Pseudodesmus condao, 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.14052231
persistent identifier	https://treatment.plazi.org/id/CE1AD5B1-0A85-447A-91FF-1B490A38097D
taxon LSID	lsid:zoobank.org:act:CE1AD5B1-0A85-447A-91FF-1B490A38097D
treatment provided by	Zoosystematics and Evolution by Pensoft
scientific name	Pseudodesmus condao
status	sp. nov.

Treatment

Pseudodesmus condao sp. nov.

Figs 15 View Figure 15 , 16 View Figure 16 , 17 View Figure 17 , 18 View Figure 18 , 19 View Figure 19 , 20 View Figure 20

Material examined.

Holotype. Vietnam • 1 male; Ba Ria-Vung Tau Province, Con Dao NP, on the way to Ong Dung Beach ; 08.70528 ° N, 106.59158 ° E, 37 m a. s. l., 7 Nov. 2019; A. D. Nguyen leg.; natural forest; IEBR-Myr 982 H . GoogleMaps

Paratypes. Vietnam • 2 males, 2 females; same data as the holotype; IEBR-Myr 982 P GoogleMaps • 3 males, 1 female Ba Ria-Vung Tau Province, Con Dao NP, on the way to Ong Dung beach , 08.70528 ° N, 106.59158 ° E, 37 m a. s. l., 7 November 2019, leg. Nguyen A. D.; natural forest; IEBR Myr 821 GoogleMaps • 8 males, 5 females; Ba Ria-Vung Tau Province, Con Dao NP, on the way to Ong Dung beach , 08.70528 ° N, 106.59158 ° E, 37 m a. s. l.; 8 Nov. 2023; A. D. Nguyen leg.; natural forest; IEBR-Myr 977 GoogleMaps • 2 males, 2 females; same data as for sample IEBR-Myr 977; HNHM GoogleMaps .

Diagnosis.

Color dark yellow, little darker in the middle. Head distinctly smaller than collum. Collum bilobed, each with three anterior lobes, no tubercles. Midbody terga with two rows, 3–4 + 3–4 large and 4 – 5 + 4 – 5 large tubercles in anterior and posterior rows, respectively. Posterior gonopods 6 - segmented, with two apical stylets.

Diagnosis remarks.

The new species is very similar with P. camptotrichus by coloration (dark yellow vs earth brown), but it differs from P. variegatus in body coloration (dark yellow vs yellow-brown with black spots). In addition, it is smaller than P. variegatus and P. camptotrichus (length: 9.33 mm vs 32 mm and 14 mm; width: 1.57 mm vs 5.8 mm and 2.0 mm, respestively), having less number of male body rings (42 vs 53–56 and 37–42), and number of metazonal tubercles (two rows of 3–4 + 3–4 and 4–5 + 4–5 tubercles vs two rows of 8–15 + 8–15 and 5–7 + 5–7, and two rows of 6–9 + 6–9 each row, respectively).

Pseudodesmus condao sp. nov. is differentiated from above three new species, P. bidoup sp. nov., P. ngoclinh sp. nov and P. karstomus sp. nov. in body coloration of generally uniformly dark yellow, smaller body size and number of stylets (two vs four, two and four, respectively).

Description.

Male holotype.

Measurements: 42 body rings plus telson, length about 9.33 mm, length of midbody metazona ca. 0.24 mm, width of midbody metazona ca. 1.57 mm, width of midbody prozona ca. 0.63 mm; ratio of width of head and width of collum = 0.89.

Coloration of ethanol-preserved specimens: dark yellow, little darker in the middle.

Head distinctly smaller than collum. Antenna stout, clavate, in situ extending to body ring 4; antennomere 6> 5> 3> 4 = 2> 7 = 1 in length. Collum (Figs 15 A View Figure 15 , 16 A View Figure 16 , 17 A View Figure 17 , 18 A View Figure 18 ) bilobed, each with three anterior lobes, no tubercles. Body rings 2–4 one row of tubercles, then each body ring with 2 rows, body rings 5–8 with 1 + 1 larger in the middle, then 2 + 2 larger tubercles, both in anterior and posterior rows (Figs 15 A View Figure 15 , 16 A – C View Figure 16 , 17 A View Figure 17 , 18 A, C View Figure 18 ). Additionally, 2–3 small tubercles in both rows laterally, but only on tergites, not extending to paraterga (Figs 15 A View Figure 15 , 16 A – C View Figure 16 , 17 A View Figure 17 , 18 A, C View Figure 18 ).

Paraterga (Figs 15 View Figure 15 – 18 View Figure 18 ) smooth, almost transparent, wider than in the other species, a little bit spoon form (the distal part is wider than the proximal part), especially in the anterior body ring (up to 10 th), later tapering towards the edge, anterior edge is bending backwards, posterior edge remains transverse. Anterior and lateral margin of paraterga serrated (Figs 17 A View Figure 17 , 18 View Figure 18 ).

Telson (Figs 16 C, F View Figure 16 , 17 C, D View Figure 17 ) 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. Claws normal. Coxal projections present until leg 71 (body ring 38) (Figs 17 B View Figure 17 , 18 D View Figure 18 ).

Gonopods (Figs 19 View Figure 19 , 20 View Figure 20 ): Two pairs of gonopods directed anteriad. Anterior gonopods (Figs 19 A View Figure 19 , 20 C, D View Figure 20 ) 6 - segmented, covered with long setae; coxite (co) broad, 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 19 B View Figure 19 , 20 A, B, E View Figure 20 ) 6 - segmented, covered with sparse long setae; coxite (co) broad, basal part sparsely covered with microgranulations; podomeres 2–5 short and stout; ultimate podomere (po 6) longest, with two apical stylets.

Variation.

Male paratypes: 46–47 body rings plus telson, length about 10.81–11.19 mm, length of midbody metazona ca. 0.25–0.28 mm, width of midbody metazona ca. 1.70–1.77 mm, width of midbody prozona ca. 0.75–0.96 mm; ratio of width of head and width of collum = 0.83–0.88. (width of collum: 0.64–0.74 mm, width of head: 0.53–0.65 mm).

Female paratypes: 48–49 body rings plus telson, length about 12.22–12.50 mm, length of midbody metazoan ca. 0.26 mm, width of midbody metazona ca. 1.75–1.77 mm, width of midbody prozona ca. 0.96–0.98 mm; ratio of width of head and width of collum = 0.84. (width of collum: 0.56–0.80 mm, width of head: 0.47–0.67 mm).

Etymology.

Named after its type locality, Con Dao National Park. Noun in apposition.

Distribution.

The species was found in evergreen forests in Con Dao National Park, Ba Ria – Vung Tau Province, southern Vietnam.

DNA barcoding.

A fragment of the COI gene is accessioned at NCBI GenBank with the following accession numbers: PQ 423226 – PQ 423227. The new species has a close COI gene similarity with Gosodesmus claremontus ( JX 962723 View Materials ) of 87.46 % in the BLAST search.