Desmoxytes gigas Golovatch & Enghoff, 1994: 56 Desmoxytes gigas Enghoff 2005: 96 Nguyen & Sierwald 2013: 1241 A revision of dragon millipedes III: the new genus Gigaxytes gen. nov., with the description of three new species (Diplopoda, Polydesmida, Paradoxosomatidae) Srisonchai, Ruttapon Enghoff, Henrik Likhitrakarn, Natdanai Panha, Somsak European Journal of Taxonomy 2018 2018-09-27 463 1 43 3G2F9 Srisonchai, Enghoff & Panha Srisonchai, Enghoff & Panha 2018 [431,974,746,773] Diplopoda Paradoxosomatidae Gigaxytes GBIF Animalia Polydesmida 10 11 Arthropoda species fusca gen. et sp. nov.  ( Figs 1, 2, 4–8, 24)    Diagnosis Collum usually with 5+5 cones/spines in anterior row, 4+4 cones/spines in intermediate row and 4+4 cones/spines in posterior row. Metaterga 2–8 usually with 4+4 cones/spines in anterior row, 4+4 cones/ spines in intermediate row and 4+4 cones/spines in posterior row. Male femora 5 and 6 with an apophysis. Similar in these repects to  G. suratensis gen. et sp. nov., but differs from this species by having brown body colouration; paraterga longer; male femora 7 unmodified; solenophore narrow laterally; lamina medialis apically sharp.    Etymology The specific epithet is a Latin adjective meaning brown and refers to the brown body colour of living specimens.    Material examined    Holotype  THAILAND: ♂, Chumphon Province, Pathio District, Phitsadarn Cave(Tham Phitsadarn), 10º45′36″ N, 99°13′46″ E, ca.  103 ma.s.l.,   29 Aug.2015, ASRUmembers leg. (CUMZ-pxDGT00166).    Paratypes  THAILAND: 7 ♂♂, 1 ♀, same data as for holotype(CUMZ-pxDGT00167-174); 1 ♂, 1 ♀, same data as for holotype( ZMUC00040247).  Additional specimens  MYANMAR: 9 ♂♂, 5 ♀♀, 1 juveniles, Tanintharyi Region, Lenya National Park, approximately 10 kmfrom Nam Yen Village, Phayarhtan Cave (Buddha Cave), 11º13′50″ N, 99°10′35″ E, ca. 85 ma.s.l., 6 Jun. 2015, Fauna & Flora International staffs, C. Sutcharit, R. Chanabun and R. Srisonchai leg. ( CUMZ). – THAILAND: 1 broken ♂– right gonopod lost, Chumphon Province, Pathio District, Phitsadarn Cave (Tham Phitsadarn), 10º45′36″ N, 99°13′46″ E, ca. 103 ma.s.l., 2 Oct. 2006, ASRUmembers leg. ( CUMZ); 1 broken  ♀, Prachuap Khiri Khan Province, Bang Saphan District, Wat Khao Tham Ma Rong, 11º12′05″ N, 99°29′52″ E, ca. 21 ma.s.l.,  12 Oct.2008, ASRUmembers leg. ( CUMZ).    Description SIZE. Length 35–38 mm(male), 35–40 mm(female); width of midbody metazona ca. 2.8 mm (male), 3.7 mm (female). Width of head <collum <2 <3 ± 4 <5–17, thereafter body gradually tapering towards telson. COLOUR ( Fig. 4A–C). Specimens in life with body brown; head, collum, antennae, metaterga, prozona, surface below paraterga (upper part), paraterga, epiproct and legs brown; surface below paraterga (lower part), base of paraterga, sterna and a few basal podomeres pale brown. Colour in alcohol: after 10 years changed to pale brown; head, collum, metaterga, paraterga, surface below paraterga, sterna, epiproct pale brown or whitish brown. COLLUM ( Figs 2A, C, 5A). With three transverse rows of setiferous cones/spines, 5(6)+5 cones/spines in