BIO 101 Lecture Notes - Lecture 23: Trachea, Priapulida, Inside Out Music
8 Apr 2016
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Protostome animals-differences in embryonic development between protostomes and. Several lineages making the water-to-land transition-new food sources. The evolution of metamorphosis in both marine and terrestrial forms. ***a lot more protostomes than there are deterostomes-chordates or echinoderms. Grow by molting-have hard outer skeleton and shed off exoskeleton-become vulnerable until new skeleton forms. Intermolt-after they lost their outer skeleton and before the next one grows-very vulnerable. Exoskeleton covers body, head, thorax, abdomen, jointed limbs, segmented body. Crustaceans exoskeleton has an addition of calcium carbonate strength. Mantle-secretes shell, visceral mass-internal organs and external gill-the gill is the for exchange of gases, muscular foot , mantle cavity. Proboscis-food particles are trapped in the mucus in the gutter of the proboscis and then moved to the mouth by cilia. Toothed, cuticle-lined throat-everts (turns inside-out) and grabs the prey and then retracts. Evertible proboscis-the barb-tipped proboscis everts and spears or entangles the prey, and then retracts it toward the mouth.
