Effect of Summer Temperatures on Aerobic and Anaerobic Metabolism in Cultured Juvenile Red Drum, Sciaenops ocellatus

• Main Author: Fuqua, Emily Margaret
• Format: Thesis
• Language: English
• Published: College of Charleston 2019
• Subjects: Biology|Climate Change|Physiology; Red drum; Sciaenops ocellatus
• Online Access: http://pqdtopen.proquest.com/#viewpdf?dispub=13883675

As ectotherms, temperature is critical in determining the aerobic metabolic rate of fishes. However, the influence of temperature on anaerobic metabolism is less clear. In particular, the amount of anaerobic metabolism fish utilize in response to exhaustive exercise across temperatures is not well studied. Red drum, a common Western Atlantic species, reside in estuaries during their juvenile years and are commonly exposed to a wide range of temperatures, including relatively high temperatures during summer months. This study investigated the impact of temperature on cultured juvenile red drum aerobic and anaerobic metabolism in a range of ecologically relevant summer temperatures (24°C, 27°C, 30°C, and 33°C). Specifically, this study tested two hypotheses: 1) juvenile red drum aerobic scope would increase with temperature and 2) juvenile red drum use a higher contribution of anaerobic metabolism to support exercise at high temperatures. Mean routine metabolic rate ± S.E.M. increased from 13.5 ± 0.67 mmolO2 kg−1 h−1 at 24°C to 17.5 ± 0.89 at 33°C. Maximum metabolic rate increased from 41.8 ± 1.33 mmolO2 kg−1 h−1 at 24°C to 56.0 ± 2.82 at 27°C and did not change from 27°C to 33°C. Aerobic scope increased significantly from 28.4 ± 1.19 mmolO2 kg−1 h−1 at 24°C to 40.0 ± 2.73 at 27 °C and remained high from 27°C to 33°C. Resting lactate (6.37 ± 0.45 μmol g−1) and mean maximum lactate (79.6 ± 2.17 μmol g−1) did not change with temperature. Percent anaerobic contribution of energy expenditure was 35% ± 1.9 and did not change with temperature. Overall, juvenile red drum metabolism was not negatively impacted at 33°C, suggesting this species is metabolically equipped to tolerate warm water temperatures. However, other factors such as hypoxia or pH shifts should be explored for a better understanding of how juvenile red drum tolerate warm summer seasons as well as future conditions.