BIOL 125 Lecture Notes - Lecture 7: Colossal Squid, Parapodium, Veliger
20 Mar 2017
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Prostomium & peristomium = 2 part mouth, trunk, pygidium. Closed circulatory system, no hearts just pumping vessels. Covered in setae (hair-like projections)for gripping and gas exchange. Paired parapodia covered in setae to generate currents: clitellata clade, oligochaetes: Monoecious (male & female gonads), clitellum = collar, reproduction mucus: hirudinea: Leeches: coelom is small, series of connected chambers. Fluid feeders, no setae or parapodia: mollusca. Veliger - swimming larvae: bivalvia (clams, mussels, scallops, oysters, anatomy: 2 shells of calcium carbonate secreted by mantle, adductor muscles close shell. Movement: burrow with aid of foot, scallops clap shells. Reproduction: sexually, develop into trochophores, metamorphose into veliger larva: gastropoda (snails, slugs, nudibranchs) - stomach foot, anatomy: Feeding: radula - scrapes algae with teeth of chitin. Movement: waves of contractions down foot allow creeping. Reproduction: asexually- females produce eggs pathogenetically, sexual- internal fertilization: torsion - twists visceral mass around to prevent sediment buildup in gills.
