Mollusks and Annelids


				Taxonomy *Mollusks and Annelids*



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Snails

Octopus

Bristleworm

Phylum Molluska:

-snails, slugs

-oysters, clams, scallops, muscles

-squid, octupi

-bilateral

-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)

-bilateral
   -segmented worms, leeches, bristle worms
   -body plan is a like a tube within a tube
   -eucoelomate
   -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.
Digestion
   -one way
   -mouth
   -pharynx, soaks up food and passes it to the crops
   -gizzard, grind the food
   -intestine, aborbs the food
Classes
   -Earthworms, Olagocheta
   -Bristleworms, Polycheta
   -Leeches, Hybroinia

anthropoda

echinoderms and invertabrates

Subphylum Vertabrata

reptiles and birds

mammals