


Most diverse in appearance
Heterotrophs, multicellular, eukaryotes, no
cell walls
Cells -> tissues- perform a specific function
 Ex: epithelial, muscle, nerve, etc.

Over 95% of all animals = invertebrates




Things look the way they do in order to
perform a certain function
Study of these functions: physiology
Homeostasis
Feedback inhibition: product (result) of a
process stops/limits the process
▪ (ex: dog panting)







1. feeding- ingest nutrients
2. respiration- O2 in / CO2 out
3. circulation- nutrients/gases/waste
4. excretion- get rid of wastes
5. response- receive/process info + react
6. movement- motility + feeding
7. reproduction- sexual: increase genetic diversity
 asexual: increase population #s

Most complex animals have:
 increase specialization
 bilateral symmetry
 cephalization w/ sense organs
 body cavity (coelom)


Blastula: protostome vs. deuterostome
Germ layers
 Endoderm (inner)
 Mesoderm (middle)
 Ectoderm (outer)

Body symmetry
 Radial/ bilateral
 Anterior/posterior
 Dorsal/ventral










Dissecting pan
Pins
Scissors
Probe
Hand lens
Forceps
Scalpel/blade
Apron
Goggles
Gloves
Chapters 26, 27 & 28




Sea sponges
Sessile- don’t move
Very different from other animals
Very few specialized cells


Choanocytes: specialized cells- use flagella
to move water inside open body cavity
Osculum: large opening where water leaves




Feeding- filter feeders
Resp/Circ/Excr- water movement
Response- can secrete toxins to
ward off predators
Reproduction- sexual (larva) and
asexual (budding or gemmules)




Soft bodies
Carnivores
Stinging tentacles
Ex: jellyfish, hydras, sea anemones, corals




Cnidocytes: stinging cells
Nematocysts: poison-filled stinging
structure
Radial symmetry
Polyp vs. medusa stages





Feeding- gastrovascular cavity (one opening)
Resp/Circ/Excr- diffusion
Response-nerve net: network of nerve cells
that react to stimuli
Movement- hydrostatic skeleton
Reproduction- asexual (budding) and sexual
(separate sexes)





flatworms
Acoelomates
Bilateral symmetry
Cephalization
Ex: flukes, tapeworms

Feeding:
 Free-living: 1 opening digestive cavity
▪ Pharynx extends out- brings food in
 Parasitic: eat digested food

Resp/Circ/Excr- diffusion
 Flame cells: remove excess water/waste



Response- ganglia: group of nerve cells
Eyespot: detect light
Movement- cilia and muscles
Reproduction- sexual (hermaphrodites)
 asexual fission: organism splits in two



Roundworms
Pseudocoelomates
C. elegans- 1st organism to have its entire
genome sequenced!

Feeding- 2 openings in
digestive tract
 mouth and anus


Resp/Circ/Excr- diffusion
Response- ganglia + nerves run
length of body


Movement- hydrostatic +
muscles along body
Reproduction- sexual (separate
sexes)




Trichinosis- burrows in organs- painful
Filarial- elephantitis swelling
Ascarid- parasitic- causes malnutrition
Hookworms- enter blood stream and
intestines- cause weakness and poor growth


Ringed worms
Segmented bodies separated by septa
 Some segments specialized


Coelomates
Ex: earthworms, leeches

Feeding- pharynx or filter feeders
 Crop (stores food) and gizzard (breaks it down)



Circulation- closed (dorsal and ventral vessels)
Respiration- gills or moist skin (diffusion)
Excretion- anus and nephridia (cellular waste)


Response- well-developed brain
Movement- specialized muscles
 Longitudinal and circular

Reproduction- most sexual (some
hermaphrodites)



Soft-bodied
Usually have a shell (internal/external)
VERY diverse
 Ex: snails, slugs, clams, squid, octopus


Share similar developmental stages
coelomates





Main Parts:
1. foot- used for crawling, hunting,
burrowing, etc.
2. mantle- covers body like a coat
3. shell- glands secrete calcium carbonate
4. visceral mass- internal organs




Feeding- radula, jaws, siphon
Respiration- gills, moist mantle
Circulation- open or closed
Excretion- nephridia



Response- from ganglia -> highly developed
brains (octopus)
Movement- secrete mucus, jet propulsion
Reproduction- external/internal, separate
sex/hermaphrodites

3 types:
 Gastropod (snails)
 Bivalves (clams)
 Cephalopods (octopus)

Human uses:
 Filter feeders build up high concentrations of
pollutants- scientists can use to monitor water
 Some snails don’t get cancer- use for research



“jointed foot”
Most diverse and successful phylum
Ex: crabs, spiders, horseshoe crabs and
insects

Segmented body
 # varies

Tough exoskeleton
 Chitin
 Varies in texture (leathery, waxy, hard)


Jointed appendages
Evolution- decreased # of segments,
specialized appendages

Feeding- mouthparts vary
 Suckers, filters, fangs etc.

Respiration- tracheal tubes
 Use of spiracles, book lungs, gills


Circulation- open system- heart
Excretion- Malpighian tubules
 N wastes into feces (land) or water (aquatic)
Response- brain->nerve cord->ganglia
in appendages
 Movement- muscle cells contract- pull
on exoskeleton to fly, swim, walk , etc.
 Reproduction- land= internal
fertilization

 Aquatic= external or internal

Molting: shed exoskeleton and grow a
new one- controlled by endocrine
system

Classified based on #/structure of segments
and appendages (mouthparts)

Subphyla:
 Crustacea
 Chelicerata
 Uniramia



Mostly aquatic (+pillbugs)
2 pairs of antennae
2-3 body sections
 cephalothorax, thorax, abdomen


Chewing mouthparts (mandibles)
ex: shrimp, crayfish, lobster, crabs, barnacles




Chelicerae mouthparts- “fangs”
2 body sections
4 pairs of legs
Spiders (Arachnids)
 Venom/digestive enzymes
 Silk glands

Horseshoe crabs* (Merostomata)
 Oldest living arthropod
 5 pairs of legs


Jaws, 1 pair antennae, unbranched
appendages
Insects:
 3 body parts and 3 pairs legs
 Advanced response system
▪ Compound eye, receptors, sensory hairs, ears
 Metamorphosis (incomplete and complete)
 Advanced communication
▪ Pheromones and dances






“spiny skin”
endoskeleton
water vascular system*
tube feet
radial symmetry
Closely related to humans!
 Bilateral larva, deuterostomes

Feeding- scraping, filter, predators
 Can extend stomach out of body

Respiration/Circulation- WVS
 Water in thru madreporite

Excretion- wastes out anus (digestive) or
diffusion (cellular)

Response- nerve ring- extends into arms
 eye spots


Movement- tube feet, WVS, spines, muscles
Reproduction- external fertilization




Sea urchins/sand dollars
Brittle stars: long/flexible arms- very fast
Sea cucumbers: “warty moving pickles”
Sea stars: can regenerate parts, carnivores
 Crown of Thorns

Sea lilies/feather stars: oldest- filter feeders