anterior row, 4(3/5)+4(3) cones/spines in intermediate row and 4(5)+4(3) cones/spines in posterior row (lateral cones/spines of anterior row located at base of collum paraterga; lateral cones/spines of posterior row displaced anteriad almost halfway to intermediate row); paraterga of collum elevated at ca. 40º–50º. ANTENNAE ( Fig. 5D). Very long and slender, reaching to body ring 6 or 7 (male) and 5 or 6 (female) when stretched dorsally. TEGUMENT. Stricture between prozona and metazona wide, quite shallow. METATERGA ( Figs 2A, D, G, 5A–C). With three transverse rows of setiferous cones/spines; metaterga 2–8 with 4(3/5)+4(3/5) cones/spines in anterior row, 4(3/5)+4(3/5) cones/spines in intermediate row and 4(3/5)+4(3/5) cones/spines in posterior row; metaterga 9–19 with 6(5)+6(5) cones/spines in anterior row, 6(5/7/8)+6(5/7) cones/spines in intermediate row and 6(5/7)+6(5/7) cones/spines in posterior row; lateral cones/spines of posterior row larger and longer than others in some specimens. PLEUROSTERNAL CARINAE. On body ring 2 long, crest-like; on ring 3 a short ridge; thereafter missing. PARATERGA ( Figs 2A–B, D–E, G–H, 5A–C, F, 6A–B). Extremely long; directed caudolaterad on body rings 2–16, elevated at ca. 50º–70º (male) 50º–60º (female), directed increasingly caudad on body rings 17–19. TELSON ( Figs 2F, L–N, 6C–G). Tip of epiproct subtruncate; apical tubercles inconspicuous. Hypoproct subtrapeziform; caudal margin subtruncate, with conspicuous setiferous tubercles. STERNUM ( Figs 2K, 6H–J). On body ring 5 with a swollen lobe; posterior surface of lobe with a pore borne on a long cylindrical stalk. LEGS ( Figs 2J, 6E–G). Male femora 5 and 6 with an apophysis. GONOPODS ( Figs 7–8). Coxa subequal in length to femorite. Cannula quite long and slender. Femorite quite long, a bit stout, curved. Solenophore narrow laterally: lamina lateralis narrow: lamina medialis quite long and narrow, distally sharp, tip in situdirected ventrad.    Distribution and habitat Known only from Thailand( Chumphonand Prachuap Khiri KhanProvinces) and Myanmar(Lenya National Park). All specimens were encountered hiding under dead leaves in limestone habitats and some were found in syntopy with  Desmoxytes planata( Pocock, 1895)at Phitsadarn Cave and Wat Khao Tham Ma Rong, or with  D. cervina( Pocock, 1895)at Phayarhtan Cave. The new species appears to have a limited distribution near the Kra Isthmus (narrowest part of the Malay Peninsula), a few locations have been recorded in Thailandand Myanmar. We regard this species to be endemic in this area. The typelocality is a tourist attraction place, being a cave belonging to a bureau of monks. Some parts of a habitat where lot of specimens were collected in front of the cave are currently being destroyed, this has raised a concern about habitat loss for  G. fusca gen. et sp. nov.    