Gonatodesmus communicans, Golovatch, Sergei I., Geoffroy, Jean-Jacques & VandenSpiegel, Didier, 2014

Golovatch, Sergei I., Geoffroy, Jean-Jacques & VandenSpiegel, Didier, 2014, Review of the millipede family Trichopolydesmidae in the Oriental realm (Diplopoda, Polydesmida), with descriptions of new genera and species, ZooKeys 414, pp. 19-65 : 48-51

Gonatodesmus communicans sp. n. Figs 11, 12

Type material.

Holotype ♂ (MNHN JC 359), Vietnam, Dongnai Prov., Cat Tien National Park, 107°10'-107°34'E, 11°21'-11°48'N, lowland tropical forest, litter and topsoil, 01.06.2005, leg. A. Anichkin.

Paratypes: 5 ♂, 1 ♀ (MNHN JC 359), 9 ♂, 1 ♀, 1 juv. (ZMUM ρ2336– 2339), 1 ♂ (SEM), 1 ♂ (ZMUC), same locality, together with holotype; 1 ♀ (MNHN JC 359), same locality, 15.07.2005, leg. A. Anichkin.

Name.

The species epithet refers to the gonopod conformation somewhat transitional between the families Trichopolydesmidae and Opisotretidae .

Description.

Length of adults ca 2.8-3.7 mm, width of midbody pro- and metazonae 0.2-0.25 and 0.28-0.4 mm (♂, ♀). Coloration in alcohol uniformly pallid, tegument often nearly translucent.

Body with 19 segments (♂, ♀). Tegument dull, texture of pro- and metazonae delicately alveolate to scaly, metaterga a little more roughly alveolate, only sterna mostly smooth (Fig. 11 A–I). Head very densely and finely pilose; epicranial suture absent (♂) or superficial (♀); genae squarish (Fig. 11A, D, G, K); gnathochilarium narrow, sparsely and uniformly setose (Fig. 11K); isthmus between antennae about 1.2 times as broad as diameter of antennal socket (Fig. 11G). Antennae short (Figs 11A, G, 12A), reaching only behind collum when stretched dorsally, not geniculate, rather strongly clavate due to a particularly enlarged antennomere 6, the latter with a usual, tight, distodorsal group of numerous, bacilliform sensilla; a similar, but smaller, also distodorsal group of sensilla on antennomere 5; antennomere 7 with a smaller distodorsal group of only a few shorter and curved sensilla in front of a tiny mid-dorsal knob.

In width, collum <segment 3 = 4 <2 = 5 <6-15 <head; body gradually tapering on segments 16-18 (Fig. 11 A–I). Paraterga poorly developed, starting from collum, set rather low (at about upper 1/3 of body height, Fig. 11J), at most small ridges with 2-3 lateral, setigerous knobs, caudal corner never produced behind rear tergal margin even in poriferous segments (Fig. 11 A–F, N). Ozopores evident, ovoid, dorsolateral, mostly lying closer to lateral edge, but in segments 15-18 slightly elevated and positioned closer to caudal edge between 2 subequal, setigerous stalks (Fig. 11N). Collum regularly rounded, transversely oblong-oval, with 3 transverse rows of 4+4, 2+2 and 3+3 rather long setae dorsally and 2 similar setae on paraterga (Fig. 11A, D). Each following metatergum with 3+3 or 4+4, similarly long, bacilliform, delicately ribbed setae arranged in 3 transverse regular rows and borne on knobs; sulci between the rows absent (Fig. 11 A–F, L–N). Stricture between pro- and metazonae rather deep and narrow, microalveolate like metazonae (Fig. 11E, L, N). Limbus very fine, delicately and densely microcrenulate (Fig. 11E, N). Pleurosternal carinae absent (Fig. 11 A–C). Epiproct short, conical, truncate, directed caudoventrally; pre-apical papillae very small (Fig. 11C, F). Hypoproct subtrapeziform, caudal setigerous papillae large and well separated, with a faintly convex edge in between (Fig. 11I).

Sterna without modifications, rather broad and sparsely setose (Fig. 11H, I). Legs short and stout, ca 1.2-1.3 (♂) or 1.0-1.1 (♀) times as long as midbody height; prefemora, femora, postfemora and tibiae clearly incrassate, especially so in ♂ (Fig. 12C), tarsi longest, slender, sphaerotrichomes missing; claws simple, slightly curved; ♂ tarsi 1 with peculiar, bi- or trifid setae ventrally (Fig. 12B); ♂ coxae 2 with very short, membranous, cylindrical gonapophyses (Fig. 11G).

Gonopod aperture transversely oblong-oval, taking up most of ventral part of metazonite 7 (Fig. 12D). Gonopod coxae (Fig. 12 D–G) rather small (gonocoel not deep), sparsely setose and clearly micropapillate laterally, each with a subtriangular ventral projection (x); telopodites clearly exposed, but lying rather tightly appressed and parallel to venter, unipartite, slender, abruptly geniculate and directed laterad distal to prefemoral parts, the latter about half as long as telopodites, held parallel to main axis, each with an apicomedian field of strong curved spines (d), set off from a twisted acropodite by a strong geniculation cingulum (c); acropodite elongate, near midway with a remarkably large hairy pulvillus (p) on top of a small accessory seminal chamber; acropodite distal to pulvillus particularly slender, slightly curved caudad, subacuminate; neither a separate solenophore branch nor a solenomere. Seminal groove (sg) running mostly on mesal side, turning caudad (= ventrad) only beyond geniculation.