Semen Collection and Ejaculate Characteristics in the Indo‐Pacific Bottlenose Dolphin (Tursiops aduncus)

Abstract

The testes of sexually mature dolphins produce large quantities of sperm. Sperm are expelled in copious amounts of seminal fluid through repeated ejaculations that can occur within a short period of time. There is currently a lack of detail about the methodology of sequential ejaculate collection in dolphins and how the traits of individual ejaculates affect the assessment of reproductive capacity. The objectives of this study were to obtain series of ejaculates from 3 dolphins by following a well-defined collection protocol and then to characterize individual ejaculates. Semen was collected weekly for 1 year from 3 sexually mature Tursiops aduncus. The end of a collection session was marked by a lack of semen, in spite of effort, or micturition. Individual ejaculates were analyzed for volume, pH, and sperm concentration, count, motility, and viability following methods previously described for dolphin semen.The first ejaculate was typically higher in volume and sperm count but lower in sperm concentration, motility, and viability. The concentration of the second ejaculate was generally the highest. Sperm motility and viability of the second and subsequent ejaculates in a series were good (ie, .80%). Collection of the first ejaculate only can lead to underestimation of reproductive capacity. Sperm output fluctuated erratically from week to week, so it was difficult to assess any seasonal pattern. Results provide information for further investigation of male dolphin reproductive patterns and any effect of collection frequency on ejaculate characteristics.

Breeding program in rehabilitated bottlenose dolphins (Tursiops truncatus gephyreus) from the Southwestern Atlantic Ocean

“…In any case, semen evaluation is an important management tool to perform an accurate breeding program. The seminal evaluations performed in the current study in T. t. gephyreus agrees with those reported previously in northern and Indo‐Pacific bottlenose dolphins concerning the high‐quality semen (Robeck & O'Brien, 2004; Robeck et al, 2005, 2013; Yuen et al, 2009). To our knowledge, this is the first report that shows semen characteristics in T. t. gephyreus .…”

Effect of Cryopreservation on the Sperm DNA Fragmentation Dynamics of the Bottlenose Dolphin (Tursiops truncatus)

“…Sperm DNA damage using the SCDt has been described in a range of mammals including humans (Evenson et al 1999;Zini and Libman 2006), non-human eutherian mammals (Fraser and Strzezek 2004), metatheria Zee et al 2009) and even a prototherian species ). As the SCDt procedure is progressively validated across these species, there is also a corresponding increasing body of knowledge on the SDF dynamics, which is revealing significant differences in the rate of DNA fragmentation, not only between species ( (Foote 1978;Squires et al 1979;England 1999;Tanaka et al 2000;Ambriz et al 2002;Robeck and O'Brien 2004;Yuen et al 2009;S anchez-Mart ın et al 2013).…”

Use of Human Chorionic Gonadotropin in a Male Pacific Walrus (Odobenus rosmarus divergens) to Induce Rut and Achieve a Pregnancy in a Nulliparous Female

“…Human Chorionic Gonadotropin Injections-Studies from more abundant marine mammal species housed in zoological institutions, such as bottlenose dolphins (Tursiops truncatus; Muraco et al, 2009Muraco et al, , 2010Yuen et al, 2009), and of seasonally breeding terrestrial mammals were consulted to further our understanding of marine mammal reproductive biology. In seasonal breeders, increases in testosterone levels are associated with augmented sperm production and the presence of ejaculated spermatozoa during the breeding season (Short and Mann, 1966;Goeritz et al, 2003).…”