Otostigmus cuneiventris Porat, 1893

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 : 240-243

Otostigmus cuneiventris Porat, 1893

( Figs 51–59 )

Otostigmus cuneiventris Porat, 1893: 10 . Mapanja, Cameroon.

Otostigmus cuneiventris Porat, 1894: 14 . Bonge, Cameroon.

Otostigmus cuneiventris: Kraepelin, 1903: 110 , Fig. 50 .

Otostigmus cuneiventris: Attems, 1909: 4 . Kilimandjaro, Tanzania.

Otostigmus ( O.) Attems, 1930b: 15 , Fig. 181.

Otostigmus ( O.) cuneiventris: Lewis, 1996: 833 , in table.

Otostigmus (Otostigmus) cuneiventris: Simaiakis & Edgecombe. 2013: 176 , Figs 4–7 . Mamfe, Mamfediu, Cameroon and Kungwe, Tanzania.

Diagnosis. Length up to 56 mm. Antennal articles 17, the basal three glabrous dorsally. Forcipular coxosternal tooth-plates longer than wide, with 4+4 teeth. Tergites with complete paramedian sutures from 6–20, marginate from 8, with a weak median keel from 6–20 and weak lateral corrugations on some posterior tergites or none. Sternites without paramedian sutures but with two transverse rows of depressions three or five mid-sternite and three posterior ( Fig. 56 ). Coxopleural process with one or two apical spines. Pore-field very slightly widened anteriorly. Legs without (sometimes a tarsal spur on leg1) or with minute or small tarsal spurs. Prefemoral spines VL 2–3, VM 2, M 0, DM 1, CS 1, alternatively could be regarded as DM 2, CS 0 (three rows, 7 spines in toto).

Type material examined. SMNH three syntypes 47, 50 and 51 mm (spms 1–3). Otostigmus cuneiventris Mapanja Cameroon 1884 –85 Valdau & Knutson. Two further syntypes not examined in detail.

Description. (Data from Kraepelin’s (1903) redescription in parentheses where relevant). Length 45–51 mm. Antennal articles 17, the basal three glabrous dorsally. Forcipular coxosternal tooth-plates longer than wide with 4+4 teeth ( Fig. 51 ), a small fifth tooth unilaterally in spm. 1. Forcipular trochanteroprefemoral process without denticles.

Tergites with complete paramedian sutures from 6–20, marginate from (6) 8. A weak median keel from 6–20, lateral corrugations from segment 7 or 10, absent in spm. 1. Tergite of ultimate leg-bearing segment with slight posterior median depression.

Sternites without paramedian sutures. Spm. 1 with a median and two lateral longitudinal depressions midsternite and two lateral and one posterior median pit-like depression on most sternites ( Fig. 52 ). Spm. 2 with five depressions mid-sternite and three posterior depressions, less obvious on sternites 18 and 19. Only three depressions on sternite 20. Spm. 3 with five mid-sternite and three posterior depressions but only four depressions from 18 to 20. Sternite of ultimate leg-bearing segment with sides slightly converging posteriorly, posterior margin slightly concave ( Fig. 53 ) with a median longitudinal sulcus (posteriorly semicircular with clear median sulcus).

Coxopleural process short with 2+2 apical spines but 2+ 1 in spm. 3. Without lateral or dorsal spines (with one apical spine). Single minute tarsal spurs on legs 1–19 in spm. 1, 1–18 in spm. 2, at least to 11 but not 16 in spm. 3 (absent or minute and scarcely detectable).

Ultimate legs missing except in spm. 2. A single regenerated leg in spm. 2 with VL 2, VM 0, M 2, DM 1,1, CS 1. Two loose legs each with VL 3, VM 0, M 2, DM 1, CS 1 ( Fig. 54 ). (VL 2–3, VM 1–2, M 0, DM 1, CS 1).

Other material examined. SMNH two spms 34 and 47 mm. Otostigmus cuneiventris Por. Kamerun, Bonge Oct 1891 colleg Sjöstedt. Determ v. Porat. Only the larger (spm. 4) examined in detail.

Cephalic plate slightly longer than wide. Antennal articles 17, the basal three glabrous dorsally. Tergite 1 relatively large ( Fig. 55 ). Forcipular coxosternal tooth-plates with 4+4 teeth. Forcipular trochanteroprefemoral process with traces of two medial denticles.

Tergites with complete paramedian sutures from 6–20, marginate from 8. A weak median keel from tergite 3– 20, weak lateral corrugations from 5–20. Tergite of ultimate leg-bearing segment with slight median posterior depression.

Sternites without paramedian sutures. With five depressions mid-tergite and three posterior depressions ( Fig. 56 ). Sternite of ultimate leg-bearing segment with sides slightly converging posteriorly, posterior margin rounded ( Fig. 57 ). Coxopleural process short with 1+2 apical spines, second spine minute ( Fig. 58 ). Pore-field very slightly widened anteriorly.

Many legs missing. Single minute tarsal spur on legs 1, 4, 5 and 19, absent on 20. Right ultimate leg VL 3, VM or M 2, DM 1, CS 1. The left (regenerated?) with VL 2, VM or M 1, DM 1, CS 1.

