- nephridia removes ammonia from blood and expels it outside
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Species within the phylum Mollusca, including gastropods, cephalopods and bivalves, are all soft-bodied organisms in various forms, but are recognized by four basic parts of a specific body plan:
- the only mollusks completely void of a shell or pen are octopi and slugs - contain a true coelem surrounded by mesosderm tissue |
Class Gastropoda
Class Bivalvia
Class Cephelapoda
- includes octopi, squid, nautiluses...
- besides the nautilus and its relatives, cephalapods wield no shell - use a siphon to create a current around the interior of its mantle, allowing movement through propulsion and allowing its gills to be oxygen enriched - carnivores - have a closed circulatory system (no blood sinuses) that allows for faster distribution of oxygen and nutrients * octopi highly developed nervous system for an invertebrate - utilize long-term memory for planning of protection - wield eyeballs that are connected to two sets of receptors behind the retina that improve acuity and remove any kind of blind spots |