ExerciseⅤ Observation of Trematodes
Purpose
1.Master the use and maintenance of microscope.
2.Master the morphological features（adult and egg）of different genius of medical trematodes include Clonorchis Sinensis（Chinese liver fluke），Fasciolopsis Buski（intestinal fluke），Paragonimus Westermani（lung fluke）and Schistosomes.
Experimental principle
To observe the morphological features（adult and egg）of different genius of medical trematodes by the optical microscope.
Laboratory equipment
1.Optical microscope.
2.Human parasitology teaching specimen.
Experiment methods and contents
Methods：find the parasites at low magnification，and then observe them with high magnification（if necessary）.
Contents：
Clonorchis Sinensis（Chinese liver fluke）
Corresponding book color chart NO.43
1.Adult worm Observe the Liquid immersion specimens.
The adult worm live in the human biliary tract for 15 years or more，it has a flat transparent body，spatulated，pointed anteriorly and rounded posteriorly.
2.Egg
Broadly ovoid 30μm×15μm with a yellowish brown shell，it has an operculum at one pole and a small hook like spine at the other.Looks like the sunflowers seed.
Fasciolopsis Buski Corresponding book color chart NO.44.
1.Adult worm
Observe the Liquid immersion specimens.（Figure 1）
Figure.1 clonorchis sinensis and egg
The adult worm：It is a large freshy worm，20-75 mm long and 8-20 mm broad.
（1）It is elongated ovoid in shape，the ventral sucker is much larger than the oral sucker，and there is no cephalic（head）cone.
（2）The two intestinal caecum do not bear any branches.
2.Egg（Figure 2）
Broadly ovoid 130μm×140μm with a yellowish brown shell，it has an operculum at one pole（not obvious）.Egg contains an embryo and dozens of yolk cell.
Figure 2 Fasciolopsis buski and egg
Paragonimus westermani Corresponding book color chart NO.45(https://www.daowen.com)
1.Adult worm
Observe the Liquid immersion specimens.
The adult worm：The thick-bodied，reddish-brown adult worm measures 7.5-12 mm long and 4-6 mm wide.
（1）The integument is covered with scale like spines.
（2）It has oral sucker placed anteriorly and a ventral sucker located towords the middle of the body.（Figure 3）
Figure 3 Paragonimus westermani and egg
2.Egg
Broadly ovoid，80～118 mm by 48～60 mm，with a yellowish brown shell，it has an operculum at flattened end.The egg contains an undivided fertilized embryo and more than 10 yolk cells.
S.japonicum Corresponding book color chart NO.46.47.
1.Adult worm
Observe the Liquid immersion specimens.
（1）Characterized by significant sexual dimorphism-Dioecious.
（2）Schistosoma=split body.
The body of the worm is thin columnar.
（3）It has oral sucker and ventral sucker.
2.The male
（1）The body is greyish white，10-15mm long by 1 mm thick and covered by a finely tuberculated cuticle.
（2）The body is slightly curled to the ventral surface to form the gynecophoric canal，in which the female worm is held，so the worm is thin columnar.
（3）The circular testes were arranged in clusters beneath the ventral sucker.
3.The female：
（1）The body is dark brown，long and slender，20mm long by 0.2mm thick with the cuticular tubercles confined to the two ends.
（2）The gravid worm contains 20-30 eggs in its uterus at one time and may pass up to 300 eggs a day.（Figure 4）4.Egg
Figure 4 S·japonicum
All Schistosomes eggs are pale yellow-brown to colorless and contains a fully developed Miracidium.No operculum.Round to oval 90μm×65μm.Rudimentary spine（Lateral spine）.
Laboratory report
To draw the morphology of eggs of Clonorchis Sinensis（Chinese liver fluke），Fasciolopsis Buski（intestinal fluke），Paragonimus Westermani（lung fluke）and Schistosomes.（Figure 5）
Figure 5 Three species of eggs