phyla platyhelminthes, nemertea, nematoda, annelida, sipuncula, & echiura the worms
TRANSCRIPT
Phyla Platyhelminthes, Nemertea, Nematoda, Annelida, Sipuncula, & Echiura
The Worms
I) Worms
A) Bilateral SymmetryB) True organs & organ systemsC) All have complete digestive tracts except for
flatwormsD) Mesoderm (middle cell layer)
1) Muscles, Reproductive Organs, & Other Organs
II) Phylum Platyhelminthes
A) AKA: Flatworms
B) ~20,000 species
C) Central Nervous System1) Brain
2) Simple Nerve Aggregation
D) Turbellarians1) Free-swimming carnivores
II) Phylum Platyhelminthes
E) Flukes (trematodes)1) Parasites: Feed on
blood, intestines, tissues
F) Tapeworms (cestodes)
III) Phylum Nemertia
A) AKA: Ribbon Worms
B) ~900 known species
C) Primitive circulatory system
D) Proboscis1) Long, flesh tube used to
entangle prey
2) Predators
E) Longest invertebrate on Earth
1) Over 100 feet long
IV) Phylum NematodaA) AKA: Roundworms
B) 10,000 – 25,000 known species1) Estimated to be ½
million species
2) Undercounted
C) Live in rich sediment or are parasitic
D) Hydrostatic skeleton
V) Phylum Annelida
A) AKA: Segmented Worms
B) ~20,000 known speciesC) SegmentedD) Gut lies in cavity known
as coelomE) Hydrostatic skeletonF) Closed Circulatory
SystemG) Respiration
1) Through skin – smaller2) Gills – larger
V) Phylum Annelida
H) Class Polychaeta1) AKA: Bristle Worms
2) Parapodia: movement
3) Setae: sharp bristles
4) Predators & Suspension Feeders
V) Phylum Annelida
I) Class Oligochaetes1) AKA: Earthworms &
Relatives
2) Suspension Feeders
3) No Parapodia
V) Phylum Annelida
J) Class Hirudinea1) AKA: Leeches
2) Suspension Feeders
3) Suckers on each end
4) No Parapodia
VI) Phylum SipunculaA) AKA: Peanut WormsB) ~320 known speciesC) UnsegmentedD) Retractable tentacles
for feeding (deposit feeders)
VII) Phylum Echiura
A) AKA: Spoon Worms
B) ~135 known species
C) Unsegmented
D) Non-retractable proboscis (deposit feeders)