Main Difference – Predation vs Parasitism
Predation and Parasitism are two types of interspecific interactions that occur in an ecosystem. Interspecific interactions are a type of interactions that occur between individuals of different species. Both predation and parasitism are harmful interactions. The active organism in predation is called predator while the passive organism is the prey. In parasitism, the active organism is called the parasite and the passive organism is the host. The main difference between predation and parasitism is that the predator immediately kills the prey in predation whereas parasite does not kill the host organism. However, in some cases, the parasite may eventually kill the host organism.
Key Areas Covered
1. What is Predation
– Definition, Characteristics, Examples
2. What is Parasitism
– Definition, Characteristics, Examples
3. What are the Similarities Between Predation and Parasitism
– Outline of Common Features
4. What is the Difference Between Predation and Parasitism
– Comparison of Key Differences
Key Terms: Ecosystem, Host Organism, Interspecific Interactions, Parasite, Parasitism, Predation, Predator, Prey
What is Predation
Predation refers to the act of preying of animal on another animal. The predator is the active organism during predation. The predator immediately kills the prey. Lions eating zebras, foxes eating rabbits, and bears eating fish are some examples of predation. This concept can also be applied to the plants as well. Bear eating berries, rabbits eating lettuce, and grasshoppers eating leaves are some examples of predation in plants. A bear catching a salmon fish is shown in figure 1.
Figure 1: A Bear Catching a Salmon Fish
Both predator and prey are evolved in the same ecosystem. The predator kills the prey for food. In order to kill the prey, predator should be stronger than the prey. The predator should have the speed, stealth, and camouflage. It should also have a good sense of hearing, sight, and smell. The predator should also have immunity against poisons of the prey. Predators that eat animals have a monogastric digestive system. The prey also has characteristics that help to escape from the predator. It may have the speed, good senses, poisons, and thorns.
What is Parasitism
Parasitism refers to the act in which one organism lives in or on another organism as a parasite. Since the parasite grows, feeds, and is sheltered upon the host organism, the relationship is harmful to the host organism. Though most parasites do not kill the host organism, some parasites may eventually kill the host. These parasites are pathogenic, causing diseases in the host. Ectoparasites such as lice, mosquitoes and fleas, protozoans such as amoeba and Plasmodium, and worms such as roundworm, tapeworm, and pinworm are parasitic in humans. Aphids and some insects are plant parasites drinking the sap. A mosquito biting a human is shown in figure 2.
Figure 2: A Mosquito Bite
The parasites in the intestine of animals feed on partly digested food. Generally, parasites are small in size than the host organism. But, they exhibit higher reproduction rates once they invade the host. Some of the developmental stages of the parasitic life cycle occur inside the host.
Similarities Between Predation and Parasitism
- Both predation and parasitism are interspecific interactions between two different species in an ecosystem.
- Both of the species in predation and parasitism are evolved in the same ecosystem.
- Both predation and parasitism are harmful to one species and are beneficial to the other.
Difference Between Predation and Parasitism
Definition
Predation: Predation refers to the act of preying of one animal on another animal.
Parasitism: Parasitism refers to the practice of living as a parasite on or with another animal or organism.
Relationship
Predation: Predation occurs between a predator and a prey.
Parasitism: Parasitism occurs between a parasite and a host organism.
Specificity
Predation: Predator may have several types of preys.
Parasitism: Parasitism is a very specific relationship.
Metabolic Dependency
Predation: Predation lacks any type of metabolic dependency on the prey.
Parasitism: Parasitism metabolically depends on the host organism.
Size
Predation: Predator is generally larger and stronger than the prey.
Parasitism: Parasite is smaller than the host organism.
Progression
Predation: Predator is very active and uses intense physical effort to catch the prey.
Parasitism: Parasite is generally passive in its progression.
Killing the Other
Predation: Predator immediately kills the prey.
Parasitism: Parasite does not immediately kill the host organism.
Completion of Life Cycle
Predation: The life cycles of predator and prey are independent of each other.
Parasitism: Parasite requires the host in order to complete its life cycle.
Examples
Predation: Predation occurs between lion and zebra, fox and rabbit, and bear and fish.
Parasitism: Parasitism occurs between mosquito and human, lice on humans, tapeworms in cows, and Cuscuta in plants.
Conclusion
Predation and parasitism are two interspecific relationships that occur between two different species of an ecosystem. In predation, the predator immediately kills the prey while in parasitism, the parasite does not kill the host organism. Generally, a predator is large in size than the prey. On the other hand, a parasite is smaller than the host organism. The main difference between predation and parasitism is the type of relationship between the individuals of the two species.
Reference:
1. “Predator-Prey Relationships.” Evolution, Available here.
2. “Parasitic Relationships.” Evolution, Available here.
Image Courtesy:
1. “Bear predation on salmon can be high in many Alaskan rivers” By Mark Wipfli, Alaska Cooperative Fish and Wildlife Research Unit. Public domain. – United States Geological Survey (Public Domain) via Commons Wikimedia
2. “Mosquito bite from Flickr” By WildTurkey (CC BY 2.0) via Commons Wikimedia
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