A remarkable new species of the millipede genus Trachyjulus Peters, 1864 (Diplopoda, Spirostreptida, Cambalopsidae) from Thailand, based both on morphological and molecular evidence

Natdanai Likhitrakarn; Sergei I Golovatch; Ekgachai Jeratthitikul; Ruttapon Srisonchai; Chirasak Sutcharit; Somsak Panha

doi:10.3897/zookeys.925.49953

A remarkable new species of the millipede genus Trachyjulus Peters, 1864 (Diplopoda, Spirostreptida, Cambalopsidae) from Thailand, based both on morphological and molecular evidence

Zookeys. 2020 Apr 8:925:55-72. doi: 10.3897/zookeys.925.49953. eCollection 2020.

Authors

Natdanai Likhitrakarn¹, Sergei I Golovatch², Ekgachai Jeratthitikul³, Ruttapon Srisonchai⁴, Chirasak Sutcharit⁵, Somsak Panha⁵

Affiliations

¹ Division of Plant Protection, Faculty of Agricultural Production, Maejo University, Chiang Mai 50290, Thailand Maejo University Chiang Mai Thailand.
² Institute for Problems of Ecology and Evolution, Russian Academy of Sciences, Leninsky pr. 33, Moscow 119071, Russia Institute for Problems of Ecology and Evolution, Russian Academy of Sciences Moscow Russia.
³ Animal Systematics and Molecular Ecology Laboratory, Department of Biology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand Mahidol University Bangkok Thailand.
⁴ Department of Biology, Faculty of Science, Khon Kaen University, Khon Kaen, 40002 Thailand Khon Kaen University Khon Kaen Thailand.
⁵ Animal Systematics Research Unit, Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand Chulalongkorn University Bangkok Thailand.

Abstract

A new, giant species of Trachyjulus from a cave in southern Thailand is described, illustrated, and compared to morphologically closely related taxa. This new species, T. magnus sp. nov., is much larger than all other congeners and looks especially similar to the grossly sympatric T. unciger Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2012, which is widespread in southern Thailand. Phylogenetic trees, both rooted and unrooted, based on a concatenated dataset of the COI and 28S genes of nine species of Cambalopsidae (Trachyjulus, Glyphiulus, and Plusioglyphiulus), strongly support the monophyly of Trachyjulus and a clear-cut divergence between T. magnus sp. nov. and T. unciger in revealing very high average p-distances of the COI gene (20.80-23.62%).

Keywords: cave; diplopod; molecular-based phylogeny; morphological character; taxonomy.

Natdanai Likhitrakarn, Sergei I. Golovatch, Ekgachai Jeratthitikul, Ruttapon Srisonchai, Chirasak Sutcharit, Somsak Panha.