Orthomorpha hydrobiologica Attems, 1930

Likhitrakarn, Natdanai, Golovatch, Sergei I. & Panha, Somsak, 2011, Revision of the Southeast Asian millipede genus Orthomorpha Bollman, 1893, with the proposal of a new genus (Diplopoda, Polydesmida, Paradoxosomatidae), ZooKeys 131, pp. 1-161 : 42-45

Orthomorpha hydrobiologica Attems, 1930 Figs 3738

Orthomorpha hydrobiologica Attems 1930a: 120 (D).

Orthomorpha hydrobiologica - Attems 1937: 63 (D); 1938: 215 (R); Jeekel 1963: 265 (M); 1964: 361 (M, D); 1968: 45 (M); Hoffman 1973: 362 (M); 1977: 700 (M); Golovatch 1998: 42 (M); Enghoff et al. 2004: 38 (R).

Oxidus hydrobiologicus - Chamberlin 1945: 10 (R).

Holotype.

♂ (NHMW-3507), Indonesia, East Java Prov., Lumajang Regency, shore of Ranu (= lake) Bedali, 10.10.1928, leg. A. F. Thienemann & H. J. Feuerborn.

Other material examined.

3 ♂, 3 ♀ (NHMW-8004), Vietnam, Khanh Hoa Prov., Cua Bé (4-6 km from Nha Trang), no date, det. C. Attems. 2 ♂, 1 ♀ (NHMW-8005), same Prov., Nha Trang, no date, det. Attems. 4 ♂, 4 ♀ (NHMW-8007), Vietnam, Tinh Soc Trang (? or Bà Ria-Vũng Tàu), Poulo Condore Island, no date, leg. C. Dawydoff, det. C. Attems. 4 ♂, 1 ♀ (NHMW-8006), Cambodia, Kampot Prov., Bokor Mt in Damrei Mountains (= Elephant Mountains), near Bok Kor Village, no date, leg. C. Dawydoff, det. C. Attems. 4 ♂, 1 ♀ (NHMW-8008), Indonesia, West Java Prov., Tjisaroea, leg. W. S. S. van Benthem-Jutting, det. C. Attems. 7 ♂, 8 ♀, 2 juv. (NHMW-8009), Indonesia, East Java Prov., Bondowoso, Ijen Caldera, no date, det. C. Attems.

Redescription.

Length 17-30 mm (♂), 19-29 mm (♀), width of midbody pro- and metazona 1.4-2.2 and 2.0-3.1 mm (♂), 1.6-2.7 and 2.0-3.4 mm (♀), respectively (vs 3.3 mm in holotype, up to 4.0 mm in width, as given in the available descriptions ( Attems 1930a, 1937)). Coloration of alcohol material upon long-term preservation rather uniformly light brown to brown (Fig. 37) (vs dark castaneous brown, as given in the original description ( Attems 1930a)) with contrasting light yellow paraterga and epiproct.

Head usual, clypeolabral region densely setose, surface of vertex smooth (vs a pair of strong setae, as given in the descriptions ( Attems 1930a, 1937)), epicranial suture distinct. Antennae rather long and slender (Fig. 37A, B & J), extending behind until body segment 3 (♂) or reaching segment 3 (♀) dorsally. Head in width <collum <segments 3 and 4 <segment 2 <segments 5-16, gently and gradually tapering thereafter. Collum with three transverse rows of setae, 4+4 anterior, 2+2 intermediate, and 3+3 posterior setae; caudal corner of paraterga subrectangular, narrowly rounded (Fig. 37A, B & J). Tegument smooth and shining, prozona very finely shagreened, metaterga finely rugulose, surface below paraterga finely microgranulate. Postcollum metaterga with two transverse rows of setae traceable as insertion points: 2+2 in anterior (pre-sulcus) row, 3+3 in posterior (postsulcus) one. Axial line barely visible, starting from collum. Paraterga very strongly developed (Fig. 37A-G, J-L), especially so in ♂, mostly slightly upturned, lying below dorsum, thin in lateral view, like blunt blades, a little thicker only on pore-bearing segments, on postcollum segments extending increasingly beyond rear tergal margin, from segment 14 pointed, on segments 16-19 tips strongly curved mesad. Calluses on paraterga 2 delimited by a sulcus only dorsally, on following paraterga both dorsally and ventrally, rather broad, especially so on pore-bearing segments. Paraterga 2 broad, anterior edge rounded, lateral edge with one larger and two smaller, but evident incisions in anterior half; posterior edge evidently concave (Fig. 37A, B & J). Paraterga 3 and 4 subequal, like subsequent paraterga, anterior edge broadly rounded, bordered and fused to callus, lateral edge with two small incisions in anterior half. Ozopores evident, lateral, lying in an ovoid groove at about 1/3 of metazonital length. Transverse sulcus complete on metaterga 5-17, incomplete on metaterga 4 and 18, shallow, not reaching bases of paraterga, ribbed at bottom, slightly sinuate anteromedially (Fig. 37A, C, F & J-L). Stricture between pro- and metazona rather narrow, shallow, beaded at bottom down to base of paraterga. Pleurosternal carinae complete crests only on segments 2-4 (♂, ♀) (Fig. 37B, D & E), each with an evident sharp denticle caudally, thereafter increasingly strongly reduced until segment 17 (♂) or 16 (♀). Epiproct (Fig. 37E, F, G & L) conical, flattened dorsoventrally, apical papillae small; tip subtruncate; pre-apical papillae small, but visible, lying close to tip. Hypoproct (Fig. 37G) subtrapeziform, setiferous knobs at a slightly convex caudal margin rather large and well-separated.

Sterna sparsely setose, without modifications, but with two small, low, rounded, fully separated, setose knobs between ♂ coxae 4 (Fig. 37H & I). A paramedian pair of conspicuous, high tubercles in front of gonopod aperture. Legs long and slender, only slightly incrassate in ♂, midbody ones ca 1.2-1.4 (♂) or 0.9-1.1 times (♀) as long as body height, prefemora without modifications, tarsal brushes present until ♂ legs 7.

Gonopods (Fig. 38) simple. Coxa long and slender, with several setae distodorsally. Prefemur enlarged, densely setose, less than 2 times shorter than femorite + “postfemoral” part. Femorite very slender, evidently curved, “postfemoral” part demarcated by an oblique lateral sulcus; tip of solenophore small, trifid, with two subequal denticles (one terminal, the other middle) and a broader subterminal lobule.

Remarks.

This species was originally described in two varieties, each based on a single male: Orthomorpha hydrobiologica var. hydrobiologica, from the shores of Lake Bedali, eastern Java, and Orthomorpha hydrobiologica var. unicolor, from Sarangan, central Java,Indonesia ( Attems 1930a). The holotype of Orthomorpha hydrobiologica var. hydrobiologica has been redescribed above, also including some more non-type samples identified as such by Attems himself. As regards Orthomorpha hydrobiologica var. unicolor, it proves to be a distinct species, likewise redescribed from the holotype just below.