Research Symposium

BIO

I'm an transfer student in the UROP program here at FSU. I grew up outside of St. Louis, Missouri and moved to Florida with my family in 2020. After graduating, I hope to pursue further education in Fisheries Science.

Oxygen Supply Capacity of Atlantic Stingray (Hypanus sabinus) and Hardhead Catfish (Ariopsis felis) Across Temperature

Abstract

The climate of the Gulf of Mexico has been warming in recent decades, spurring interest into how this change will impact fish in the region. The Atlantic stingray (Hypanus sabinus) and the hardhead catfish (Ariopsis felis) have ranges which overlap along the Southeastern coast of the U.S. and the gulf. This research aimed to quantify the thermal sensitivity of physiological metrics in these species, such as low oxygen tolerance (Pcrit), oxygen supply capacity (α), and blood oxygen carrying capacity (measured in hematocrit, HCT), known to influence fish performance and viable fish habitat. Fish subjects were exposed to exhaustive exercise and low oxygen over a range of temperatures (20, 26, 30, 34C). Blood samples were taken at each temperature to measure HCT. Direct metabolic rates across a spectrum of activity were then measured via respirometry at each temperature and under declining ambient oxygen. These measures facilitated the calculation of Pcrit and α across temperature. So far, results demonstrate that α and Pcrit increase with temperature in all species, but that Atlantic stingrays demonstrate less temperature sensitivity across metrics. Findings indicate that tolerance to low oxygen is compromised as temperatures rise, with differential sensitivity among species. No significant thermal trend in HCT has been demonstrated, thus the measured increase in α with temperature is likely facilitated by something other than red blood cell volume. These findings are preliminary, and research is still ongoing, but this work offers insight into the robust thermal tolerance of these species in the face of climate change.

Keywords: oxygen, gulf, ocean, fish, stingray