Eutrichodesmus
Eutrichodesmus is a genus of millipedes in the family Haplodesmidae. Containing 54 species, this genus is among the genera with the greatest number of species not only in the family Haplodesmidae but also in the order Polydesmida. This genus includes the species E. peculiaris, notable for featuring sexual dimorphism in segment number: The adult females have 20 segments, but the adult males have only 19 segments. Millipedes in this genus are found in southern Japan, Taiwan, southern China, mainland Southeast Asia, Indonesia, and Vanuatu.
Description
Millipedes in this genus are small, ranging from 3.5 mm to 14 mm in length. These millipedes can have 19 or 20 segments. Species in this genus are capable of volvation, which is usually complete but sometimes incomplete.
The basal element of the gonopod in adult males in this genus usually features abundant setae. The distal element of the gonopod is usually slender and long, with dense setae on the basal half. The telopodite often features a conspicuous outgrowth on the lateral side. The distal part of the telopodite is conspicuous and well developed but rarely branches into a separate lobe.
The millipedes in this genus resemble those in the genus Doratodesmus, which are also capable of volvation. Like the adult males in Eutrichodesmus, those in Doratodesmus also usually feature gonopod coxae with abundant setae. The adult males in Doratodesmus, however, feature gonopod telopodites that are usually stout and markedly enlarged toward the sides, unlike those usually observed in Eutrichodesmus, which are slender.
Species
This genus includes the following species:Eutrichodesmus arcicollaris Zhang, 1993Eutrichodesmus armatocaudatus Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2009Eutrichodesmus aster Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2009Eutrichodesmus asteroides Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2009Eutrichodesmus basalis Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2009Eutrichodesmus cavernicola Sinclair, 1901Eutrichodesmus communicans Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2009Eutrichodesmus curticornis Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2009Eutrichodesmus demangei Silvestri, 1910Eutrichodesmus deporatus Liu, Golovatch & Wesener, 2017Eutrichodesmus distinctus Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2009Eutrichodesmus dorsiangulatus Zhang, 1993Eutrichodesmus filisetiger Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2009Eutrichodesmus gremialis Hoffman, 1982Eutrichodesmus griseus Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2009Eutrichodesmus incisus Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2009Eutrichodesmus latus Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2009Eutrichodesmus macclurei Hoffman, 1977Eutrichodesmus monodentus Zhang, 1993Eutrichodesmus multilobatus Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2009Eutrichodesmus paraster Liu, Golovatch & Wesener, 2017Eutrichodesmus parvus Liu, Golovatch & Wesener, 2017Eutrichodesmus peculiaris Murakami, 1966Eutrichodesmus reclinatus Hoffman, 1977Eutrichodesmus reductus Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2009Eutrichodesmus regularis Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2009Eutrichodesmus similis Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2009Eutrichodesmus steineri Liu, Golovatch & Wesener, 2017