BIO 362 Lab Fouling Communities

Pre-lab Assignment – Fouling Communities

Name: ______850______

Date: ______

All pre-labs need to be completed prior to coming to lab. You will hand these in to your TA before class. If you don’t complete the pre-lab assignment then you will NOT be allowed to participate that week's lab/field trip and you will receive a zero grade for that particular lab.

Please provide brief answers or calculations to the following questions in the space provided. You should read Ch. 11-12 in Levinton prior to arriving in lab.

1. What two components of diversity does the Shannon-Weiner index measure? Explain how they are different.

2. How do the three major seaweed groups (Rhodophyta, Phaeophyta, and Chlorophyta) differ in photosynthetic pigment, photosynthate storage medium, and cell wall composition?

3. What are the two basic body plans of cnidarians? Which one is exhibited by Anthozoans such as anemones?

4. What is a lophophore? What group possesses it?

5. What marine invertebrate group is most closely related (phylogenetically) to vertebrates? BIO 362 Lab Fouling Communities

Bio 362 – Fouling Communities Lab

Objectives

 Become familiar with common members of fouling communities

 Compare and contrast communities in intertidal and subtidal environments

 Use statistical methods to quantify differences in biodiversity between communities

Procedure

1. On the piling just above the floating dock place the small sampling quadrat over an area (above the water line) and identify and count all the organisms present. Pick an area that is undisturbed. These organisms can be counted in situ. Also be sure to collect a few barnacles or any other organisms in a separate bucket for later examination in the lab aquaria.

2. On the floating dock just below the water place the small sampling quadrat against the plastic float and carefully use the paint scrapers to remove everything inside the quadrat. Use the dip nets to collect the falling organisms. Place these in a bucket with enough sea water to cover them. We will take these back to the lab.

3. Back in the classroom, sort through the buckets. Place organisms into aquaria and wait several minutes to allow epifaunal organisms to emerge. Identify and count all the organisms present in the sample.

4. At the end of class type your species enumeration data from both sample sites into the class spreadsheet. This will be sent to you after class. Use the pooled class data to calculate the Shannon index of diversity (H’) for each sample site (see next page). Your instructor will show you how to use a t-test to see if the diversity of organisms is statistically different between the intertidal and subtidal habitats. Your instructor will also show you how to create a frequency histogram for your data. BIO 362 Lab Fouling Communities BIO 362 Lab Fouling Communities

From your abundance data for each sub-sample, you will need to estimate diversity. In this case we are interested in the diversity of the groups counted in the data sheet. Diversity is comprised of two elements. First there is the total number of types of groups in the set (richness). Then there is the relative abundance of each group (evenness). The Shannon-Wiener index (H’) and the antilogarithm of H’ (exp H’) takes both these facets of diversity and combines them into one measure for each sub-sample, by weighting the abundance of a group as well as its presence in the sample. A rare group will make a smaller contribution than a common group to the index. The formula is as follows

H’ =∑ pi/pT*ln(pi/pT)

where H’ is the Shannon-Wiener Diversity index, pi is the number of individual of species i, pT is the total number of individuals of all species, and ln is the natural logarithm (log base e). The summation is taken over all species, i = 1, 2, … S.

Example:

Table 1.0. Counts of epifauna in a sub-sample (in your data you will classify to lower organizational levels)

Number in sample Relative abundance

Tunicate 8 8/16 = 0.50

Caprellid 4 4/16 = 0.25

Gammarid 2 2/16 = 0.125

Bryozoan 2 2/16 = 0.125

Total 16 1.00

Using these data, the Shannon-Wiener Index is calculated as follows:

H’ = - [0.50 ln(0.50) + 0.25 ln(0.25) + 0.125 ln(0.125) + 0.125 ln(0.125)]= 1.21

Note: Groups that are absent from a sample are not used in the calculation. Example: if there were no Gastrotrichs in the sample, calculate H’ based on a total sample that includes Nematodes, Copepods, and Polychaetes.

When the Shannon-Wiener Index is expressed as the inverse logarithm e(H’) (in excel use =exp(H’)) it has the following useful properties: -It can range from 1 to the species richness (S). -It is equal to species richness if all species are equally represented. BIO 362 Lab Fouling Communities

-For our example above: e 1.21 = 3.36 Assignment

(use this document as a template; complete all calculations and graphs in Excel and paste the figures into this document)

1. The organisms in the intertidal face a suite of different biotic and abiotic factors compared to those in the subtidal. Name at least 4 differences between these two tidal zones. (4 points)

2. Is Shannon-Weiner diversity statistically different between the two habitats (use the statistical techniques you learned to answer this question). Please report the mean S-W results as well as the t-statistics, degrees of freedom, and p-value for the t-test. If they are different why do you think this is so? (4 points)

3. Describe the trophic level and feeding mode of 4 organisms you looked at today. (eg. Crassostrea virginica – Eastern oyster, Primary consumer, suspension feeder). (8 points)

4. Create a frequency histogram of the species present in each habitat and paste below. (4 points) BIO 362 Lab Fouling Communities BIO 362 Lab Fouling Communities

Common species in the fouling community

CHLOROPHYTA

Ulva sp.

RHODOPHYTA

PHAEOPHYTA

PORIFERA

Class Demospongiae

Aplysilla longispina or A. sulfurei – sulfur sponge

CNIDARIA

Class Anthozoa

Aiptasia pallida – pale or brown anemone

Astrangia danae – star coral or Northern cup coral

Class Hydrozoa

Halocordyle disticha – feather hydroid

Eudendrium carneum – primary food source for sea spiders

BRYOZOA

Class Gymmnolaemata

Bugula neritina – common or bushy bugula

Schizoporella unicornis – “orange crust”

MOLLUSCA

Class Bivalvia

Modiolus americanus – tulip mussel

Crassostrea virginica – Eastern oyster BIO 362 Lab Fouling Communities

ARTHROPODA

Class Cirripedia

Balanus amphitrite – striped barnacle (only species that my groups found)

Class Malacostraca

Palaemonetes vulgaris – grass shrimp

Panopeus herbstii – common mud crab

Pilumnus sayi – hairy crab

Class Pycnogonida

Anoplodactylus lentus – lentil or black sea spider

ECHINODERMATA

Class Echinoidea

Arbacia punctulata – purple sea urchin

CHORDATA

Class Ascidiacea

Styela plicata – pleated sea squirt or rough sea squirt

Symplegma rubra – red/orange colonial tunicate (growing over some dead barnacles)