Nagaxytes gracilis Srisonchai, Enghoff & Panha, 2018

Ruttapon Srisonchai, Henrik Enghoff, Natdanai Likhitrakarn & Somsak Panha, 2018, A revision of dragon millipedes II: the new genus Nagaxytes gen. nov., with the description of three new species (Diplopoda, Polydesmida, Paradoxosomatidae), European Journal of Taxonomy 462, pp. 1-44 : 27-34

publication ID	https://doi.org/ 10.5852/ejt.2018.462
publication LSID	urn:lsid:zoobank.org:pub:60992A95-1F59-4407-9774-B8FC1545A8B4
DOI	https://doi.org/10.5281/zenodo.5946412
persistent identifier	https://treatment.plazi.org/id/A6CF5E48-B6AF-4FBD-A02D-D07E4DCDD605
taxon LSID	lsid:zoobank.org:act:A6CF5E48-B6AF-4FBD-A02D-D07E4DCDD605
treatment provided by	Plazi
scientific name	Nagaxytes gracilis Srisonchai, Enghoff & Panha
status	gen. et sp. nov.

Treatment

Nagaxytes gracilis Srisonchai, Enghoff & Panha View in CoL gen. et sp. nov.

urn:lsid:zoobank.org:act:A6CF5E48-B6AF-4FBD-A02D-D07E4DCDD605

Figs 1 View Fig. 1 , 4 View Fig. 4 , 5 View Fig. 5 , 17–21 View Fig. 17 View Fig. 18 View Fig. 19 View Fig. 20 View Fig. 21

Diagnosis

Metaterga 4–19 with one row of 2+2 posterior spines (anterior row absent). Similar in this respect to N. acantherpestes gen. et comb. nov., but differs from this species by having paraterga longer; degree of elevation of paraterga higher; sternal lobe between male coxae 4 incompletely bilobed; lamina lateralis long, lamella-like, thin, slender, tip round and directed ventrad.

Etymology

The name is a Latin adjective, referring to the slender lamina lateralis of the gonopod telopodite.

Material examined

Holotype THAILAND: ♂, Kanchanaburi Province, Sai Yok District, Daowadueng Cave , 14°28′23″ N, 98°50′04″ E, ca. 133 m a.s.l., 15 Aug. 2016, ASRU members leg. ( CUMZ-pxDGT00090 ). GoogleMaps

Paratypes THAILAND: 7 ♂♂, 21 ♀♀, same data as for holotype ( CUMZ-pxDGT00091-118 ); 1 ♂, 1 ♀, same data as for holotype (ZMUC 00040245 ).

Further specimens, not paratypes

THAILAND – Kanchanaburi Province, Sai Yok District : 1 ♂, 1 broken ♂, 1 broken ♂ (right gonopod lost), 5 ♀♀, Daowadueng Cave, 14°28′23″ N, 98°50′04″ E, ca. 133 m a.s.l., 8 Sep. 2008, ASRU members leg. (CUMZ); GoogleMaps 2 ♂♂, 6 ♀♀, Daowadueng Cave, 14°28′23″ N, 98°50′04″ E, ca. 133 m a.s.l., 11 Jul. 2009, ASRU members leg. ( CUMZ); 2 ♂♂, Daowadueng Cave , 14°28′23″ N, 98°50′4″ E, ca. 133 m a.s.l., 12 Oct. 2015, ASRU members leg. (CUMZ); GoogleMaps 8 ♂♂, 21 ♀♀, 1 broken ♂, 1 ♂ (right gonopod lost), 1 ♂ fragment (gonopods lost), Wat Tham Phrom Lok Khao Yai, 14°12′15″ N, 99°07′57″ E, ca. 122 m a.s.l., 9 Jul. 2009, ASRU members leg. ( CUMZ); 1 ♂, Wat Tham Phrom Lok Khao Yai, 14°12′15″ N, 99°07′57″ E, ca. 122 m a.s.l., 15 Aug. 2016, ASRU members leg. ( CUMZ); GoogleMaps 1 ♂, Kra Sae Cave , 14°06′05″ N, 99°10′09″ E, ca. 79 m a.s.l., 10 Dec. 2006, ASRU members leg. (CUMZ); GoogleMaps 3 ♂♂, 3 broken ♂♂, 1 ♂ (right gonopod lost), 5 ♀♀, Hellfire Pass, 14°21′20″ N, 98°57′09″ E, ca. 216 m a.s.l., 29 Aug. 2011, ASRU members leg. (CUMZ); 2 ♂♂, 2 ♀♀, Hellfire Pass, 14°21′20″ N, 98°57′09″ E, ca. 216 m a.s.l., Aug. 2014, ASRU members leg. (CUMZ); 1 ♂, 1 ♀, Ban Thung Kang Yang, 14°24′17″ N, 98°55′04″ E, ca. 263 m a.s.l., 15 Aug. 2016, ASRU members leg. (CUMZ); 4 ♂♂, 5 ♀♀, Wat Sunantha Wanaram, 14°32′11″ N, 98°49′51″ E, ca. 161 m a.s.l., 17 Aug. 2016, ASRU members leg. (CUMZ); 7 ♂♂, 6 ♀♀, Wat Phuttha Vimooddhi Wanaram (Wat Tham Phu Mood), 14°18′07″ N, 98°59′27″ E, ca. 213 m a.s.l., 17 Aug. 2016, ASRU members leg. (CUMZ).

