Eukaryotes, multicellular, heterotrops, no cell wall, muscle and nerve cells

reproduce sexually, diploid dominant, mitosis

multiple germ layers

Hox genes - control expression of other genes

ectoderm - outer covering, some CNS

endoderm - inner, lines digestive tract, liver, lungs

mesoderm - between endoderm and ectoderm 

• each cell has its own fate determined early on
• spiral cleavage
• coelom cavity in mesoderm 
• mouth developes from blastophore 

• cells develop later on
• coelom buds off from archeateron
• anus develops first
• radial cleavage
• humans 

Multicellular, lack true tissue, filter feeders

• Comb Jellies
• propelled by 8 combs of cilia
• capture prey with sticky tentacles

Sea Anenomes, jelly fish

Central gastovascular cavity w/ single opening

sessile polyp or mobile medusa

contractile tissue and nerve net, no brain

alternate between medusa and polyp

polyp-asexual, medusa-sexual

jellyfish, sea nettles

marine, mostly medusa

• Box Jelly, Sea Wasp
• cube or box shaped
• complex eyes
• dangerously toxic

• Sea Anemone, Coral
• all marine, only polyp
• Coral-solitary but mostly colonial, may secrete CaCO₃

• flatworms, small marine animals, simple anatomy
• no gut, coelom-parachyma, nerves dense at front end
• Lyphotrachozoa, Platyhelminthes

• lophaphore-crown of tentacles with cilia for feeding
• trochopore-larva stage

• flatworms, more complex than Acoela
• have gastrovascular cavity, distinct ganglia, 2 ventral nerve cords
• flattened body, covered by cilia, no respiratory or circulatory system, simple excratory system to maintain osmotic balance

• free-living, marine and freshwater
• glide with cilia and mucus, undulating muscles
• fission and sexual reproduction

• internal parasites
• oral and ventral sucker
• complex multinucleate covering - heps fool immune system and resist digestion
• complex lifecycle - intermediate hosts, larvae
• hermaphroditic 

external parasites of fish

simple life cycle - 1 host species 

• tapeworms, specailized parasites of vertebrates
• head w/ sucker and hook 
• no mouth or digestive system
• body contains sex organs

• tiny aquatic organism
• complex bodies - alimentary canal - mouth and anus, jaws, pseudocoelum

• bryozoans
• colonial filter feeders, retractable lophophore
• most marine, some freshwater

• tiny clams on a stalk with lophophore inside
• 2 half shells, dorsally arranged
• marine, scarse today, abundant in Paleazoic 

• shell secreting mantel covers viceral mass
• foot for locomotion
• mantel cavity houses gills and anus
• Polyplacophora, Gastropoda, Bivalvia, Cephalopoda

chitons

oval body, 8 plate shell, foot for locomotion and suction

rasping rodula for feeding

• snails and slugs
• marine, freshwater, terrestrial
• head w/ eyes on tentacles
• embryo undergoes torsion during development, brings anus near oral cavity

• left and right shells, clams, musscles, oysters
• no head or radula
• mantel gavity - gills for gas exchange and feeding
• borrow, move slowly, or jet propulsion

• squid, octopus
• active predators with tentacles, eyes, break
• very intelligent invertebrates

segmented worms

marine, freshwater, damp soil

Oligocheta, Leeches, Polychaeta

• Earthworms
• bristles or chaetae
• tunnel through soil - consume dirt, excrete waste
• ganglia conected to ventral nerve cord
• hermaphrodites
• Leeches - 2 suckers for attachment

• Marine bristle worms
• each segment has parapodia w/ many cristae for locomotion and respiration

• ecdysis-shedding old covering, secreting new covering to increase size
• Nemotoda, Anthropoda

• round worms
• unsegmented round bodies, tough cuticle
• aquatic habitat-soil, other organisms
• no circulatory system
• feed on living and dead food
• separate sexes, internal fertilization

• segmented body, hard exoskeleton, jointed appendages, simple or compound eyes
• olfactory and taste receptors, antenna for touch and smell
• spiracles, branches tracheal system-respiration
• open circulatory system
• Chelceriforms, Myriapods, Hexapods Crustaceans

• claw-like feeding appendages, arachnids
• 2 body segments, cephalothorax and abdomen
• 6 pairs of walking appendages
• book lungs/gills

• antenna, 3 pairs of feeding appendages, lots of legs
• millipedes - 2 pairs of legs per segment, eat dead of live matter
• centipedes - 1 pair of legs per segment, predators

• insects, 3 pairs of legs, 3 body segments
• have wings, antenna, cuticle, compound eye, complex mouthparts
• Coleptera, Diplera, Hymnoptera, Lepidoptera

