The anatomy and histology of the reproductive tract of the male Babirusa (Babyrousa celebensis)

The anatomy and histology of the reproduction organs of the male Babirusa (Babyrousa celebensis) were studied in 21 specimens collected between birth and approximately 17 years of age. In adult animals the testes were located in a subanal position against the caudal surface of the thigh musculature. Average adult testis length was 68.9 ± 5.1 mm, width was 40.3 ± 5.7 mm, and depth was 47.9 ± 7.0 mm (N = 11). The average combined adult testicular weight was estimated to be 82.7 ± 23.2 g (N = 11). The testes of newborn Babyrousa had descended through the inguinal canal into the scrotum before birth. Adult seminiferous tubules had an average diameter of 199 ± 33.6 μm (N = 9) and were randomly distributed among a smaller volume of Leydig cells. Connective tissue was sparse. In one 13-month-old prepubertal animal the diameter of the seminiferous tubules was 85.3 ± 16.1 μm (N = 7). The spermatozoa was 42.2 ± 4.9 μm (N = 19) long and had a flat, paddle shaped head, 6.3 ± 0.6 μm (N = 50) long, 3.9 ± 0.5 μm (N = 47) wide, and a thickness of approximately 0.5 μm. An apical ridge along its front represented the acrosome. The two adult vesicular glands each had an irregular shape and were approximately 48.7 ± 7.4 mm long, 25.6 ± 4.3 mm wide, and 20.6 ± 8.7 mm deep (N = 6). The prostate, comprising a corpus and disseminate parts, lay ventral to the vesicular glands partly embedded in the dorsal wall of the urethra. The paired adult bulbourethral glands were approximately shaped like prolate (elongated) spheroids and had a length of 51.2 ± 14.2 mm, a width of 22.6 ± 4.5 mm, and a depth of 14.4 ± 4.5 mm (N = 7). The secretions from the bulbourethral glands drained into the urethral recess, which in adults measured approximately 10 to 14 mm in length and was located caudodorsal to a narrowing of the pelvic urethra. The penis was 330 ± 16 mm long and 8.2 ± 0.6 mm in diameter, and rotated approximately two and a half turns counterclockwise along its longitudinal axis toward its free end. The small prepucial diverticulum situated dorsocranial to the penis tip in adult and prepubertal Babyrousa, in adults measured 22.0 ± 1 mm in length and 17.5 ± 2.6 mm (N = 3) in width.