comparison of single and multiple stressor protocols to assess acute stress in a coastal shark species, Rhizoprionodon terraenovae

• Published in: Fish physiology and biochemistry Vol. 41; no. 5; pp. 1253 - 1260
• Main Authors: Hoffmayer, Eric R, Hendon, Jill M, Parsons, Glenn R, Driggers, William B., III, Campbell, Matthew D
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-10-2015; Springer Nature B.V
• Subjects: Animal Anatomy; Animal Biochemistry; Animal Physiology; Animals; Biomedical and Life Sciences; Blood; blood glucose; Blood Glucose - physiology; blood sampling; Elasmobranchii; Female; Fisheries; Freshwater & Marine Ecology; Glucose; hematocrit; Histology; Laboratories; Lactic Acid - blood; Life Sciences; Male; Marine; Morphology; osmolality; Osmolar Concentration; Physiology; R&D; Research & development; Rhizoprionodon; Rhizoprionodon terraenovae; Sharks; Sharks - physiology; Stress response; Stress, Physiological - physiology; Time Factors; Zoology; United States > US; A, Atlantic; Glucose; Lactate; Stress response; Osmolality; Carcharhinidae; Hematocrit
• ISSN: 0920-1742; 1573-5168
• DOI: 10.1007/s10695-015-0083-4

Elasmobranch stress responses are traditionally measured in the field by either singly or serially sampling an animal after a physiologically stressful event. Although capture and handling techniques are effective at inducing a stress response, differences in protocols could affect the degree of stress experienced by an individual, making meaningful comparisons between the protocols difficult, if not impossible. This study acutely stressed Atlantic sharpnose sharks, Rhizoprionodon terraenovae, by standardized capture (rod and reel) and handling methods and implemented either a single or serial blood sampling protocol to monitor four indicators of the secondary stress response. Single-sampled sharks were hooked and allowed to swim around the boat until retrieved for a blood sample at either 0, 15, 30, 45, or 60 min post-hooking. Serially sampled sharks were retrieved, phlebotomized, released while still hooked, and subsequently resampled at 15, 30, 45, and 60 min intervals post-hooking. Blood was analyzed for hematocrit, and plasma glucose, lactate, and osmolality levels. Although both single and serial sampling protocols resulted in an increase in glucose, no significant difference in glucose level was found between protocols. Serially sampled sharks exhibited cumulatively heightened levels for lactate and osmolality at all time intervals when compared to single-sampled animals at the same time. Maximal concentration differences of 217.5, 9.8, and 41.6 % were reported for lactate, osmolality, and glucose levels, respectively. Hematocrit increased significantly over time for the single sampling protocol but did not change significantly during the serial sampling protocol. The differences in resultant blood chemistry levels between implemented stress protocols and durations are significant and need to be considered when assessing stress in elasmobranchs.