Defense Date


Document Type


Degree Type

Master of Science

Degree Name

Marine Science

First Advisor

David Kerstetter

Second Advisor

Jeffrey Hoch

Third Advisor

Paul Arena


spells, CTM, LOE, thermal tolerance polygon, acclimation, endpoint


Mangroves serve as important nursery habitats for several species of subtropical fishes and invertebrates. Southeastern Florida mangrove environments have experienced an increasing frequency of strong hot and cold weather front systems, but little information is known about the temperature thresholds for mangrove-associated prey species that lethally disrupts homeostasis. To assess the vulnerability of mangrove-associated prey species to these short-duration temperature fluctuations, critical thermal methodology (CTM) was used to determine thermal tolerances for two fishes and two invertebrates, using loss of equilibrium (LOE) as the endpoint to determine CTmax and CTmin values as a survivable proxy for death. Physiological tolerances were determined for locally captured specimens at five different acclimation temperatures (10, 15, 20, 25, 30, and 35 °C). Through the construction of thermal tolerance polygons, a graphical outline of the lower and upper thermal avoidance temperatures can represent the thermal ranges of these four test species. The thermal tolerance polygons broadly showed a strong correlation between CTM and acclimation temperature (~5 °C), but not by individual animal size. The CTM polygons of Squareback Marsh Crab (624 °C2) and Grass Shrimp (600 °C2) are slightly larger than those of Eastern Mosquitofish (609.25 °C2) and Gulf Killifish (483.25 °C2). Invertebrates were also able to withstand a broader temperature spike, compared to the fishes that could handle colder temperatures. As global temperatures continue to change at an increasing pace, CTM-derived polygons can provide vital information on the range of temperature tolerance for mangrove-associated organisms.

Available for download on Tuesday, July 01, 2025