Description

SIZE. Length 30–33 mm (male), 35–38 mm (female); width of midbody metazona ca. 2.2 mm (male), 3.1 mm (female). Width of head <collum <body ring 2 = 3 = 4 <5–17, thereafter body gradually tapering towards telson.

COLOUR ( Fig. 17A–B View Fig. 17 ). Specimens in life with body pinkish brown; paraterga vivid pink or reddish pink; collum, prozona, metaterga, surface below paraterga pinkish brown; head, antennae (except whitish distal part of antennomere 7 and antennomere 8) sterna and legs brown; a few basal podomeres whitish brown; epiproct pink. Colour in alcohol: after 3–9 years changed to pale brown; head, collum, metaterga, surface below paraterga, sterna, epiproct pale brown or whitish brown; paraterga brownish white.

COLLUM ( Fig. 18A View Fig. 18 ). With three transverse rows of setae/tubercles and spines, 3+3 setae/tubercles in anterior row, 1+1 setae/tubercles in intermediate row (tubercles small) and 2+2 spines in posterior row; paraterga of collum long and broad, elevated at ca. 40°–45° (male) 35°–40° (female), directed caudolaterad, with 2 conspicuous notches at lateral margin.

ANTENNAE ( Fig. 18D View Fig. 18 ). Moderately long and slender, reaching to body ring 5 or 6 (male) and 4 or 5 (female) when stretched dorsally.

TEGUMENT. Quite shiny. Stricture between prozona and metazona shallow, wide.

METATERGA ( Fig. 18A–C View Fig. 18 ). Metatergum 2 with 1(2)+1(2) anterior tubercles/cones and 2+2 posterior spines; metatergum 3 with 1+1 anterior tubercles (inconspicuous) and 2+2 posterior spines; metaterga 4–19 with 2+2 posterior spines (anterior row absent; lateral spines of posterior row in all rings very long, longer than mesal ones).

PLEUROSTERNAL CARINAE. On body ring 2 long, crest-like; on body rings 3 and 4 small ridges; thereafter missing.

PARATERGA ( Figs 18F–G View Fig. 18 , 19B View Fig. 19 ). Directed caudolaterad on body rings 2–18, elevated at ca. 70° (male) 60°–70° (female), directed increasingly caudad on body ring 19; notch near the tip at lateral margin of body rings 5–7, 9, 10, 12, 13, 15–18 absent on some rings in some specimens.

TELSON ( Fig. 19C–G View Fig. 19 ). Epiproct quite short; tip usually subtruncate (in some specimens slightly emarginate); lateral setiferous tubercles conspicuous, long, digitiform; apical tubercles conspicuous. Hypoproct subtriangular; caudal margin subtriangular, with inconspicuous setiferous tubercles.

STERNA ( Fig. 19H–J View Fig. 19 ). Cross-impressions quite deep. Sternal lobe between male coxae 4 incompletely bilobed; base broad; tip deeply emarginate; surface near pores swollen.

GONOPODS ( Figs 4–5 View Fig. 4 View Fig. 5 , 20–21 View Fig. 20 View Fig. 21 ). Coxa subequal in length to femur. Cannula long and slender. Telopodite quite long and slender. Prefemoral part ca. half as long as femur. Femur long and slender, slightly enlarged distally. Mesal sulcus conspicuous, deep, wide; lateral sulcus quite deep and very wide. Postfemoral part conspicuous, short. Solenophore well-developed: lamina lateralis long, lamellalike, thin, slender; tip round, directed ventrad: lamina medialis very long; slightly enlarged distally; apically fringed with several small spines; tip directed mesoventrad. Solenomere long and slender, tip directed ventrad.

Distribution and habitat

Nagaxytes gracilis gen. et sp. nov. is known only from Sai Yok District, Kanchanaburi Province. All specimens were collected on humid rocks, superficial tree roots and litter in limestone habitats. It lives in the same habitat with D. purpurosea , D. golovatchi Srisonchai, Enghoff & Panha, 2018 and N. erecta gen. et sp. nov. (q.v.). The new species occurs in a narrow distribution area along the huge limestone range which is entirely contained within Sai Yok District. We thus consider this species to be endemic to Kanchanaburi Province, Thailand.

Remarks

The vivid pink paraterga are probably aposematic. Nagaxytes gracilis gen. et sp. nov. was noticeable in the field by the contrast of its bright pink colour to brown rocks.

There is a variability in the tip of the epiproct: in some specimens subtruncate, in others slightly emarginate.