1. PSEUDOCOELOMATE PHYLA

2. CHARACTERISTICS Pseudocoelom
space between gut and mesoderm parts of body wall
space filled with fluid
for differentiation of systems
storage of waste products
used as hydrostatic skeleton

3. CHARACTERISTICS Cuticle acellular outer covering, over epidermis
for protection against water loss or gain
resistant to environmental chemicals

4. CHARACTERISTICS Systems Don’t have: circulatory system
respiratory system
true skeletal system
Do have:
Reproduction: usually dioecious
excretion: protonephridia
digestive: complete
muscles: longitudinal only
nerve: ladder like with cerebral ganglia
hydrostatic skeleton: for movement

5. PSEUDOCOELOMATE PHYLA
Major
Nematoda
Rotifera
Gastrotricha
Nematomorpha
Acanthocephala
Minor (see text)
Kinorhyncha
Loricifera
Priapulida
Entoprocta

6. Nematoda (roundworms)
numerous, slender, cylindrical
Unsegmented
found in all types of habitats, terrestrial, marine, freshwater
dioecious

7. Nematodes - Characteristics
Sense organs – Bristles for Chemoreception
Amphids – unique
Digestive system – Complete
Excretion
Free living Marine species – Renette gland
Freshwater and Terrestrial - Tubular

8. Ascaris lumbricoides (intestinal roundworm)
- 64% of SE is infected
may produce 200,000
eggs/day
life cycle
ingested by humans as eggs
intestinal larvae get into blood
carried to lungs
get coughed up and swallowed
adult develops in small intestine
eggs released through feces

9. Ascaris

10. Necatur americanus (hookworm)
% of SE infected
1963 4% infected
life cycle
penetrates skin on bottom of feet
gets into blood and goes to lungs
coughed up and swallowed
attached to intestine
produce anticoagulant and feed on blood

11. Trichinella spiralis (trichinosis)
very bad to contract
get it from eating undercooked pork
humans not in natural cycle
in humans encysts in muscles, causes aching
life cycle
one host
larvae feed in intestine
adults live in intestine

12. Enterobius vermicularis (pin worm)
in 46% of population
most common parasite in humans in world
life cycle
adults in folds of anus
female emerges at night to lay eggs
eggs get under nails, are also airborne
larvae develop in digestive tract
not very serious, more of a nuisance

13. Filariasis

14. Dog Heartworm

15. Phylum Rotifera (rotifers)
have a corona with cilia, like norelco shaver head
no cilia elsewhere
with forked “foot” with cement glands for attachment
complex digestive structures such as mastax

16. Rotifer Reproduction dioecious
Parthenogenesis

17. Phylum Gastrotricha (Gastrotrichs)
ventrally flattened with bands of cilia
also have adhesive glands on foot
with spiny, scaly or warty cuticle
no corona or mastax, etc.
hermaphroditic, male system in some reduced
reproduction similar to that of rotifers

18. Phylum Nematomorpha (horse hair worms)
larvae parasitic in insects like grasshoppers
adults aquatic, but do not feed
life cycle
eggs ingested by grasshopper
larva develops in gut
emerges when host near water
develops into adult
dioecious

19. Phylum Acanthacephala (spiny headed worms)
have characteristic spiny proboscis
have no digestive tract
life cycle
larvae found in arthropod, such as insect
all adults endoparasites in guts of vertebrates
Dioecious
Acanthor Larva