A new species of Illacme from southern California (Siphonophorida, Siphonorhinidae)

The millipede fauna inhabiting deep soil are poorly known. They are small
and threadlike, slow moving, lacking pigmentation, and rarely encountered
due to their obscure underground way of life. One family, the
Siphonorhinidae, encompasses four genera and 12 species in a fragmentary
distribution in California, southern Africa, Madagascar, the Malay
Archipelago, and Indo-Burma. The family is represented in the Western
Hemisphere by a single genus, Illacme Cook & Loomis, 1928 from
California, with its closest known relative, Nematozonium filum Verhoeff,
1939, from southern Africa. We document a new species of this family from
soil microhabitats in the Los Angeles metropolitan area, Illacme socal n.
sp. Based on this discovery and the recent documentation of other endogean
millipede species, we show that these grossly understudied subterranean
fauna represent the next frontier of discovery. However, they are
threatened by encroaching human settlement and habitat loss, and
conservation of this species and other subterranean fauna is of high
importance.

栖息于深层土壤的马陆类群（millipede fauna）目前研究程度极低。这类马陆体型微小、呈丝状，行动迟缓且无色素沉着，因其隐秘的地下生活习性而极难被观测到。目前已知管马陆科（Siphonorhinidae）包含4个属、12个物种，其分布呈碎片化格局，涵盖加利福尼亚州、非洲南部、马达加斯加、马来群岛以及印缅地区。该科在西半球仅存1个属——产自加利福尼亚州的Illacme Cook & Loomis, 1928，其已知最近缘类群为产自非洲南部的Nematozonium filum Verhoeff, 1939。本研究记述了该科的1个新种，发现于洛杉矶大都会区的土壤微生境中，命名为Illacme socal n. sp.。基于本次发现及近期其他地下生马陆物种的相关记述，本研究证实这些长期被严重忽视的地下动物类群，正是未来生物多样性发现的前沿领域。然而，这类类群正面临人类聚居区扩张与栖息地丧失的威胁，保护该新种及其他地下类群具有极高的重要性。