Arthropods

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Arthropods!
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C Arachnida
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O Araneae

• Spiders
• Note Chelicera,
• Pedipalps, Spinnerets

Prosoma
Opisthosoma
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O Acari

• Ticks and Mites
• Often Chelicera are modified or less apparent.
• Prosoma and Opisthosoma not distinctive

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O Amblypygi

• Tail-less whip scorpions
• Very raptorial
• pedipalps

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O Opiliones

• Harvestmen, Daddy Long Legs
• NOT spiders
• Prosoma/Opis
• not clearly divided
• No fangs,
• no spinnerets
• Harmless

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O Scorpiones

• Pedipalps are modified into large pincers
• Chelicera have three joints
• Long stinging tail held curled above the body.

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O Pseudoscorpiones

• Pseudo-scorpions
• Very small-
• 2-4mm
• Lack post-
• abdomen
• and stinger
• Dont see
• them very often

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O Solifugae

• Sun Scorpions, Wind Scorpions
• Not venomous
• Very powerful biting pedipalps
• Front legs modified into sensory organs
• Waist not very constricted between segments

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Arthropods!
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C Xiphosura

• Horseshoe crabs
• Only chelicerate with a compound eye
• Long tail called telson
• Hard shell divided into two segments (pro and
  opisthosoma)
• Have chelicera like arachnids

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C Diplopoda

• Millipedes
• Many Segments
• Two legs per segment
• Not harmful

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C Chilopoda

• Centipedes
• Many segments
• One (pair) legs per segment
• First pair of legs modified as jaws, hold venom
  glands.

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C Crustacea

• Crustaceans Shrimp, lobsters, crabs, barnacles,
  copepods, etc
• Diverse body shapes, ecologies
• All crustaceans have two pairs of antennae
• Most have more than 6 legs
• Many are marine, and important sources of food