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1. Title Types of Biotic Interaction I: Symbiosis

2. Module Objectives At the end of this module, you should be able to: • Define the symbiotic relationship between biotic factors. • Define the terms commensalism, parasitism, and mutualism. • Provide examples for each type of symbiotic relationship.

3. Prerequisites Knowledge Before starting this module, you should have gone through the following module: Module 6.1.2: Identify the biotic factors in an ecosystem

4. Introduction

5. Introduction In science terminology, we call it Symbiosis, where we, as living species, interact with each other to benefit each other. Very simple, I am good with Science and you are good with Maths. I will complete your assignment and you will help me completing mine. I am so happy, Mark that you came here. • I have a Maths assignment and I am struggling like hell!! I have an idea! No mate! Rather, we can help each other. Let me just explain you briefly. Hmmm!!! I have heard of this term. Not sure what it means. Haaa!! Sam, I think, we are sailing in the same boat. Even I have a Science assignment that I am struggling with. What is it? Don’t tell me that we can skip our assignments! • And, how will that happen?

6. Symbiosis Let me first explain you the meaning of Symbiosis.

7. Symbiosis Symbiosis is defined as a close relationship between two or more different species, regardless of the effect on the species involved.

8. Symbiosis Oh my god! That was over my head. Could you please repeat that?

9. Symbiosis Mark is finding it difficult to recall the definition of Symbiosis. Could you help him by completing the missing words in the definition written below? Select the relevant word from the drop-down list. Click the Submit button. Symbiosis is defined as a close relationship between two or more different species, regardless of the effect on the species involved. Submit

10. Symbiosis Correct Feedback Well done! You are right. Mark is finding it difficult to recall the definition of Symbiosis. Can you help him by completing the missing words in the definition? Select the relevant word from the drop-down list and click the Submit button. Incorrect Feedback You are almost there! Symbiosis is defined as a close relationship between two or more different species, regardless of the effect on the species involved. Symbiosis is defined as a close relationship between two or more different species, regardless of the effect on the species involved. Submit

11. Symbiosis Symbiosis are of three kinds. Commensalism Symbiosis Parasitism Mutualism

12. Symbiosis Let’s first understand Commensalism.

13. Commensalism That is the perfect example of Commensalism, where bird gets food from the back of the cow but the cow is not affected. Let me just define Commensalism for you. Hey Mark, do you remember our visit to the local zoo last month? Do you remember the bird sitting at the back of a cow? Yeah! The white bird and black cow. Yeah! Why?

14. Commensalism Commensalism is a relationship between different species where one species known as the commensal benefits, while the other species or host is not harmed but neither does it experience any particularly positive effects.

15. Commensalism Let’s see if you know the definition of Commensalism by now. Construct the definition of Commensalism from the below jumbled words. Click the Submit button. Commensalism while harmed not a relationship is species is where symbiotic the species one other benefits Submit

16. Commensalism Correct Feedback Well done! You are right. Let’s see if you know the definition of Commensalism by now. Construct the definition of Commensalism from the below jumbled words and click the Submit button. Commensalism while harmed not Incorrect Feedback You are almost there! Commensalism is a symbiotic relationship where one species benefits, while the other species is not harmed. a relationship is organism is where symbiotic the organism one other benefits Submit

17. Commensalism Commensalism can be of two kinds. Epiphytes Commensalism Epizoics

18. Commensalism Let’s first understand Epiphytes.

19. Commensalism • Epiphytes Epiphytes are usually green autotrophic plants that grow on trees. They depend on trees to provide support and access to sunlight and air, but they do not obtain nutrients from the trees and therefore do not pose any harm to them. Examples of epiphytes are pigeon orchids, lichens, and bird nest ferns.

20. Commensalism • Epiphytes Epiphytes carry out photosynthesis and produce their own food. However, they also have other requirements that they cannot get from photosynthesis, such as water and minerals. Hence, epiphytes have adapted in other ways to obtain these requirements for survival from the environment but not from their hosts.

