Why do spiders need 8 legs?

Here’s one answer: Our ancestors – and the spiders’ ancestors – with different numbers of legs didn’t live and reproduce. 8-legged spiders and 2-legged people survived and reproduced. Spiders have 8 legs, because their ancestors had 8 legs. Spiders and horseshoe crabs evolved from the same ancestors!

Are spiders the only animals with 8 legs?

No, all arachnids have 8 legs, spiders are probably the largest amount of 8-legged creatures, but there’s also scorpions , ticks , mites , harvestmen , and solifuges (camel spiders, wind scorpions, sun spiders) in that category.

Can a spider live without 4 legs?

Spiders can live without one or two, and even three of their legs. It can make life more difficult for them, but they’ll be alright. If the spider has at least one molt left in it’s life (molt meaning they shed their exoskeleton because they grew out of it and have a new one underneath) then it can regrow it’s leg.

Can spiders have less than 8 legs?

All spiders START OUT with 8 legs. But it’s not unusual to see a spider with 7 legs, or even fewer. If a spider’s leg is trapped, it can self-amputate at a specific joint, dropping the leg to free itself.

Why do so many animals have 8 legs?

Having eight legs allows well distributed support and might allow more simplified motor control. Having more than eight legs would tend to lengthen the body (for animals with bilateral symmetry) which might tend to bias movement direction (as well as possibly being wasteful of resources).

Are there any mammals with 8 legs?

Spiders, scorpions, mites, ticks, whip scorpions, and pseudoscorpions are all arachnids that can be found in Everglades National Park. Unlike insects, arachnids have eight legs and no antennae, and their body is divided into two main segments: a cephalothorax and abdomen.

Are there spiders with more than 8 legs?

Myth: You can always tell a spider because it has eight legs. Fact: Not exactly. Scorpions, harvestmen, ticks, and in fact all arachnids—not just spiders—have four pairs of legs (see illustrations).

Is there a 4 legged spider?

spider with 4 legs – Philodromus – BugGuide.Net.

Do spiders have 6 legs or 8 legs?

As mentioned earlier, spiders are arachnids and all arachnids have eight legs. This means that they are structurally different from insects, which have six legs. Usually, a spider will have two pairs of legs on the cephalothorax and two others on the abdomen. But this may differ from species to species.

Why do spiders and octopus have 8 legs?

In general the possession of 8 legs allows these animals to move with greater facility in directions other than forwards. Both spiders and octopi can often be seen moving backwards or sideways rather than forwards.

How many legs does a spider have?

Spiders and harvesters can get around on 7 legs, although the harvester (or Daddy-long legs) depends on 2 of its 8 legs to use as ‘feelers’ or antennae. Sight is not developed, and despite spiders having several eyes (also PAIRED), their vision isn’t very good.

How many legs do arachnids and insects have?

Arachnids all have 8 legs {spiders, mites, harvesters}, Insects have 6 legs (3 pair). The last word is your clue.

Do spiders have flexors and extensors?

Flexors and extensors give us smoth motion in the movement in our muscles. Spiders don’t have this same movement. A spider’s legs has 7 joints (Photo: Eky.edu). Humans only have one major joint per limb (knee, elbow, etc), but spiders have seven joints for each leg.

How does a spider’s cephalothorax work?

The cephalothorax acts something like a very finely-tuned, fluid-filled bellows that pushes hemolymph around the body of the spider in a fraction of a second. The flexor muscles in the spider’s legs naturally want to contract, but the hydraulic pressure allows the legs to move outward and resist this contraction.