Mate choice, copulation, genital morphology, and sperm storage are not very well understood in millipedes. The use of three-dimensional x-ray computed tomography (μCT) provides new morphological data regarding millipede reproductive systems in both the female and male, including chitinous sclerites and membranes, muscles, glands, oviducts, and sperm conduits. Here we present a complete integrated account of the morphology and function of the female genital organs in the family Polydesmidae (Diplopoda: Polydesmida) using μCT, UV fluorescence imaging, and scanning electron microscopy. These data allow us to consider competing hypotheses regarding millipede vulva formation. We additionally present the morphology of copulatory interface in Pseudopolydesmus Attems, 1898 using images of a mating pair in copula and by simulating the interface of the organs using 3D models from μCT, allowing us to tentatively identify a lock-and-key-like mechanism. Finally, we use μCT to reveal the topology of the seminal canal in the gonopod of male Pseudopolydesmus, a topic that has remained unresolved for nearly 80 years.

中文翻译：

---

千足虫假多角纲（Diplopoda：Polydesmida：Polydesmidae）的生殖器形态和交配机制。

在千足虫中，人们对伴侣的选择，交配，生殖器形态和精子的储藏不是很了解。三维X射线计算机断层摄影（μCT）的使用提供了有关雌性和雄性千足虫生殖系统的新形态学数据，包括几丁质硬脂岩和膜，肌肉，腺体，输卵管和精子导管。在这里，我们使用μCT，UV荧光成像和扫描电子显微镜技术，全面地揭示了Polydesmidae（Diplopoda：Polydesmida）家族中女性生殖器官的形态和功能。这些数据使我们可以考虑有关千足虫外阴形成的竞争假设。我们还介绍了假性多角膜Attems中交配界面的形态，1898年，他们使用了在copula中的一对配对的图像，并使用来自μCT的3D模型模拟了器官的界面，从而使我们能够初步确定类似锁匙的机制。最后，我们用μCT揭示了男性假性多角膜的精足动物的精囊管的拓扑结构，这个话题已经有将近80年的历史了。