Difference Between Roundworm and Tapeworm

Main Difference – Roundworm vs Tapeworm

Roundworm and tapeworm are two types of invertebrates that live as intestinal parasites in other animals. Roundworms belong to the phylum Nematoda and tapeworms belong to the class Cestoda under the phylum Platyhelminthes. The main difference between roundworms and tapeworm is that roundworm has a cylindrical body tapered to a fine point at each end whereas tapeworm has a dorso-ventrally flattened, tape-like body. Both roundworms and tapeworms are triploblastic animals with bilateral symmetry. They are protostomes as well, exhibiting spiral, determinate cleavage. 

Key Areas Covered

1. What is a Roundworm
     – Definition, Body Structure, Pathology
2. What is a Tapeworm
     – Definition, Body Structure, Pathology
3. What are the Similarities Between Roundworm and Tapeworm
      – Outline of Common Features
4. What is the Difference Between Roundworm and Tapeworm
      – Comparison of Key Differences

Key Terms: Cestoda, Intestinal Parasites, Nematoda, Platyhelminthes, Roundworm, Sucking Mouthparts, Tapeworm

What is a Roundworm

Roundworm is a parasitic worm found in the intestines of mammals. More than 80,000 species of roundworms have been identified worldwide. Roundworms belong to the phylum Nematoda. Nematodes are cylindrical shape invertebrate worms. Most roundworms are parasitic. They are pseudocoelomates, consisting of a hard outer covering called cuticle in their epidermis. The outer covering prevents the expanding of the body and builds up a fluid pressure in the pseudocoelom. The body surface of roundworms consists of ridges, warts, and rings. The head of the roundworms possesses sensory bristles and solid shields. Roundworms consist of a complete digestive system. The mouth consists of a sharp stylet used for sucking liquid. A roundworm is shown in figure 1.

Figure 2: A roundworm

Some nematodes are hermaphrodites and others are dioecious. Hermaphrodites reproduce through self-fertilization. Separate male and female individuals reproduce through copulation. Filaria worms (cause elephantiasis), Ascaris (cause ascariasis), hookworms (infestation for a long time causes anemia and helminthiasis), Trichinella (cause trichinosis), and pinworms (infest the large intestine) are examples of roundworms. 

What is a Tapeworm

A tapeworm is a long, ribbon-like parasitic flatworm that lives in the intestine. It belongs to the class Cestoda under the phylum Platyhelminthes. There are over 5000 tapeworm species. The body of tapeworms is dorso-ventrally flattened and segmented. The segments are called proglottids. More segments are added to the body during the growth. The head of a tapeworm is called scolex. Scolex contains tentacles for sucking liquids. Tapeworms consist of an incomplete digestive system. A tapeworm is shown in figure 2.

Figure 2: A tapeworm

Tapeworms are hermaphrodites. Both types of sex organs are present in each individual. But, self-fertilization is rare in tapeworms. Most of the times, cross-fertilization occurs as the reproduction method. Taenia solium (pig tapeworm), Taenia saginata (beef tapeworm), Diphyllobothrium latum (fish tapeworm), and Echinococcus granulosus (dog tapeworm) are examples of tapeworms.

Similarities Between Roundworm and Tapeworm

• Both roundworm and tapeworm belong to the kingdom Animalia.
• Both roundworm and tapeworm are multicellular, mobile, invertebrates.
• Both roundworm and tapeworm show bilateral symmetry.
• Both roundworm and tapeworm show organ level organization.
• Both roundworm and tapeworm are triploblastic animals.
• Both roundworm and tapeworm are protostomes.
• Both roundworm and tapeworm show spiral, determinate cleavage.
• Most of the Roundworm and Tapeworm are parasitic worms.
• They require a host to complete their life cycle.
• Both roundworm and tapeworm feed on sucking liquids. On that account, both types of worms consist of specialized mouthparts.
• Both types of worms can be eliminated by deworming programmes.

Difference Between Roundworm and  Tapeworm

Definition

Roundworm: A roundworm is a parasitic worm found in the intestines of mammals.

Tapeworm: A tapeworm is a long, ribbon-like parasitic flatworm found in the intestine.

Classification

Roundworm: Roundworms belong to the phylum Nematoda.

Tapeworm: Tapeworms belong to the class Cestoda under the phylum Platyhelminthes.

Coelom

Roundworm: Roundworm is a pseudocoelomate animal.

Tapeworm: Tapeworm is an acoelomate animal.

Type of Protostomes

Roundworm: Roundworm belongs to the superfamily Ecdysozoa.

Tapeworm: Tapeworm belongs to the superfamily Lophotrochozoa.

Size

Roundworm: Ascaris lumbricoides, which is the largest roundworm in humans, may grow up to 35 cm.

Tapeworm: The size of the tapeworm may vary from 1 mm to 15 m.

Body Structure

Roundworm: Roundworm consists of a cylindrical body tapered to a fine point at each end.

Tapeworm: Tapeworm consists of a flat, tape-like body.

Outer Covering

Roundworm: Roundworm consists of a hard outer covering called cuticle.

Tapeworm: Tapeworm lacks a cuticle.

Segments

Roundworm: Roundworm has an unsegmented body. Its body is covered with ridges, warts, and rings.

Tapeworm: Tapeworm has a segmented body. The segments are called proglottids.

Head

Roundworm: The head of the roundworms consists of a sharp stylet for sucking.

Tapeworm: The head of the tapeworm, called scolex, is composed of four tentacles used for sucking.

Digestive System

Roundworm: Roundworm consists of a complete digestive system.

Tapeworm: Tapeworm consists of an incomplete digestive system.

Locomotion

Roundworm: Roundworm exhibits a gliding locomotion.

Tapeworm: Tapeworm exhibits a thrashing motion.

Reproduction

Roundworm: Roundworms are hermaphrodites, who reproduce through cross-fertilization.

Tapeworm: Tapeworms are unisexual animals, who reproduce through copulation.

Transmission

Roundworm: Roundworm can be transmitted by infected fecal matter or consuming animal tissue with worm larva.

Tapeworm: Tapeworms are transmitted by consuming infected fleas.

Location

Roundworm: Roundworms live in the small intestine.

Tapeworm: Tapeworms live in the intestine.

Diagnosis

Roundworm: Roundworms can be diagnosed by the fecal flotation exam. Adult roundworms may reveal through the vomit.

Tapeworm: Tapeworm segments can be identified in the feces. Diarrhea and vomiting may occur in large infections.

Pathology

Roundworm: Roundworm may cause large infections in lungs.

Tapeworm: Tapeworm infections may cause weight loss and tiredness.

Examples

Roundworm: Filaria worms, Ascaris, Trichinella, hookworms and pinworms are examples of roundworms.

Tapeworm: Taenia solium, Taenia saginata, Diphyllobothrium latum, and Echinococcus granulosus are examples of tapeworms.

Conclusion

Roundworms and tapeworms are two types of parasitic worms in the intestine of animals. Roundworms belong to the phylum Nematoda. They consist of a cylindrical body. Tapeworms belong to the class Cestoda under the phylum Platyhelminthes. They consist of a tape-like body. The main difference between roundworm and tapeworm is the structure of the body of each type of worm.

References:

1. Sandhyarani, Ningthoujam. “Roundworm Characteristics.” Buzzle, Buzzle.com, 31 July 2016, Available here.
2. “Tapeworms natural treatment.” Botanical-Online, Available here.

Image Courtesy:

1. “Canine roundworm 1” By Joel Mills – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Tapeworm SEM2” By Mogana Das Murtey and Patchamuthu Ramasamy – (CC BY-SA 3.0) via Commons Wikimedia