HCNSO Student Theses and Dissertations

Defense Date

12-6-2018

Document Type

Thesis

Degree Name

M.S. Marine Biology

First Advisor

David Kerstetter, Ph.D.

Second Advisor

Richard Brill, Ph.D.

Third Advisor

Andrij Horodysky, Ph.D.

Fourth Advisor

Tracey Sutton, Ph.D.

Abstract

Lionfish (Pterois spp.), an invasive species native to the Indo-Pacific, have permanently established themselves throughout the greater Caribbean, Gulf of Mexico, and regions of the Western Atlantic ranging from as far north as North Carolina to central Brazil. As their fundamental range expands, lionfish threaten to migrate into estuarine environments as they have been found to tolerate low salinities and an eclectic range of temperatures. The physiological capacity of invasion was assessed by quantifying the visual ecology of lionfish utilizing corneal electroretinography (ERG) as well as their metabolic scope and hypoxia tolerances under various temperature-oxygen-regimes utilizing intermittent-flow respirometry. Seasonal changes in temperature-dissolved oxygen levels consistent with Atlantic/Gulf of Mexico inshore estuaries not only exceed the physiological tolerances of lionfish, but also constrain metabolic scope at sub-lethal levels by significantly limiting maximum metabolic rate across all temperatures. Median Scrit values were 33%, 39%, 46%, and 54% at 15, 20, 25, and 30℃ respectively. Luminous sensitivities, temporal resolutions (Flicker fusion frequency), and spectral sensitivities scaled similarly with other estuarine piscivores indicating lionfish possess a visual system that can function effectively within estuarine photic conditions. Overall, visual characteristics of estuaries will not pose as a significant barrier to lionfish, but minimum winter temperatures and hypoxia will pose controlling and limiting factors substantially preventing further inshore invasion. However, caution should still be advised as lionfish may capitalize on specific temporal and spatial scales that provide suitable habitat quality and abundance of prey items. Further insight is needed to forecast the effects of temperature-dissolved oxygen on lionfish metabolic-scope.

Comments

Fixed figure/table caption orientation

Available for download on Thursday, February 06, 2020

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