Demonstration Sheets for Adult Cestodes (Lab 3)
(Page numbers for figures from 8th 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
st
Serves as 1 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 2nd 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