4 Classes; Most are parasitic; sense organs present, NO circulatory, skeletal, or respiratory system,
gastrovascular activity=food comes in same way as goes out
bilateral, cephalization, triploblastic
cavity: acoelomate
reproduce asexually by fission, fragmentation or regeneration
gastrovascular activity=food comes in same way as goes out
bilateral, cephalization, triploblastic
cavity: acoelomate
reproduce asexually by fission, fragmentation or regeneration
Phylum Platyhelminthes
(Nickname = Flatworms)
(Nickname = Flatworms)
Free living flatworm; Phylum Platyhelminthes; Class Turbellaria; Incomplete digestive tract (one opening) “Pharynx”
Planarians
trematodam, monogenea and cestoda are parasitic
turbellaria are free-living
turbellaria are free-living
Of the four classes of Platyhelminthes, which are parasitic and which are free-living?
Complete digestive tract (two openings); Use “flame cells” as primitive kidneys to remove excess water; Use ring of cilia around mouth “sweep” food into the organism; free living
Phylum Rotifera
(Nickname = Wheel Bearers)
(Nickname = Wheel Bearers)
Have a Pseudocoelom; Have a complete digestive system (2 openings); Are parasitic (Ascaris, Necator, Trichinella); 1st Phylum discussed with a body cavity…
Phylum Nematoda
(Nickname = Roundworms)
(Nickname = Roundworms)
Fluid in the cavity helps to circulate material; Fluid in the body can make the body rigid, allowing for use of muscles (movement); Organ function improves when there is room to move in a cavity
Importance of a body cavity
turbellaria
trematoda
monogenea
cestoda
trematoda
monogenea
cestoda
what are the four classes of Platyhelminthes?
Fluid filled cavity between the gut and the body wall
Psuedocoelom
non-parasitic
swim in water using a wave-like motion over solid surfaces, they glide or beat cilia
pharynx-muscular tube for feeding
excretory system: flame cells-collect excess water and send it through canals to exit body
cerebral ganglia (simple brain)
fission or regeneration (asexual) or sexual reproduction
planaria
swim in water using a wave-like motion over solid surfaces, they glide or beat cilia
pharynx-muscular tube for feeding
excretory system: flame cells-collect excess water and send it through canals to exit body
cerebral ganglia (simple brain)
fission or regeneration (asexual) or sexual reproduction
planaria
Class Turbellaria
muscular tube for feeding
pharynx
excretory system, collect exces water and send it through canals to exit body
flame cells
eyespots
ocelli
tasting chemicals in environment
auricle
parasitic flukes
what is the nickname for classes trematoda and monogenea?
leaf-shaped flatworms
poor sense organs, poor sense organs, no cilia, no eyespots
tegument: out sheet of cells for protection
2 suckers for attachment
ex) human liver fluke, swimmer’s itch
poor sense organs, poor sense organs, no cilia, no eyespots
tegument: out sheet of cells for protection
2 suckers for attachment
ex) human liver fluke, swimmer’s itch
trematoda and monogenea
Thick protective layer covering the body of endoparasites; helps to keep them from being digested
Tegument
parasitic tapeworms
what is the nickname for class cestoda?
tegument
no digestive system-absorb nutrients from hosts
hermaphrodite reproduction
life cycle (form cysts)
no digestive system-absorb nutrients from hosts
hermaphrodite reproduction
life cycle (form cysts)
cestoda
“head” with hooks and suckers
scolex
Rectangular sections of a tapeworm; Phylum Platyhelminthes; Class Cestoda
Proglottids
Roundworms
Nickname for Phylum Nematoda
Bilateral symmetry, cephalization
dorsal and ventral nerve cord/brain
digestive tract with 2 openings
triploblastic
cavity: pseudocoelom
body covered by cilia for protection
dorsal and ventral nerve cord/brain
digestive tract with 2 openings
triploblastic
cavity: pseudocoelom
body covered by cilia for protection
Nematoda
asexually
How do flatworms reproduce?
through the anus
how do nematodes remove waste?
flame cells and excretory tubules
How rotifers get rid of waste?