Remarks Brown live specimens blended perfectly with the brown leaf litter on the ground, making them difficult to find. Specimens from Myanmarshowed the same morphological characters as found in Thai material – no intrapopulational and interpopulational variations were found. On some specimens we found small white phoretic deutonymphs (the ‘hypopus’ stage) of mites of the family Histiostomatidae (Astigmata)( Fig. 4D, E). The mites can usually be found on specific sites especially on metaterga or paraterga, attaching to areas with a smooth surface.   Gigaxytes gigas( Golovatch & Enghoff, 1994) gen. et comb. nov. ( Figs 3, 9–13, 24)      Desmoxytes gigas Golovatch & Enghoff, 1994: 56, figs 49–52.    Desmoxytes gigas–  Enghoff 2005: 96. —  Nguyen & Sierwald 2013: 1241.    Diagnosis Collum usually with 5+5 cones/spines in anterior row, 3+3 cones/spines in intermediate row and 4+4 cones/spines in posterior row. Similar in this respect to  G. parvoterga sp. nov.Differs from this species by having paraterga longer; the degree of elevation of paraterga higher; male femora 5, 6 and 7 unmodified.    Material examined    Holotype  THAILAND: ♀, Krabi Province, road between Krabiand Phuket, 10 km Southof Krabi, 8º09′ N, 98°50′ E, lowland rainforest, <  200 m,  13 Oct. 1991, M. Anderson, O. Martin& N. Scharffleg. ( ZMUC000101460) [the exact location is  10 kmNorthof Krabi].  Additional specimens  THAILAND–  Krabi Province: 1 broken ♂– gonopods lost, Ao Luek District, Than Bok Khorani, 8º23′28″ N, 98°44′07″ E, 15 Jan. 2014, ca. 46 ma.s.l., ASRUmembers leg. ( CUMZ); 2 ♀♀, Ao Luek District, Than Bok Khorani, 8º23′28″ N, 98°44′07″ E, ca. 46 ma.s.l., 23 Aug. 2014, P. Pimvichai, P. Prasankok and N. Nantarat leg. ( CUMZ); 1 juvenile, Ao Luek District, Than Bok Khorani, 8º23′28″ N, 98°44′07″ E, ca. 46 ma.s.l., 30 Aug. 2015, P. Pimvichai, P. Prasankok and N. Nantarat leg. ( CUMZ); 1 ♀, Ao Luek District, Than Bok Khorani, 8º23′28″ N, 98°44′07″ E, ca. 46 ma.s.l., 12 Mar. 2017, ASRUmembers leg. ( CUMZ); 1 ♂– gonopods lost, Muaeng Krabi District, Wat Tham Sue (Tiger Cave), valley behind Tiger Cave, 8º07′38″ N, 98°55′26″ E, ca. 87 ma.s.l., 25 Oct. 2007, ASRUmembers leg. ( CUMZ); 1 broken  ♀, Muaeng Krabi District, Wat Tham Sue (Tiger Cave), valley behind Tiger Cave, 8º07′38″ N, 98°55′26″ E, ca 87 ma.s.l., 15 Jan. 2009, ASRUmembers leg. ( CUMZ); 2 ♂♂, 1 ♂– gonopods lost, 2 ♀♀, Muaeng Krabi District, Wat Tham Sue (Tiger Cave), valley behind Tiger Cave, 8º07′38″ N, 98°55′26″ E, ca 87 ma.s.l., 18 May 2010, ASRUmembers leg. ( CUMZ); 1 ♂, 2 ♀♀, Muaeng Krabi District, Wat Tham Sue (Tiger Cave), valley behind Tiger Cave, 8º07′38″ N, 98°55′26″ E, ca. 87 ma.s.l., 15 Jan. 2013, ASRUmembers leg. ( CUMZ); 9 ♂♂, 3 ♀♀, Muaeng Krabi District, Wat Tham Sue (Tiger Cave), valley behind Tiger Cave, 8º07′38″ N, 98°55′26″ E, ca. 87 ma.s.l., 24 Aug. 2014, leg. ASRUmembers leg. ( CUMZ); 1 ♂, 1 ♀, Muaeng Krabi District, Wat Tham Sue (Tiger Cave), valley behind Tiger Cave, 8º07′38″ N, 98°55′26″ E, ca. 87 ma.s.l., 24 Aug. 2014, ASRUmembers leg. ( ZMUC); 6 ♂♂, 5 ♀♀, Muaeng Krabi District, Wat Tham Sue (Tiger Cave), valley behind Tiger Cave, 8º07′38″ N, 98°55′26″ E, ca. 87 ma.s.l., 30 Aug. 2015, ASRUmembers leg. ( CUMZ); 3 ♂♂, 3 ♀♀, Muaeng Krabi District, Wat Tham Sue (Tiger Cave), valley behind Tiger Cave, 8º07′38″ N, 98°55′26″ E, ca. 87 ma.s.l., 9 Jul. 2017, ASRUmembers leg. ( CUMZ); 1 ♂, Muaeng Krabi District, Wat Tham Sue (Tiger Cave), valley behind Tiger Cave, 8º07′38″ N, 98°55′26″ E, ca. 87 ma.s.l., 25 Jul. 2017, ASRUmembers leg. ( CUMZ); 1 ♂, Muaeng Krabi District, near Ban Na Mee, Tham Na Mee (Na Mee Cave), 8º08′12″ N, 98°48′23″ E, ca. 70 ma.s.l., 30 Aug. 2015, ASRUmembers leg. ( CUMZ); 2 ♂♂, Plai Phraya District, Wat Khao Hua Sing, 8º30′47″ N, 98°45′34″ E, ca. 155 ma.s.l., 12 Mar. 2017, ASRUmembers leg. ( CUMZ). –  Nakhon Si Thammarat Province: 1 ♀, Thung Song District, Weruwan Bureau of Monks (Tham Rad), 8º02′48″ N, 99°43′43″ E, ca. 83 ma.s.l., 11 Jan. 2009, ASRUmembers leg. ( CUMZ); 1 ♂, 2 ♀♀, Thung Song District, Talod Cave Park (Talod Cave), 8º09′32″ N, 99°40′42″ E, ca. 74 ma.s.l., 5 Jan. 2017, ASRUmembers leg. ( CUMZ); 1 ♀, Nopphitam District, Krung Ching Waterfall, 8º43′27″ N, 99°40′04″ E, ca. 173 ma.s.l., 17 Jan. 2013, ASRUmembers leg. ( CUMZ). –  Phatthalung Province: 1 ♂– gonopods lost, Khuan Khanun District, Tham Wang Thong, 7º40′57″ N, 100°00′58″ E, ca. 44 ma.s.l., 11 Jan. 2009, ASRUmembers leg. ( CUMZ); 2 broken ♀♀, Khuan Khanun District, Tham Wang Thong, 7º40′57″ N, 100°00′58″ E, ca. 44 ma.s.l., 6 Jul. 2017, ASRUmembers leg. ( CUMZ); 1 ♂– gonopods lost, Si Banphot District, Khao Pu-Khao Ya National Park, 11 Jan. 2009, ASRUmembers leg. ( CUMZ); 1 ♂, Srinagarindra District, Wat Tham Sumano (Sumano Cave Temple), 7º35′08″ N, 99°52′08″ E, ca. 75 ma.s.l., 23 Oct. 2010, ASRUmembers leg. ( CUMZ); 6 ♂♂, Srinagarindra District, Wat Tham Sumano (Sumano Cave Temple), 7º35′08″ N, 99°52′08″ E, ca. 75 ma.s.l., 16 Jan. 2013, ASRUmembers leg. ( CUMZ); 1 ♂, Srinagarindra District, Wat Tham Sumano (Sumano Cave Temple), 7º35′08″ N, 99°52′08″ E, ca. 75 ma.s.l., 16 Jan. 2013, ASRUmembers leg. ( CUMZ); 2 ♂♂, 1 ♀, Kong Ra District, Khao Phaya Hong, 7º27′46″ N, 99°57′50″ E, ca. 55 ma.s.l., 6 Jul. 2017, ASRUmembers leg. ( CUMZ). –  Trang Province: 1 ♀, Hui Yot District, Khao Phra Yot, Bua Nguen-Bua Thong Pagoda, 7º48′10″ N, 99°37′05″ E, ca. 66 ma.s.l., 14 Jan. 2009, ASRUmembers leg. ( CUMZ); 4 ♂♂, Hui Yot District, Wat Khao Huai Hang, 7º47′37″ N, 99°38′40″ E, ca. 83 ma.s.l., 24 Aug. 2014, ASRUmembers leg. ( CUMZ); 1 broken ♂– gonopods lost, 1 ♀, Na Yong District, Khao Chang Hai Cave, 7º35′23″ N, 99°40′08″ E, ca. 35 ma.s.l., 15 Jan. 2009, ASRUmembers leg. ( CUMZ); 1 ♂, 2 ♀♀, Na Yong District, Khao Chang Hai Cave, 7º35′23″ N, 99°40′08″ E, ca. 35 ma.s.l., 25 Aug. 2014, ASRUmembers leg. ( CUMZ); 1 ♂, 2 juveniles, Na Yong District, Khao Chang Hai Cave, 7º35′23″ N, 99°40′08″ E, ca. 35 ma.s.l., 9 Jul. 2017, ASRUmembers leg. ( CUMZ); 5 ♂♂, 3 ♀♀, Ratsada District, Wat Tham Phra Phut, 7º57′42″ N, 99°44′42″ E, ca. 103 ma.s.l., 5 Jul. 2017, ASRUmembers leg. ( CUMZ).    