LABORATORIO:Parte2

FiloNematodayotros

EJERCICIO10

Goalsfortoday

•  LearntorecognizedthePhylumNematodaandothersmallerphylafromotheranimals

•  Learnthemain‘diagnos>c’characteris>cs

•  Learnaboutsomefree‐livingandparasi>cspeciesbiology

Nematoda:roundworms

Nematod are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals

KeycharacterisBcsofthephylum:•  Bodyelongateandroundbody.

•  Unsegmented•  Cu>cle

•  Nervoussystemwithpharyngealnervering

•  Hasnotcirculatorysystem

•  Unlikecnidariansorflatworms,roundwormshaveadiges>vesystemthatislikeatubewithopeningsatbothends.

•  Pseudocoelomate•  Widespreadandabundantinallhabitats;

someparasi>c

Nematoda:YourTasksExercise9A:

–  Phylum:Nematoda•  Genus:Ascarislumbricoides,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:Ascaris1.Takeaslidefromyourboxwithacrosssec>onofamaleandfemaleAscaris.

Nematoda:Ascaris2.Dissec>on.Useglovesatall>mes!

Female

Male

Select one sex and then search for student the a dissection of the opposite sex. Either can be in the exam!

Ascarislumbricoidescont.

Female

vagina

genital pore

uterus

gut oviduct

Ascarislumbricoidescont.

seminal vesicle sperm duct

testes gut

Male

Male spicules

Nematoda:YourTasksExercise9A:

–  Phylum:Nematoda•  Genus:Ancylostomacaninum(doghookworm)

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:YourTasksExercise9A:

–  Phylum:Nematoda•  Genus:Trichinellsspiralis(trichinaworm)

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:YourTasksExercise9A:

–  Phylum:Nematoda•  Genus:Enterobiusvermicularis(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:YourTasksExercise9A:

–  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.

Therearepseudocoelomates

Habitanenaguasdulces,>errahúmeda,musgos,líquenes,hongos,einclusoaguasalada

Nematoda:YourTasksExercise9A:

–  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

Therearepseudocoelomates

ImportantLinksNematods and others

http://faculty.evansville.edu/de3/b10802/PPoint/Pseudocoelomates/sld001.htm

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