Is Every Spider Web Unique?

Live Science

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?

Transcript

00:00Is every spider web unique?

00:05Spider webs are delicate, but also amazingly complex.

00:09Even if webs don't literally spell out the words terrific

00:12and radiant like in Charlotte's Web,

00:14each is still an intricate engineering marvel.

00:18But a web wouldn't be much use to a spider

00:20if it were just pretty to look at.

00:22Webs also trap insects and other prey

00:25long enough for a spider to immobilize them

00:27with venom or silk wrappings.

00:30Building these delicate traps is a process

00:32that follows patterns shared among spider species.

00:36But is there room for individual variation

00:39that makes one species web, or one individual spider's,

00:42recognizably different from another's?

00:45Are all webs identical, or is every spider web unique?

00:49There are about 48,000 known spider species worldwide.

00:54And while all spiders have silk-producing organs,

00:56known as spinnerets, and can produce several varieties of silk,

01:00not all spiders spin webs and lie in wait for their prey.

01:04The web is only affected by the kind of prey

01:07that spiders can expect,

01:10and by the kind of support spiders have to build their webs.

01:15Picture a spider web, and you might imagine a wheel-like structure

01:18with a spiral and spokes radiating outward from the center.

01:22These are known as orb webs, and they're made by fewer than 10% of known spider species.

01:28This type of web is ideal for catching flying insects

01:30because it covers a wide area for prey capture and is nearly invisible.

01:37Spiders that build orb webs typically begin with a few threads

01:40that center on a single point in a Y shape.

01:42The spider then establishes a frame around the Y, connecting a few more threads in the middle.

01:48Next come the spokes in the wheel, extending from the middle to the frame.

01:53Then the spider builds a spiral starting from the center.

01:57But this is a non-sticky placeholder.

01:59The real spiral, made of sticky silk, comes last.

02:04Once the spider removes the first non-sticky spiral, the web is ready to catch its first victim.

02:10To some extent, all orb webs resemble each other, but there are details that differ between species.

02:17For example, spiders in the Cyclosa genus, also known as trash-line orb weavers,

02:22install a decoration in the middle of their webs made of prey leftovers and bits of leaves,

02:27which the spider may use as camouflage.

02:30Some time ago, I observed a web in Switzerland,

02:35and at that time there was just one Cyclosa species known in Switzerland.

02:39And I knew, well, it's not the Cyclosa species I know.

02:42So it must be another one which had been documented to occur in Switzerland.

02:48Other orb weavers incorporate a zigzag structure into the web center, known as a stabilimentum.

02:54And while most orb weavers produce webs that are perpendicular to the ground,

02:59some, such as the silver orb spider, spin webs that are oriented horizontally.

03:04A web's physical location can also influence what it looks like.

03:08An orb web spider might build its web in flexible grass.

03:12Or spin its web in a tree.

03:14So if you think of a spider building a web in a forest with a strong wood,

03:19it has very good support, sturdy support.

03:23Spider building a web in grassland has to...

03:26Well, it's a bit more difficult because the grasses tend to be soft and they move around,

03:33so it has to give additional flexibility to the web.

03:37Even though the webs follow the same basic construction plan,

03:40they won't look exactly the same.

03:42Spiders make a fresh web every night or so,

03:45which means that a spider can produce about 100 to 200 webs over the course of its lifetime.

03:51Each web is likely just a little different from the other,

03:54though it might be tricky for a human to detect.

03:58And each web, if you look close enough, each web will be somewhat different.

04:05Intricate spider webs. Just one of life's little mysteries.

04:12I'll see you next time.

04:13I'll see you next time.

04:15I'll see you next time.

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