Kingdom Animalia
Eukaryotic
Heterotrophic
Multicellular
Motile at some point
Evolution of Animal Phyla
Porifera Echinodermata
Cnidaria Chordata
Platyhelminthes
Nematoda
Mollusca
Annelida
Arthropoda
Habitat
>9,000 species
Most are in shallow, marine water
Body Structure
Asymmetrical
Attached to firm surface
Two layers of cells with spicules
and spongin in between
Osculum – hole at the top
Obtaining Nutrients
Sessile filter feeders
Water in through pores
Cells lining inner chamber have
flagella to collect microorganisms
Water out through osculum
Reproduction
Asexual
Regeneration or budding
Sexual
Hermaphroditic
Internal OR external fertilization
Cloud of sperm released by one
and taken in by another
Larva are motile
Habitat
Very diverse - coral, sea
anemones, jellyfish, hydra
All are marine
Most harmless to humans
Body Structure
** Radial symmetry
** Specialized tissues
Polyp & medusa
Obtaining Nutrients
** Extracellular digestion
One opening into gut
Tentacles with nematocysts
draw food in
Digestion by enzymes in gut
Wastes back out
Reproduction
Variations among species
Asexual – budding from polyp
Sexual
Alternation of generations
Asexual polyp & sexual medusa
(Flatworms)
Habitat
20,000 species
Free-living aquatic OR parasitic
Variety of sizes but all are FLAT
Body Structure
** Bilateral symmetry
** Cephalization – a definite head end
** Internal organs
Solid body – no cavity
Obtaining Nutrients
Highly-branched two-way gut with
one opening
Pharynx of Planarians can move
outside of body
Parasites have hooks & suckers
Reproduction
Asexual – regeneration
Sexual
Hermaphrodites
Exchange of sperm
Internal fertilization
(Roundworms)
Habitat
Extremely abundant – found
almost everywhere
Body Structure
** One-way gut with separate
mouth & anus
Obtaining Nutrients
Parasitic or free-living
Reproduction
Separate sexes
(Segmented Worms)
Habitat
15,000 species
Earthworm, leech, bristleworm
Body Structure
** Segmentation
Body cavity divided into segments
Evolutionary flexibility
Obtaining Nutrients
Earthworm
Soil & decaying matter in
Castings of inorganic matter out
Tunnels aerate soil
Leech
Anesthetic & anti-clotting
Reproduction
Hermaphrodites exchange sperm
Capsule formed for fertilization
Deposited in soil to develop