Remember to send me your GOOD wildlife photos. Today is Spider Saturday, and we have photographs by Jacques Hausser from Switzerland, along with his notes:
Agelena labyrinthica, Agelenidae. A male on a part of his web extending across a leaf. Male spiders collect and store their sperm in the end part of their palps, used like syringes to transfer it into females. Note the long spinnerets.
Argiope bruennichi, Araneidae. The wasp spider. The whitish ribbon of silk crossing the center of the web is called the stabilamentum. Its function is unknown – but it allows you to identify the web easily!
Tetragnatha extensa, Tetragnathidae, trying to go unnoticed, but still controlling her web with two legs.
I’m adding a note from Wikipedia here, along with their photo, just to show the camouflage behavior:
When alarmed, it will sit along a plant stem, a blade of grass or the central vein of a leaf, with its four front legs pointing forwards, and its four back legs pointing backwards for camouflage.T. extensa is able to walk on the surface of water, where it can move faster than on land.
Enoplognatha ovata, Theridiidae. This one belongs to the pale “lineata” morph; I never spotted the colored form “redimita”, AKA “Candy Stripe Spider” in my surroundings.
Salticus scenicus, Slaticidae [JAC: often called the “zebra spider” for obvious reasons]; a jumping spider running on a plastic bag (sorry for this poor “landscape”, but here it was).
Phalangium opilio. A harvestman or “Daddy-long-legs” (order Opiliones). It is not a spider (they don’t build webs or produce silk), but still belongs to the class of Arachnids. This one is a male, recognisable by his very long palps.
A terrific way to spend my morning, sipping coffee and looking at your spider pix. I very much enjoyed that.
My hobby in macrophotography began in earnest this last summer, and early on I was trying to get pictures of Tetragnatha but they never turned out. This was likely due to inexperience at that point. We will see how I do next summer.
Would not think of Switzerland as having a high population of spiders – not sure. Here in the Midwest it seems we have a high population but of course, seasonal.
Given how tiny zebra hopping spiders are, you captured this one, with it’s little eyes, very well.
I had the compulsion to touch the poofy abdomens of the spiders in these pictures!
Harvestmen aren’t arachnids, PCCE! They are in their own class, Opiliones. They are, however, part of the phylum Chelicerata. – MC
Depends of the point of view… According to Fauna Europaea, the (almost) complete and (more or less) official taxonomic index for non-marine European animals:
Harvestmen:
Phylum Arthropoda
Subphylum Chelicerata
Class Arachnida
Order Opiliones
and the true spiders:
Phylum Arthropoda
Subphylum Chelicerata
Class Arachnida
Order Araneae
I agree FE taxonomy is not universally accepted (which one is ?), but it is very practical to organise my photographies.
From Fauna Europaea “Taxonomic scope”:
It is important to underline that the Fauna Europaea hierarchy does not purport to be the phylogenetically “most correct” one. There is considerable disagreement between taxonomists about what is the best hierarchy, and anything like a consensus is not within view. For purely managerial purposes, however, Fauna Europaea needed to settle on one common hierarchy.
I thought Opiliones was an order. When did that change?
OOPS. My very very bad. Brain melt. Yes opiliones are an order in the class arachnida. MC
Great spider photos Jacques.
I love Tetragnatha extensa’s sneaky behavior. A very apt binomial as well.
I never see Harvestmen in the northwest (western Washington). Maybe they don’t thrive in dampness.
Actually most if not all harvestmen require mesic environments. I’m sure there must be plenty in western Washington–I remember them all over the place in western Oregon when I was growing up.
I suggest you embark on a new wildlife quest. 🙂
Yes, I see those guys everywhere. I even saw one trying to blend in on a building wall at work. I saw another in my backyard who had lost several of his legs & was trying to move through blades of grass using the leg parts that evolved into mouth parts to propel him forwards. Poor thing. There are no evil children around my yard so he probably got into a appendage losing fight.
I have read of studies concerning the purpose of the “stabilamentum”: it appears that webs with these visible bands of silk average far less damage from birds flying through them than unadorned webs do.
Interesting! I didn’t know that. Do you have a reference ?
I can’t remember where I saw the text about actual, “hands-on” studies counting and comparing damage in adorned and unadorned webs; all I found in searching the web just lists that as one of several “possible” reasons for spiders expending energy creating them. I’m thinking it was in a book.
Jacques, thank you so much for that engrossing set of arachnids!
Wow, there are some very cool spiders here, thanks for sharing.