Transcript A35-Annelid Worms

Annelid Worms
Annelid Worms
Segmented worms
3 Classes:
 Oligochaetes- live in soil
or freshwater
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Ex.: earthworms
Leeches- suck blood and
body fluids from host
Polychaetes- live in ocean
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Ex.: sandworms,
bloodworms
Annelid Worms: Anatomy
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Long narrow body
without legs
Invertebrates
Have septa (walls that
separate segments)
Closed circulation
(blood vessels), but
no (true) heart
Annelid Worms: Digestion
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Feeding methods: filter feeding, capture and
eat, parasitic
Annelid Worms: Digestion
Earthworm digestion:
Mouth
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Esophagus
Crop (stores food)
Gizzard (grinds food)
Intestines – food absorbed
Waste expelled through anus
(castings)
http://www.ncsu.edu/scivis/lessons/earthworm/Overview.html
Annelid Worms: Respiration &
Reproduction
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Breathe through gills
if it lives in water and
through skin if it lives
on land
Most reproduce
asexually;
earthworms are
hermaphrodites and
can fertilize each
other
Earthworm Benefits
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Earthworms are
beneficial to plants
because they dig
tunnels through the
ground to allow
beneficial bacteria
and water to
penetrate.
Annelid Worms: Movement
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Have 2 sets of
muscles – one set
contracts to make the
worm shorter and
fatter, one set
contracts to make it
longer and thinner
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The worm moves by
alternately contracting
muscles
http://www.fed.cuhk.edu.hk/~johnson/teaching/support/support_and_move
ment.htm
Harmful Worms
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Parasitic Worms:
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Tapeworms
Roundworms
Hookworms
Pinworms
Trichinella
Caught by contact with infested ground, infected
people, animals, or linens, or by eating
undercooked infected meat
Harmful Worms
Roundworms can grow
up to 13 inches inside
your intestines.
Symptoms are flu-like,
and include abdominal
pain and vomiting. Can
cause blockage in
intestines, and have
been seen floating in
the toilet after vomiting
or diarrhea.
http://www.liveleak.com/view?i=520_1220214479
Harmful Worms
Have you ever been awakened in the middle of the night by an itchy bung hole? If so
you may be infested with pinworms. They sneak out at night to lay their eggs on the
fertile skin surrounding your anus. Mmm fun! The eggs can live up to 3 weeks, so be
sure to wash yourself well. If you’ve experienced the itchy bung hole you’ve already
been infected for 2-3 months. Chances are you were exposed to contaminated food
which means you swallowed pinworm eggs. If you think you’re infected just put a
clear piece of tape over your anus while you sleep. In the morning take the tape to
the doctor and have them examine it for pinworms. He’ll think you’re a genius!
From http://www.notsoboringlife.com/ramblings/what-everyone-oughtto-know-about-parasites/
Harmful Worms
Hookworms can be caught by stepping on infected feces. Watch your step!
Harmful Worms
Trichinosis is caused by a
parasitic roundworm called
Trichinella. This worm can be
found in undercooked pork.
The victim, once infected, will
suffer from abdominal pain,
diarrhea, vomiting, and then
later, muscle aches, itching,
fever, and joint aches. The
worm feeds off the host and
reproduces.
Trichinella spiralis
larva inside muscle
tissue.
Harmful Worms
In the true spirit of parasites, I’ve
saved the best for last. Tapeworms are
the mack daddy of parasites that can
measure upwards of 20 FEET long!
Keep an eye on your dung heaps
because these guys are so long they
tend to break off. As long as the head
remains attached in the intestine they
will continue to grow. Humans are
generally infected by tapeworms
through cattle. Tapeworms will bore
through the intestinal wall of the cow
and lodge themselves in the muscle
where you ingest them (I’ll take my
steak well done, please). Symptoms
are similar to the others including
abdominal discomfort, diarrhea, and
constipation. If you’re looking to lose a
couple pounds you might consider
letting a couple tapeworms take up
residence in your intestines. It is
rumored that tapeworms were a core
ingredient of some diet pills.
From http://www.notsoboringlife.com/ramblings/whateveryone-ought-to-know-about-parasites/
Tapeworm
http://www.liveleak.com/view?i=bd9_1194369203
* http://www.liveleak.com/view?i=807_1194370140