Ultrasonographic imaging of the testis and epididymis of the bottlenose dolphin, Tursiops truncatus aduncas

B-Mode ultrasonographic evaluation of the testis in relation to serum testosterone concentration in male Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientalis) during the breeding season

“…The presence of free spermatozoa may also increase echodensity. Indeed, the homogeneous and highly echodense pattern was characteristic of mature testes in many mammals, including bottlenose dolphins [23,29]. Nevertheless, in two YFP individuals with body length >160 cm, the testicular parenchyma had a coarse and moderate echo pattern (Fig.…”

“…Ultrasound measurements of the testes were conducted using methods previously described by Brook et al [23]. Briefly, the examination was performed with the animals lying laterally on a wet sponge mattress.…”

“…After capturing this image on the monitor, the width and depth of the testis were measured directly from the image with electronic calipers. The volume of each testis was determined using Lambert's formula for an ellipsoid, volume (cm 3 ) = length  width  depth  0.71, which had been employed similarly in a previous study of bottlenose dolphins (Tursiops truncatus) [23].…”

“…Similar to other cetaceans, YFPs have internal testes located near the kidney [23,26]. The testes are cylindrical in shape, comparatively large, and easily visualized with transabdominal ultrasonography.…”

“…In past decades, the clinical application of ultrasonography in veterinary medicine and animal reproduction has expanded dramatically, and the value of this technique in breeding both domestic and nondomestic species has been well documented [14][15][16][17][18][19]. As animals are trained to cooperate, ultrasonographic examinations have aided in determining the reproductive status of captive cetaceans [20][21][22][23]. Nevertheless, no previous research has used this approach to evaluate the reproductive physiology of YFPs.…”