Taiwaneuma crinitum, Mikhaljova, Elena V., Golovatch, Sergei I. & Chang, Hsueh-Wen, 2011

Mikhaljova, Elena V., Golovatch, Sergei I. & Chang, Hsueh-Wen, 2011, The millipede family Niponiosomatidae new to the fauna of Taiwan, with descriptions of a new genus and two new species (Diplopoda, Chordeumatida), Zootaxa 2980, pp. 49-60 : 50-55

Taiwaneuma crinitum sp. nov.

Figs 1–18

Material examined. Holotype: male ( TFRI –40000385), Taiwan, Ilan County, Datong Township, near Lakes Jialuohu, ca 2250 m, 26.XII.2002, leg. Y.M. Chen; Paratypes: 1 male ( IBSS –40000383), same locality, 14.III.2003, leg. Y.M. Chen; 1 male (NSYSUB–40000386), same locality, 27.IV.2003, leg. Y.M. Chen; 1 male, 1 female ( IBSS – 40000387, 40000382), 1 male ( ZMUM –40000388), 1 female ( TFRI –40000389), Taiwan, Taichung County, Shengguang, 25.IV.2003, leg. W.C. Yeh.

Diagnosis. Differs from T. ramuligerum sp. nov., the only other congener, mainly in the presence of two pairs of very long flagella on the anterior gonopod colpocoxite which are concealed inside a groove formed by the excavated postgonopodal coxae, and in the third pair of flagella which is short, as well as by the structure of male leg pair 9.

Description. Male. Length about 9 mm, width with paraterga about 0.8 mm. Coloration in alcohol grey-brown with three broad, light, longitudinal stripes extending from anterior to posterior ends of body: one stripe axial, both others lateral, level to paraterga so that dorsal halves of the latter light while ventral halves brown. Legs pale with marbled brown distal parts. Venter and lower portions of pleura lighter. Ocellaria black. Antennae marbled brown.

Head with a marbled brown vertex, two transversely oval, marbled straw-coloured spots in occipital part, and marbled straw-coloured front part and genae.

Body with 28 segments. Paraterga small, rounded. Head covered both with relatively long and short setae. Ocellaria subtriangular, each composed of at least 20 ocelli. Antennae long, slightly clavate. Distal margin of antennomere 6 with a corolla of short strong setae.

Collum oval. Metatergal setae short, blunt. Posterior body half with both medial and anterolateral tergal setae clavate. Tegument of metatergites alveolate, resembling fish scales with scattered short, low, longitudinal crests ( Figs 1, 2 ). One legless body segment in front of telson. All setae on telson and 1–2 segments in front of it pointed. Spinnerets as usual, each with a long apical seta.

Legs long and slender, ventral setae on all podomeres except tarsi with stronger and sharper setae, especially on midbody coxae where these setae spiniform. Tarsal papillae absent. Claw normal, at base with only a tiny setoid structure dorsally. Pregonopodal legs normal, neither enlarged nor otherwise modified. Each vas deferens opening through coxa 2 on a short tube surrounded by a cup-shaped structure open anteriorly and sparsely setose ( Fig. 7 ). Claws of leg pair 2 at base with a tiny additional claw dorsally and a short filament ventrally. Leg pair 7 normal, but each coxa slightly excavate mesally ( Fig. 8 ); claw with a tiny setoid structure dorsally and a short filament ventrally. Postgonopodal legs until about those on body segment 13 or 14 with coxae excavate mesally ( Fig. 12 ), all these excavations forming a special groove for accommodation of long flagella of anterior gonopod colpocoxites; those flagella kept inside the canal also with the help of the spiniform, partly curved setae. Legs 10 and 11 with coxal glands. Each coxa 10 with a small outgrowth ventrally ( Figs 3 , 9 ). Coxae 11 unmodified ( Fig. 10 ). Claws of legs 10 and 11 at base with neither dorsal additional small claws nor ventral filaments. Prefemora 10 and 11 swollen ventrally ( Figs 4 , 11 ).

Anterior gonopods bipartite: (1) angiocoxite part consisting of two pairs of angiocoxites, i.e. two mesal angiocoxites fused into a single plate and two lateral angiocoxites, and (2) colpocoxite part containing three pairs of flagella, i.e. two pairs of very long and one pair of short and particularly slender flagella, and a soft, poorlysclerotized, elongate, coniform structure flagelliform apically. Gonopods partly sunken into body lumen and strongly inclined caudad, leaving exposed only angiocoxites ( Figs 5–6 , 13–15 ) and covering remaining parts of gonopods from below. Angiocoxite part in front view ( Figs 5 , 13 ) with fused mesal angiocoxites (ma), these being swollen at base and carrying on this swelling a knob beset with long setae. Distal part of fused ma with a long, median, rod-like process (r), two lateral lobes (lp) beset with long setae laterally, as well as apically on each side with a compact group consisting of three outgrowths (ou) and two long caudal branches (b). Each lateral angiocoxite (la) in front view ( Figs 5 , 13 ) alveolate at base, with long setae in proximal half, as well as lateral lobe (lal) curved caudally and densely setose on caudal face (in front view, only tips of the setae visible). Lateral angiocoxites (la) in caudal view ( Figs 6 , 14 ) with a slender median outgrowth (k) in distal part ( Fig. 6 ), this outgrowth also serving as a site of la fusion. Each la in caudal view at about midway bearing a lateral process (p) with three long apical and one basal seta. Distal half of each la not only with a lal beset with rather long setae, but also with a mesal lobe (ml), the latter evidently fringed and carrying several long and strong processes and a small outgrowth at base.