Redescription (first description of male) SIZE. Length 30–40 mm(male), 34–40 mm(female); width of midbody metazona ca. 3.0 mm (male), 3.5 mm (female). Width of head <collum <2 ± 3 ± 4 <5–16, thereafter body gradually tapering towards telson. COLOUR ( Fig. 9A–E). Specimens in life with body brownish pink/pinkish brown; head and antennae brown/dark brown (except distal part of antennomere 7 and antennomere 8 whitish); prozona, metaterga and surface below paraterga brownish pink/pinkish brown; paraterga dark brown/black; collum, epiproct and leg brown; tip of paraterga, sterna and a few basal podomeres pale brown. Colour in alcohol: after 5–16 years changed to pale brown; head, antennae, collum, metaterga, paraterga, surface below paraterga, sterna, epiproct and legs pale brown. COLLUM ( Fig. 10A). With three transverse rows of setiferous cones/spines, 5(6)+5(6) cones/spines in anterior row, 3(4/5)+3(4/5) cones/spines intermediate row and 4(3)+4(3) cones/spines in posterior row (lateral cones/spines of anterior row located at base of collum paraterga); paraterga of collum elevated at ca. 30º–40º. ANTENNAE ( Fig. 10D). Very long and slender, reaching to body ring 7 or 6 (male) and 5 or 4 (female) when stretched dorsally.   Fig. 13.  Gigaxytes gigas( Golovatch & Enghoff, 1994) gen. et comb. nov., ³, specimen from Wat Tham Sue (Tiger Cave) – right gonopod. A. Lateral view. B. Mesal view. C. Ventral view. D, F. Subdorsal view. E. Dorsal view. TEGUMENT. Stricture between prozona and metazona wide, quite deep. METATERGA ( Fig. 10A–C). With three transverse rows of setiferous cones/spines; metaterga 2–8 with 4(5)+4(5) cones/spines in anterior row, 4(3/5)+4(3/5) cones/spines in intermediate row and 4(3)+4(3) cones/spines in posterior row; metaterga 9–19 with 5(4/6)+5(4/6) cones/spines in anterior row, 5(4)+5(4) cones/spines in intermediate row and 5(4/6)+5(4/6) cones/spines in posterior row. PLEUROSTERNAL CARINAE. On body ring 2 long, crest-like; on ring 3 a long ridge; on ring 4 a short ridge; thereafter missing. PARATERGA ( Figs 10A–C, H, 11A–B). Moderately long, directed caudolaterad on body rings 2–17, elevated at ca. 50º–70º (male) 40º–60º (female), directed increasingly caudad on body rings 18 and 19. TELSON ( Fig. 11C–G). Tip of epiproct usually subtruncate (in some specimens slightly emarginate); apical tubercles inconspicuous. Hypoproct usually subtrapeziform (in some specimens subrectangular); caudal margin subtruncate, with conspicuous setiferous tubercles (in specimens from Khao Phaya Hong inconspicuous). STERNUM ( Fig. 11H–J). On body ring 5 with a swollen lobe; posterior surface of lobe with a pore, pore not borne on a stalk. LEGS ( Fig. 11E–G). Male femora without modification (Male femora 5, 6 and 7 unmodified). GONOPODS ( Figs 3, 12–13). Coxa subequal in length to femorite or longer than femorite. Cannula quite short and stout. Femorite long and slender, curved. Solenophore wide laterally: lamina lateralis broad: lamina medialis wide, distally blunt, in situdirected mesoventrad.    