Lesson 9: Kingdom Animalia Invertebrates Flashcards
Phylum Porifera
Includes sea sponges
Adults are sessile
Obtain food through filter feeding
Obtain oxygen through diffusion, as
they are only a few cells thick
Remove wastes through diffusion
No need for internal transport
system
They have no nervous system or
sensory cells, however, pressure
will cause a contractile response.
Phylum Cnidaria
Soft bodied animals with
stinging tentacles arranged in
circles around their mouths
Have a sessile stage (polyp)
and a motile stage (medusa)
Aquatic organisms
Radial symmetry
Have specialized cells called
nematocysts that release a
poison dart to stun their
prey.
Digest food in a gastrovascular cavity
Obtain oxygen through diffusion
Expel waste through diffusion (they are
only a few cells thick)
Do not need a transport system
Acoelomate
Have no centralized “brain” but do have a
nerve net and specialized cells that detect
chemicals from food and the touch of
foreign objects
Fertilization is external
Phylum Platyhelminthes
Flatworms
Flat, ribbon-like body
Live in water, soil or other inside other
organisms as parasites
Unsegmented
Bilateral symmetry
Acoelomate
Body has a distinct head and simple
nervous system
Digestion is extracellular
Fertilization is internal, some species are
hermaphrodites.
Class Turbellaria
Ex. Planarians
Class Trematoda
Ex. Fluke worms
Class Cestoda
Ex. Tapeworms
Phylum Nematoda
Roundworms
Live in water, soil and inside other organisms
as parasites
Bilateral symmetry
Coelomate
Distinct head and body organs
Digestion is extracellular
Fertilization is internal, some species are
hermaphrodites
Ex. Hookworm, pinworm, heartworm
Phylum Annelida
Segmented worms
Live in water or underground
Body displays bilateral symmetry and
three germ layers
Have a coelom and distinct organ
systems (nervous and digestive
systems)
Digestion is extracellular
Reproduction is sexual
Fertilization is internal (some species
are hermaphrodites)
Class Oligochaeta
Ex. Earthworms
Class Polychaeta
Ex. Bristle worms
Class Hyrudinea
Ex. Leeches
Phylum Mollusca
Soft bodies
Hard Shells
Live on land or in water
Bilateral symmetry
Coelomate
Digestion is extracellular
Reproduction is sexual
have a circulatory system and a complex
nervous system.
Important food source for humans
Class Gastropoda
May have one shell
Stomach footed – move on
stomach
Ex. snails and slugs
Class Bivalvia
Two shells hinged together
Ex. clams, oysters, scallops and
mussels
Class Cephalopoda
Have an internal mantel
Ex. squids and octopuses
Phylum Arthropoda
Aquatic and terrestrial – largest group of
organisms on Earth
Have an exoskeleton and well- developed
nervous system.
Bilateral Symmetry
Coelomate
Reproduce sexually
Digestion is extracellular
Fertilization is internal
3 subphyla
Subphylum Chilicerata
3 classes
Class Arachnida – spiders,
scorpions, ticks and mites
Class Merostomata –
horseshoe crabs
Class Pycnogonida – sea
spiders
Subphylum Crustacea
5 classes
Include lobsters, crabs, shrimp,
barnacles and isopods
2 antennae
Aquatic species have gills
Subphylum Hexapoda
4 classes
Class Insecta
Antennae on head
3 pairs of legs
3 body segmnents– head,
thorax, abdomen
Grasshoppers, ants, butterflies,
bees
Subphylum Myriapoda
4 classes
Class Diplopoda
Millipedes
Segmented
2 pairs of legs per segment
Primarily herbivores and
decomposers
Subphylum Myriapoda
Class Chilopoda
Centipedes
Usually terrestrial carnivores
1 pair of antennae
Phylum Echinodermata
Aquatic
Radial symmetry
Coelomate
Distinct organ system
Digestion is extracellular
Fertilization is external
Class Asteroidea
Ex. Sea stars
Class Holotheroidea
Ex. Sea cucumber
Class Echinoidea
Ex. Sea urchins and sand
dollars
