Biology 3484A/B Lecture Notes - Lecture 12: Arachnid, Solifugae, Chelicerae
28 Jul 2017
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Document Summary
Large palps like scorpions; but missing large tail. 6,000 described species two body regions fused. Antenniform legs specialized for chemo- and mechanoreception. 4 pairs of legs; palps and chelicerae present: 2nd pair legs very long, used like antennae. Eat (cid:862)(cid:271)ad(cid:863) (cid:271)ugs: male parental care in opiliones (male protects eggs, only arachnid w/ male and female parental care. Some larger: ticks: some mites are phoretic, phoresy: one animal attaches to another for transportation. Chelicerae (fangs) w/ venom in nearly all araneae. 40,000 described species spiders are natural pest control (salticid eating) Synapomorphies (see image: silk-producing glands at end of abdomen, spinnerets venom of only a few species dangerous to humans. Behavior: non-aggressive (if aggressive; spiders make themselves seem larger) silk: mostly protein; strong, elastic, sticky: primarily used for capturing prey, constantly producing silk. Basal spiders: tarantulas and relatives fangs go up and down only largest spiders, long-lived: ambush predators: puts out silk then retreats, most harmless to humans.
