Elongeuma reductum, Gordana & Ambros, 2022

Golovatch, S. I. & Spelda, J., 2022, Review of the Central Asian millipede genus Elongeuma Golovatch, 1982, with descriptions of two new species (Diplopoda: Chordeumatida: Kirkayakidae), Arthropoda Selecta 31 (1), pp. 1-9 : 2-6

publication ID	https://doi.org/10.15298/arthsel.31.1.01
DOI	https://doi.org/10.5281/zenodo.15556909
persistent identifier	https://treatment.plazi.org/id/03A0AB75-E648-FF9B-FE98-8DD6FDCBAA78
treatment provided by	Felipe
scientific name	Elongeuma reductum
status	sp. nov.

Treatment

Elongeuma reductum sp.n.

Figs 1 View Figs 1, 2 , 3–18 View Figs 3–7 View Figs 8–18 , Map.

Elongeuma sp. 2 — Read, Golovatch, 1994: 61, 62 (R, M).

HOLOTYPE ♂ ( ZMUM), Tien-Shang (= Tian Shan) Mts, Kyrgyzstan (= Kirghizia), Chatkal Mt. Range , Sary-Chelek Nature Reserve , near Arkit , E 71.9499º, N 41.850º, Khodzha-Ata River valley, 1,550–2,200 m a.s.l., Juglans regia , Picea schrenkiana , Malus, Pyrus etc. forests, litter, 29–31.V.1993, S.I. Golovatch leg. GoogleMaps

PARATYPES: 1 ♂, 4 ♀♀, 5 juv. ( JSP180122 -007, 008, 009), same locality, together with holotype, 29–31.V.1993; GoogleMaps 1 ♂ ( JSP020694 -001), 1 ♀ ( JSP180120 -002), Sary-Chelek Nature Reserve , E 71.9499º, N 41.850º, surroundings of Lake Sary-Chelek , Malus litter, 1800–1950 m a.s.l., 29–31.V.1993; GoogleMaps 1 ♂ ( JSP020694 - 002), 1 ♀ (anterior part of body), 1 ♀ (posterior part of body) ( JSP180120 -003), same locality, forests, 1500–2200 m a.s.l., 29– 31.V.1993; 2 ♀♀, 3 juv., Sary-Chelek Nature Reserve, E 71º67′, N 41º51′, Khoja-Ata River valley , Juglans , Picea , Malus etc. forest, 1500–1800 m a.s.l., 31.V.1993, all S. Golovatch leg.; GoogleMaps 1 ♂ ( JSP180122 -013), Sary-Chelek Nature Reserve ,. E 71º57′, N 41º51′, below Khoja-Ata river valley , in wet flushes, 1500–1600 m a.s.l., 30.V.1993, H. Read leg., GoogleMaps 1 ♀, 2 juv., Sary-Chelek Nature Reserve , E 71º57′, N 41º51′, Meteorological Station , Juglans & Malus forest, 1500 m a.s.l., 31.V.1993, H. Read leg.; GoogleMaps 2 ♂♂, 1 ♀ subad., 1 ♂, 4 ♀♀, 4 ♂ juv., 4 ♀ juv. ( JSP180122 -006, JSP120793 -004, JSP070794 -001), Sary-Chelek Nature Reserve , E 71.9499º, N 41.85º, head of Lake Sary-Chelek , litter in Abies forest on slope, 22.IX.1983, A.B. Ryvkin leg.; GoogleMaps 1 ♀, 1 ♂ juv., 1 ♀ juv. ( JSP180122 - 002, 003, -004), Sary-Chelek Nature Reserve , edges of Lake Sary-Chelek , Picea litter, 1950 m a.s.l., 22.IX.1993, H. Read leg.; 2 ♂♂, 1 ♀ juv. ( JSP180122 -010, 011, 012), Sary-Chelek Nature Reserve , E 71.9499º, N 41.85º, 1500–1600 m a.s.l., 27–31.V.1993, W. Schawaller leg. GoogleMaps

NAME. To emphasize the particularly strongly reduced posterior gonopods.

