BIO 165 General Zoology
R. Walter, Instructor
Summer 2004
ACOELOMATES and PSUEDOCOELOMATES
Be sure you know the classification, habitat, important structures, and key concepts for these organisms
Resources
o Lab book Exercises 9 (pgs. 135-152) and 10 (pgs. 157-166)
o Textbook Chapters 14 and 15
Taxonomy
Acoelomates
Kingdom Animalia
Phylum Platyhelminthes
Class Turbellaria (free-living flatworms)
Example: Dugesia (planaria)
Class Trematoda (flukes)
Examples: Clonorcus (live fluke), Schistosoma (blood fluke)
Class Cestoda (tapeworms)
Example: Taenia (dog tapeworm)
Psuedocoelomates
Kingdom Animalia
Phylum Nematoda (free-living nematodes)
Examples: Ascaris (intestinal roundworm), Trichinella, Tubatrix
Phylum Rotifera
Example: Philodina
Key Concepts: proboscis, scolex, pharynx, rostellum, stobila, proglottids, corona, parthenogenesis
Structures to Identify for Practical
Acoelomates
o Dugesia (Live specimens, slide, model)
Whole mount slide: Eyespot, auricle, anterior & posterior trunk of intestine, and the pharynx (use Figure
9-1 as a guide)
Cross section slide: ventral nerve cord, diverticula of intestines, ciliated epidermis, anterior trunk of the
intestines, parenchyma cells, area of the body the cross section was taken from. (use Figure 9-2 in
your lab book as a guide)
o Clonorcus ( slide, model)
Whole mount slide: oral sucker, mouth, pharynx, intestine, uterus, anterior and posterior testes. (use
Figure 9-3 in your lab book as a guide).
o Taenia ( slides, model)
Slide: Rostellum with hooks, sucker, and the neck. (use Figure 9-7 in your lab book as a guide)
Psuedocoelomates
o Ascaris ( preserved specimens, model)
Model: mouth, pharynx, pseudocoel, intestine, oviducts, vas deferens, spicule, and anus (Use Figure 10-1
as a guide).
Cross section slide: intestine, cuticle, pseudocoel, longitudinal muscles, uterus with eggs. Make sure you
can tell male verses female cross sections
Study Lab Book Figures: 9-1, 9-2, 9-3, 10-2, 10-5, 10-7, pie-charts exercises 9 and 10.
Learning Activities
Acoelomates
Dugesia (Planarians)
Read pages 136-140 in your lab book
1. Observe the live specimen using your dissecting scope.
Observe the feeding behavior and movement of the Planarian.
*Make notes concerning its movement and speed. Compare to the Protozans you observed in lab
#5.
2. Observe the whole mount slides of the Planarian using your dissecting microscope and/or your
compound microscope.
Draw the specimen and label the important structures
(Eyespot, auricle, anterior & posterior trunk of intestine, and the pharynx)
View the Dugesia slides (cross sections) using your compound light microscope.
Draw the three cross sections and label the important structures.
(ventral nerve cord, diverticula of intestines, ciliated epidermis, anterior trunk of the
intestines, parenchyma cells, area of the body the cross section was taken from)
Clonorcus (liver fluke)
Read page 144 in your lab book.
1. Observe the whole mount slide using your compound light microscope and the model of the liver
fluke on the back table.
2. Draw the specimen and label the important structures.
(oral sucker, mouth, pharynx, intestine, uterus, anterior and posterior testes)
Taenia (Tapeworm)
Read pages 148-152 in your lab book.
1. Observe the model of the tapeworm on the back table. Observe the slides of the Taenia scolex.
Observe the preserved specimens.
2. Draw a picture of the tapeworm scolex. Label the important features.
(rostellum with hooks, sucker, and the neck)
3. Answer the following questions.
1. What is the difference between a proglottid and a strobila?
2. How long is the preserved specimen?
3. Where do you find gravid proglottids?
4. Is a tapeworm monoecious or dioecious?
Psuedocoelomates
Ascaris (Roundworms)
Read pages 157-160 in your lab book.
1. Observe the preserved specimens and the model located on the back table.
2. Observe slides containing cross sections of male and female Ascaris.
3. Draw the cross sections and label important structures.
(intestine, cuticle, pseudocoel, longitudinal muscles, uterus with eggs. Make sure you
can tell male verses female cross sections)
Identify the Unknowns on the back table
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