• beetles
• chewing mouthpars
• often herbivores

• flies, mosquitoes
• mouthparts for sucking or lapping

• bees, ants
• chewing or sucking
• many are parasites - lay eggs in host

butterflies and moths

sucking mouthparts - feed on nectar

• crabs, shrimp, krill
• 2 pairs of antenna, 3 mouthparts
• Decapoda, Isopoda, Copepods, Cirripedia

• crabs, shrimp, lobester
• 10 legs, cuticle hardned by CaCO₃ and chiten

isopods, pill bugs

small, terrestrial

1-2 mm in water, very numerous

important food source

barnacles

fixed to substrate by cemente glands

secrete shell, large dong

online marine

• sea stars, sea urchines
• radial cleavage, anus from blastophore, mostly bilaterally symmetrical
• water vascular system-water filled tubes connected to feet - locomotion, feeding, gas exchange

• sea stars
• moving predators-use adhesive feet to feed on bivalves
• can regenerate 

• bristle stars
• long flexible arms
• live in deep water
• suspension feeders, predators, scavengers 

sea urchin, sand dollar

spring w/ tube feet, 5 pairs of rows

sea lilies, feather stars

many arms for filter feeding

• sea cucumber
• elongated body, endoskeleton plates reduced
• 5 rows of tube feet

• notocord-flexible rod between digestive tract and nerve cord
• dorsal hollow nerve cord
• pharyngeal slits - can only be in embryos
• muscular, post anal tail
• Cephalochordata, Urocordata, Craniates, Myxini

• small suspension feeders-bury posterior end in sand
• swim with V shaped muscles - flex body
• Muscles segments develop from blocks of mesoderm called somites

• sea squirts
• sessile, marine, suspension feeders
• chordate charateristics seen in larva
• metamorphasis-tain and notocord absorbed, organs and nerves degrade 

• 2 clusters of Hox genes, and others
• pharyngeal cells evolve into gills and skull
• neural crest cell-near dorsal margins of closing neural tube of embryo
• forms cerain bone, neurons, smoothe muscle and hormone producing cells

• Hagfish
• predators of invertebrates or dead vertebrates
• cartilaginous skull, small brain, no jaw or vertebrae, keratin teeth
• lateral line system-detects vibrations in water and sensory tentacles

have vertebrae

evolved in Cambrian

more genetic duplication

• Lampreys
• parasites of fish - round sucking mouth, resping teeth on tongue
• larvae are suspension feeders
• have notocord with covering, cartilage plats along it

• have true jaws-hinged, grasp food
• gill slits for respiration
• addition duplication of Hox Genes
• enlarged forebrain-enhanced vision and smell
• mineralized skeleton-shoulder girdle
• 2 sets of paired appendages 
• Chondrichthyes 

• sharks and rays
• cartilaginous skeletons, predators or filter feeders, well developed jaws
• paired fins, dorsal fin, streamlined body, well developed sight and smell
• lateral line system, electrical field detectors

• bony fish
• have lungs or swim bladder
• Actinopterygii, Sarcopterygii

• ray finned fish
• ossified skeleton-CaPO4, thin skin, bony scales, mucus covering
• fins supported by long rags-bone
• 4-5 pairs of gills with protective operculum
• swim bladder-bouncy, simple lung

• lobe fins
• short linear bones, thick muscles
• actinistia-cealacanths, large predators, move limbs alternatively 
• Dipnoi-lung fishes, large rivers and swamps, have lungs, estivate in mud

• evolution of limbs, basically aquatic with gills, tail, feet with digits, pelvic girdle fused with vertebral column
• neck-allows head to move, no pharyngeal clefts, ears for air
• Amphibia

• dependent on water, moist habitats, skin for gas exchange
• develop as larvea in freshwater, terrestrial as adults
• Urodela, Anura, Apoda

• salamanders
• aquatic or terrestrial 

• frogs and toad
• specailized for hopping and swimming
• sticky tongue
• aposomatic coloration - warsn of poison

Caeilians

legless, short tentacles, bury in soil, ponds, streams

• adaptations for terrestrial life
• Amniotic Egg-no water, amnior surrounds embryo in fluid-protection, yolk sac-food for embryo, allartois- stores waste, Chorion-respiration
• Reptiles and Mammals

• turtles
• shell of bony shields
• mostly in water
• Cloaca-gas echange when underwater

• birds, closest relative to dinosaurs
• flight-light weight, flexible feathers, hollow bones, bipedal, large muscles
• gizzard-reduces weight from teeth, better balance
• good vision
• small size

• Rhynchocephalia, Squamata, Mamalia

• tuatara
• resemble lizards
• different skull
• third eye

• lizards and snakes
• most in tropical, warm, temperate climates
• all predators
• sample odor with tongue
• comeronasal organs-detect odor direction

evolved from synapsida, therapsids

hair, mammory glands, endothermy, 4 chambered heart, diaphragm, 1 lower jaw bone