Trematoda: Flukes Anatomy and Life Cycle

What is a defining characteristic of trematodes in terms of their body structure?

What type of organs do trematodes use for attachment?

Which of the following statements about trematode eggs is accurate?

What is the primary role of the muscular pharynx in trematodes?

Which feature distinguishes schistosomes from other trematodes?

What is the significance of the tegument in trematodes?

Which aspect of trematodes is true regarding their reproductive strategy?

In which host does the adult stage of trematodes typically develop?

Trematoda

Flukes
Tough outer layer, called a tegument, protects against digestive enzymes and allows for gas exchange
Unsegmented body
Flattened, leaf-shaped body, except for schistosomes which are cylindrical
Organs of attachment: Oral sucker around the mouth, Ventral sucker on the underside of the body

Anatomy

No respiratory organs
Mouth connects to a muscular pharynx, then a short esophagus (except in schistosomes, which lack a pharynx)
No anus, waste is egested through the mouth
Eggs are operculated (have a lid), except for schistosomes
Excretory system present in some species, consists of proton ephridia
Nervous system consists of a pair of ganglia in the head region connected to nerve cords
No specialized sense organs
Most are hermaphrodites (both male and female reproductive organs present in one worm)

Life Cycle

Adult stage lives in the definitive host
Intermediate hosts are required for asexual reproduction
Intermediate hosts undergo the following stages: miracidium - sporocyst - daughter sporocyst - redia - cercariae
Eggs require water and snails to complete their life cycle

Fasciola

Fasciola gigantica is one species
Fasciola hepatica is another species
Egg:
- 150 x 90 µm
- Ovoid shape
- Thin, operculated shell
- Yellowish-brown color due to bile staining
- Contains immature embryonic cells

Explore the fascinating world of Trematoda, commonly known as flukes. This quiz delves into their unique anatomical features, reproductive strategies, and life cycles. Test your knowledge on their morphology, physiology, and ecological roles.