Bone Mineral Density Of The Common Bottlenose Dolphin Radius: A Primary Skeletal Site For Clinical Bone Densitometry And Preliminary Descriptive Data Set Using Archival Specimens

We examined bone mineral density (BMD) in the pectoral flipper of the common bottlenose dolphin, Tursiops truncatus. These data addressed the need to define a comprehensive target site for osteodensitometric assessment and to provide a descriptive bone density data set for this species. We analyzed 388 radii from 279 bottlenose dolphins using dual energy X-ray absorptiometry (DXA), the accepted standard in human medical studies. Radii were examined for differences based on sex, age, total body length, handedness, geographical affinity, and nutritional status at death. BMD increased with age and body length (R-2 = 0.58, p < .05). No statistically significant differences were observed in BMD measurements for male and female dolphins (t = -1.60, p > .05) or right and left flippers (t = -1.76, p > .05). Additionally, no statistically significant differences were observed based on geographical region (t = -0.190, p > .05) or nutritional status (F = 0.83, p > .05). These results support the use of these findings as a preliminary descriptive data set for BMD in bottlenose dolphins and detail a primary skeletal site for clinical assessment of bone density for the species. As this study relies on archived museum specimens collected from dolphins at time of death, further studies regarding bone density may be better addressed using live dolphins with known health status.