Kingdom Animalia INVERTEBRATES: NO BACK BONE Sponges Cnidarians Flatworms Roundworms Mollusks
Sponges Assymetrical: similar parts regularly arranged around a central axis Freshwater or saltwater Sessile – do not move Filter feeders: filter food out of the water Body covered with many pores (openings)
Sponges All cells function independently Some produce spicules: thin, spiny structures that form the endoskeleton Some produce soft fibers as a skeleton These are the ones people use
Sponge Reproduction: Asexually –budding Sexually – joining of sperm and egg
Other Sponge Facts: Sponges can regenerate – replace lost body parts through mitotic cell division. Commercial sponge harvesting for personal care industry. Used as medicines
Cnidarians – Stinging Animals Radial Symmetry: similar parts regularly arranged around a central axis Hollow central cavity with 1 opening called a mouth
Cnidarians – Stinging Animals 2 body types: Polyp: vase shape that doesn’t move Medusa: umbrella shape that moves around
Cnidarians – Stinging Animals Mostly saltwater Corals Jellyfish Sea anemones Hydra
Cnidarian Movement POLYP is sessile – does not move MEDUSA is motile – squeezes bell (umbrella) to move uses simple ring of contractile tissue (not muscle tissue yet)
Feeding Use tentacles to capture food. Tentacles have NEMATOCYSTS – stinging cells that grab and immobilize prey using toxins. Waste products and undigested materials are expelled through the mouth.
Organization Nerve net – conducts impulses from all parts of the body. No brain. Two layers of tissues derived from endoderm and ectoderm
Cnidarian Reproduction Asexually – budding (polyp form) Sexually –produces egg and sperm
Flatworms - Platyhelminthes Bilateral Symmetry: body the same on both sides Acoelomate – no body cavity.
An Important Group Free-living in freshwater or parasitic in a host Many nasty parasitic infections. Dugesia Tapeworms Flukes
Flatworm Feeding Free living flatworms are scavengers. Parasitic flatworms use specialized structures (usually with hooks) to attach to a host.
Respiration & Excretion Excretion - Flame cells remove excess water Respiration - Oxygen diffuses into body cells directly.
Flatworm Nervous Systems Primitive brain. Eyespots: sensitive to light
Flatworm Reproduction Sexually - Hermaphrodites – internal fertilization. Asexually – fission – when damaged, regenerates new body parts.
Roundworms - Nematoda Bilateral Symmetry Free-living in soil or parasitic in a host Pseudomate – false body cavity. Movement - Longitudinal muscles produce a thrashing movement
Respiration & Excretion Respiration - Oxygen diffuses into body cells. Digestive wastes are excreted through the anus. Flame cells remove excess water through pores in body surface.
Roundworm Feeding Have a simple digestive system. Have a mouth and an anus Parasitic roundworms use specialized structures called hooks and suckers to attach to a host.
An Important Group Many nasty parasitic infections in humans, livestock Pinworms, Ascaris, hookworms, Trichinella
Segmented Worms- Annelida Bilateral Symmetry Body is divided into segments Body covered with mucus to aid in movement Have tiny setae (bristles) to pull it through the soil
Segmented Worms- Annelida Have a closed circulatory system: all fluids are in tubes Have a simple nervous system Ex. Earthworm
MOLLUSKS Soft bodied animals that have an inner and outer shell They have a tube foot to: Open and close their shell Movement Bury themselves in the sand
MOLLUSKS They have a head with a sense organ (like an eye) 3 Groups separated by shell characteristics Single or no shell 2- Shell Tentacled
Single or No Shell Mollusks Ex. Slugs and snails Also called gastropods Radula: tongue that’s used to get food
2-Shell Mollusks Ex. Clams, oysters, mussels, and scallops Also known as bivalves Filter feed If sand gets stuck for many years, it becomes a pearl
Tentacled Mollusks Ex. Octopus, Squid, and nautiluses Also known as cephalopods Use tentacles to catch food