WORMS Flatworms soft flattened worms carnivores scavengers or

WORMS

Flatworms: soft, flattened worms • carnivores, scavengers, or parasites – one opening for food and waste • Respiration, Circulation, & Excretion – diffusion – Flame cells – remove excess water • Response – ganglia – group of nerve cells that control the nervous system – eyespots – detects amounts of light

Flatworms • Movement – cilia, twits and turn • Reproduction: hermaphrodites & fission • Groups – Tubellarians: marine or freshwater; • Bottom Feeders – Fluke – parasitic worms that infect internal organs of host – Tapeworms – long, flat parasitic worms that are adapted life inside intestines of host

Roundworms: unsegmented • • Pseudocoelom Mouth and Anus Feeding – predators & parasites Respiration, Circulation, Excretion – diffusion • Response – ganglia & simple nervous system • Movement – Muscles • Reproduction – Sexually & internal fertilization

Parasitic Roundworms • Trichinosis-Causing Worms – Larvae form cysts in host’s muscles • Filarial Worms – – Elephantiasis: blocks lymph vessels – Transmitted through mosquitoes

Parasitic Roundworms • Ascarid Worms – absorbs food from host’s intestines – Block intestines • Hookworms: ¼ of the world – Hatch in soil and attach to bare feet – Travel to the intestines

Annelids: segmented bodies • True Coelom • Filter feeders to predators • Closed circulatory system – blood is in blood vessels • Respiration – aquatic annelids – gills – Land dwelling – skin

Annelids • Excretion – waste anus • Response – well-developed nervous system • Movement – muscles • Reproduction – sexual – Leeches & earthworms: hermaphroditic

Groups of Annelids • Oligochaetes – streamlined bodies – Live in the soil or freshwater – Earthworms, Tubifex worms • Leeches – external parasites that suck blood and body fluids from host • Polychaetes – marine annelids – Parried, paddlelike appendages