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