BIOL 1604 Lecture Notes - Lecture 13: Sensillum, Pollination, Ecdysis
Document Summary
Nervous system similar to that of annelids with dorsal brain and double nerve chain of ventral ganglia. Respiration by body surface, gills, trachea, or book lungs. Tagmatization: tagmata (singular tagma): functional body regions. Sclerotization: proteins, lipids, chitin, and often calcium carbonate. Complex muscular system: striated and smooth muscles, exoskeleton for attachment. Respiratory systems: air piped directly to cells. Metamorphosis: tropic breadth through developmental stages. Characteristics: prosoma (cephalothorax) and opithosoma (abdomen, no antennae, first pair of appendages: chelicerae, second pair of appendages: pedipalps, 4 pairs of walking legs, most with hair-like sensorial setae. Class merostomata (horseshoe crabs and giant water scorpion) Order araneae (true spiders: chelicerae function as fangs with venom glands, pedicel, silk producing glands and spinnerets, terrestrial, freshwater, and intertidal habitats. Male uses special cavities of his pedipalps. Black widow: 5 species in the us, hourglass on ventral surface of abdomen, webs in dark, sheltered sites, neurotoxic venom, males harmless. Brown recluse: nocturnal, only small retreat webs, necrotic venom.
