Demonstration Sheets for Adult Cestodes (Lab 3) (Page numbers for figures from 8 th ed of Roberts & Janovy) All specimens on display except the two arthropod intermediate hosts are Phylum Platyhelminthes, Class Cestoidea, Subclass Eucestoda
Proteocephalus Know the following structures on the proglottid (indicated on accompanying diagram). Uterus, Genital pore, Vitellaria, Ovary P5 1870, Dissecting scope
Order Pseudophyllidea Diphyllobothrium latum Know the following structures on the proglottid (indicated on accompanying diagram). Uterus, Genital pore, Vitellaria, Ovary, Testis CBS PS 1610, Dissecting
Order Pseudophyllidea Scolex of Diphyllobothrium latum Observe the groove-like bothria See Figs. 20.5l (p. 317) & 21.2 (p. 342) PS 1605, 10X
Phylum Arthropoda, Class Crustacea, Subclass Copepoda Copepod Serves as 1 st intermediate host for D. latum. Contains a metacestode when infected. (These specimens are not infected.) When infected copepods are eaten by fish, the fish become 2 nd intermediate hosts. Turtox Z9.124, 4X
Order Cyclophyllidea Proglottids of Taeniarhynchus saginatus (= Taenia saginata ) Human beef tapeworm. Be able to identify the following structures on model: scolex, neck, proglottid, uterus, testes, genital pore, vitellaria PS 1851, no scope
Order Cyclophyllidea Scolex of Taenia solium Human pig tapeworm. The adult stage of T. solium is found only in humans. People become infected when they eat undercooked pork containing the cysticerci. Scolex has a rostellum with hooks and acetabular suckers. Same species is depicted on model. See Fig. 21.14; p. 349 92W 5452, 10X
Order Cyclophyllidea Taenia solium Cysticercus (= metacestode stage), Dark red scolex with hooks is visible inside PS 1866A, 4X
Order Cyclophyllidea CYSTICERCOSIS caused by T. solium Cross-section of pig muscle showing the cysticercoid metacestode stage of T. solium . Humans can also harbor cysticerci develop from ingested ova or from proglottids that are carried back to the stomach from the small intestine by reverse peristalsis. This condition can be fatal. Cysticercosis is a major medical problem in Mexico. See Figs. 21.17 thru 21.19 (pp. 251-252) PS 1866, Dissecting
Order Cyclophyllidea Ova of Taenia pisiformis The outer embryophore layer surrounds the onchosphere inside. The pattern of the covering is characteristic of tapeworm eggs. Notice that there are pairs (3) of “teeth” or spines inside the ova. You will have to focus up & down to see all of them. See Figs. 20.20d (p. 326) & Fig. 21.13 (p. 348) PS 1830, 40X
Order Cyclophyllidea Taenia pisiformis Adult specimen The life-cycle and anatomy is much like its congener, T. solium. Intermediate hosts are rodents that are likely to be eaten by canines, e.g. rabbits, rats & squirrels. Definitive hosts are foxes, coyotes, wolves, dogs and domestic cats. Specimen, No scope
Order Cyclophyllidea Echinococcus granulosis Be able to distinguish: 1. Scolex, 2. Immature proglottid, 3. Mature proglottid, 4. Gravid proglottid (uterus filled with fertilized eggs) See Fig. 21.21, p. 354. Trop Biol Adult 2, 10X
Order Cyclophyllidea HYDATIDOSIS caused by Echinococcus granulosus Large hydatid cysts (= metacestodes) form in the organs of the mammals that serve as intermediate hosts. The cysts are filled with “hydatid sand” of which each “grain” contains one potential adult. A scolex with spines is visible inside each grain. See Figs. 21.23 & 21.24, p. 354 PS 1705, 10X
Phylum Arthropoda, Class Hexapoda (= Insecta), Order Siphonoptera Flea Ctenocephalus First intermediate host of the dog tapeworm, Dipylidium caninum. WM PS4822, 4X
Order Cyclophyllidea Scolex of Dipylidium caninum Observe: 1. Sucker-like acetabula, 2. Crown-like CORONA (= rostellum) bearing hooks anterior to the acetabula. This species is found in dogs, cats, and children in families with those pets who become infected by eating infected fleas. Trop Biol 1, 10X
METACESTODE Specimen was taken from the dorsal muscles of an amberjack off Dauphin Island. Whole Specimen, Dissecting
Order Trypanorhyncha Adult trypanorhynch tapeworms taken from the spiral valve (specialized organ in intestines of sharks) of a blacktip shark at the Dauphin Island Fish Rodeo. See Fig. 20.4b (p. 314), Fig. 20.5f (p. 315) & 21.40 (p. 362) Whole Specimen, Dissecting
Representative Scolices Moniezia, Taenia, and Dipylidium all have acetabular scolices. Two of the three scolices seen here have rostella with hooks. You will have to move the slide to see all specimens. Wards 92 W 5221, 4X