Feeding Selectivity and Habitat Usage of <i>Esox americanus</i>

<p>Patterns of piscine prey selection and habitat usage of <em>Esox americanus</em> were assessed through a series of field and experimental studies. Although few detailed studies exist on the foraging behavior and habitat usage of <em>E. americanus</em>, throughout its range it may be an important trophic component in maintaining fish assemblage structure in many lower order streams. Across 17 sampled streams, the presence of <em>E. americanus</em> among reaches within streams was found to be strongly correlated with increasing levels of habitat complexity. Reaches occupied by <em>E. americanus</em> featured increased amounts of in-stream physical structure, increased variability in stream width and depth, decreased water temperatures and dissolved oxygen content. Because of its lie-in-wait, ambush attack strategy, habitat complexity was likely a facilitator of prey selection. In a series of outdoor mesocosms experiments featuring alternative forms of structural cover types, four prey species were offered and <em>E. americanus</em> exhibited differing intensities of selectivity among prey types. Field selectivity was assessed from 18 sites by clustering species of potential prey assemblages into a series of functional groups using a suite of traits representing species’ habitat affinities and morphological characteristics. A pattern of non-random feeding in both field and experimental mesocosm studies indicate that <em>E. americanus</em> was selecting prey of a similar body type, choosing soft-rayed, fusiform prey over alternative morphologies.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Masters Thesis

Discipline thesis:degree_discipline

Biological Sciences

Year dc:date.available

2011

Author dc:creator

• Clark, Scott Richard

Contributors dc:contributor

• Jake Schaefer
• Michael Davis
• Carl P. Qualls

• Esox americanus
• prey
• stream analysis
• Biology
• Marine Biology

Repository record dc:identifier

https://aquila.usm.edu/masters_theses/237

OAI identifier oai:identifier

oai:aquila.usm.edu:masters_theses-1254