Nipponesmus minor, Golovatch, Sergei I., Mikhaljova, Elena V. & Chang, Hsueh-Wen, 2011
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publication ID |
https://dx.doi.org/10.3897/zookeys.93.1167 |
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persistent identifier |
https://treatment.plazi.org/id/3E7D32C0-7898-0992-1714-515F90355BAC |
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scientific name |
Nipponesmus minor |
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sp. n. |
Nipponesmus minor ZBK sp. n. Figs 1423
Type material:
Holotype ♂ (TFRI), Taiwan, Ilan County, Tatong Township, near Lakes Jialuohu, ca 2,250 m, 27.04.2003, leg. Y.M. Chen. Paratypes: 3 ♂, 1 ♀ (TFRI), same locality, 14.03.2003; 12 ♂, 8 ♀, 1 fragm. (TFRI), same locality, 28.04.2003; 1 ♂ (TFRI), same locality, 27.04.2003; 2 ♂ (ZMUM), 1 ♂ (IBSS), 2 ♂ (NSYSU), same locality, 25.12.2002; 1 ♂ (ZMUC), 1 ♂, 1 ♀ (TFRI), same locality, 7.11.2001; 1 ♂, 1 ♂ fragm. (TFRI), same locality, 4.06.2003, all leg. Y.M. Chen; 1 ♂ (ZMUM), same locality, 24.10.2002, leg. J.T. Chao; 1 ♂ (TFRI), Taichung County, Shengguang, 24.09.2002; 1 ♂ (TFRI), same locality, 24.01.2003; 1 ♀ (TFRI), same locality, 26.03.2003; 1 ♂ (MNHN JC 332), same locality, 24.01.2003; 1 ♂ (TFRI), same locality, 24.09.2002, all leg. W.C. Yeh; 1 ♂ (NMNS-6556-001), Nantou County, Ren-ai Township, Mei-Feng, 19.02.2002; 1 ♂ (NMNS-6556-002), same locality, 11.07.2002; 4 ♂ (NMNS-6556-003), same locality, 15.04.2002, all leg. S.H. Wu.
Name:
To emphasize the smaller body size and the shorter gonopod telopodite.
Diagnosis:
Differs from Nipponesmus shirinensis , the only other congener known from Taiwan, in the smaller size, as well as in the collum being narrower than the head and in the gonopod telopodite being stouter and shorter (see also Key below).
Description:
Length of both sexes ca 12-16 mm; width of pro- and metazona varying between specimens from 0.8-1.3 to 1.5-2.0 mm, respectively. Holotype ca 12 mm long, and 0.8 and 1.5 mm wide on pro- and metazona, respectively. Usually ♂♂ somewhat smaller than ♀♀. Coloration in alcohol from uniformly pallid (faded?) to yellowish to reddish-brown; in the latter case, sides, venter and legs light grey-brown (Figs 14-19).
All characters as in Nipponesmus shirinensis , except as follows.
Antennae a little shorter, usually reaching midway of segment 3. In width, collum <head <segment 2 <3 <4 <5=15(16), thereafter body gradually tapering towards telson. Starting from segment 16 (♂, ♀), paraterga extending increasingly beyond rear tergal contour, caudal corners invariably evidently rounded, but even on paraterga 17-19 not spiniform (Figs 15, 18). Paraterga less evidently rounded laterally even in ♀, lateral edges mostly subparallel in ♂ (Figs 15, 18), incisions being visible. Metatergal sculpture typical, rather superficial, with three transverse rows of setiferous, polygonal bosses (Figs 15, 18). Tergal setae very short, usually retained at least on collum and/or metatergum 19 (Figs 15, 16, 18).
Gonopod telopodite (Figs 20-23) much stouter; endomere (en) slightly longer than exomere (ex), beset with long, bacilliform setae nearly throughout, usually supplied with an evident spine (s) or tooth mesally, as well as a usually somewhat less prominent pulvillus near base; ex often not so strongly unciform apically, often with an additional lateral tooth in distal part.
Remarks.
This species is not so widely distributed in Taiwan. Allopatry is prevailing, as it is only at Mei-Feng that both the congeners co-occur (Map 1). However, Nipponesmus minor sp. n. quite often lives even syntopically together with Epanerchodus orientalis (see below).
