Is Every Spider Web Unique?
Building these strong yet ephemeral traps is a process that follows patterns shared among spider species. But is there room for individual variation that makes one species' web — or one individual spider's — recognizably different from another's? Are all webs identical, or is every spiderweb unique? And what factors cause spiders to vary their silky webs?
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00:00 Is every spider web unique?
00:05 Spider webs are delicate, but also amazingly complex.
00:09 Even if webs don't literally spell out the words "terrific" and "radiant" like in
00:13 Charlotte's web, each is still an intricate engineering marvel.
00:18 But a web wouldn't be much use to a spider if it were just pretty to look at.
00:22 Webs also trap insects and other prey long enough for a spider to immobilize them with
00:27 venom or silk wrappings.
00:30 Building these delicate traps is a process that follows patterns shared among spider
00:34 species.
00:35 But is there room for individual variation that makes one species' web, or one individual's
00:41 spiders, recognizably different from another's?
00:45 Are all webs identical, or is every spider web unique?
00:49 There are about 48,000 known spider species worldwide, and while all spiders have silk-producing
00:55 organs known as spinnerets and can produce several varieties of silk, not all spiders
01:00 spin webs and lie in wait for their prey.
01:04 The web is only affected by the kind of prey spiders can expect, and by the kind of support
01:11 spiders have to build their webs.
01:15 Picture a spider web, and you might imagine a wheel-like structure with a spiral and spokes
01:19 radiating outward from the center.
01:22 These are known as orb webs, and they're made by fewer than 10% of known spider species.
01:28 This type of web is ideal for catching flying insects because it covers a wide area for
01:32 prey capture and is nearly invisible.
01:37 Spiders that build orb webs typically begin with a few threads that center on a single
01:41 point, in a Y shape.
01:43 The spider then establishes a frame around the Y, connecting a few more threads in the
01:47 middle.
01:48 Next, come the spokes in the wheel, extending from the middle to the frame.
01:53 Then the spider builds a spiral, starting from the center.
01:56 But this is a non-sticky placeholder.
01:59 The real spiral, made of sticky silk, comes last.
02:04 Once the spider removes the first non-sticky spiral, the web is ready to catch its first
02:08 victim.
02:10 To some extent, all orb webs resemble each other, but there are details that differ between
02:15 species.
02:17 For example, spiders in the Cyclosa genus, also known as trashline orb weavers, install
02:22 a decoration in the middle of their webs made of prey leftovers and bits of leaves, which
02:27 the spider may use as camouflage.
02:29 Some time ago, I observed a web in Switzerland, and at that time there was just one Cyclosa
02:36 species known in Switzerland.
02:39 And I knew, well, it's not the Cyclosa species I know.
02:43 So it must be another one which hadn't been documented to occur in Switzerland.
02:48 Other orb weavers incorporate a zigzag structure into the web center, known as a stabilimentum.
02:55 And while most orb weavers produce webs that are perpendicular to the ground, some, such
02:59 as the silver orb spider, spin webs that are oriented horizontally.
03:04 A web's physical location can also influence what it looks like.
03:08 An orb web spider might build its web in flexible grass, or spin its web in a tree.
03:14 So if you think of a spider building a web in the forest with strong wood, it has very
03:21 good support, sturdy support.
03:24 Spider building a web in grassland has to, well, it's a bit more difficult because the
03:31 grasses tend to be soft and they move around, so it has to give additional flexibility to
03:36 the web.
03:38 Even though the webs follow the same basic construction plan, they won't look exactly
03:42 the same.
03:44 Spiders make a fresh web every night or so, which means that a spider can produce about
03:48 100 to 200 webs over the course of its lifetime.
03:52 Each web is likely just a little different from the other, though it might be tricky
03:57 for a human to detect.
03:58 And each web, if you look close enough, each web will be somewhat different.
04:07 Intricate spider webs, just one of life's little mysteries.
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