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Mollusks and Annelids

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Phylum Molluska:
   -snails, slugs
   -oysters, clams, scallops, muscles
   -squid, octupi
   -eucoelomate body cavity
   -muscular foot, for locomotion
   -visceral mass, organs
   -mantle, secreets the shell
 Snails and slugs mainly eat plants. They have bivavles which makes them filter feeders and a rasping tongue used to scrap up food. They are hermaphoditic, internal fertilization.
 Squid and octupi are hunters (predacios). They reproduce using external fertilization. Octupi are really smart.
   -all have a brain of two nerve cords, except octuopi
   -gills are outfilliings of ectoderm
   -collect waste from hemolynth and excrete it from the body
  Major classes
  • Class Cephaloda, octupi and squids, they only have a head and feet. They have suckers on their tentacles and advanced brains.
  • Class Bilivia, oysters and clams, use their muscular foot to bury in the sand.
  • Class Gastropoda, slugs and snails, have one shell 

 Phylum Annelid: (tiny rings)

   -segmented worms, leeches, bristle worms
   -body plan is a like a tube within a tube


   -internal segmentation, each section is is metamere
   -muscles run lengthwise and are circular

 Their nervous system has a brain which communicates with ganglia in each segment. They have sensory organs.
 Their circulatory system is closed which helps them move faster. They have dorsel and ventral vessels and a "series" of hearts. They breath through their skin.
   -one way
   -pharynx, soaks up food and passes it to the crops
   -gizzard, grind the food
   -intestine, aborbs the food
   -Earthworms, Olagocheta
   -Bristleworms, Polycheta
   -Leeches, Hybroinia


echinoderms and invertabrates

Subphylum Vertabrata

reptiles and birds