Kingdom Animalia Sponges Cnidarians Flatworms Roundworms.

Kingdom Animalia

Sponges CnidariansFlatworms

Roundworms

Sponges

Assymetrical Freshwater or saltwater Sessile – do not move Filter feeders No Nervous System Multicellular organization (no true tissues

yet) 

Other Sponge Facts:

Sponges can regenerate – replace lost body parts through mitotic cell division.

Economic Importance: Commercial sponge harvesting for personal care industry.

Sponge Reproduction:

Asexually – fragmentation or budding

Sexually – sponges are hermaphrodites External fertilization Internal fertilization - eggs remain inside parent sponge’s body.

Cnidarians – Stinging Animals

Radial SymmetryMostly saltwater

CoralsJellyfish

Sea anemonesHydra

Cnidarian Movement

POLYP is sessile – does not moveMEDUSA 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 –have separate male and

female medusae that produce gametes that join through external fertilization to produce polyps.

Flatworms - Platyhelminthes

Bilateral Symmetry Free-living in freshwater or parasitic

in a hostHas all three layers (endoderm,

mesoderm, ectoderm)Acoelomate – no body cavity.

An Important Group

 Many nasty parasitic infections.

DugesiaTapeworms

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

First appearance of cephalization.Primitive brain.Eyespots

Flatworm Reproduction

Sexually - Hermaphrodites – internal fertilzation.

Asexually – fission – when damaged, regenerates new body parts.

Proglottids – found in tapeworms – each is shed off individually.

Roundworms - Nematoda

Bilateral SymmetryFree-living in soil or parasitic in a

hostPseudoomate – false body cavity.Movement - Longitutdinal 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 anusParasitic roundworms use specialized

structures (usually with hooks) to attach to a host.

An Important Group

Many nasty parasitic infections in humans, livestock

Importance and IMPORTANT AGRICULTURAL PEST

Pinworms, Ascaris, hookworms, Trichinella