Martensodesmus spiniger, Golovatch, Sergei I., Geoffroy, Jean-Jacques, Stoev, Pavel & Spiegel, Didier Vanden, 2013

Golovatch, Sergei I., Geoffroy, Jean-Jacques, Stoev, Pavel & Spiegel, Didier Vanden, 2013, Review of the millipede family Opisotretidae (Diplopoda, Polydesmida), with descriptions of new species, ZooKeys 302, pp. 13-77 : 51-55

publication ID

https://dx.doi.org/10.3897/zookeys.302.5357

persistent identifier

https://treatment.plazi.org/id/7DAD024E-665C-82AB-0E51-C5B177595587

treatment provided by

ZooKeys by Pensoft

scientific name

Martensodesmus spiniger
status

sp. n.

Martensodesmus spiniger   ZBK sp. n. Figs 33-36

Type material.

Holotype ♂ (IZAS), China, Guangxi, Chongzuo County, Longzhou Xian, Shanglong Xiang, Lenglei, Nonggang Forest, 106.964835°E, 22.467175°N, litter, Berlese extraction, 07.03.2005, leg. L. Deharveng & A. Bedos (CHIgx05-062).

Paratypes.

1 ♂ (SCAU), same locality, together with holotype; 1 ♂ (MNHN JC 345), same locality, Shanglong Xiang, Nonghang, Nonggang Forest, 106.90575°E, 22.48617°N, litter, sieving and Berlese extraction, 14.04.2010, leg. L. Deharveng & A. Bedos (CHIgx10-07).

Non-type: 1 ♀ (MNHN JC 345), 1 ♂ subadult, 1 ♀ (SEM), same locality (CHIgx10-07); 1 ♂ subadult (SEM), same data as holotype (CHIgx05-062).

Diagnosis.

Differs readily fromcongeners by the presence of only two transverse rows of setae on metaterga, combined with five strong spines on the caudal face of a rather strongly curved gonopod telopodite which lacks even traces of a solenomere.

Name.

To emphasize the highly spinose gonopod telopodite.

Description.

Length of holotype ca 4.0 mm, width of midbody pro- and metazona ca 0.35 and 0.5 mm, respectively. Length of paratype ♂ ca 4.5 mm, width of midbody pro- and metazona ca 0.4 and 0.6 mm, respectively. Length of adult ♀ ca 4.7 mm, width of midbody pro- and metazona ca 0.5 and 0.6 mm, respectively. Coloration in alcohol from uniformly pallid to head, several anterior segments and following metaterga clearly infuscate, rusty reddish, increasingly poorly pigmented towards telson.

Body with 19 (♂) or 20 (♀) segments. All characters like in Retrodesmus cavernicola sp. n., except as follows.

Antennae broken off, but obviously medium-sized.

In width, collum << segments 2 & 3 <head = 4 ≤ 5 <6=15 (16); thereafter body gradually tapering towards telson. Paraterga medium-sized, keel-shaped (Figs 33 A–F, 34A, 36C, D), a little better developed in ♂ compared to ♀, starting from a broadly rounded collum, mostly faintly declivous and continuing the outline of a rather convex dorsum, largely set rather high, at about ¼ to 1/3 of midbody height, with faint shoulders frontolaterally (Figs 33 D–F, H). Caudal corner of postcollum paraterga mostly dentiform, always clearly rounded to narrowly rounded and extending increasingly well behind rear tergal margin only in segments 15-18 (♂) or 16-19 (♀). Lateral edge of paraterga with 2 or 3 small setigerous indentations in poreless and poriferous segments, respectively. Ozopores evident, round, flush open on dorsal surface, mostly clearly removed from caudal margin, lying slightly above and close to caudalmost lateral incision (Figs 33B, C, F, 34B, 36C, D), lateral tooth being shorter than medial one, in segment 17 clearly lateral, in 18th caudal (Figs 36C, D). Each postcollum metatergum until 18th (♂) or 19 (♀) with 3+3, long, bacilliform setae arranged in two regular transverse rows, only collum and segment 18 with three transverse rows of bacilliform setae, in segment 18 (♂) or 19 (♀) both posterior rows being placed close to each other; polygonal bosses flat, barely visible, even transverse sulcus very faint (Figs 33 A–F).

Legs rather long, but stout, ca 1.4-1.5 times as long as midbody height (♂); tarsi longest and particularly slender (Fig. 34D), sphaerotrichomes or other modified setae missing.

Gonopod telopodite (Fig. 35) clearly curved, but stout, unipartite; apical piece (a) distal to orifice of seminal groove complex, consisting of a very strong apical spine (sp) protected in its basal half by a membranous ventral velum (ve) with a faintly fringed apical margin and a similarly membranous, apically spinigerous, dorsal lobe (k); caudal face below a with three distinct spines (x, y and z), z being longest. Neither bacilliform ornamentations, nor accessory seminal chamber, nor even traces of a solenomere, nor a hairy pulvillus.

Remarks. This new Martensodesmus species appears to co-occur, even syntopically, together with another opisotretid, Carlotretus triramus sp. n., described just below. Moreover, these two species are superficially so similar that only adult males can be separated with confidence. We therefore prefer to regard the females and juveniles as non-type material.