Contreras L, Bustos-Obregón E
Arch Androl. 1980 Mar;4(2):115-24. doi: 10.3109/01485018008986477.
O. degus reproductive tract is characterized externally by a perianal circle with the penis pointing posteriorly. Beneath the perianal circle is the cremasteric sac. Testes are always inside the abdomen, with the epididymis attached to them but the cauda epididymis lays inside the cremasteric sac. Vas deferens and seminal vesicles open independently into the urethra. Three pairs of lateral prostatic lobes open by many ducts into the urethra. The corpora spongiosa holds the urethra in the ventral groove of the corpus cavernosum. The corpus cavernosa are inserted into the bulbo cavernosum muscle and at its distal end are attached to the base of the baculum, that lay under the dorsal face of the glans. The glans has two openings: the urinary meatus and the intromittent sac. The characteristics of the testicular artery agree with the anatomy expected for animals with intrabdominal testes; it is relatively short, with few loops and a wide diameter. Many of these anatomical features are shared by other caviomorphal rodents. If testicular temperature is similar to body temperature in these animals as in O. degus (36.0 degrees and 37.2 degrees C respectively), they would exhibit little testicular thermal sensibility. Among these rodents O. degus has the lowest body temperature. Moreover this work reinforces the hypothesis that descent of the testis into the scrotum has occurred secondarily to the immigration of the cauda epididymis.
八齿鼠的生殖道外部特征为肛周环，阴茎指向后方。肛周环下方是提睾囊。睾丸始终位于腹腔内，附睾附着于睾丸，但附睾尾部位于提睾囊内。输精管和精囊分别独立开口于尿道。三对前列腺侧叶通过许多导管开口于尿道。海绵体将尿道容纳在阴茎海绵体的腹侧沟内。阴茎海绵体插入球海绵体肌，其远端附着于阴茎骨基部，阴茎骨位于龟头背面下方。龟头有两个开口：尿道口和交配囊。睾丸动脉的特征与腹腔内睾丸动物预期的解剖结构相符；它相对较短，几乎没有袢且直径较宽。许多这些解剖特征与其他豚鼠型啮齿动物相同。如果这些动物的睾丸温度与八齿鼠一样与体温相似（分别为36.0摄氏度和37.2摄氏度），它们的睾丸热敏感性就会很低。在这些啮齿动物中，八齿鼠的体温最低。此外，这项研究强化了这样一种假说，即睾丸下降到阴囊是在附睾尾部移入之后发生的。
