Ap 11 invertebrates

Inve

rtebr

ates

Porifera• Fw & m• Suspension feeders• Lack true tissue• Asymmetrical • Sequential

hermaphrodites – (1 then other)

• Produce antibiotics & other defensive cmpds – (Pettit @ AzSU cribostatin – can kill penicillin

resistant strains of Strep & looking for anticancer cmpds)

Cnidarians

• True tissue• Gastrovascular cavity

(mouth = anus)• 2 forms: polyp &

medusa• Cnidocytes • Nematocysts

(stinging cells)

4 classes:

Hydroz

oa

Cubozo

a

Antho

zoa

Scypho

zoa

Hydrozoa

• Most m, few fw• Polyp & medusa stages

in most sp• Polyp stage often

colonial

Back to Cnidarians

Scyphozoa

• All m• Polyp reduced• Free swimming medusa • Up to 2m in d

Back to Cnidarians

Cubozoa

• All m• Box-shaped medusa• Highly toxic cnidocytes– Sea wasp (Chironex

fleckeri) n Australia• Intense pain• Respiratory failure• Cardiac arrest• Death w/in min• Amt of poison in 1 org can

kill 60 people

Back to Cnidarians

Anthozoa

• All m• Medusa absent• Most sessile• Many colonial

Back to Cnidarians

Platyhelminthes

• Bilateral symmetry• Free living &

parasitic• Microscopic -20m• Triploblastic• Acoelomate

4 classes:

Turbel

laria

Trema

toda

Cestod

a

Monoge

nea

Turbellaria

• Mostly m, some fw, few terr

• Predators & scavengers• Body surface ciliated

Back to Platyhelminthes

Monogenea

• M & fw parasites• Most infect surfaces of

fishes• Simple life history• Ciliated larva starts host

infection

Back to Platyhelminthes

Trematoda

• Parasites of mainly verts• 2 suckers attach to host• Most life cycles include

intermediate hosts

Back to Platyhelminthes

Cestoda• Parasites of verts• Scolex attaches to

host• Proglottids prod eggs

and break off after fert

• No head of digestive system

• Lc with 1 or more intmdt host

Back to Platyhelminthes

Rotifers

• Specialized organ systems• Alimentary canal

(digestive tube w/2 openings)

• Psuedocoelomate• Parthenogenesis (only

females – make only females from unfert eggs)

Lophophorates

• Lophophore – horseshoe-shaped or circular crown of ciliated tentacles that surround mouth

• Coelomates

Ectoprocts - bryozoans

Phoronids – tube-dwelling marine worms

Brachiopods – lamp shells – dorsal /ventral shells instead of bivalve lateral

Nermeteans

• Proboscis & ribbon worms

• Acoelomate• 1mm-sev m• Some toxic• Motly m• Swim or burrow• Closed circulatory

system, no heart

Molluscs

• Mostly m, some fw, some terr• Soft bodied• Most protected by CaCO3 shell, some have

reduced, internal shell or no shell• Muscular foot, visceral mass, mantle, radula• Trochophore (ciliated larval stage)• 4 classes:

Chitons

• Polyplacophora• M• Shell w/8 plates• Foot for locomotion• Radula• No head

Gastropods

• Torsion• Asymmetrical body• Foot for locomotion• Radula

Bivalves

• M & fw• Flattened shell w/2 halves• Head reduced• No radula• Paired gills• Most suspension feeders• Mantle forms siphons

Cephalopods

• Head surrounded by grasping tentacles• Locomotion by jet propulsion using siphon

made from foot• Only mollusc w/ closed circ sys

Annelids

• Segmented worms, fw & damp soil• Length <1mm-3m• 3groups:

Oligochaeta Polychaeta HirudineaReduced headNo parapodiachaeta

Well developed headEach segment has parapodia w/chaetaTube dwelling & free living

Body flattenedReduced coelom and segChaetae abSuckers @ ant & post endsParasites, predators & scavengers

Nematodes

• Roundworms• most widespread of all animals• Cuticle – tough outer coat• Alimentary canal• No circ sys, nut spread thru fluid in psd-c• Soil• Trichinosis

Arthropods

• Hard exoskeleton (protein + chitin)– Molting/ecdysis

• Jointed appendages• Open circ sys• 4 groups:

Cheliceriformes

• 1-2 main body parts• 6 prs of appendages• Mostly terr or m

• Herbivorous• 2 prs walking legs/segment

•Distinct head w/antenna •Chewing mouth parts•Terr

Myriapoda

Millipedes Centipedes• Carnivorous• 1 pr walking legs/segment• Poison claws on first body

segment

Hexapoda• 3 body segments• Antenna present• Mouthparts modified

for chewing, sucking or lapping

• 3 prs of legs• Us. 2 prs of wings• Mostly terr

Crustacea

• Body 2-3 parts• Antenna pres• Chewing mouthparts• 3+ prs of legs• Mostly m & fw

Deuterostomes

Echinoderms• Spiny skin• Slow moving or sessile• Water vascular sys• Tube feet• Radial (adult) bilateral

(larvae)• 6 groups

Chordates• Doral hollow nerve cord• Notochord• Post anal tail• Pharyngeal slits