BIOL 123: Biodiversity Lab 

Objectives: Following this lab you should be able to…​

• Identify various species and taxonomic groups under the microscope and describe key characteristics including: how/what they eat, if/how they move, key organelles and life history traits
• Calculate common indices of protist biodiversity (abundance, richness, diversity) in water samples
• Discuss the effect of each protist on the ecology or health of biological systems
• Evaluate the health of the watersheds from which the samples originated depending on protist diversity 

Overview

• Exercise I. You will review a slide show of common protists and make a quick taxonomic key. You will view prepare slides of each protist and test your key

• Exercise II. You will collected data of the type and quantity of each protist in two different water samples.

• Exercise III. ​Using this raw data you will calculate the species abundance, richness and diversity of each samples. You will then evaluate the health of each samples' watershed.

• Exercise I
• Exercise II
• Exercise III

<

>

Exercise I. Learn to ID protists

The photo gallery below depicts two images of each protist discussed in your lab manual and in the accompanying PowerPoint.
The first image on each slide is from a past BIOL 123 lab and was taken under the compound microscope. The second image is more idealized photo. 
​
Procedure.

1. Go through the images of the 7 listed protists and create a dichotomous key for identifying them under the microscope.
2. Once your key is finished, test it using the prepared slides provided for each listed protist.
3. ​Take pictures as you go! You will have to ID these on your final and you'll need to be good at this to complete Exercise II. 
   

Protist List

1. Amoeba proteus
2. Plasmodium falciparum
3. Volvox sp.
4. Diatoms
5. Euglena gracilis​
6. Paramecium caudatum
7. Spirogyra sp.

1

3

5

7

2

4

6

Exercise II. Identify live protists from different stream samples

​Please view the videos below of protist movement. This will help get you prepared to identify living protists!

Procedure. Identify the protists in each water sample

1. You will be investigating protists found in two different streams: stream A and stream B. 
2. Open this table in Excel: Biodiversity Data Collection Table.
3. To view a sample: Place two drops from stream A or B onto depression slide. Add a drop or two of proto-slow so you can count individual protists (otherwise they'll be too fast). Scan the entirety of the samples and fill out the correct column on your data table in tab one.
4. Repeat this process (share tasks) until you have collected data on two different samples from stream A and two different samples from stream B.
5. Get an OK from your instructor before proceeding to Exercise III. 

Your data table in tab 1.

---

--- Can you tell which is which in this video? ---

Using Protist Biodiversity to evaluate stream health

Primary components of biodiversity:

• Species abundance describes the total number of individuals of a particular species type or across all species' types. 
• Species richness describes the number of different species present in an area (more species = greater richness). Determine the species richness “S” by counting the number of species of taxonomy of interest. Suppose there are 10 orchids, 20 roses and 100 marigolds in a garden. The species richness of flowers in this garden equals three.
• Species evenness describes the relative abundance of the different species in an area (similar abundance = more evenness). Evenness ca be calculated using other biodiversity indicators, but just use a subject measurement like low, moderate or high for this exercise. 
• Simpson's Biodiversity Index  (SDI) measures community diversity. Although it’s commonly used to measure biodiversity, it can also be used to gauge diversity differences of populations in schools, communities and other locations.
  • The range is from 0 to 1, where:
    • ​High scores (close to 1) indicate high diversity.
    • Low scores (close to 0) indicate low diversity.
  • One of more the useful aspects of the index is to compare two sets of data to see which is more diverse. For example, if one has an SDI of 0.5 and another has an SDI of 0.35, then the set with the SDI of 0.5 is more diverse.
    Watch the video for an overview, or read on below:
    

Review the concepts of richness and evenness in the example below.

​Community 1
Abundance = 16
Richness = 4
​Evenness = High

Community 2
Abundance = 16
Richness = 4
​Evenness = Low ​

Review the concept of diversity (D) and learn how to calculate Simpson's Diversity Index in the example below.

Example data collected from a water sample.

Simpson's Diversity Index formula, where n = number of individuals of each species N = total number of individuals of all species

Work through this example: According to the table:

• There were five species were found in this water sample.
  • 9 individuals of species A (n=9)
  • 7 individuals of species B (n=7)
  • 2 individuals of species C (n=2)
  • 1 individual of species D (n=1)
  • 1 individual of species E (n=1)
• Total there were 20 individuals of all species combined (N=20)

Work through this example: Complete the calculation

• Total there were 20 individuals of all species combined (N=20)
• Numerator = sum of n(n-1) = 116
• Denominator = 20 * 19 = 380
• D = 1 - (116/380) = 0.69

---

Procedure. Identify the protists in each water sample

1. Be sure you have reviewed all the above information on biodiversity indictors. 
2. Use your data from Exercise I to calculate these biodiversity indices for each sample you analyzed.
3. Calculation tables and data tables for this task are on Tab 2 of your data sheet.
4. Get your instructors OK before answering the questions below.