terrific experiment for some enterprising graduate student to accomplish. "Paint over" the bright spots and see if the insects are still lured to the plant.

 

Thirty one years later (almost to the day) and I just made the same old discovery.

That doesn't mean it is not valuable to have confirmation. :D It is always good to repeat such tests.

I would imagine that if we thoroughly searched the scientific literature we would find a multitude of UV subjects already recorded in someone's experiment. After all, scientific UV photography was already being performed in 1891. See:

• Knuth, P. (1891a). Die Einwirkung der Blütenfarben auf der photographische Platte. Biol. Centralbl. 48, 160-165.
  
• Knuth, P. (1891b). Weytere Beobachtungen uber die Anlockungsmittel der Blüten von Sycos angulata L. and Bryonica dioica L. Biol Centralbl. 48, 314-318.
  

[nfoto]

Sarracenia mitchelliana x leucophylla. UV