Enghoffosoma anchoriforme, Likhitrakarn, Natdanai, Golovatch, Sergei I. & Panha, Somsak, 2014

Likhitrakarn, Natdanai, Golovatch, Sergei I. & Panha, Somsak, 2014, Review of the Southeast Asian millipede genus Enghoffosoma Golovatch, 1993 (Diplopoda, Polydesmida, Paradoxosomatidae), with descriptions of new species, Zootaxa 3811 (4), pp. 491-514 : 503-505

Enghoffosoma anchoriforme sp. n.

Figs 11–13

Holotype male ( CUMZ), Laos, Champasak Province, Khong District, Khone Phapheng Waterfall, ca 80 m a.s.l., 13°57'47"N, 105°59'17"E, 23.07.2013, leg. W. Siriwut.

Name. To emphasize an anchor-shaped parabasal lateral process (p); noun.

Diagnosis. This species seems to be especially similar to E. zebrae sp. n., but differs in the paraterga being strongly developed, the sternal lobe between male coxae 4 large and subcordiform while apicoventral spine b of the gonopod large and anchor-shaped (see also Key below).

Description. Length 34 mm, width of midbody pro- and metazonae 2.9 and 4.1 mm, respectively.

Coloration of live animal dark brown ( Fig. 11 A), posterior halves of paraterga and epiproct whitish yellow to pale brown, head and antennae dark brown, legs pale brownish; coloration in alcohol, after half a year of preservation, faded to brownish ( Figs 11 B–H), posterior halves of paraterga and epiproct pale light brown to whitish, head and antennae dark brown, posterior halves of metaterga brown to light brown, venter and legs pale brown to whitish distally ( Figs 11 B, C, F–J).

All characters as in E. zebra sp. n., except as follows.

Antennae long ( Fig. 1 B), reaching body segment 4 when stretched dorsally. Postcollum metaterga with two transverse rows of setae traceable at least as insertion points when setae broken off: 3+ 3 in anterior (pre-sulcus), 4+ 4 in posterior (post-sulcus) row, caudal row barely traceable as insertion points. Axial line visible both on pro- and metazonae. Paraterga well-developed ( Figs 11 B–F & G), mostly slightly upturned, all lying faintly below dorsum, set at about half of body height, subhorizontal, caudal corner almost or fully pointed, produced beyond rear tergal margin until segment 16, increasingly rounded and smaller on following segments; posterior edge nearly straight ( Figs 11 B–F). Transverse sulcus incomplete, at most faint ( Figs 11 B–F & H). Stricture between pro- and metazonae rather wide, deep, line-shaped, clearly beaded at bottom down to base of paraterga ( Figs 11 B–E). Epiproct ( Figs 11 F & H) conical, flattened dorsoventrally, with two evident apical papillae; tip subtruncate; preapical papillae very small, but traceable, lying rather close to tip.

Sterna very densely setose, with a small cone caudally near each coxa; a large, subcordiform, sternal lobe between male coxae 4 ( Figs 11 I & J). Legs moderately long and slender, midbody ones ca 1.2–1.3 times as long as body height; ventral brushes on male tibiae and tarsi traceable until legs of segment 13 and 15, respectively.

Gonopods ( Figs 12 & 13 ) with a large, anchor-shaped, parabasal, mesal process p.

Figures

FIGURE 1. Enghoffosoma zebra sp. n., habitus, live coloration. A: holotype. B: male paratype from Numtip Temple. C: male paratype from Tadtone. D: male paratype from Ban Xanapho.

FIGURE 11. Enghoffosoma anchoriforme sp. n., holotype. A: habitus, live coloration. B, C: anterior part of body, dorsal and lateral views, respectively. D, E: segments 10 and 11, dorsal and lateral views, respectively. F – H: posterior part of body, dorsal, ventral and lateral views, respectively. I, J: sternal cones between coxae 4, subcaudal and sublateral views, respectively.

FIGURE 12. Enghoffosoma anchoriforme sp. n., holotype. A – C: right gonopod, lateral, mesal and subcaudal views, respectively. Scale bar: 0.5 mm. Designations explained in text.

FIGURE 13. Enghoffosoma anchoriforme sp. n., holotype, left gonopod. A, B: lateral and mesal views, respectively. C – F: distal part, lateral, mesal, subcaudal and suboral views, respectively. Scale bar: 0.2 mm.