Demonstration Sheets for Filarial Nematodes & Acanthocephalans (Lab 5) Page Numbers are from 8 th ed of Roberts & Janovy

Phylum Nematoda Enterobius vermicularis Eggs Female worms emerge from the rectum during the night and lay their eggs around the anus. Eggs can be detected by microscopic examination of Scotch Tape ® that had been placed with the sticky side down, on the anal area. See Fig 27.5 (p. 449) Wards 92W 5693, 10X

Phylum Nematoda, Order Oxyurida Enterobius vermicularis Adult & Pinworm Body cavity is filled with eggs. The pointed tail is responsible for the common name. See Fig. 27.4, p. 449 92W 5695, 4X

Phylum Nematoda, Order Oxyurida Enterobius vermicularis Adult % Pinworm The tails of males are shorter and more curved than those of females. The mouth and esophageal bulb are easy to recognize. See Fig. 27.1 (p. 448) Trop. Biol. E. vermicularis male, 10X

Phylum Nematoda, Superfamily Filaroidea Wucheria bancrofti Elephantiasis This specimen is an advanced embryo or MICROFILARIAL LARVA. The surface is covered with a thin layer of epidermal cells in which the nuclei are well-stained. This is the stage that infects the mosquito. See Fig. 29.3 (p. 465). Tropical Biological, 40X

Phylum Nematoda, Superfamily Filaroidea Onchocercerca volvulus River Blindness Adults live in subcutaneous connective tissue where they are found in nodules. This slide is a section through such a nodule and shows cross-sections of the adult worms. See Fig. 29.5 (p. 468). Examine the slide under both 4X and 10X lenses to acquire a good perspective of the sample. Tropical Biological, 4 X – 10X

Phylum Nematoda, Superfamily Filaroidea Dirofilaria immitis Dog Heartworm This is the MICROFILARIAL LARVA stage that is transmitted to mosquitoes. As with the Wucheria example, the nuclei of the surface cells on the microfilaria stain very well. CBS Z 1020, 40X

Phylum Nematoda, Superfamily Filaroidea Dirofilaria immitis Dog Heartworm Adult worms are usually found in the right atrium, right ventricle, and pulmonary artery of dogs. The worms may lodge in the lungs of hosts after they die causing extensive damage. The most effective treatment is to destroy the infective larval stages before they become adults. Specimen

Phylum Acanthocephala Macracanthorhynchus This slide is a cross-section of the pig’s intestine showing the positioning of structures of the cephalic region of the worm imbedded in host tissue. See accompanying diagram and Fig. 32.13 (p 506) PS 2600, Dissecting scope

Phylum Acanthocephala Macracanthorhynchus hirudinaceus This large acanthocephalan (The specimen is broken into two parts) parasitizes pigs throughout the world. Pigs acquire the parasite by eating scarab beetle (larvae or adults) containing the infective cystacanth stage. Specimen

Phylum Arthropoda, Class Insecta, Order Coleoptera Scarab Beetle Species of scarab beetles feed on dung, carrion, and decomposing vegetation and are likely to be on pig farms where they can serve as intermediate hosts for Macracanthorhynchus hirudinaceus. Specimen

Phylum Acanthocephala Eggs Eggs of acanthocephalans can be recognized by the three concentric rings in the shell coating. The egg contains an acanthor larva. See Fig. 32.10a (p. 504) PS 2620, 10X

Phylum Acanthocephala Adult Male and Female Be able to recognize the sex of the specimens as well as the anterior from the posterior ends. See Figure 32.3 (p 498). CBS PS 2652, Dissecting scope

Phylum Acanthocephala Worms are embedded in the intestinal tissue of a bluegill (fish) taken from the Causeway in Mobile Bay.) Specimen, Dissecting scope

Phylum Acanthocephala Observe the spines on the proboscis. This structure is characteristic of the phylum. The specimen was taken from a gar caught in the Mobile Delta. (You will not be responsible for this latter piece of information.)