Spinaxytes hasta Srisonchai, Enghoff & Panha

Srisonchai, Ruttapon, Enghoff, Henrik, Likhitrakarn, Natdanai & Panha, Somsak, 2018, A revision of dragon millipedes IV: the new genus Spinaxytes, with the description of nine new species (Diplopoda, Polydesmida, Paradoxosomatidae), ZooKeys 797, pp. 19-69: 19

publication ID

http://dx.doi.org/10.3897/zookeys.797.29510

publication LSID

lsid:zoobank.org:pub:A5403588-F43D-40FF-81EE-2009E49823B4

persistent identifier

http://treatment.plazi.org/id/C9605402-C710-4E70-8A7B-9F41F4249C0E

taxon LSID

lsid:zoobank.org:act:C9605402-C710-4E70-8A7B-9F41F4249C0E

treatment provided by

ZooKeys by Pensoft

scientific name

Spinaxytes hasta Srisonchai, Enghoff & Panha
status

sp. n.

Spinaxytes hasta Srisonchai, Enghoff & Panha  sp. n. Figs 4F, G; 5C; 12, 13, 14

Material examined.

Holotype. ♂, THAILAND, Chumphon Province, Thung Tako District, Khao Ma Ngaen, 10°05'27"N, 99°04'25"E, ca. 28 m a.s.l., 23 Oct. 2016, ASRU members leg. (CUMZ-pxDGT00209). Paratypes. 5 ♂♂, 6 ♀♀, same data as for holotype (CUMZ-pxDGT00210); 1 ♂, 1 ♀, same data as for holotype (ZMUC00040251). Further specimens, not paratypes, all from THAILAND, Chumphon Province. Mueang Chumphon District: 8♂♂, 1 ♀, Wat Tham Sanook, 10°28'52"N, 99°04'29"E, ca. 54 m a.s.l., 3 Jul. 2017, ASRU members leg. (CUMZ). Lang Suan District: 2 ♀♀, Wat Ratcha Burana School, 9°56'21"N, 99°02'26"E, ca. 34 m a.s.l., 10 Sep. 2016, ASRU members leg. (CUMZ); 1 ♂, 5 ♀♀, Wat Tham Khao Kriap (Khao Kriap Cave), 9°49'08"N, 99°02'22"E, ca. 102 m a.s.l., 5 Jun. 2009, ASRU members leg. (CUMZ). Sawi District: 8 ♂♂, 3 ♀♀, Wat Nam Cha, 10°17'54"N, 99°01'57"E, ca. 95 m a.s.l., 5 Jun. 2009, ASRU members leg. (CUMZ).

Etymology.

The name is a Latin noun in apposition meaning spear, referring to the shape of the sternal lobe between male coxae 4 which is somewhat similar to a spear.

Diagnosis.

Sternal lobe between male coxae 4 not bilobed, not bifurcate; male femora without modification. Similar in this respect to S. efefi  sp. n., but differs by having: collum with 4+4 tubercles in anterior row, 1+1 tubercles in intermediate row and 2+2 tubercles in posterior row; metaterga 2-8 with 2+2 cones in anterior row and 2+2 cones in posterior row; metaterga 9-18 with 2+2 cones in anterior row and 2+2 cones in posterior row; metatergum 19 with 2+2 tubercles/cones in anterior row and 2+2 tubercles/cones in posterior row; lamina medialis (lm) with a large lobe in middle part.

Description.

SIZE. Length 23-33 mm (male), 26-33 mm (female); width of midbody metazona 1.7-2.2 mm (male), 2.1-2.8 mm (female). Width of collum = ring 2 = 3 = 4 < head = 5-16, thereafter body gradually tapering towards telson.

Colour (Figure 12 A–C). Specimens in life with body black/brownish black; paraterga white/yellowish white/whitish yellow; antennae (except whitish distal part of antennomeres 7 and 8) and metaterga (posterior part) brown/brownish black; head and collum brown/blackish brown; prozona and metaterga (anterior part) black; surface below paraterga black/brownish black; sterna and epiproct brown; legs brown/pale brown; a few basal podomeres pale whitish brown.

Antennae (Figure 13M). Reaching to body ring 9 or 10 (male) and 7 (female) when stretched dorsally.

Collum (Figure 13A). With three transverse rows of setiferous tubercles, 4+4 tubercles in anterior row, 1(0)+1 tubercles in intermediate row and 2+2 tubercles in posterior row; with two inconspicuous setiferous notches at lateral margin; paraterga wing-like, quite short and broad, tip sharp, elevated at ca. 10°-15° (male) 10°-15° (female), directed caudolaterad.

Tegument. Quite dull; collum, metaterga and surface below paraterga finely microgranulate.

Metaterga (Figure 13A, C, E). With two transverse rows of setiferous tubercles/cones and spines; metaterga 2-8 with 2+2 tubercles/cones in anterior row and 2+2 spines in posterior row; metaterga 2-18 with 2+2 tubercles/cones in anterior row and 2+2 spines in posterior row; metatergum 19 with 2+2 tubercles in anterior row and 2+2 tubercles in posterior row; lateral spines of posterior row bigger and longer than mesal ones, gradually reduced in length and size on the following rings.

Paraterga (Figure 13 A–E, H). Very long; directed dorsolaterad on body rings 4-16, elevated at ca. 60°-70° (male) 50°-60° (female); directed caudolaterad on rings 2, 3 and 17; directed increasingly caudad on body rings 18 and 19. Ozopore visible in lateral view.

Telson (Figure 13E, H, I). Epiproct long; tip subtruncate; lateral setiferous tubercles conspicuous (in some specimens inconspicuous); apical tubercles inconspicuous. Hypoproct subtrapeziform (in some specimens subsemicircular); caudal margin round (in some specimens angular), with inconspicuous setiferous tubercles.

Sterna (Figs 4F; 13F, G). Sternal lobe between male coxae 4 coniform, long, spear-like; base stout; tips sharp, in situ directed almost ventrad; posterior surface bearing one pore.

Legs (Figs 4G, 13J). Male femora without modification.

Gonopods (Figs 5C, 14). Coxa shorter than femur. Prefemoral part ca. 2/3 as long as femur. Femur not enlarged distally, basally indented. Postfemoral part narrow. Mesal sulcus and lateral sulcus wide. Solenophore bigger and longer than postfemoral part: lamina lateralis broad and long, flattened laterally: lamina medialis long; base enlarged, slightly attenuated near the tip; middle part with a large lobe; tip a bit curving up, terminating in several small spines. Solenomere circular in transverse section, curving up, tip directed anteriad.

Distribution and habitat

(Figure 12D). The specimens were found on rocks or walls with plants, and some were found in a small cave. S. hasta  sp. n. is distributed only in Chumphon Province, and we regard the new species as endemic for the Thai fauna. At Wat Nam Cha the new species coexists with Desmoxytes cervina  .

Remarks.

There are some variations: the lateral setiferous tubercles of the epiproct are conspicuous in some specimens, inconspicuous in others; the hypoproct is subtrapeziform in some individuals, subsemicircular in others; the caudal margin of the hypoproct is rounded in some specimens, angular in others.