DIAGNOSIS. Differs from congeners by the particularly strongly reduced posterior gonopods usually lacking any traces of coxal sacs ( Figs 7 View Figs 3–7 , 10, 15–17 View Figs 8–18 ), and by the structure of ♂ leg-pair 7 ( Figs 3 View Figs 3–7 , 9 View Figs 8–18 ) (see also key below).

DESCRIPTION. Length of adults 8–9 (♂) or 9–11 mm (♀), width 0.8–0.9 (♂) or 1.0–1.1 mm (♀). Holotype ca 8 mm long and 0.8 mm wide. Coloration of adults and subadults yellowish to brown, often apparently faded due to long preservation in ethanol ( Fig. 1 View Figs 1, 2 ), sometimes with marbled, brown to blackish spots dorsally and on sides of prozonae, divided by a pale axial line and paler patches laterally and ventrolaterally. Metazonae almost entirely pale yellowish to brown, only sometimes with somewhat darker, marbled knobs supporting macrochaetae. Antennae brown to dark brown throughout, except for a pallid tip. Head especially dark on vertex, distinctly marbled. Venter yellowish. Legs pale to brown, increasingly darker toward distal podomeres.

Body with 28 segments, including telson (26p+1a+T), subcylindrical, without evident lateral swellings, let alone keels, on metazonae ( Fig. 1 View Figs 1, 2 ), somewhat more slender in ♂ compared to ♀. Antennae long and slender, in situ reaching past segment 4 or 5 when stretched laterally, antennomere 3 being the longest. Frons flattened (♂) or regularly convex (♀). Eyes black, 16–18 ocelli in a roundly triangular field from each side of head. In width, collum <head = segment 2 = 3 <4–22(23), gently and regularly tapering thereafter. Only two or three postcollum segments with poorly-developed, rounded, lateral swellings instead of paraterga. Metatergal macrochaetae borne on minute knobs, arranged in an almost transverse row, either medium-sized, pointed and thin on two or three anteriormost segments or increasingly thick, short, blunt and subbacilliform thereafter towards telson; lateral macrochaetae longest, reaching in length ca 1/4 metatergal width ( Figs 1 View Figs 1, 2 , 8 View Figs 8–18 ).

Legs long and slender, a little shorter in ♀, with accessory claws, but only ♂ tarsi 3–6(7) sometimes with ventral papillae ( Fig. 9 View Figs 8–18 ), mostly apapillate ( Figs 3, 4 View Figs 3–7 ). Pairs 1 and 2 distinctly reduced in size as usual, ♂ pairs 3–7 almost normal, only slightly enlarged due to coxites; ♂ leg 7 ( Figs 3 View Figs 3–7 , 9 View Figs 8–18 ) with a peculiar distoventral swelling on coxa and a smaller caudoparabasal cone on prefemur; ♂ pairs 10 and 11 each with coxal glands ( Fig. 4 View Figs 3–7 ), like a number of following pairs each with a ventral row of strong and spiniform setae on both femur and, especially, prefemur ( Fig. 4 View Figs 3–7 ); each ♀ coxa 2 with a strong, ventral, distally rounded, digitiform process forming a medially subcontiguous pair.

Anterior gonopods ( Figs 5, 6 View Figs 3–7 , 10–14 View Figs 8–18 ) placed on an evident plate-like sternum (st) with lateral tracheal apodemes, high, held parallel to each other, fully independent, curved caudally, clearly tripartite: each composed of a lateral, relatively short, blunt to subacuminate, hyaline lamella (hl), vs slender and finger-shaped in E. reductum sp.n., semi-circular with a basal constriction in E. chichkan sp.n., and linguiform and blunt in E. speophilum ; more mesally a longer, conspicuously divided solenomere (sl) carrying a small, midway, caudal lobule (j) and a barbed/ fringed distal quarter; and a very long pseudoflagellum (pfl), slightly serrate or undulate at caudal margin. Posterior gonopods ( Fig. 7 View Figs 3–7 , 10, 15–17 View Figs 8–18 ) particularly simple, mostly composed of medially contiguous, elongated coxites, both somewhat excavate on caudal face, usually produced apically into a small and setose appendage (telopodite remnant) of varying shapes ( Figs 15–17 View Figs 8–18 ), often showing traces of a dark pigment inside, and only occasionally with discernible coxal pouches or sacs (cs) with small projections medially.