New species of millipede (Litostrophus and Atopochetus) from Thailand

Assistant Professor Dr Piyatida Pimvichai, a SCIMSU researcher from the Department of Biology at Mahasarakham University, and her colleagues published an article in Invertebrate Systematics (2018). The publication entitled “Morphological and mitochondrial DNA data reshuffle the taxonomy of the genera Atopochetus Attems, Litostrophus Chamberlin and Tonkinbolus Verhoeff (Diplopoda: Spirobolida: Pachybolidae), with descriptions of nine new species.”

Abstract: Species-level taxonomy and phylogeny of two genera of South-East (SE) Asian pachybolid millipedes are analysed with a combination of morphological characters and DNA sequences (two mitochondrial gene fragments: COI and 16S rRNA). Strong support is found for the genera Litostrophus Chamberlin, 1921 and Atopochetus Attems, 1953 and for a clade consisting of Litostrophus + Atopochetus. Four species of Litostrophus are recognised and (re)described: L. segregatus Chamberlin, 1921 (type species of the genus), L. scaber (Verhoeff, 1938), comb. nov., L. chamaeleon, sp. nov. and L. saraburensis, sp. nov. The genus Tonkinbolus Verhoeff, 1938 (type species T. scaber Verhoeff, 1938) is synonymised under Litostrophus. Atopochetus (type species A. rubropunctatus Attems, 1953), hitherto considered a dubious synonym of Aulacobolus Pocock, 1903, is re-instated for several species until now placed in Tonkinbolus and seven new species. All in all, 10 species of Atopochetus are (re)described: A. dollfusii (Pocock, 1893) (= Aulacobolus rubropunctatus Attems, 1938, syn. nov.), A. moulmeinensis (Pocock, 1893), A. sumatranus (Carl, 1906) (= Trachelomegalus laciniatus Attems, 1937, syn. nov.), A. anaticeps, sp. nov., A. helix, sp. nov., A. setiferus, sp. nov., A. spinimargo, sp. nov., A. truncatus, sp. nov., A. uncinatus, sp. nov. and A. weseneri, sp. nov. Three species recently included in Tonkinbolus are left incertae sedis because they are based exclusively on female type specimens: Spirobolus capucinus Porat, 1896, S. caudulanus Karsch, 1881 and S. macrurus Pocock, 1893. The results of the DNA analysis (COI and 16S rRNA) are congruent with morphological (gonopodal) characters in terms of delimitation of species of Litostrophus and Atopochetus. This is the first DNA study of SE Asian Pachybolidae and as such it provides a basis for further evolutionary and biogeographic studies of SE Asian millipedes. 

4. Atopochetus helix Pimvichai, Enghoff, Panha & Backeljau 2018 (กิ้งกือหางมนปลายเกลียว)

Holotype: Thailand, Kanchanaburi Province, Thong Pha Phum District, Suan Pa Thong Pha Phum, 14º40′ 12″N, 98º35′ 36″E, 8.v.2007, C. Sutcharit and P. Pimvichai leg. (CUMZ-D00094).

Etymology: The name is a Latin noun in apposition and refers to the helicoid tip of the posterior gonopod.

6. Atopochetus spinimargo Pimvichai, Enghoff, Panha & Backeljau 2018 (กิ้งกือหางมนสงขลา)

Holotype: Thailand, Songkhla Province, Rattaphum District, Charoen Phupha temple, 7º 08′ 54″N, 100º 15′ 35″E, 12.i.2009, S. Panha and P. Pimvichai leg. (CUMZ-D00099).

Etymology: The name is a Latin noun in apposition and refers to the spined mesal margin of the posterior gonopod telopodite.

7. Atopochetus truncatus Pimvichai, Enghoff, Panha & Backeljau 2018 (กิ้งกือหางมนสิมิลัน)

Holotype: Thailand, Phang Nga Province, Khuraburi District, Koh 8, Similan islands, 8º 39′ 09″N, 97º 38′ 27″E, 7.iv.2010, S. Panha and P. Pimvichai leg. (CUMZ-D00101).

Etymology: The name refers to the truncate posterior gonopod tip.

Piyatida Pimvichai, Henrik Enghoff, Somsak Panha, and Thierry Backeljau “Morphological and mitochondrial DNA data reshuffle the taxonomy of the genera Atopochetus Attems, Litostrophus Chamberlin and Tonkinbolus Verhoeff (Diplopoda: Spirobolida: Pachybolidae), with descriptions of nine new species,” Invertebrate Systematics 32(1), 159-195, (1 February 2018). https://doi.org/10.1071/IS17052