phylum chart 2 nematoda phylum annelida phylum mollusca circulatory distribution through coelomic...
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Phylum Nematoda Phylum Annelida Phylum Mollusca Defining Traits -roundworms
-complete digestive system
-metamerism (segmented) -setae -well-developed organ-systems
-soft bodies -one or more shells -3 parts: head, foot, visceral mass -mantle -radula-rasping tongue
Symmetry bilateral bilateral bilateral Coelom pseudocoelomate coelomate coelomate Level of Organization
organ-system organ-system organ-system
Nervous -ganglia -nerve cords -sense organs
-ganglia -ventral nerve cord with segmental ganglia -sense organs
-ganglia -nerve cord -sense organs
Skeletal hydrostatic skeleton
hydrostatic skeleton -hydrostatic skeleton -shell
Muscular longitudinal layer of muscles
circular layer and longitudinal layer
-mantle -muscle contractions in foot
Digestive complete: mouth intestine anus
complete: mouth pharynx esophagus crop gizzard intestine anus
complete: mouth esophagus stomach intestines anus digestive gland
Respiratory diffusion
diffusion through cuticle gills
gills or lungs
Phylum Nematoda Phylum Annelida Phylum Mollusca Circulatory distribution through
coelomic fluid
closed system with 5 pairs of aortic arches
open system with heart, blood vessels, and sinuses
Excretory excretory tubules and pores
nephridia nephridia or simple kidney
Reproduction -sexual reproduction -distinct sexes -external or internal fertilization
-hermaphrodites with sexual reproduction -external fertilization
-sexual reproduction -distinct sexes or hermaphrodites -external fertilization
Classes
1.Oligochaeta-earthworms 2.Polychaeta-tube worms, marine worms 3.Hirudinea-leeches
1.Gastropoda-snails, slugs, nudibranchs 2.Bivalvia-clams, oysters 3.Cephalopoda-octopus, squid, nautilus, cuttlefish
Miscellaneous -non-living cuticle for outer covering -most are free-living, some are parasites -important decomposers
-burrowing may have saved the planet from global ice age
-siphons: incurrent and excurrent