Pseudodesmus ngoclinh, Nguyen & Nguyen & Korsós, 2024

Nguyen, Anh D., Nguyen, Lien T. P. & Korsós, Zoltán, 2024, A review of the millipede genus Pseudodesmus Pocock, 1887 (Diplopoda, Platydesmida, Andrognathidae) from Vietnam, with descriptions of five new species and notes on its phylogeny, Zoosystematics and Evolution 100 (4), pp. 1515-1541 : 1515-1541

publication ID	https://doi.org/ 10.3897/zse.100.132111
publication LSID	lsid:zoobank.org:pub:B39508EB-6EB2-4CC0-88D8-B3E87BDCED02
DOI	https://doi.org/10.5281/zenodo.14052224
persistent identifier	https://treatment.plazi.org/id/AEB04568-1A0F-5198-9153-C08ABF220F73
treatment provided by	Zoosystematics and Evolution by Pensoft
scientific name	Pseudodesmus ngoclinh
status	sp. nov.

Treatment

Pseudodesmus ngoclinh sp. nov.

Figs 6 View Figure 6 , 7 View Figure 7 , 8 View Figure 8 , 9 View Figure 9 , 10 View Figure 10

Material examined.

Holotype. Vietnam • 1 male; Kon Tum Province, Ngoc Linh Mts ; 15.07134 ° N, 107.97158 ° E; 1,800–1,900 m a. s. l.; 21 Mar. – 9 Apr. 2006; Anh D. Nguyen leg.; primary forest, decaying wood, under the bark; IEBR-Myr 986 H . GoogleMaps

Paratypes. Vietnam • 1 male, 2 females; same data as for the holotype; IEBR-Myr 986 P GoogleMaps • 2 females; same data as for the holotype; HNHM GoogleMaps .

Diagnosis.

Head slightly broader than collum. Collum with distinct paraterga directed anterad, with two rows of 1 + 1 smaller and 2 + 2 larger tubercles. Body covered with dense minute pubescence. Midbody body rings with two rows of tubercles on metazona, posterior row of 4–5 + 4 – 5 tubercles, shorter and extending to base of paraterga; anterior row of 5–10 + 5–10 small tubercles, longer, extending to about midlength of paraterga. Posterior gonopods 6 - segmented, with two apical stylets.

Diagnosis remarks.

The new species is easily distinguished from P. camptotrichus by coloration (yellowish / brownish plus dark spots vs whole earth brown). It also differs from P. variegatus and P. camptotrichus in having smaller size (length: 11.4 mm vs 32 mm and 14 mm; width: 2.74 mm vs 5.8 mm and 2.0 mm, respestively), number of metazonal tubercles (two rows of 5–10 + 5–10 and 4–5 + 4 – 5 vs two rows of 8–15 + 8 – 15 and 5–7 + 5 – 7, and two rows of 6 + 6 to 9 + 9 each row, respectively).

Description.

Male holotype.

Measurements: 51 body rings plus telson; length about 11.40 mm, length of midbody metazona about 0.19 mm, width of midbody metazona about 2.74 mm, width of midbody prozona about 1.26 mm; ratio of width of head and width of collum = 1.05.

Coloration of ethanol-preserved specimens: first 6 body rings including collum yellowish in the middle, then most body rings with a light median section, dark spots (on tubercles) irregularly on one side or both sides, dark spots on paraterga, asymmetrically, and almost every body ring different, sometimes repeating 3–4 body rings, last 5–6 body rings uniformly brownish.

Head (Figs 6 A, B, F View Figure 6 , 7 A – D View Figure 7 ) round-shaped, moderately densely setose. Antenna stout, clavate, in situ reaching to body ring 5; antennomere 6> 5> 3> 4 = 2> 7 = 1 in length. Collum with distinct paraterga directed anterad, with two rows: anterior row with 1 + 1 tubercles, posterior row with 2 + 2 tubercles, paramedian ones being larger (Figs 6 A View Figure 6 , 7 A, B View Figure 7 ). Body covered with dense minute pubescence. Slopes of dorsum steep, so body in cross-section subtriangular. Body rings 2–4 with a single row, each of 1 + 2, 1 + 1, 3 + 4 tubercles, respectively (Figs 6 A, C View Figure 6 , 7 A View Figure 7 ). Midbody body rings with two rows of tubercles on metazona, posterior row of 4–5 + 4 – 5 tubercles, shorter and extending to base of paraterga; anterior row of 5–10 + 5–10 small tubercles, longer, extending to about midlength of paraterga. Paramedian tubercles considerably larger, and posterior paramedian tubercles much larger than anterior paramedian ones (Figs 6 D View Figure 6 , 8 A View Figure 8 , 8 C View Figure 8 ). The last 6 body rings with only a row of 4 + 4 tubercles (Figs 6 E View Figure 6 , 8 C View Figure 8 ).

Paraterga curved strongly anteriad on body rings 2–5, increasingly less so on body rings 6–10 (to body ring 11 on paratype specimens), slightly curved caudad on body ring 11 (to body ring 12 on paratype specimens) and following body rings; caudal curvature of paraterga increasingly clear on 6–7 posteriormost body rings in front of telson; paraterga of penultimate body ring produced strictly caudad and flanking telson (Figs 6 E, G View Figure 6 , 8 C, D View Figure 8 ). Caudal paratergal margins entire, without notches (Figs 6 View Figure 6 – 8 View Figure 8 ).

Telson (Figs 6 C View Figure 6 , 8 C, D View Figure 8 ) short, caudal margin rounded; epiproct with 2 + 2 small / tiny tubercles at caudal margin. Paraprocts and hypoproct semi-circular.

Legs slender, shorter than width of body ring together with paraterga, terminating before lateral paratergal margins. Prefemur = tarsus> femur> postfemur = tibia in length. Claws normal. Coxal sacs present on body rings 3–41 (Figs 6 G View Figure 6 , 8 B View Figure 8 ).

Gonopods: Two pairs of gonopods directed mesoanteriad. Anterior gonopods (Figs 9 A View Figure 9 , 10 A, B View Figure 10 ) 6 - segmented, covered with long setae; coxite broadly stout, basal part sparsely covered with microgranulations; podomeres 2–5, short and stout; podomere 6 slightly longer than other podomeres, distally carrying macrosetae (mse). Posterior gonopods (Figs 9 B View Figure 9 , 10 C, D View Figure 10 ) 6 - segmented, covered with sparse long setae; coxite broad, basal part sparsely covered with microgranulations; podomeres 2–5 short and stout; ultimate podomere (po 6) longest, with two apical stylets (sty).

Variation.

Male paratype: 53 body rings + telson; length about 11.73 mm, length of midbody metazona about 0.21 mm, width of midbody metazona about 2.79 mm, width of midbody prozona about 1.28 mm.

Female paratypes. 48–51 body rings + telson. Length ca 12.21–13.52 mm, width of midbody metazona about 2.84–3.02 mm; width of prozona about 1.32 mm; length of metazona about 0.26 mm, average ratio of width of head and width of collum = 1.14. Nonsexual characters as in male.

Etymology.

Named after the “ Ngoc Linh ” Mountain, the type locality. Noun in apposition.

Distribution.

The species has been found in Ngoc Linh Mts at the high elevation of 1800–1900 m a. s. l. in Kon Tum Province, Vietnam.

DNA barcoding.

A fragment of the COI gene is accessioned at NCBI GenBank with the following accession numbers: PQ 423222 – PQ 423223. The new species has a COI gene similarity with Andrognathidae spp. ( MF 983566 View Materials and MF 983567 View Materials ) of 89.13 % and 89.37 % identity, respectively.