LABORATORIO:
Parte
2
Filo
Nematoda
y
otros
EJERCICIO
10
Goals
for
today
•  Learn
to
recognized
the
Phylum
Nematoda
and
other
smaller
phyla
from
other
animals
•  Learn
the
main
diagnos>c characteris>cs
•  Learn
about
some
free‐living
and
parasi>c
species
biology
Nematoda:
roundworms
Nematod are the most diverse phylum of pseudocoelomates, and
one of the most diverse of all animals
Key
characterisBcs
of
the
phylum:
Body
elongate
and
round
body.
Unsegmented
Cu>cle
Nervous
system
with
pharyngeal
nerve
ring
Has
not
circulatory
system
Unlike
cnidarians
or
flatworms,
roundworms
have
a
diges>ve
system
that
is
like
a
tube
with
openings
at
both
ends.
•  Pseudocoelomate
•  Widespread
and
abundant
in
all
habitats;
some
parasi>c
• 
• 
• 
• 
• 
• 
Nematoda:
Your
Tasks
Exercise
9A:
–  Phylum:
Nematoda
•  Genus:
Ascaris
lumbricoides,
A.
suum
Ascaris lumbricoides is a common
intestinal parasite of humans. A.
suum paralyzes pigs. Nearly ¼ of
the human population is infected
with this roundworm. The eggs
are resistant to chemicals,
remaining viable in 2% formalin,
and 50% solutions of the
common laboratory acids
So be careful!! Use gloves and wash your hands after the dissection
Nematoda:
Ascaris
1.
Take
a
slide
from
your
box
with
a
cross
sec>on
of
a
male
and
female
Ascaris.
Nematoda:
Ascaris
2.
Dissec>on.
Use
gloves
at
all
>mes!
Select one sex and then search for
student the a dissection of the
opposite sex. Either can be in the
exam!
Female
Male
Ascaris
lumbricoides
cont.
Female
gut
oviduct
genital pore
uterus
vagina
Ascaris
lumbricoides
cont.
Male
sperm duct
seminal vesicle
testes
gut
Male spicules
Nematoda:
Your
Tasks
Exercise
9A:
–  Phylum:
Nematoda
•  Genus:
Ancylostoma
caninum
(dog
hookworm)
Observe a slide of the dog
hookworm. This is a common
parasite of domestic dogs and
cats. Try to note the cutting plates
which uses to attach itself to the
intestinal mucosa of its host.
Read page 161 on hookworms
Nematoda:
Your
Tasks
Exercise
9A:
–  Phylum:
Nematoda
•  Genus:
Trichinells
spiralis
(trichina
worm)
Observe a slide of the trichina
worm a parasite of humans, hogs,
rats and other mammals
Your slide is a cyst of the parasite
Read page 162 on trichina worms
Nematoda:
Your
Tasks
Exercise
9A:
–  Phylum:
Nematoda
•  Genus:
Enterobius
vermicularis
(pinworms)
Observe a slide of a pinworm
which parasites humans in USA.
The live in the large intestine and
cecum.
Read page 162-163 on pinworms
Nematoda:
Your
Tasks
Exercise
9A:
–  Phylum:
RoBfera
Observe a slide of a rotifer: Rotifers
have a corona of cilia that is use for
swimming and feeding. The foot has a
pedal gland that secrets a cement to
cling on substrate. The mastax is fitted
with jaws for grinding food particles. The
body is cover by a cuticle which in
many roftifers is rigid and called
lorica.
There
are
pseudocoelomates
Habitan
en
aguas
dulces,
>erra
húmeda,
musgos,
líquenes,
hongos,
e
incluso
agua
salada
Nematoda:
Your
Tasks
Exercise
9A:
–  Phylum:
Acanthocephala
Observe a slide of a spiny-headed worm. This worm is a parasite of pigs,
where it attaches to the intestinal lining and absorbs digested food from
its host. Like tapeworms it has not digestive system at all.
probóscide invaginable erizada de espinas
There
are
pseudocoelomates
Important
Links
Nematods and others
http://www.savalli.us/BIO385/Diversity/13.Nematoda.html
http://en.wikipedia.org/wiki/Nematode
http://en.wikipedia.org/wiki/Rotifer
http://en.wikipedia.org/wiki/Acanthocephala
http://faculty.evansville.edu/de3/b10802/PPoint/Pseudocoelomates/
sld001.htm