Demonstration Sheets for Amebas, Ciliates, Miscellaneous Phyla (Lab 10) [Figures & page numbers are from Roberts & Janovy, 2009, 8 th ed.]

Phylum Sarcodina, Class Lobosea, Family Endamoebidae Trophozoite Entamoeba histolytica Observe: 1. Nucleus, 2. Endosome (= nucleolus) in center of nucleus, 3. Chromatin on periphery of nucleus, 4. Vacuoles, 5. One pseudopod 92W 4083, oil

Phylum Sarcodina, Class Lobosea, Family Endamoebidae Cyst Entamoeba histolytica Transmission stage has 4 nuclei. See Fig. 7.4, p. 110. 4-2, oil

Phylum Sarcodina, Class Lobosea Naegleria fowleri These cells have been cultured free of host tissue, so they represent the free- living stage of this facultative parasite. Pseudopodia are more easily seen if one focuses up and down. See Fig. 7.13 (p. 117). 92W 4128, oil

Phylum Sarcodina, Class Lobosea Naegleria fowleri in situ Cells of this facultative parasite have invaded vertebrate brain tissue. Darkly stained cells of the parasite are visible inside and around the periphery of the lighter stained host tissue. It is difficult to recognize pseudopodia in this preparation. See Fig. 7.18 (p. 120) for photograph of a related species in a baboon brain. 92W 4129, 40X

Ciliophora, Class Litostomatea Balantidium coli Trophozoites in fecal smear. Individuals can be easily recognized as ciliates by the prominent, large macronucleus. See Fig. 10.3 (p. 176). CBS PS 1100, 40X

Phylum Ciliophora, Order Entodiniomorphida These ciliate symbionts were collected from the lumen of a sheep. Members of this order are found as commensals in ruminant mammals. See Fig. 10.5 (p. 177). 92W 0494, 10X

Phylum Mollusca; Class Bivalvia; Family Unionidae Glochidium larvae Freshwater unionid mussels are able to colonize upstream habitats by producing larvae that parasitize fish. The larvae burrow into fin and gill tissues where they feed upon host fluids as a true parasite. Upon completion of development, the juveniles drop off hosts, who have moved up and downstream since infection, burrow into the substrate of the stream and become filter feeders. CBS Z 1480, 10X

Phylum Annelida; Class Hirudinea Leech Leeches are segmented worms with two suckers. Although many are true predators of invertebrates, their infamous reputation comes from the few species that are micropredators on vertebrates. 92W 1851, Dissecting scope

Phylum Nematomorpha Horsehair Worm These fairly large worms have juvenile stages that parasitize the body cavities of large arthropods. When nematomorphs mature in terrestrial hosts, their hosts seek out and enter freshwater which stimulates the worms emerge resulting in host death. This specimen was found in a well in Brazil. The sudden appearance of adult horsehair worms in water troughs led to the “folk wisdom ” explanation that these worms developed from hairs that had been shed by drinking horses. Nematomorphs can be distinguished externally from nematodes by the presence of blunt (rather than pointed) ends. Specimen, Dissecting scope

Phylum Nemertea Carcinonemertes Most nemerteans are free-living predatory worms that catch their prey with a conspicuous proboscis that you cannot see on these specimens. Members of the family represented by these specimens are symbionts that feed on the eggs of crabs. They live in the external egg masses of egg-bearing females and feed on the eggs and are known as “egg predators. ” Specimen, Dissecting Scope

Kingdom Plantae Haustoria of Dodder This twig is from an oak growing across the street from the Life Science Building. It was parasitized by a dodder plant whose yellow tendrils have since fallen off. Open “wounds ” or scars where the dodder ’s haustoria penetrated the host tree are visible. Specimen, Dissecting scope

Kingdom Plantae Dodder Although some species of dodder contain low numbers of chloroplasts giving them a slight yellow green tinge as seen in these specimens, the plants are true parasites in that they acquire nutrients from host plants. Specimen

Kingdom Plantae Indian Pipe This specimen was collected from the pine forest along the university ’s Nature Trail. Indian pipes have no chlorophyll and can be recognized in the wild by their opaque white coloration. The dark coloration of this specimen is an artifact of preservation. Indian pipes actually parasitize ectomychorrhizal fungi that form mutualistic associations with plants. The parasitic plant extracts sugars from the fungus that were produced in the tree. Specimen

Phylum Myxozoa PANSPOROBLAST The cyst located on gills of this fish is a pansporoblast and is filled with spores that will infect any predatory fish that feeds on this host. CBS PS 445, 10X

Phylum Myxozoa Myxosoma This genus was introduced to North America from fish stock imported from Europe. It causes “whirling disease ” in native North American trout and salmon. Spores inside the pansporoblast contain polar capsules each filled with a filament ending in a harpoon-like structure that becomes embedded in a cell lining the digestive tract of the new host. The polar filaments reflect light fairly well and glisten under oil immersion. Focus up and down to see the nucleus clearly. CBS PS 445, oil

Phylum Apicomplexa; Subclass Gregarinasina; Suborder Septatorina Cephaline Gregarines Gregarines in this suborder are common in insects. The two slides on display are cross-sections through larval mealworms. Members of the Septatina or cephaline gregarines are characterized by a septum that divides the cell into two sections. The posterior portion or deutomerite contains the nucleus. Observe the protomerite, septum, epimerite (hard to see), deutomerite, and nucleus in deutomerite. PS 415, 40X

Phylum Apicomplexa; Subclass Gregarinasina; Suborder Septatorina Gregarine Reproduction Two individuals or gamonts have paired prior to forming a cyst. See Figure 8.3d (p. 126). Wards 92W 4543, 40X

Phylum Cnidaria; Class Anthozoa Parasitic Sea Anemone Edwardsia sp. This specimen (undescribed species) was collected from the medusa stage of another cnidarian, the moon jellyfish Aurelia, in the Gulf of Mexico. The parasite feeds on the gonads of its hosts. Due to the fixation process, the tentacles of the sea anemone have withdrawn into its body cavity. Specimen

Phylum Chordata; Subphylum Vertebrata; Class Osteichthyes CANDIRU These catfish live in the Amazon and Orinoco Rivers of South America. They feed on gills of other fish which they locate by following an ammonia trail. Strictly speaking, their trophic and ecological interactions classify them as micropredators and along with vampire bats, they have adapted a life-style that is close as vertebrates have come to true parasitism. Occasionally candiru, responding to ammonia in a urine stream from a mammal “taking a leak ” in a stream, will become lodged in the urethra of the unfortunate victim. Specimen