Abstract:
Dental radiography can be used to estimate the age of toothed animals, based on the ratio of the pulp area to tooth area. To evaluate whether this is a viable technique in common bottlenose dolphins (Tursiops truncatus), we collected radiographs of live dolphins during health assessments in Barataria Bay, Louisiana; Mississippi Sound, Mississippi/Alabama; and Sarasota Bay, Florida (5/6/2013-7/20/2018), as well as radiographs of carcasses from stranded dolphins in Barataria Bay, Louisiana (1/25/2011-5/19/2014). This dataset supports the publication: Herrman, Jean M Jeanine S. Morey, Ryan Takeshita, Sylvain De Guise, Randall S. Wells, Wayne McFee, Todd Speakman, Forrest Townsend, Cynthia R. Smith, Teresa Rowles, and Lori Schwacke. 2020. Age determination of common bottlenose dolphins (Tursiops truncatus) using dental radiography pulp:tooth area ratio measurements. PLOS ONE, 15(11), e0242273. doi:10.1371/journal.pone.0242273
Suggested Citation:
Herrman, Jean M., Jeanine Morey, Ryan Takeshita, Sylvain De Guise, Randall S. Wells, Wayne McFee, Todd Speakman, Cynthia Smith, Teresa Rowles, and Lori Schwacke. 2021. Dental radiography analysis of common bottlenose dolphins from strandings and health assessments in the northern Gulf of Mexico, 2011-01-25 to 2018-07-20. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/ABXDG4P5
Publications:
Herrman, J. M., Morey, J. S., Takeshita, R., De Guise, S., Wells, R. S., McFee, W., … Schwacke, L. (2020). Age determination of common bottlenose dolphins (Tursiops truncatus) using dental radiography pulp:tooth area ratio measurements. PLOS ONE, 15(11), e0242273. doi:10.1371/journal.pone.0242273
Purpose:
The purpose of this project is to estimate ages of wild common bottlenose dolphins using dental radiography and to compare those estimates to other aging techniques.
Data Parameters and Units:
Accession.number- Gene expression omnibus (GEO) Accession number
Sample.type- Sample tissue type (Blood or Skin)
Field.ID- Unique identifier for each dolphin
Date-Date of data collection (mm/dd/yyyy)
Location-General description of where capture/release took place (BB: Barataria Bay; MS: Mississippi Sound; SB: Sarasota Bay)
Latitude-Latitudinal geographic coordinates from the collection location in decimal degrees
Longitude-Longitudinal geographic coordinates from the collection location in decimal degrees
Collection-Status of dolphin during data collection (stranded dead carcass or living animal during capture/release)
Sex-Sex of dolphin (M/F)
Length.cm-Length of dolphin (cm)
Pulp.to.Tooth.Ratio-Ratio between the area of pulp and area of tooth based on radiograph. * indicates that pulp:tooth area ratio < 0.1 results in increased uncertainty and exact ages were not calculated.
LH.Age-Age estimate based on field observations of birth year
GLG.Age-Age estimate based on growth layer group counting of pulled teeth
Methods:
Dental radiographs were collected using living dolphins during capture-release health assessments (e.g., Barratclough et al., 2020) or using carcasses of dead, stranded dolphins. Radiographs were performed using a lead-shielded, FDA-approved hand-held X-ray generator and a high-resolution standard dental digital phosphor plate (Herrman et al., 2020). The X-ray beam was directed at a bisecting angle for lateral views of the maxillary teeth 6 to 12. Images were scanned and digitized, then the number of pixels in the pulp area and the tooth area was calculated using Adobe Photoshop using the average from three teeth. Life history ages are given, where available, and are based on observations of when dolphins were first seen as calves in the field. Age estimates based on counting dentinal layers ("growth layer groups") are also given, where available, and were generated based on established methods (e.g., Hohn et al., 1989).
Instruments:
Radiographs using a lead-shielded, FDA-approved hand-held X-ray generator and a high-resolution standard dental digital phosphor plate
Provenance and Historical References:
Barratclough, Ashley, Randall S. Wells, Lori H. Schwacke, Teresa K. Rowles, Forrest M. Gomez, Deborah A. Fauquier, Jay C. Sweeny, Forrest I. Townsend, Larry J. Hansen, Eric S. Zolman, Brian C. Balmer, and Cynthia R. Smith. 2019. Health Assessments of Common Bottlenose Dolphins (Tursiops Truncatus): Past, Present, and Potential Conservation Applications. Frontiers in Veterinary Science 13(6):444. DOI: 10.3389/fvets.2019.00444
Herrman, Jean M., Jeanine S. Morey, Ryan Takeshita, Sylvain De Guise, Randall S. Wells, Wayne McFee, Todd Speakman, Forrest Townsend, Cynthia R. Smith, Teresa Rowles, and Lori Schwacke. 2020. Age determination of common bottlenose dolphins (Tursiops truncatus) using dental radiography pulp:tooth area ratio measurements. PLoS One 15(11):e0242273. DOI: 10.1371/journal.pone.0242273
Hohn, Aleta A., Michael D. Scott, Randall S. Wells, Jay C. Sweeney, and A. Blair Irvine. 1989. Growth layers in teeth from known-age, free-ranging bottlenose dolphins. Marine Mammal Science 5(4): p. 315-342. doi: 10.1371/journal.pone.0242273