Acoelomates: Phylum Platyhelminthes and Nemertea - Biosciweb.net

Acoelomates: Phylum Platyhelminthes and Nemertea and
Pseudocoelomates: Phyla Nematoda and Rotifera & Parasitism 6.15
Lab #6 - Biological Sciences 102 – Animal Biology
Phylum Nemertea (Rhynchocoela = ribbonworms)
‣ Observe the specimens and/or diagrams of the species listed below.
‣ Record the descriptive information requested at the end of the lab for this species.
‣ Baseodiscus punneti or other
‣ List one anatomical structure seen in nemerteans that is not seen in other types of
aceolomate or pseudocoelomate worms.
Phylum Nematoda (roundworms)
‣ Observe the specimens and/or diagrams of the species listed below.
‣ Record the descriptive information requested at the end of the lab for this species.
‣ Ascaris lumbricoides = human intestinal parasite
‣ Observation of Nematode Body Structures
‣ Using a microscope and the preserved, prepared slides identify the following structures of
cestodes.
‣ Examine a prepared slide of Ascaris lumbricoides male and female. Note the
following structures: (you do not need to draw this, but you should be able to
identify these in a diagram)
‣ epidermis
‣ cuticle
‣ muscle cells & processes
‣ intestine
‣ pseudocoel
‣ longitudinal muscles
‣ lateral lines/nerve cords
‣ excretory canals (as visible)
‣ In the female Ascaris cross section locate the following:
‣ ovary
‣ oviduct
‣ uterus Can you recognize the ova?
‣ In the male Ascaris cross-section (on the same slide) locate the :
‣ testes
‣ vas deferens (as visible)
‣ Observation of a Free-Living Nematode Roundworm
Obtain a sample of living “vinegar eels”, Turbatrix aceti, and examine under the 10X
objective and the 20X or 40X of the compound microscope. You should add Proto-Slo
to the preparation before adding the cover slip.
‣ Note the direction of movement, which is actually dorso-ventral (rather than
lateral) bending.
‣ What is it about the muscular structural arrangement in nematodes that permits
only this characteristic “whip-like” motion?