Distribution and habitat   Gigaxytes gigas gen. et comb. nov.is presently known only from Krabi, Nakhon Si Thammarat, Phatthalungand TrangProvinces. Specimens were collected from limestone habitats and were mostly seen hiding under dead leaves, sometimes crawling on leaf litter. It has been found in syntopy with two species of other dragon millipedes at several locations across its distribution:  Desmoxytes cervinaand  Desmoxytes delfae( Jeekel, 1964). Notably,  G. gigas gen. et comb. nov.was usually seen living and crawling on the ground whereas  D. cervinaand  D. delfaewere collected from rocks and tree branches. Based on extensive fieldwork focused on this genus in southern Thailand,  G. gigas gen. et comb. nov.is one of the most common and widely distributed dragon millipedes in many provinces. It is sometimes encountered close to the areas that have been developed as tourist attractions such as caves, as well as a temple or bureau of monks. However, it is still found in natural habitats and has a rather limited distribution in southern Thailand; we here regard this species as endemic for the Thai fauna.   Note on material ‘  Desmoxytes’  gigas Golovatch & Enghoff, 1994was described on the basis of a single adult female (in ZMUC) collected from Krabi Province. We have collected additional specimens in many areas, males as well as females. After examination of all material, it is clear that morphological characters of adult females collected from Krabi, Nakhon Si Thammarat, Phatthalungand TrangProvinces match perfectly with the female holotype.    Remarks The living colouration of adults is generally pinkish brown that blends perfectly with brown/pinkish brown leaves or litter on the ground; juveniles are brown. Two main populations, eastern and western, can be distinguished on the basis of morphological differences in combination with distribution. The two populations differ in characters of paranota and gonopod femorite: specimens of the western population have obviously longer paraterga and the femorite more slender than those of the eastern one. Intrapopulational variation also exists: epiproct with conspicuous apical setiferous tubercles in some specimens, inconspicuous in others; hypoproct subtrapeziform in some specimens, subrectangular in others. Some specimens of  G. gigas gen. et comb. nov.were infested with parasitic mite larvae, probably belonging to the genus  LeptusLatreille, 1896. Several mites appeared on metaterga in anteriormost rings and could easily be discerned ( Fig. 9B, C) by their remarkable orange colour. Mite larve assigned to the genus  Leptuswere reported from a few dragon millipede species (genera  Desmoxytesand  Nagaxytes) by Srisonchai et al.(2018a, b). We suspect that all?  Leptuslarvae from dragon millipedes might belong to the same species. However, an exact identification of the mite species has not been undertaken, and in any case, the relationship between the millipede and  Leptusstill requires further studies. As mentioned in the diagnosis, the new species is noticeably different from other  Gigaxytesspecies due to its unmodified male femora 5–7. 2620323304 2015-08-29 ASRU Thailand 103 10.76 Phitsadarn Cave 21 99.22945 Pathio District 10 11 1 Chumphon holotype 2620323302 10 11 paratype 2620323303 1991-10-13 ZMUC M. Anderson & O. Martin & N. Scharff Thailand 200 8.15 South 1302 98.833336 15 16 ZMUC000101460 1 1 Krabi holotype