Inducible Chemical Defenses in Temperate Reef Sponges of the South Atlantic Bight, U.S.A.

<p>Sessile organisms employing inducible defenses may receive protection from consumers while simultaneously minimizing the metabolic costs of maintaining these defenses. To investigate if reef sponges in the South Atlantic Bight employ inducible chemical defenses, I tested two predictions with Ircinia campana, I. felix, and Aplysina fulva. First, concentrations of antipredator compounds should covary with the abundance of sponge predators. Second, higher compound concentrations should be more effective at deterring predators. Secondary metabolite concentrations in two (I. campana and I. felix) of the sponge species showed temporal variation, which is consistent with the inducible defense hypothesis. Interestingly, higher concentrations of these compounds did not deter feeding by fish or urchins. In contrast, A. fulva, showed no significant temporal variation in the concentration of secondary metabolites, but had deterrent effects on fish predators even at low concentrations. Combined, these results do not support an antipredator strategy based on inducible chemical defenses.</p>

Name thesis:degree_name

Master of Science in Biology (M.S.)

Level thesis:degree_level

Thesis (open access)

Discipline thesis:degree_discipline

Department of Biology

Year dc:date.available

2008

Author dc:creator

• Sarmiento, Leslie Vanesa

Contributors dc:contributor

• Bruce A. Schulte
• Risa A. Cohen

• ETD
• Temperate reefs
• Sponge
• Inducible chemical defenses
• South atlantic bight
• Secondary metabolites
• Postcolonialism in literature
• Maori in literature

Repository record dc:identifier

https://digitalcommons.georgiasouthern.edu/etd/691

OAI identifier oai:identifier

oai:digitalcommons.georgiasouthern.edu:etd-1691