BIO 200 Lecture 10: Mollusks Ecdysozoans Echinoderms Hemichordates and Chordates (1)
13 Jul 2015
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Bio 200_evolutionary biology- lecture 10: mollusks (lophotrochozoans), ecdysozoans, Three part body plan which led to the group"s diversity. Each group may contain differences i. e. the visceral mass in the cephalopods is in the head cavity. Some do not have shells but still have mantles to cover their organs. A large group of teeth (hundreds or thousands) Allows them to eat or scrape off algae from rocks. Some use these teeth to drill through shells for food. Some are hermaphroditic and can alternate between the sexes. Typically live in shallow water for the food supply. They creep along substrates on their foot. Tentacles common (for eyes and chemo/mechanosensing to feel its surroundings) Even poisonous ones and capture the poison for their own protection, reason why they are so bright; warn others they are poisonous when eaten. Places on the body where food enters (incurrent) and wastes leave (excurrent) They attach to substrates or bury themselves deeply.
