Abstract

Blubber and serum testosterone levels were compared among 55 individual common bottlenose dolphins, Tursiops truncatus, in Sarasota Bay, FL during 2011–2019. A significant positive relationship between the matrices was found in male testosterone concentrations in 29 paired samples (r2 = 0.932). Mature males (n = 17) had 300 times greater mean testosterone concentration in serum than immature males (n = 17). A comparison of blubber samples, including 12 females, 24 immature males, and 19 mature males, revealed significant differences in mean blubber testosterone values among all three demographics. Immature males had greater than 6 times the average blubber testosterone concentration of females and mature males had almost 100 times that of immature males. Estimated testis volume was highly correlated with blubber testosterone concentration and mature males had 60 times greater average testis volume than immature males. We observed seasonal variation in blubber testosterone in mature males, consistent with known reproductive patterns. These data suggest males can be distinguished from females and designated as mature or immature via blubber testosterone concentrations, an observation that validates dart biopsy sampling as a means of obtaining demographic data.

Details

Title
Serum correlation, demographic differentiation, and seasonality of blubber testosterone in common bottlenose dolphins, Tursiops truncatus, in Sarasota Bay, FL
Author
Sherman, Kathryn K. 1 ; Beaulieu-McCoy, Nicole E. 2 ; Wurster, Elyse L. 1 ; Wells, Randall S. 3 ; Smith, Cynthia R. 4 ; Barleycorn, Aaron A. 3 ; Allen, Jason B. 3 ; Kellar, Nicholas M. 5 

 National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Environmental Assessment Services, LLC, Southwest Fisheries Science Center, La Jolla, USA (GRID:grid.422702.1) (ISNI:0000 0001 1356 4495) 
 National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Volunteer With Southwest Fisheries Science Center, La Jolla, USA (GRID:grid.422702.1) (ISNI:0000 0001 1356 4495) 
 Chicago Zoological Society’s Sarasota Dolphin Research Program, c/o Mote Marine Laboratory, Sarasota, USA (GRID:grid.285683.2) (ISNI:0000 0000 8907 1788) 
 National Marine Mammal Foundation, San Diego, USA (GRID:grid.419692.1) (ISNI:0000 0004 0611 5554) 
 National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Southwest Fisheries Science Center, La Jolla, USA (GRID:grid.422702.1) (ISNI:0000 0001 1356 4495) 
Publication year
2021
Publication date
2021
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2707112703
Copyright
© This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply 2021. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.