Mollusca
common names (examples): clams, snails, and squids
habitat: many marine, some in fresh water and others on land
strucures: foot, radula, gut, mantle, shell, nephridia, trochophores
charactoristics of each class: snails-shell for protection slugs-bad taste clams, mussels, oysters, and scallops have to shells connected by a flexivle hinge squids and octopuses emit dark-colored ink
feeding and digestion: can be carnivores, herbivores, filter feeders, detritur feeders, scavengers, or parasites
circulatory system: open circulatory- clams and oysters closed circulatory system -squids and octopuses
nervous system: different kinds, clams have few ganglia and nerve cords
life cycles: separate males and females fertilized eggs develops into a type of freeswimming lava called trochophore







Annelida
common name (examples): segmented worms
habitat: ocean, fresh water, and land
body plan: indivdual segments, filled with fluids and are tightly sealed by body walls called septa. longitudinal muscles that run up and down the annelids. ringshaped or circular muscles
digestive system: pharynx is the muscular widening in the digestive tract that helps earth worms swallow soil and force it to the gut
nervous system: small brain sits atop the gut and controls the nervous system
circulatory system: ring vessels pump blood, functioning as miniature hearts
reproductive system: clitellum secreter a ring of mucus into which eggs and sperms are released.
structure and organs: setae, ring veseels, crop, gizzard, pharynx, nephridia, clitellum, aortic arches