Transcript Representative Pseudocoelmate Phyla - UCO

Representative
Pseudocoelmate
Phyla
Nematomorpha
Rotifera
Acanthocephala
Jenna Hellack F 2000
Nematoda
Pseudocoelomates
• The phyla are eumetatzoans, have bilateral
symmetry (grade Bilateria) and are in
division Protostomia.
• The blastocoel of the embryo is the body
cavity. The body cavity is not lined with a
mesoderm.
Jenna Hellack F 2000
Taxonomy
• Phylum Nematomorpha
• Phylum Acanthocephala
• Phylum Rotifera
– Philodina
• Phylum Nematoda
– Ascaris, Enterobius, Necator, Ancylostoma,
Wuchereria, Dracunculus, Turbatrix, Dirofilaria,
Trichinella
Jenna Hellack F 2000
Taxonomy
Phylum Nematomorpha
• Larva parasites arthropods
• Adults free-living in freshwater (do not
feed)
• Works are striking because of the extremely
long and threadlike body.
Jenna Hellack F 2000
Taxonomy
Phylum Acanthocephala
• Have a short anterior
proboscis covered with
recurved spines
• Has ability to secrete
chemicals that modify
the behavior of host
species.
Jenna Hellack F 2000
Taxonomy
Phylum Rotifera
• Genus - Philodina
• Some unique characteristics
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Jenna Hellack F 2000
Mastax
Ciliated corona
Toes
Parthenogenesis
Systems
Taxonomy
Phylum Nematoda
• Some characteristics
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Amoeboid sperm
Longitudinal muscle only
Muscle attach to nerves
6-layered cuticle
Carrot root
nematodes
Heart worms
(Dirofilaria)
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Pepper
nematodes
Systems of Nematoda
• System I
– Integumentary, skeletal, muscle and digestive
• System II
– Excretory, respiratory, circulatory and nervous
• System III
– Endocrine and reproductive
Jenna Hellack F 2000
Taxonomy
Systems I
• Integumentary - syncytial, one cell layer;
secretes 6-layered cuticle.
• Skeletal - hydrostatic
• Muscle - longitudinal muscle only, muscles
send fibers to nerves
• Digestive - complete but not complex;
mouth pharynx, intestine, anus; no digestive
glands
System II
Jenna Hellack F 2000
System III
Taxonomy
Systems II
• Excretory - excretory tubes and renette
glands probably remnants of flame cells like
system.
• Respiratory - none; many are anaerobic
• Circulatory - none; use pseudocoelom
• Nervous - nerve ring around pharynx;
dorsal and ventral cords with lateral lines
System III
Jenna Hellack F 2000
Taxonomy
Systems III
• Endocrine - chemicals secreted by nervous
system
• Reproductive - Mostly dioecious
– Sexual dimorphism - male usually smaller and
has copulatory structure
– Amoeboid sperm
– Many with complex life cycles - particularly
the parasites
Jenna Hellack F 2000
Representative Genera of
Nematoda
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Ascaris
Enterobius
Necator
Ancylostoma
Wuchereria
Jenna Hellack F 2000
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Taxonomy
Dracunculus
Turbatrix
Dirofilaria
Trichinella
Taxonomy
Genus Ascaris
Dissection
Male
• Intestinal roundworm
– Ingested as eggs in contaminated food or dirt
Jenna Hellack F 2000
Dissection Ascaris female
Jenna Hellack F 2000
Taxonomy
Taxonomy
Ascaris male copulatory spicule
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Taxonomy
Genus Ancylostoma
Hookworm infected by juveniles in soil
burrowing into skin.
Dog
Hookworms
Mouth
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Copulatory structure of male
Taxonomy
Genus Dirofilaria
(dog heart worms)
Adult worms
live in heart
while the
juveniles
circulate in
blood.
They are
transmitted by
mosquitoes.
Jenna Hellack F 2000
Taxonomy
Trichinella
Encysted stage
In pork
Jenna Hellack F 2000