21. Commensalism • Epiphytes These adaptations include aerial roots to absorb moisture from the air; thick and waxy cuticles to reduce water loss through transpiration; and swollenstems to store water.

22. Commensalism Next, let’s talk about Epizoics, which is an another kind of Commensalism.

23. Commensalism • Epizoics Epizoics are animals that attach themselves to their hosts for transportation and access to food.

24. Commensalism • Epizoics For example, the tiny remora fish attaches itself to a shark which carries it around. The remora also gets to eat the leftovers of prey which the shark catches and eats. The shark does not suffer due to the remora's presence, but it also does not get any benefit.

25. Commensalism • Epizoics Epiphytes such as ferns grow their fronds or leaves in a way where they easily catch falling dead organic matter like tree bark and leaves. This collection of organic matter acts like a sponge that absorbs water from the environment.

26. Commensalism Let’s test your understanding on Epiphytes and Epizoics. Drag and drop the correct definition of Epiphytes and Epizoics. Click the Submit button. Epiphytes Epizoics Animals that attach themselves to their hosts for transportation and access to food. Plants that grow upon or are in some manner attached to another plant or object merely for physical support. Submit

27. Commensalism Let’s test your understanding on Epiphytes and Epizoics. Drag and drop the correct definition of Epiphytes and Epizoics and click the Submit button. Correct Feedback Well done! You are right. Incorrect Feedback You are almost there! Epiphytes are plants that grow upon or are in some manner attached to another plant or object merely for physical support. While Epizoics are animals that attach themselves to their hosts for transportation and access to food. Epiphytes Epizoics Animals that attach themselves to their hosts for transportation and access to food Plant that grows upon or is in some manner attached to another plant or object merely for physical support. Submit

28. Parasitism What happened? Sorry to hear that. But, what a coincidence! I was about to discuss our next Symbiosis category, Parasitism. Mosquitoes are indeed a very good example of Parasitism, where one species known as the parasite benefits, while the other species or host is harmed. In your case, Mosquito is the parasite benefits and you are host who is harmed by the bite. Let me explain you in detail. What mosquito has to do with Parasitism? I think a mosquito just bit me. Outch!

29. Parasitism Parasitism is a relationship between different species where one species known as the parasite benefits, while the other species or host is harmed.

30. Parasitism Let’s test your understanding on Parasitism. Drag and drop the words to complete the definition of Parasitism. Click the Submit button. Parasitism is a relationship between different species where one species known as the parasite benefits, while the other species or host is harmed. parasite host harmed benefits Submit

31. Parasitism Correct Feedback Well done! You are right. Let’s test your understanding on Parasitism. Drag and drop the words to complete the definition of Parasitism and click the Submit button. Parasitism is a relationship between different species where one species known as the parasite benefits, while the other species or host is harmed. • Incorrect Feedback • You are almost there! Parasitism is a relationship between different species where one species known as the parasite benefits, while the other species or host is harmed. parasite host harmed benefits Submit

32. Parasitism Parasitism can be of two kinds. Endoparasites Parasitism Ectoparasites

33. Parasitism Let’s first understand Endoparasites.

34. Parasitism • Endoparasites Parasites that live inside a host, such as tapeworms, are called endoparasites. These parasites have generally simplified digestive tracts and nervous systems, and the ability to absorb nutrients through the surface of their bodies, similar to unicellular organisms.

35. Parasitism • Endoparasites Most endoparasites have slightly flattened shapes that allow them to cling to surfaces inside the host. This body shape also allows maximum absorption of nutrients from their hosts. At the same time they have also developed certain adaptations to survive inside a host body.

36. Parasitism Now, let’s talk about Ectoparasites.

37. Parasitism • Ectoparasites Parasites that live on the outside of an organism – such as the mosquito mentioned earlier – are called ectoparasites. They usually have evolved sharp hooks or mouth parts that enable them to bite and latch on to their hosts, and suck out their nutrients.

