By: Kaylee Stanton

Mentor: Gretchen Goodbody-Gringley

Lytechinus variegatus• Variegated sea urchin

• Found in the Atlantic

Ocean and Caribbean

Sea

• Generalist grazers

• We hope to determine

feeding behaviors of L.

variegatus before and

after periods of

undernourishment

lookfordiagnosis.com (Beddingfield and McClintock 1997)

(Souza et al. 2008)

Macroalgae

Dictyota dichotomaCaulerpa verticillata

Hypnea musciformis• Important for primary

productivity on reefs

• Subject to daily grazing

(Fong and Paul 2011) (Hay and Fenical 1988)

Chemical Deterrents• Terpenoid compounds are found in varying

quantities in many different species of algae

• Phlorotannins are specific to brown algae

• These types of chemical defenses are

utilized by algae to protect them against

herbivory

(Hay and Fenical 1987)

Experiments• Experiment #1

o Fed L. variegatus while performing the experimental feeding trials with

algae

• Experiment #2o Starved L. variegatus for four days and performed the feeding trials

looking for change in feeding behaviors

• Preference Experimento The fourth tank during both experiments looked for preference of algae

when all food sources were presented to L. variegatus

Hypotheses• Experiment #1

o H0: L. variegatus will not consume any one genera of algae more than any other food source provided

o Ha: L. Variegatus will consume more C. verticillata in comparison to the other food sources provided

• Experiment #2o H0: Algal consumption will not increase after the starvation of

L. variegatus

o Ha: Algal consumption will increase after the starvation of L. variegatus

• Preference Tank o H0: L. variegatus will not favor live rock

o Ha: L. variegatus will favor live rock

Weighing Methods• Algae is laid out and patted

dry to remove a majority of

excess water

• Each algae is weighed to

equivalent amounts before the

experiments

• At the end of the experiments

the algae is siphoned from the

tanks and collected to be

reweighed

• Algae is laid out and patted

dry to remove excess water

• Look for change in weights

0

5

10

15

20

25

30

35

40

45

Brown Red Green All

Per

cen

t E

ate

n (

%)

Algae Types

Fed

Unfed

Results

Figure 1 shows the average percent algae eaten (±SE) by L. variegatus during the two experiments: Fed and Unfed

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

Brown Red Green All

Ma

ss e

ate

n (

gra

ms)

Algae Types

Fed

Unfed

Results

Figure 2 shows the total mass of each alga consumed (±SE) by L. variegatus during the two experiments: Fed and Unfed

• Lytechinus variegatus prefers Caulerpa verticillata

over the other algae presented to it!

• The type of algae that L. variegatus prefers in our

experimental trials indicates what it may eat in its

natural habitat

• There is not a change in feeding in a majority of the

experiments after a period of undernourishment of

L. variegatus

• L. variegatus avoided algae with known

allelochemicals (Dictyota dichotoma)

o Covering behavior (Verling et al. 2008)

Hypotheses• Experiment #1

o H0: L. variegatus will not consume any one genera of algae more than any other food source provided

o Ha: L. Variegatus will consume more C. verticillata in comparison to the other food sources provided

o Reject H0

• Experiment #2o H0: Algal consumption will not increase after the starvation of L.

variegatuso Ha: Algal consumption will increase after the starvation of L.

variegatuso Accept H0

• Preference Tank o H0: L. variegatus will not favor live rock o Ha: L. variegatus will favor live rock o Accept H0

Future Research• Souza et al. 2004 experiments looking at two

species of each genera of algae

o These types of experiments are possible and display results

with statistically significant results

o Observed changes in feeding preferences over various periods of time and how behaviors changed

o Changes in consumption depending on time spent on a

food source

o The pattern of consumption by most popular sources goes

Chlorophyta > Rhodophyta > Phaeophyta

Thank you!• Gretchen Goodbody-Gringley

• Dready

• BIOS

• University of Rhode Island

Any Questions?

References• Beddingfield, S.D., McClintock, J.B., (1998) Differential survivorship,

reproduction, growth and nutrient allocation in the regular echinoid

Lytechinus variegatus (Lamarck) fed natural diets. Journal of

Experimental Marine Biology and Ecology 226, 195-215.

• Fong, P., and Paul, V.J., (2011) Coral Reef Algae. Coral Reefs: An Ecosystem in

Transition. 241-272.

• Hay, M.E., Fenical, W., and Gustafson, K., (1987) Chemical Defense Against

Diverse Coral-Reef Herbivores. Ecology 68, 1581-1591.

• Hay, M.E., and Fenical, W., (1988) Marine Plant-Herbivore Interactions: The

Ecology of Chemical Defense. Annual Review of Ecology and

Systematics 19, 111-145.

• Souza, C. F., de Oliveira, A.S., and Pereira, R.C., (2008) Feeding Preference Of

The Sea Urchin Lytechinus variegatus (Lamarck, 1816) On Seaweeds.

Brazilian Journal of Oceanography 56, 239-247

• Verling, E., Crook, A. C. & Barnes, D. K. A. 2004. The dynamics of behavior in

dominant Echinoid populations from American and European West

coasts. Marine Ecology 25, 191-206.