Reader Jennifer sent several pictures of spiders and salamanders; here are two, with her one caption (click to enlarge).
Goldenrod crab spider [Misumena vatia] with bumblebee prey:
Wikipedia notes that this spider has chameonlike tendencies:
These spiders change color by secreting a liquid yellow pigment into the outer cell layer of the body. On a white base, this pigment is transported into lower layers, so that inner glands, filled with white guanine, become visible. If the spider dwells longer on a white plant, the yellow pigment is often excreted. It will then take the spider much longer to change to yellow, because it will have to produce the yellow pigment first. The color change is induced by visual feedback; spiders with painted eyes were found to have lost this ability.
The color change from white to yellow takes between 10 and 25 days, the reverse about six days. The yellow pigments have been identified as kynurenine and 3-hydroxykynurenine.
Wikipedia gives pictures of the color change. Because of its dimpled abdomen, I suspect that a crab spider is the subject of Robert Frost’s sonnet “Design” (below). It’s one of the Frost poems I like (“The Road Not Taken” has lost its force since I stopped believing in free will), and gives nice contrast between the horrors of natural selection and the natural beauty in which they’re embedded. The last line is ambiguous, but I prefer to believe it’s anti-religious—perhaps the despairing nihilism that we atheists are supposed to assume when convinced there’s no God.
I found a dimpled spider, fat and white,
On a white heal-all, holding up a moth
Like a white piece of rigid satin cloth —
Assorted characters of death and blight
Mixed ready to begin the morning right,
Like the ingredients of a witches’ broth —
A snow-drop spider, a flower like a froth,
And dead wings carried like a paper kite.What had that flower to do with being white,
The wayside blue and innocent heal-all?
What brought the kindred spider to that height,
Then steered the white moth thither in the night?
What but design of darkness to appall?–
If design govern in a thing so small.
Jennifer also sent a red eft (Notophthalmus viridescens). The “red eft” is a juvenile stage of the red-spotted newt, common in the eastern U.S. It has three life stages: the larval stage, which has gills, and which then transforms itself into the reddish “eft” stage, which is a terrestrial dispersal stage that can last several years. (Natural selection can favor wandering abilities if the chances of finding a better pond give you higher reproductive ability than staying in your own—and presumably crowded—pond.) The eft then transforms into the final, adult stage, in which it finds a pond and becomes an olive-green, aquatic adult that is ready to reproduce.
Don’t forget to send your wildlife pictures to me (do make sure they’re good ones!) as well as cat pictures, with information enclosed about the animals and a paragraph or so about the cat.
Great pics! I love the spider and bee, great info about the color change.
The plant is a Verbena, likely V. bonariensis or V. rigida. Looks most like the first.
lovely photos!
Fascinating newt – why the bright colour? Does it say ‘I am unpleasant to eat’ as it makes it stand out if you have full colour vision?
RE Frost, that poem ‘The road less traveled’ was subject of a BBC radio 4 documentary on New Year’s Eve – I think they referred to the recent book about Frost & Edward Thomas who were friends & the suggestion is that the ‘choice’ is related –
http://www.guardian.co.uk/books/2011/jul/29/robert-frost-edward-thomas-poetry
I reckon Frost knows that any choice is no choice at all really…
PS A recent article on vision in this spider (abstract)
http://www.ncbi.nlm.nih.gov/pubmed/22309704
The Road Not Taken I meant…
I just remembered there is this Scienceonline short video on how humans are changing salamanders –
http://scienceline.org/2012/05/video-no-exit-how-humans-are-changing-salamanders/
Yep, the plant is V. bonariensis.
As far as the vivid color of the eft, I believe it is part of a warning system to alert would-be predators that the eft exudes poison from its skin.
Thanks for posting my photos, Jerry.
Ugh – I didn’t know this would sign me in under a never-used wordpress handle. Annoying. I can’t seem to delete my account there and when I comment at a wordpress site I am forced to log in with my wordpress info. Anyone know a work-around?
Jennifer
Never looked up the eft efter all that –
http://www.ncbi.nlm.nih.gov/pubmed/22164212
“a well known secretor of tetrodotoxin (TTX)”; “We found that adult eastern newts were unpalatable to predatory fishes (Micropterus salmoides, Lepomis macrochirus) and a crayfish (Procambarus clarkii), but were readily consumed by bullfrogs (Lithobates catesbeianus)”.
Great pictures, Jennifer, and I of course especially like the crab spider. Any time you find a perfectly lifelike (albeit lightweight) ex-bee perched on a flower, the explanation is probably a satisfied crab spider.
Lovely photographs, Jennifer. I really like the action in the spider/bee shot, and the eft is a real eye-catcher.
I’m new to this blog and still catching up on the complex issues. I appreciated the Frost poem. My own interests are less in the fallacies of religion than in the potential for science’s depiction of evolution and selection as a source to understand human purpose, search for meaning, and morality. Frost sticks those issues right in our face. Please visit my new blog at http://www.livingasmeaning.com. Thanks.
Jerry-
I think you’ve misinterpreted, please read my take (written for a speech I gave a few years ago)…
Almost everyone is familiar with the poem entitled The Road Not Taken written by Robert Frost. It’s a testament to rugged American individualism. Most of us even have parts of it memorized…Let’s see if that’s true… Please help me recite the concluding line of the poem out loud… “And I- I took the road less traveled by and that has made all the difference”…. All the difference. It gives us license to be explore new possibilities. It’s inspirational and optimistic. It encourages us to embrace the unpopular, to lead instead of follow. Ultimately, the poem proposes the idea that our choices are critically important- that we must have the foresight to choose the right path.
Except, it doesn’t do this. And, most of the other things I just said about the poem won’t stand up upon a critical re-reading. The poem doesn’t belong on a hallmark card.
If we go right to that moment in the poem where the walker is remembering his past experience analyzing the two roads, we read the following:
“Though as for that the passing there had really worn them about the same.”
Prior to that, he’s looking back on that moment trying to work through the haze of memory to convince himself that one path was truly different from another, but then he realizes that he’s embellishing. The paths were the same, and he could not discern any difference looking down both for as far as the eye could see.
In this interpretation, choice and chance are equal partners in determining our paths. One path leads to another which leads to another. As we branch down these paths, we are by definition, excluded from pursuing others. We later make sense of the direction of our lives by placing exaggerated meaning upon past choices and ignoring the possible interplay of chance. We try to control our future by navigating to the right forks in the road and pursuing the “correct” paths. And, yet, chance will inevitably throw us a curveball.
…An anti-“free will” interpretation. We construct narratives to explain the direction of our lives ex post facto and these narratives place us as the central protagonist directing the action. An adaptation of some sort?
Are videos ok?
That reminds me – I’ve been meaning to take some modern dinosaur photos.