Study
Biology of Spiders
Foelix, Rainer F.
Oxford University Press, 2011
The standard reference on spider structure and function: body plan, respiration, circulation, silk production, sensory systems, venom, development and reproduction, synthesised across the order rather than from one family.
- Studied in
- Araneae
- Sample size
- monographic synthesis of spider biology
Spiders have two body sections rather than three, eight legs and no antennae. Respiration is by book lungs, tracheae or both depending on lineage. Legs are extended hydraulically by haemolymph pressure rather than by extensor muscles, which is why a dead spider curls. Silk is produced by abdominal glands and drawn from spinnerets; digestion is largely external. Growth requires periodic moulting, and only immature spiders can regenerate a lost leg.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
Spider anatomy is best understood as a set of solutions to being a small, soft-bodied predator with an external skeleton, several of which have no counterpart in insects.
How NatureHQ reads it
The hydraulic legs are the detail that reorganises everything else. A spider has flexor muscles and no extensors, so extending a leg means pumping fluid into it — which is why a spider must maintain internal pressure to walk, why it curls up when it dies or dries out, and why a spider that has just moulted is helpless until its new cuticle hardens enough to hold pressure.
- A synthesis across roughly 50,000 described species; respiratory and sensory anatomy vary considerably between lineages.
- Behavioural coverage is secondary to structure and function.
- Predates much of the molecular phylogeny that has since rearranged spider relationships.
What this study is used for on NatureHQ
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Published by: Academic book publishersPublished as an academic monograph.
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