Smaller Protostome Phyla: Rotifera, Gastrotricha, Nematomorpha & Acanthocephala Bio 1413: General Zoology Lab (Ziser, 2008) [Exercise 10B] Lab Activities: 1. Rotifers (p167) slide: Rotifers, wm • Examine prepared slide of a rotifer and be able to identify the following structures: corona, foot, mastax, digestive tract, reproductive tract • Attempt to locate and to identify living rotifers from the water samples provided • Recognize and identify rotifers on illustrations and be able to identify to Phylum 2. Gastrotrichs (p167) slide: Gastrotrichs, wm • Observe living specimens (if available) and note their appearance and movement • examine prepared slides of a gastrotrich and identify: mouth, pharynx, adhesive gland, scales 3. Nematomorpha (p168) preserved: horsehair worms • examine living and/or preserved horsehair worms as available and be able to recognize them and distinguish them from other “wormlike” phyla 4. Acanthocephala (p168) • examine preserved specimens and slides as available and be able to recognize them and distinguish them from other “wormlike” phyla eg. Macracanthorhynchus preserved: Macracanthorhynchus this animal is parasitic in the intestine of pigs, the larvae develop in beetle grubs which are eaten by pigs to complete its life cycle eg. examine the prepared slide slide: acanthoceophala, wm identify the following: retractable proboscis with hooks, proboscis receptacle, ligament sac Notebook Suggestions:

 Describe the kinds of movement seen in live rotifers and compare to the movement seen in roundworms; is it similar?

 Diagram some of the variety of rotifers in samples and illustrations; what characteristics do all share; how do each differ

 If living gastrotrichs are available, describe how their movement differs from that of rotifers.  Can you identify any organs on the gastrotrich

 Describe the similarities and differences between acanthocephala and nematomorpha

 make a diagram of the general life cycle of a horsehair worm and an acanthocephalan