38. Parasitism • Ectoparasites Interestingly, the largest flower in the world, Rafflesia, is a parasite that lives on the Tetrastigma vine. Rafflesia has no roots, stems or leaves, but it has threadlike tissues that are similar to fungal mycelia. It embeds these strands into the host vine in order to obtain nutrients from it.

39. Parasitism Let’s see if you remember the types of Parasitism. Below is the list of few examples. Drag and drop the type of Parasitism to its relevant example. Click the Submit button. • Ectoparasites • Endoparasites Rafflesi Mosquitos Tapeworm Submit

40. Parasitism Correct Feedback Well done! You are right. Let’s see if you remember the types of Parasitism. Here is the list of few examples. Drag and drop the type of Parasitism to its relevant example and click the Submit button. Rafflesi Mosquitos Tapeworm Incorrect Feedback You are almost there! Rafflesi and Mosquitos are examples of Ectoparasites and Tapeworm is an example of Endoparasites. • Ectoparasites • Endoparasites Submit

41. Mutualism And what about species that are mutually beneficial to each other. We call it Mutualism, where two species exist in a relationship in which each individual benefits. For example, bees and flowers have a mutualistic relationship. Let me just explain this to you in detail.

42. Mutualism Mutualism is a symbiotic relationship between individuals of different species, which in our example is flowers and bees, in which both individuals benefit from the association.

43. Mutualism • Mutualism As the bee flies from flower to flower collecting nectar for food, the bee picks up the flowers' pollen and spreads it to other flowers. This allows the flower to be pollinated by pollen from others, which helps to generate genetic diversity and ensure the flower species' survival.

44. Mutualism • Mutualism Some organisms in a mutualistic relationships help to protect each other from predators. The little clownfish that live among sea anemones on the ocean floor chases away the anemone's predators. In return, the anemone protects the clownfish's nest and eggs with its poisonous tentacles.

45. Mutualism Identify the correct definition of Mutualism. Click the drop-down list and choose the correct option. Click the Submit button. Relationship in which both species benefit from the association. Relationship in which one species benefits from the association. Relationship in which none of the species benefits from the association. Submit

46. Mutualism Correct Feedback Well done! You are right. Identify the correct definition of Mutualism. Click the drop-down list and choose the correct option. Click the Submit button. Relationship in which both species benefit from the association. Incorrect Feedback You are almost there! Mutualism is a relationship in which both species benefit from the association. Relationship in which one species benefits from the association. Relationship in which none of the species benefits from the association. Submit

47. Let’s Check Your Knowledge • Assessment Question 1 What are the three different kinds of Symbiotic relationship exist in Ecosystem? Select the correct options. Click the Submit button. Commensalism Parasitism Benelism Mutualism Submit

48. Let’s Check Your Knowledge • Assessment Question 2 Drag the definitions to their respective symbiotic relationship. Drag the options on the right to the titles on the left. Click the Submit button. One species benefits, while the other species is harmed. Commensalism Parasitism Both species are benefited. One species benefits, while the other species is not harmed. Mutualism Submit

49. Let’s Check Your Knowledge • Assessment Question 3 Match the examples to their respective symbiotic relationship. Drag the options on the right to the titles on the left. Click the Submit button. Epiphytes Pigeon Orchids Epizoics Remora Fish Endoparasites Tapeworms Ectoparasites Mosquitoes Submit Mutualism Bees and Flowers

50. Interesting Fact Many species of fishes that live deep in the ocean have mutualistic symbiotic relationships with bioluminescent bacteria. One example of a fish that lives in mutualism with a luminous bacteria, is the Japanese pinecone fish, also known as the pineapple fish. These bacteria brighten up the surroundings, enabling the fish to see and hunt prey, as well as to communicate. In return, the bacteria receive nourishment from their host fish. This fish has organs on each side of its jaw that light up and give the appearance of a smiley face. The organs glow with the help of a bioluminescent bacteria species that lives in the fish's organs.