Otostigmus ( O .) sulcipes Verhoeff, 1937

Lewis, John G. E., 2015, On Verhoeff’s Otostigmus subgenus Malaccopleurus, the nudus group of Otostigmus subgenus Otostigmus Porat, 1876, and Digitipes Attems, 1930, with a description of the foetus stadium larva in O. sulcipes Verhoeff, 1937, (Chilopoda: Scolopendromorpha: Scolopendridae), Zootaxa 4039 (2), pp. 225-248 : 227-229

Otostigmus ( O.) sulcipes Verhoeff, 1937

( Figs 1–16 )

Otostigmus (Malaccopleurus) sulcipes Verhoeff, 1937 , 204 (key), 205, Pl. 12, Fig. 5, 6 . Gunong Brinchang, Pahang in 1500– 1800 m. Malacca [ Melaka, Peninsular Malaysia].

Otostigmus (Malaccopleurus) trisulcatus Verhoeff, 1937 , 204 (key), 207, Pl. 12, Fig. 7 . Syn. nov. Melaka, Malaysia.

Diagnosis. Body slender. Length up to 47 mm. Antennal articles 18, the basal three glabrous dorsally. Forcipular coxosternal tooth-plates typically with 4+4 teeth. Tergites with complete paramedian sutures from 5, marginate from 7, 8 or 9, without keels or spinules. Sternite paramedian sutures almost complete, a median longitudinal and small round posterior median depression present on most sternites or absent. Coxopleural process with two apical spines. Coxopleural pore-field narrow, not expanded anteriorly. Legs without or leg 1 or legs 1 and 2 with a tarsal spur. Ultimate leg prefemur, femur and tibia with a low longitudinal dorsal ridge demarcated by grooves, prefemoral spines VL 3, VM 2 or 3, M 2, 3 or 4, DM 2 or 3, CS 1 (four rows, 10–12 spines in toto).

Type material examined. ZMB 13364 syntype (s). O. sulcipes Malacca (one vial and 2 slides, 3613 & 3614). In vial: Otostigmus sulcipes Malacca, Verh. Slides: Otostigmus sulcipes Verh. Pahang 15–1800 m Malacca. Syntypus 3613 with segments 18–21 and ultimate legs. 3614 with head, mandibles and first four segments.

Description of syntype in ethanol. (Verhoeff’s data in parentheses where relevant). Slender (very drawn out). Length 35 mm (36–43 mm). Trunk greyish orange with faint turquoise grey paramedian and marginal stripes on segments 7–20 (greyish yellow with four green longitudinal stripes).

Antennae of 18 articles, the basal three glabrous dorsally (the two basal little haired). Forcipular coxosternal tooth-plates as long as wide, each with four teeth, the central two the larger ( Fig. 1 ) (base obtuse without deep incision (i.e. not separated by a deep groove into two groups of two teeth)). Trochanteroprefemoral process with a single low medial denticle.

Tergites elongated with complete paramedian sutures from 5, marginate from 8 (7 or 8). Tergite of ultimate legbearing segment with shallow posterior median depression.

Sternites 2–19 with almost complete paramedian sutures in sulci and ending in depressions (pits) and with a median longitudinal and small round posterior median depression on most sternites ( Fig. 2 ) (three deep sulci (Furchen) and a posterior pit). Sternite of ultimate leg-bearing segment with sides converging posteriorly and posterior margin slightly concave. Coxopleural process with two (one) apical spines. The pore-field narrow ( Fig. 3 ) (pore-field narrow, scarcely widened anteriorly where it is no more than six pores across).

Leg 1 with a tarsal spur, 2–21 without. Ultimate legs slender, prefemur and femur with a dorsal longitudinal ridge demarcated by a groove on each side and pitted ( Fig. 4 ), the tibia with a weak longitudinal ridge. Prefemoral spines VL 3, VM 2, M 3, DM 2/3, CS 1 (with 11 spines, 3 ventral, 5 medial, 2 dorsomedial). Prefemora of penultimate legs also with a weak dorsal ridge.

Description of syntype on slides 3613 & 3614. Antennae of 18 articles. Articles1 and 2 with a few fine setae dorsally increasing on 3 ( Fig. 5 ), dense on 4.Ventrally with scattered setae on articles 1 and 2, dense on article 3 ( Fig. 6 ). Presumably Verhoeff’s “the two basal little haired” refers to the ventral surfaces. Each forcipular coxosternal tooth-plate with four teeth. Trochanteroprefemoral process with one or two low medial denticles.

