Spontaneous Ejaculation in a Wild Indo-Pacific Bottlenose Dolphin (Tursiops aduncus)

Tadamichi Morisaka,Kazunobu Kogi,Motoi Yoshioka,Mai Sakai,Akane Nakasuji,Kasumi Sakakibara,Yuria Kasanuki,Kentaro Q Sakamoto

doi:10.1371/journal.pone.0072879

Abstract

Spontaneous ejaculation, which is defined as the release of seminal fluids without apparent sexual stimulation, has been documented in boreoeutherian mammals. Here we report spontaneous ejaculation in a wild Indo-Pacific bottlenose dolphin (Tursiops aduncus), and present a video of this rare behavior. This is the first report of spontaneous ejaculation by an aquatic mammal, and the first video of this behavior in animals to be published in a scientific journal.

Highlights

Spontaneous ejaculation, which is defined as the release of seminal fluids in the absence of apparent sexual stimulation, has been reported in several male land mammals, including Rodentia, Cetartiodactyla (mountain sheep, warthogs, tsessebes [6]), Carnivora (domestic cats [7], spotted hyenas), Perissodactyla, and Primates (chimpanzees [9], humans)
We report spontaneous ejaculation in a wild Indo-Pacific bottlenose dolphin (Tursiops aduncus), and present an accompanying video. This is the first report of spontaneous ejaculation in an aquatic mammal, and the first video of spontaneous ejaculation in animals to be published in a scientific journal
The ejaculation occurred at about 10 m water depth within 200 m of Mikura Island (33u5490230 N, 139u3694890E), Tokyo, Japan

Summary

Introduction

Spontaneous ejaculation, which is defined as the release of seminal fluids in the absence of apparent sexual stimulation, has been reported in several male land mammals, including Rodentia (rats [1], hamsters [2], guinea pigs [3], mice [4]), Cetartiodactyla (mountain sheep, warthogs (reviewed in [5]), tsessebes [6]), Carnivora (domestic cats [7], spotted hyenas (reviewed in [5])), Perissodactyla (horses [8]), and Primates (chimpanzees [9], (reviewed in [10]), humans (reviewed in [11])). Spontaneous ejaculation could possibly be widespread in various animals, including humans, but has passed unrecognized because it is an unpredictable and rare behavior that lasts only a few seconds, making it difficult to observe. We report spontaneous ejaculation in a wild Indo-Pacific bottlenose dolphin (Tursiops aduncus), and present an accompanying video.

Results

Conclusion