A study of the ample material representing not only the type species Nipponesmus shirinensis , but also the above new congener from Taiwan allows for the identity of Nipponesmus Chamberlin & Wang, 1953 to finally become clarified.
This genus has hitherto remained enigmatic, originally described too poorly ( Chamberlin and Wang 1953) to shed any significant light on its affinities. It was only based on the gonopod conformation of the beautifully described Nipponesmus tangonis (Murakami, 1973), a species from Honshu, Japan definitely most similar to Nipponesmus shirinensis , that Golovatch (1991) suggested the relationships of Nipponesmus as a genus possibly somewhat intermediate between Schizoturanius Verhoeff, 1931 and Epanerchodus Attems, 1901.
In Nipponesmus shirinensis , the gonopod telopodite (Figs 11-13) is indeed biramous only distally, being divided into subequally prominent endo- and exomere. Furthermore, the endomere (en) is beset with a characteristically bacilliform trichome, whereas the exomere (ex) is simple. The seminal groove runs mostly mesally to recurve neatly between ex and en and then to debauch somewhat basally into a prominent hairy pulvillus which is also beset with the same peculiar trichome, and is devoid of an accessory seminal chamber. The same general pattern is observed both in Nipponesmus tangonis and Nipponesmus minor (Figs 20-23). What we term here as endomere is the branch which Murakami (1973) erroneously referred to as solenomere in his Nipponesmus tangonis . Yet it can hardly be called such, because the seminal groove ends somewhat basally of it and thus fails to support it at all. This is where one of the basic distinctions between Nipponesmus and Schizoturanius seems to lie, because in Schizoturanius the recurvature point of the seminal groove between both distal branches ex and en is about level to the pulvillus ( Golovatch 1979). So we can speak in this case about a true solenomere. In addition, in Schizoturanius an accessory seminal chamber, however small, is present. Another characteristic feature of Nipponesmus vis-à-vis not only Schizoturanius , but also all other genera of Polydesmidae is an abundant bacilliform trichome on the endomere. Although a similar trichome is known to occur in some European Polydesmus species as well, it is always located either on the exomere or on a solenomere. These three apomorphies distinguish Nipponesmus from the obviously most similar Schizoturanius , a genus encompassing several species in Central Asia, Siberia and the southern part of the Eastern European Plain ( Golovatch 1979, 1991).
As regards Golovatch’s (1991) placement of Nipponesmus also near Epanerchodus , following Hoffman (1980) who had synonymized these genera, this idea is false, as they appear to show too many profound differences in gonopod structure. Thus, in Epanerchodus the endomere is mostly absent, rarely present as only a rudimentary structure, while the seminal groove after the recurvature point still makes a long way basad to debauch into a prominent, simple-haired, accessory seminal chamber placed at the bottom of a profound parabasal cavity in the telopodite (see also below). Based on the gonopod conformation of one of the new Taiwanese species (see below), Usbekodesmus Lohmander, 1932, differing from Epanerchodu s only in a somewhat better developed exomere, albeit also simple and more or less spiniform, is to be regarded as another junior synonym of Epanerchodus , syn. n. Arguments for synonymizing both these genera have long been put forth ( Geoffroy and Golovatch 2004), but until now no formal synonymy has been advanced.
This results in the following new formal transfers: Epanerchodus redikorzevi (Lohmander, 1932), from Uzbekistan, Tajikistan and Afghanistan, Epanerchodus swatensis (Golovatch, 1991), from Swat Province, northern Pakistan, Epanerchodus varius (Geoffroy & Golovatch, 2004), from Hubei Province, southern China, as well as the Nepalese Epanerchodus anachoretus (Golovatch, 1986), Epanerchodus buddhis (Golovatch, 1986), Epanerchodus occultus (Golovatch, 1986), Epanerchodus sacer (Golovatch, 1987), Epanerchodus theocraticus (Golovatch, 1990) and Epanerchodus theosophicus (Golovatch, 1986), all comb. n. ex Usbekodesmus .
The following key can serve to separate all three currently known species of Nipponesmus .
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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