Sternite of ultimate leg-bearing segment with sides converging posteriorly and posterior margin slightly concave. Coxopleural process with two apical spines. This preparation shows the narrow pore-field, scarcely widened anteriorly where it is no more than six pores across ( Fig. 7 ). Leg 1 with a tarsal spur, 2–4 and 18–21 without. Ultimate leg prefemur with 11 spines VL 3, VM 2 or 3, M 2 or 3, DM 2, CS1 ( Fig. 8 ). The dorsal grooves on the ultimate leg not seen in this cleared material.

Remarks. The characteristics of Otostigmus sulcipes are seen in a number of Otostigmus (Otostigmus) species and it, and the other two “ Malaccopleurus ” species are here assigned to the subgenus Otostigmus . It is proposed below that O. trisulcatus is a junior subjective synonym of O. sulcipes .

Other material examined. ZSM. Two foetus stage larvae in ethanol labelled Otostigmus sulcipes Verh. Colln. , two on slides labelled Otostigmus sulcipes Verh. Fötus. The first (spm. 1) without a registration number, the second (spm. 2) Reg. Nr.A 20030600 with head, forcipules and segment 1, segments 19, 20 and 21, detached ultimate legs and four trunk segments.

Composite description of foetus stadium. (Verhoeff’s data in parentheses where relevant). Length 9–10 mm. Unpigmented apart from pale orange brown yolk-filled mid-gut. Antennae of 17 articles, the elongated penultimate showing a subdivision into two beneath the foetal cuticle ( Fig. 9 ) (18 segmented but 16 and 17 still not clearly divided). With a few scattered setae, the basal articles wider than long. Cephalic plate slightly wider than long, the sides converging posteriorly ( Fig. 10 ). A possible indication of ocelli as round subcuticular structures in spm. 2 ( Fig. 11 ) but not spm. 1. Clypeus without setae. Labral mid-piece present but without tooth. Second maxillary telopodite with a rudimentary pretarsus but without a dorsal brush and very sparsely setose ( Fig. 12 ). No spur on article 2.

(Forcipules with all parts clearly developed. Poison gland present but without secretory duct). Forcipular coxosternal tooth-plates rounded, bi- or tri-lobed ( Fig. 13 ). Forcipular trochanteroprefemoral process present.

Tergites without sutures or sulci. Only the tergite of the ultimate leg-bearing segment marginate. Sternites without sutures or sulci. sternite of ultimate leg-bearing segment with sides converging posteriorly. Coxopleural process digitiform. No indication of spines or pores ( Fig. 14 ).

Legs with divided tarsi, a terminal whorl of setae on each article. Claws present but without accessory spines. Ultimate leg with four rows of unsclerotised spines 3,2,1,3 and 3,2,2,3 ( Fig. 15 ). Detail of spines shown in Fig. 16 .

Spiracles round, on hump-like stigmatopleurite (tracheae seen as weak filaments so must be air-free).

Figures

FIGURES 1 – 8. Otostigmus sulcipes. 1. Forcipular coxopleural tooth-plates and left forcipular trochanteroprefemoral process, syntype ZMB 13364 Malacca, spm. in ethanol. 2. Sternite 11, the same. 3. Coxopleuron and sternite of ultimate leg-bearing segment, the same, ventral view. 4. Left ultimate leg prefemur and femur dorsal, the same. 5. Antennal article 3, syntype ZMB 13364, slide 3614, dorsal view. 6. Antennal articles 1 to 3, the same, ventral view. 7. Coxopleuron and sternite of ultimate legbearing segment syntype ZMB 13364, slide 3613, ventral view. 8. Ultimate leg prefemur, the same, ventral view. Scale bars = 1 mm except Figs 1, 3, 5 & 6 = 0.5 mm.

FIGURES 9–16. Foetus stadium Otostigmus sulcipes Malacca. 9. Distal four articles showing article 16 subdivided into two beneath the foetal cuticle spm 1. 10. Cephalic plate spm. 1. 11. Detail of cephalic plate showing possible ocelli spm. 2. 12. Pretarsus of second maxillary telopodite spm.1. 13. Forcipular coxosternal tooth-plates spm. 1. 14. Coxopleuron and sternite of ultimate leg-bearing segment spm. 1, ventral view. 15. Ultimate leg prefemur spm. 2. 16. Detail of ultimate leg prefemur showing developing spines. FIGURES 17–22. Otostigmus trisulcatus 17. Forcipular coxopleural tooth-plates syntype 13365. 18. Left forcipular trochanteroprefemoral process, the same. 19. Sternite 14, the same. 20. Coxopleuron and sternite of ultimate leg-bearing segment and ultimate leg prefemoral, the same, ventral view (coxal pores not shown). 21. Right coxopleuron syntype ZMB 13365, slide 4002. 22. Ultimate leg prefemur syntype 13365, dorsal view. Scale bars = 0.5 mm except Fig. 12, 13 & 16 = 0.1 mm.