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

Radial Symmetry in Cnidarians

Coral spawning

Stay Far Away!!!

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

Moon Jelly Life CycleLife cycle video

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

Candy Striped flatworm

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

Segmented worms, earthworms, leaches

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

Clam

Spawning

Nudibranchs

• Nudibranch feeding off of a Man-o-War and using the nemotocysts

• Chitons

Octopus, Squid and Cuttlefish

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

=Asian seafood market

Horseshoe Crab is not a true crab. Its not a horsehoe eitherHorseshoe babies

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

What’s a water vascular system?

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

sea stars, sea urchins, sea cucumbers, brittle stars

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

Chordates but not Vertebrates

Phylum Chordata

Class Agnatha

• Agnatha – jawless fishes (Hagfish, lamprey)

Video clip

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 Osteichthyes

• bony fish -Osteo = bone-ichthyes = fish

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!

Fringed Lizard, Alligator

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

MonotremesDuck Billed Platypus and Echidna

Egg laying mammals

Marsupials

• Live birth – worm-like• Develops in mother’s

pouch

Placental Mammals

• Placenta = spongy, blood-filled tissue of fetal and maternal tissues which delivers nutrients and oxygen to embryo and removes wastes