Unit 8 Invertebrate Animals

Porifera (sponges) Digestive: filter feeders Respiration: diffusion (through water) Circulatory: diffusion Excretion: diffusion, or through the osculum Nervous: none Movement: none (sessile) Reproduction: sexual and asexual (budding)

Cnidaria (jellyfish, hydra) Digestive: use nematocysts (stinging cells) food in a gastrovascular cavity Respiration: diffusion Circulatory: diffusion Excretion: diffusion, or out mouth Nervous: nerve net Movement: some sessile, some by “jet propulsion”

Cnidaria cont’d… Reproduction; sexual and asexual (budding) https://www.youtube.com/watch?v=rzNI1Yh0F5A

Platyhelminthes (flatworms, tapeworms, planaria) Digestive: carnivores, scavengers, or parasites, may have a gastrovascular cavity Respiration: diffusion Circulatory: some diffusion. Some have a gastrovascular system Excretion: NEW:flame cells, or out mouth Nervous: ladder-like nervous system with brain in some, light sensitive

Platyhelminthes cont’d… Movement: cilia and muscle movement Reproduction: sexual, asexual, hermaphrodites

Nematoda (roundworms, nematodes, Trichina, heartworms, hookworms) Digestive: some free-living, some parasitic Respiration: diffusion Circulatory: diffusion Excretion: diffusion, NEW: anus Nervous: simple ganglia, sense organs

Nematodes cont’d… Movement: snake-like or thrashing, uses muscles Reproduction: sexual, some hermaphrodites

Mollusca (snails, clams, octopus, squid) Digestive: herbivores, carnivores, filter- feeders, detritus feeders, parasites have a simple stomach and intestine Respiration: through gills or mantle cavity Circulatory: open circulatory system (But octopus, squid – closed) Excretion: anus – feces; nephridia – liquid wastes

Mollusca cont’d… Nervous: clams-simple; octopus-very complex, well-developed brain, sense organs Movement: swim-”jet propulsion’, crawl with tentacles Reproduction – separate sexes, external fertilization, some internal fertilization, some hermaphrodites https://www.youtube.com/watch?v=gAOb2sv3onU

Annelida (earthworms, leeches) Digestive: digestive tract (mouth, pharynx, esophagus, crop, gizzard, anus); some filter feeders Respiration: some gills, some diffusion through skin Circulatory: closed circulatory system with primitive heart Excretion: feces–anus; liquid-nephridia

Annelida cont’d… Response: brain, well-developed nervous system, sense organs, ventral nerve cord Movement: longitudinal and circular muscles: crawl, swim, burrow Reproduction: most-sexually, external fertilization, separate sexes, some hermaphrodites

Arthropoda (ants, grasshoppers, spiders, lobsters, centipedes) Feeding: herbivores, carnivores, parasites, filter-feeders, detritus feeders Respiration: gills (crabs); book lungs (horseshoe crabs and spiders); tracheal tubes (grasshoppers) Internal transport: heart with open circulatory system Excretion: feces-anus; liquid- Malpighian tubules, green glands

Arthropoda cont’d… Nervous: brain, well-developed nervous system, complex senses (ex: compound eyes) Movement: well-developed muscle systems coordinated with nervous system and connected to exoskeleton fly, swim, walk, crawl Reproduction: sexual- internal fertilization

4 subphyla of Arthropoda: Trilobites (all extinct) Chelicerates - (spiders and, ticks- Arachnida, horseshoe crabs) Crustaceans (crabs, crayfish, lobsters, pill bugs) Uniramia (centipedes, millipedes, insects)

Insects reproduce in two life cycles: Complete metamorphosis Egg  larva  pupa  adult Butterflies, flies, moths Incomplete metamorphosis Egg  nymph  adult Grasshoppers, cockroaches

Echinodermata (starfish, sea urchins, sand dollars) Digestive: carnivores, filter-feeders, detritus feeders Respiration: diffusion through tube feet Circulatory: all systems shared, no specific system Excretion: feces-anus, other- through tube feet and gills

Echinodermata cont’d… Nervous: primitive, nerve ring around mouth, chemo and light sensitive cells statocysts – balance Movement: tube feet, muscles attached to endoskeleton swim, crawl Reproduction: separate sexes, some hermaphroditic, external fertilization

Chordata (tunicates, lancelets, fish, frogs, humans) Digestive: all types; digestive system Respiration: gills – pharyngeal slits, lungs Circulatory: closed circulatory system Excretion: feces-anus; excretory systems (kidneys, etc.)

Chordata cont’d… Nervous: complex brain and nervous system; hollow dorsal nerve cord Movement: complex muscular system coordinated with nervous system Reproduction: sexual, some external and some internal fertilization; have systems

Unit 7 Review How are animal cells different from plant cells? The front of an organism is called… What is the difference between a brain, ganglia, and a nerve net? How do planarians get rid of excess water?

Review page 2 Humans can get trichinosis by eating undercooked ____ Reefs are made of what animals? Describe three evolutionary trends. What are the basic characteristics of animals? What is a cephalopod?

Review page 3 Ammonia is removed from the blood of mollusks by… List the subphyla of arthropods and give examples Muscles of arthropods are attached to the…. An arthropod that has three distinct body parts is a(an)...

Review page 4 Concentration of nerves and sense organs in the head is called… The main advantage of sexual reproduction is Where are the gills of a clam? Snails and slugs breathe by… Spiders (arachnids) have how many legs? How many pairs?

Review page 5 Larvae of echinoderms change from ____ symmetry to ____ symmetry. Tunicates are classified as (invertebrates, vertebrates) and in phylum ____