This experiment is from the official website of Parasitology, School of Medicine, Shandong University.
Operation method
Tick morphology observation experiment
Principle
Ticks are parasitic and have a wide range of hosts, from amphibians to mammals. It is a vector and reservoir host for many pathogens, such as viruses, bacteria, rickettsiae and spirochetes. It also transmits certain animal diseases to humans and plays an important role in the epidemiology of naturally occurring diseases. Move A hard tick: the back of the carapace has a hard shield plate, so it is called a hard tick. Take the full-grooved tick as an example, first observe the shape and size with the naked eye, the position of the palpal body, the shape and number of feet. Note the size of the shield plate to distinguish between male and female. Then observe its general morphological structure under a low-power microscope. For more product details, please visit Aladdin Scientific website.
1. Palatal body (prosthesis): embedded in the concave edge of the anterior end of the torso and consists of the following parts.
(1) Chelicerae: 1 pair, protruding from the dorsal front of the palatine base, divided into chelicerae and chelicerae, chelicerae are divided into fixed and movable toes, chelicerae are outsourced with chelicerae sheaths, and their function is to cut the skin of the host to draw blood.
(2) Palatine base (base of pseudocapitate): behind the chelicerae and connected to the carapace, its dorsal shape is related to the classification.
(3) Suboral plate: protrudes from the center of the ventral surface of the palatine base, and has several rows of left-right symmetrical inverted teeth on the ventral surface, which are used to attach to the skin of the host when sucking blood. The suboral plate is usually not easily visible from the dorsal surface because it is located below the chelicerae.
(4) Tentacles: 1 pair, protruding from the anterior corners of the palpal body, on both sides of the chelipeds, consisting of four segments, the fourth segment being extremely small and located on the ventral surface of the terminal end of the third segment. The tentacles mainly play a fixed and supportive role when sucking blood. See figure below.
2. Carapace: fused from cephalothorax and abdomen, oval, dorsoventrally flattened. The surface is leathery and elastic.
(1) Dorsal surface: one shield, the shield of female ticks is smaller, covering only a small part (about 1/3) of the anterior part of the carapace. The shield of the male tick covers the entire dorsal surface.
(2) Ventral surface: four pairs of feet, note that the tarsal segment of the first pair of feet has a harpactic apparatus near the end of the dorsal surface with sensory function.
(3) Genital foramen: in the middle of the anterior 1/3 of the carapace, its opening is a transverse fissure.
(4) Anus: in the middle of the posterior 1/3 of the carapace, the anus is preceded by a curved groove called the anal sulcus. 
(5) Valves: posterior to the basal segment of the fourth pair of legs, with peripheral ovoid valve sieve plates. Male ticks still have several bony plates on the ventral surface. 
Note: The shape of the palatal base, the presence or absence and position of the anal groove, the presence or absence of eyes, the presence or absence of the ventral bony plates, and the presence or absence of patterns and rims are all characteristic of the subgenus Sclerotinia. -The following are the characteristics of the hard ticks in the family.
Second, soft ticks; observed with a magnifying or dissecting microscope. Brownish-brown in color, the basic morphology is similar to that of the hard ticks, the main differences are as follows:
1. The palatine body is in the anterior part of the ventral surface of the carapace, and cannot be seen from the back.
2. No shield.
3. Valves between third and fourth pairs of basal segments of legs.
4. Male and female are similar in appearance and not easy to recognize, the genital pore is transverse furrowed in females and semilunar in males. 