What is the Difference Between Flukes and Tapeworms

The main difference between flukes and tapeworms is that flukes belong to class trematodes while tapeworms belong to class cestodes.

Flukes and tapeworms are two classes of helminths: worm-like parasites. Generally, flukes are leaf-shaped while tapeworms are elongated, flat, and segmented. Both are hermaphroditic worms except for blood flukes, which are bisexual. The main characteristic features of flukes and tapeworms are the presence of flame cells, a ladder-like nervous system, the presence of parenchyma cells in the body cavity, and self-fertilization. Moreover, both types of worms are responsible for pathogenic changes in humans. However, flukes are mostly parasitic while tapeworms are exclusively parasitic.

Key Areas Covered

1. What are Flukes
   • Definition, Structure, Function
2. What are Tapeworms
   • Definition, Structure, Function
3. Similarities Between Flukes and Tapeworms
   • Outline of Common Features
4. Difference Between Flukes and Tapeworms
   • Comparison of Key Differences

Key Terms

Flukes, Helminths, Tapeworms

What are Flukes

Flukes are helminth worms that make up the class Trematoda. They are leaf-shaped, ranging in length from a few millimeters to 7 to 8 cm. Their tegument is morphologically and physiologically complex. Furthermore, flukes possess an oral sucker around the mouth and a ventral sucker or acetabulum to adhere to host tissues.

Figure 1: Flukes

However, they lack a body cavity. On the other hand, their organs are embedded in specialized connective tissue or parenchyma. The layers of somatic muscle permeate the parenchyma and attach to the tegument.

What are Tapeworms

Tapeworms are the helminths that make up the class Cestoda. Usually, the adult tapeworms are flattened, elongated, and consist of segments: proglottids. They also vary in length from 2 to 3 mm to 10 m and may have three to several thousand segments. Anatomically, the body of the tapeworms contains three parts: the head, neck, and proglottids.

Figure 2: Taenia proglottids

Here, the head or scolex bears the organs of attachment; the neck is the region of segment proliferation; a chain of proglottids is called the strobila. Furthermore, strobila elongates as new proglottids form in the neck region.

Similarities Between Flukes and Tapeworms

• Flukes and tapeworms are two classes of helminths.
• They are parasites: parasitic on vertebrates.
• They possess a dorsoventrally flattened body, bilateral symmetry, and a definite anterior end.
• Flukes and tapeworms are triploblastic and acoelomate.
• Their body has a soft covering with or without cilia.
• In general, they have organ-level organizations.
• They lack a circulatory system.
• Platyhelminths have a mouth but, no anus.
• But both have hooks and suckers.
• They breathe through simple diffusion.
• Generally, both are hermaphroditic and undergo both sexual and asexual reproduction.
• Their life cycle contains one or two larval stages.
• Furthermore, both types of worms are capable of regeneration.
• Their flame cells help excretion and osmoregulation.
• Moreover, their nervous system comprises the brain and two longitudinal nerve cords arranged in a ladder-like fashion.
• In addition, they have parenchyma cells in their body cavity.

Difference Between Flukes and Tapeworms

Definition

Flukes refer to the leaf-shaped parasitic flatworms while tapeworms refer to the flattened, elongated, helminths that consist of segments called proglottids.  

Shape

Usually, flukes are leaf-shaped while tapeworms are elongated and have segments called proglottids.

Alimentary Canal

Flukes have a well-developed alimentary canal while tapeworms lack an alimentary canal.

Conclusion

Both flukes and tapeworms are hermaphrodites. In brief, flukes are trematodes, a class of Platyhelminthes worms with dorsoventrally flat bodies. Moreover, flukes have a leaf-shaped body and a complete digestive system. On the other hand, tapeworms are another class of Platyhelminthes worms with an elongated body with segments called proglottids. However, they do not have a complete digestive system. Hence, the main difference between flukes and tapeworms is their classification. 

References:

1. Castro GA. Helminths: Structure, Classification, Growth, and Development. In: Baron S, editor. Medical Microbiology. 4th edition. Galveston (TX): University of Texas Medical Branch at Galveston; 1996. Chapter 86.

Image Courtesy:

1. “Botulus microporus ” By en:User:Anilocra – Own Work (Public Domain) via Commons Wikimedia
2. “Taenia solium tapeworm proglottids 5261 lores ” (Public Domain) via Commons Wikimedia