The physiology of polar bear mating (Ursus maritimus)

• Published in: The FASEB Journal
• Main Authors: Nikitin, Georgy, Malev, Alexander, Batrakov, Alexey
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2022
• Subjects: polar bear; Ursus maritimus
• Online Access: http://dx.doi.org/10.1096/fasebj.2022.36.s1.l7916

The well‐being of any species depends on successful reproduction, so the study of mating is essential, mainly to prevent the extinction of rare animals. In the process of evolution, each new species has adapted to environmental conditions in the struggle for survival through the morphological and physiological characteristics of the reproductive anatomy. Polar bear mating lasts 10‐20 minutes and corresponds to uterine insemination, but the description of the physiology of polar bear mating is lacking due to technical difficulties. Studies of the penis of a polar bear during an erection caused by the impact of electrical impulses of an electro‐ejaculator on the pudendal and external spermatic nerves and smooth muscles of the genital organs before reaching ejaculation to obtain sperm suggest how this happens. We studied the manifestation of sexual reflexes in a male polar bear (Ursus maritimus), age 10 years. The bear was kept in the Kazan Zoo from birth and did not participate in mating. An electro‐ejaculator was used to collect sperm. We have established the following features: the penis was covered entirely with a prepuce (praeputium) in a not erect state. The length of the penis is 19 cm. It practically does not change due to the presence of the os penis, which is 18.6 cm long and extends into the head of the penis. The diameter of the body of the penis is 1.5 cm. Initially, the head was 2 cm in diameter, two plates stood out on it, filling with blood during an erection. The opening of the urogenital canal (canalis urogenitalis) extends with its free end outside the head and has soft processes at the end of the canal. The length of the processes of the free end of the canal is 6 mm, and the width of their bifurcation is 4 mm. During an erection, the shape and size of the body of the penis (corpus spondiosum glandis) change and increase. The spongy body of the glans penis swells like a conus from the main shaft with the broadest part at the end. It has a length of 4 cm. The upper part is like an ellipse ...