Eutrichodesmus paraster Liu & Wesener

Liu, Weixin, Golovatch, Sergei & Wesener, Thomas, 2017, Four new species of the millipede genus Eutrichodesmus Silvestri, 1910 from Laos, including two with reduced ozopores (Diplopoda, Polydesmida, Haplodesmidae), ZooKeys 660, pp. 43-65 : 47-49

Eutrichodesmus paraster Liu & Wesener sp. n. Figs 1C, 8, 9, 10

Material examined.

Holotype male (SEM), (SMF), Laos, Huaphan Prov., Xop, Cave Tham Long Puang (F 48-123-001), N20°28'25.7", E103°21'44.4", 16.I.2009, coll. H. Steiner (101/09-).

Paratypes.

1 female (SMF), same data as holotype; 1 juvenile (ZFMK MYR6131), same data.

Etymology.

To emphasize the similarity to Eutrichodesmus aster Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2009; adjective.

Diagnosis.

Differs from other species of the genus primarily by the completely reduced ozopores. Superficially very similar to Eutrichodesmus aster , but distinguished from the latter through the smaller body, laterally 3-lobulated paraterga, and the relatively complex gonopod showing a large, laterally denticulate, distofemoral process; the acropodite subapically has a very small mesal tooth and an evident, digitiform, dorsal lobule. See also Key above.

Description.

Length of adults ca. 8.0 mm (holotype) or 9.0 mm (paratype), width 1.0 mm and 2.5 mm on midbody pro- and metazona, respectively.

Coloration uniformly pallid (Fig. 1C).

Adults with 20 segments (Fig. 1C), body conglobation complete.

Antennae short, but slender; in length, antennomere 6 = 3> 2> 4 = 5> 7> 1 (Fig. 9A).

Labrum with three teeth (Fig. 8A).

Head (Fig. 8A), bacilliform sensilla on antennae (Fig. 9A), gnathochilarium (Fig. 9B), mandibles (Fig. 9D), prozona (Fig. 8G), endoterga (Fig. 9J), metatergal setae (Fig. 9E), sterna (Fig. 8F), pleurosternal keels, stigmata (Fig. 9K), legs (Fig. 9H), gonopod aperture, telson (Fig. 8I) and vulvae (Fig. 9I) all similar to those in Eutrichodesmus steineri sp. n.

Collum subtrapeziform, with six transverse rows of round microvillose tubercles (Fig. 8 B–C).

Stricture between pro- and metazona broad and shallow, more finely alveolate-microgranulate than prozona (Fig. 8G). Limbus regularly microcrenulate (Fig. 9G).

Front margin of metaterga 2-4 strongly elevated, each latter with three transverse mixostictic rows of similar tubercles (Fig. 8B, D–E). Following metaterga with three transverse rows of small, flattened, microvillose tuberculations (Figs 8D, 9E). Metaterga 4-19 each with a very high mid-dorsal projection, slightly smaller on metatergum 4 (Fig. 8 D–F, H); tip of projections usually bilobed, always bilobed on each side on metaterga 5 and 6 (Fig. 8D). Projections upright, directed slightly caudad only on metatergum 19 (Fig. 8H).

Paraterga 2 strongly enlarged, vaguely 4-lobulated laterally (Fig. 9C). Following paraterga bi- or trilobate laterally in anterior and posterior parts of body, respectively, each with two small caudal lobulations (Figs 1C, 9F).

Ozopores absent.

Gonopods (Fig. 10) relatively complex. Coxae large, micropapillate and sparsely setose ventrolaterally, with two small apicolateral lobes (cl). Telopodite slightly longer than coxite, slender throughout, setose in basal half, with a prominent, laterally denticulate, distofemoral process (dp) at about midway. Acropodite twisted, subapically with a very small mesal tooth (t) and an evident digitiform lobule (lo) dorsally; seminal groove terminating subapically in a hairpad.

Remarks.

As this species was collected in a cave, and has a pallid body it appears to be a real troglobite. The absence of ozopores is unique for the family Haplodesmidae .