BIO 200 Lecture Notes - Lecture 19: Onychophora, Jet Propulsion, Chiton
27 Jun 2015
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Document Summary
Lophotrochozoans (grow by layering: three body segments, visceral mass: centrally clustered organs, foot: locomotion, attachment, foot capture, mantle: thickened skin around dorsal area. Polyplacophora (chitins): eight dorsal plates on bodies, herbivorous (scrape algae off surfaces, broad, flat foot used to creep across floor, usually external fertilization. Live in shallow water: may be internal, may have internal embryos. Ligament (hinge) holds shell closed: must actively open shell. Live in freshwater or saltwater: filter feeding (substrates, syphons (tubes, incurrent: draws nutrients in, excurrent: flushes water and gametes out. Larvae are free-swimming: adults are sedentary, external fertilization, examples: clams, mussels, oysters, and scallops. Cephalopoda/cephalopods: marine predators, arms and tentacles to seize and hold prey, can change colors (camouflage and communication, highly intelligent, examples: squid and cuttlefish. Jet propulsion: store water and then force it out to move: eight arms, two tentacles, example: nautilus, thousands of tentacles, example: octopus, eight arms, eyes have no blind spots, unique brains and nervous systems.
