Lab Activity 8.3
Marine Symbiosis

  Directions

Study the instructional material below. Be sure to click on each of the photographs for an enlarged view in a separate window. The larger version is necessary to complete the assignment. It opens in a separate window which can be resized by grabbing the bottom right corner and dragging it. It can also be moved by grabbing the top heading bar and dragging it. Be sure to close the extra window by using the X in IBM, or the close box in MAC when you are finished using them.

  Introduction


Symbiosis is the close, special relationship that has evolved between two species of marine organisms over a long period of time. It involves a symbiont that always benefits from the relationship living with a host that may or may not benefit from the relationship. In any case symbioses allow for greater species diversity by providing additional, highly specialized ecological niches in an environment. In this lab activity you will study the symbiotic relationships between sea slug hosts and their chloroplast or dinoflagellate symbionts. This example will provide insight into the complexity of such relationships.

Top  Instruction

Answer the following questions about symbiosis in marine slugs by visiting the Sea Slug Forum Web Site.

Click on these links to search for the answers to the questions listed below:

Solar-powered sea slugs
Symbiosis, commensalism, mutualism and parasitism
Zooxanthellae in Cnidarians
Zooxanthellae in nudibranchs

Prepare an answer for each of the questions listed below. You can print out the charts and fill them in or create similar charts in your notebook.

Be sure to write about what you are learning in the lab section of your notebook. You will be expected to answer questions about the lab activity during the lab self test and lab quiz. It helps to have your text and coloring books open beside you for support.

 
Supporting Information
Refer to the Assigned Readings Below:
Marine Biology Textbook Chapter 10, page 220 to 221
Marine Biology Coloring Book Plate 91
 

Solar Powered Sea Slugs
Questions Answers
1. How do the herbivorous sacoglossans use the ability of plants to convert the sun's energy into sugars and other nutrients?  
2. How do the carnivorous nudibranchs use the ability of zooxanthellae to convert the sun's energy into sugars and other nutrients?  
3. What type of symbiosis is illustrated in these examples?  

 

What are Zooxanthellae
Questions Answers
1. What are zooxanthellae?  
2. How do zooxanthellae multiply once a few enter the body of their host animal ?  

 

Zooxanthellae in Cnidarians
Questions Answers
1. What is the best known association involving zooxanthellae?  
2. Where are the zooxanthellae located in the soft coral Xenia?  

 

Zooxanthellae in Nudibranchs
Questions Answers
1. What are the nudibranchs cerata and what part do they play in the nudibranch-zooxanthellae symbiosis?  
2. How do nudibranchs get their zooxanthellae?  

Lab Activity 8.4 Marine Food Webs