Colpocoxite part ( Fig. 18 ) containing three pairs of flagella (А, В, С) and a soft structure (s) in the form of a long, slender, coniform sac with a flagelliform distal half. Flagella located somewhat behind and lateral to s. Flagella А slender and short, whereas both В and С thicker, very long, reaching in length about midbody coxae, C also being finely spiculate subapically. Colpocoxital flagella in situ placed inside a special groove formed by medially excavate coxae ( Fig. 12 ) and kept there with spiniform, often curved setae located on ventral and mesal parts of coxae. Hence, flagella of colpocoxites can remain invisible in a non-dissected male.

Legs 9, removed and studied in two paratype males, one from Ilan County (40000383) ( Fig. 16 ), the other from Taichung County (40000387) ( Fig. 17 ), placed on large, mesally fused, flexible, subtriangular, sternal plates. Each plate supporting a coxite or coxoprefemorite (no clear division being visible between a broadened basal and a slen- der distal part) and superficially a 1-segmented acropodite, both segments being strongly setose distomesally. Acropodite varying in shape even within a single individual ( Fig. 17 ), with ( Fig. 17 ) or without ( Fig. 16 ) a bare apical knob. Coxoprefemorite supplied with a caudomesal outgrowth in its distal part. Basal part (coxite proper?) rounded basally, thin-walled and setose ventrally, with mesalmost seta being strongest, subtended laterally with a rounded ventral part of sternite; right coxite of Taichung County paratype showing a structure resembling a coxal gland and its canal ( Fig. 17 ), only something like a canal being traceable in coxites of Ilan County paratype ( Fig. 16 ).

Female. Length about 9.0 mm, width with paraterga about 0.8 mm. Body with 28 segments. Leg pair 2 normal. Other nonsexual characters as in male.

Name. The specific epithet refers to the two pairs of very long, hair-like flagella of the anterior gonopods. Remarks. Korsós (2004), in his checklist of the Diplopoda of Taiwan, referred to 4 males and 3 females from Ilan County, kept in TFRI. He assigned them to Speophilosoma montanum or a closely related congener. Even though we have failed to trace this sample in the TFRI collection, based on provenance and a similarly small size, we believe that Korsós, without precise study, misidentified our Taiwaneuma crinitum sp. nov. In any event, no Speophilosoma species has hitherto been reliably documented in Taiwan.

Figures

FIGURE 18. Taiwaneuma crinitum sp. nov., male paratype. Colpocoxites of anterior gonopods, lateral view; А, В, С, flagella of colpocoxites of anterior gonopods; s, soft structure of colpocoxites of anterior gonopods. Scale bar in mm.

FIGURES 1 – 6. Taiwaneuma crinitum sp. nov., male paratype. 1, midbody segments, dorsal view; 2, fragment of metatergal surface; 3, coxae 10, caudal view; 4, leg 10; 5, angiocoxites of anterior gonopods, front view; 6, distal half of angiocoxites of anterior gonopods, caudal view; ma, mesal angiocoxites; r, rod-like process of mesal angiocoxites of anterior gonopods; lp, lateral lobe of mesal angiocoxites of anterior gonopods; ou, apical outgrowths of lateral lobe of mesal angiocoxites of anterior gonopods; b, posterior branches of mesal angiocoxites of anterior gonopods; la, lateral angiocoxite of anterior gonopods; lal, lateral lobe of lateral angiocoxites of anterior gonopods; p, posterolateral process of lateral angiocoxites of anterior gonopods; ml, mesal lobe of lateral angiocoxites of anterior gonopods; k, slender process of lateral angiocoxites of anterior gonopods.

FIGURES 7 – 11. Taiwaneuma crinitum sp. nov., male paratype. 7, leg pair 2, front view; 8, coxae 7; 9, coxae 10, caudal view; 10, coxae 11, front view; 11, leg 11. Scale bars in mm.

FIGURES 12 – 17. Taiwaneuma crinitum sp. nov., male paratype. 12, coxae of legs of midbody segment; 13, angiocoxites of anterior gonopods, front view; 14, angiocoxites of anterior gonopods, caudal view; 15, angiocoxites of anterior gonopods, lateral view, slightly skewed frontally; 16, leg pair 9 and its sternite of male from Ilan County; 17, leg pair 9 and part of sternite of male from Taichung County; ma, mesal angiocoxites; r, rod-like process of mesal angiocoxites of anterior gonopods; lp, lateral lobe of mesal angiocoxites of anterior gonopods; ou, apical outgrowths of lateral lobe of mesal angiocoxites of anterior gonopods; b, posterior branches of mesal angiocoxites of anterior gonopods; la, lateral angiocoxite of anterior gonopods; lal, lateral lobe of lateral angiocoxites of anterior gonopods; p, posterolateral process of lateral angiocoxites of anterior gonopods; ml, mesal lobe of lateral angiocoxites of anterior gonopods. Scale bar in mm.