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.
","abstract_html":"<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>","abstract_has_math":false,"creators":["Sarmiento, Leslie Vanesa"],"institution":null,"degree_name":"Master of Science in Biology (M.S.)","degree_level":"Thesis (open access)","degree_discipline":"Department of Biology","degree_department":null,"school":null,"contributors":["Bruce A. Schulte","Risa A. Cohen"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2008,"date_issued":"2008-01-01T08:00:00Z","date_published":"2008-01-01T08:00:00Z","updated_at":"2026-07-24T02:27:19Z","subjects":["ETD","Temperate reefs","Sponge","Inducible chemical defenses","South atlantic bight","Secondary metabolites","Postcolonialism in literature","Maori in literature"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://digitalcommons.georgiasouthern.edu/etd/691","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Bruce A. Schulte","Risa A. Cohen"]},{"key":"dc:creator","label":"Author","values":["Sarmiento, Leslie Vanesa"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2013-10-17T07:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Department of Biology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis (open access)"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science in Biology (M.S.)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["ETD","Temperate reefs","Sponge","Inducible chemical defenses","South atlantic bight","Secondary metabolites","Postcolonialism in literature","Maori in literature"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://digitalcommons.georgiasouthern.edu/etd/691"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["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.
"]},{"key":"dc:title","label":"Title","values":["Inducible Chemical Defenses in Temperate Reef Sponges of the South Atlantic Bight, U.S.A."]}]}],"canonical_facts":{"dc:contributor":["Bruce A. Schulte","Risa A. Cohen"],"dc:creator":["Sarmiento, Leslie Vanesa"],"dc:date.available":["2013-10-17T07:00:00Z"],"dc:description.abstract":["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.
"],"dc:identifier":["https://digitalcommons.georgiasouthern.edu/etd/691"],"dc:subject":["ETD","Temperate reefs","Sponge","Inducible chemical defenses","South atlantic bight","Secondary metabolites","Postcolonialism in literature","Maori in literature"],"dc:title":["Inducible Chemical Defenses in Temperate Reef Sponges of the South Atlantic Bight, U.S.A."],"thesis:degree_discipline":["Department of Biology"],"thesis:degree_level":["Thesis (open access)"],"thesis:degree_name":["Master of Science in Biology (M.S.)"]},"updated_at":"2026-07-24T02:27:19Z"}