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Phylum Porifera
• no symmetry, tissues or organs
• sessile (=attached)• filter feeders – have
incurrent pores to allow food to enter
• reproduce by budding• hermaphroditic
Phylum Cnidaria• jellyfish, hydras, sea
anemones• tissues• 2 layers – ectoderm and
endoderm• specialized stinging cells =
nematocysts –barbs tipped w/ toxin
• digestive sac with mouth (only one opening)
• radial symmetry
Who has the Worst Sting?
• Box Jelly or Sea Wasp: Causes respiratory failure. There are many (about 70) reported deaths in Australia per year. Wearing pantyhose has been shown to prevent the jelly from stinging
TERMS used to describe cephalized (with a head end) organisms:
• Anterior• Posterior• Dorsal• Ventral
Phylum Platyhelminthes• primitive organs• acoelomates – tissue fills
region between gut and body wall
• bilateral symmetry• cephalized• 3 layers – endo- , ecto,
and meso – derm• No circulatory system-• digestive cavity has one
opening
Phylum Nematoda
• pseudocoelomates – false coelum
• bilateral symmetry• separate sexes• mouth and anus =simplest
animal with complete digestive system
• nerve cord and nerve rings
Phylum Annelida
• Name means ‘little rings’• =Segmented worms• true coelum – mesoderm + body cavity
lined w/ peritoneum and housing organs• 3 tissue layers – well defined systems• Cephalization – having forward end that
encounters food/stimuli first
Phylum Mollusca
• 2nd largest –60,000 species
• Most abundant marine species
• Classes include chitons, gastropods, bivalves and cephalopods
• soft body
Mollusc Body Plan• 3 parts:
• Head/foot – with sensory and motor organs• Visceral Mass – organs for digestion, excretion,
reproduction• Mantle – hangs over visceral mass and secretes
shell
• bilateral symmetry• Coelomate• Large group during Cambrian explosion
Phylum Arthropoda
• largest phylum ~ 1,000,000 species
• hardened jointed exoskeletons of chitin
• specialized appendages
• segmented – head, thorax and abdomen
• organ systems
3 Classes/Subphyla of ArthropodsOver 90% of all Animals
3 classes:• Insects: - 3 prs of legs
tracheal breathing tubes• Arachnids: - 4 prs of legs• Crustaceans –
segmented bodies, gills, molting replaces exoskeleton: Includes
lobsters, crayfish and shrimp
Phylum Echinodermata
• marine coelomates• radial symmetry and
bilateral symmetry mixed• water vascular system =
network of hydraulic canals branching into tube feet.
• Tube feet for locomotion, feeding and gas exchange
• regeneration
tubefeet
I thought evolved organisms were bilaterally symmetrical??
• Larval forms of echinoderms are bilaterally symmetrical
• Bipinnaria are planktonic
Water Vascular System• Hydraulic system that
functions in locomotion, feeding, and respiration
• Water enters madreporite into ring canal
• Each ring canal leads into each ray
• Tube feet (thousands) have a sac like structure (ampullae) that are squeezed and create a suction
Phylum Chordata* Bilateral Symmetry* Most are vertebrates ( 47,000 species)
Compared to 2,100 invertebrate chordates* Share embryonic similarities:
*Notochord – dorsal rod supports body becomes backbone in most.*Nerve cord – runs parallel to notochord – becomes spinal cord and brain*Slits in pharynx ( Pharyngeal slits)*Embryos have tails that extends past anus
Phylum Chordata
Class Chondrichthyes
• Cartilaginous fish• Includes sharks and
skates• No Bone – have
cartilage for skeleton• Chondro = cartilage• Ichthyes = fish
Octopus vs Shark
Phylum Chordata
Class Amphibia
• Made transition from water to land
• Require water to lay eggs, and to keep skin moist for gas exchange
• Frogs, toads, salamanders
Phylum Chordata
Class Reptilia
• Includes turtles, snakes, lizards, crocs, alligators
• Have fully developed lungss and systems
• Have AMNIOTE EGG – shelled so it can be laid on land!
Phylum Chordata
Class Aves
• Birds• hollow bones • Feathers for flight,
insulation or both• Resemble reptiles in
many ways
Phylum Chordata
Class Mammalia
• Hair• Mammary glands
(milk-producing) feed young
• divided into 3 groupsMonotremesMarsupials
Placentals