SMNH Otostigmus cuneiventris Por. Two specimens 45 mm. Kilimandjaro, Kibonoto Kulturzonen 1,000– 1,900 m. Ostafrika [ Tanzania] 130... 1905 Yngve Sjöstedt.

(Data from Attems’ (1909) description in parentheses where relevant). (Colour olive brownish to olive greenish, head and first tergite dark brown).Two specimens. Length 45 mm (to 56 mm). Antennal articles 17+16[r] and 17+17, the basal three glabrous dorsally. Forcipular coxosternal tooth-plates longer than wide with 4+4 small teeth ( Fig. 59 ). Forcipular trochanteroprefemoral process with a very small medial denticle or none.

Tergites with complete paramedian sutures from 6–20, marginate from 8. A weak median keel from 6–20, without or with trace of corrugations from segment 12. Ultimate tergite with slight median posterior depression

Sternites with three or five depressions mid-sternite and three posterior depressions (with very short paramedian sutures on anterior wall of sternites). Sternite of last leg-bearing segment with sides converging posteriorly and curved posterior margin and a median longitudinal sulcus. Coxopleural process short with 2+2(1) apical spines. Pore-field very slightly widened anteriorly. Spm. 1 with a tarsal spur on leg 1, absent on 2–21. First pair of legs missing in spm. 2, tarsal spurs absent at least from leg 2 (All legs without tarsal spurs. Only one specimen has a spur on the anterior surface of the first pair of legs). Ultimate legs with VL 3, VM or M 2, DM 1, CS 1.

Remarks. Kraepelin (1903) would appear to have examined the Cameroon material. He described the sternite of the ultimate leg-bearing segment as little attenuated, almost parallel sided, with posterior margin semicircular. The Bonge specimen is the only one examined with a rounded posterior margin. Attems (1909) clearly examined more than the two Tanzanian specimens examined here.

Simaiakis and Edgecombe (2013) described further material from Cameroon and Tanzania: sternites with three longitudinal median depressions, an ovate lateral depression, and a round posteromedian depression. The prefemoral spine formula DM 2 (including a corner spine), VM 2, VL 3 but one Tanzanian specimen had DM1, M 1, VM 2, VL 2, i.e. atypically four spine rows rather than three but the data are for a regenerated leg. The sternite of the ultimate leg-bearing segment in the specimens they examined both from Cameroon and Tanzania has the same trapezoidal shape. They reported that specimens from Cameroon have small tarsal spur on legs 1–19, their Tanzanian sample includes two specimens with a tarsal spur on leg 1 only and one entirely lacking tarsal spurs. Their results confirm that the West African populations have small or minute tarsal spurs on most legs whereas East African populations lack tarsal spurs or only have a tarsal spur on the first pair of legs.

The Bonge specimen is unusual in the shape of the sternite of the ultimate leg bearing segment namely with sides only slightly converging posteriorly and posterior margin rounded and also the large size of T1. It may represent a closely related but separate species.

The most obvious difference between O. cuneiventris and the other species considered here in that the sternites lack paramedian sutures and have up to eight depressions ( Table 2 ).

Figures

FIGURES 51 – 59. Otostigmus cuneiventris. 51. Forcipular coxopleural tooth-plates, syntype spm. 2, Mapanja. 52. Sternite 12 syntype spm. 1. 53. Sternite of the ultimate leg-bearing segment syntype spm. 2. 54. Loose ultimate leg prefemur of a syntype ventral view. 55. Head and tergites 1 & 2, Bonge spm. 56. Sternite 12 Bonge spm. 57. Coxopleuron and sternite of ultimate legbearing segment and right ultimate leg prefemur Bonge spm. 58. Detail of right coxopleural process, ventral view. 59. Forcipular coxopleural tooth-plates Kilimanjaro spm. 1.

FIGURES 46 – 50. Otostigmus taeniatus. 46. Head and tergite 1 Holotype (after Lewis, 1996). 47. Forcipular coxopleural tooth-plates Holotype (after Lewis, 1996). 48. Sternite 12, Holotype (after Lewis, 1996). 49. Right coxopleuron and part of ultimate leg prefemur Leikipia spm., lateral view. 50. Right ultimate leg Merifano spm., dorsal view.

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.

Tables

TABLE 2. Comparison of morphological characters of the nudus group of Otostigmus (Otostigmus). Significant differentiating characters in bold.

	O. nudus	O. taeniatus	O. cuneiventris	O. lawrencei
	India	Kenya	Cameroon, Tanzania	South Africa
Maximum length (mm)	57	63	56	65
Antennal articles	17	17	17	17
Basal articles glabrous	3	4(5)	3	4
Cephalic paramedian sutures	Absent	Absent	Absent	Present
Forcipular coxosternal tooth-plates	Longer than wide	Longer than wide	Longer than wide	No data
Teeth on coxosternal tooth-plates	4+4	4+4	4+4	4+4
Complete tergite paramedian sutures from	6	5 or 6	6	2
Tergites marginate from	8	7, 8 or 9	8	10
Median suture on tergite of ultimate leg-bearing segment	Absent	Absent	Absent	Present
Sternite paramedian sutures/sulci	Almost complete	Complete	None	Complete
Sternite longitudinal depressions	One median	One median	3 or 5	No data
Sternite posterior round depressions	One median	One median	3 transverse	No data
Coxopleural process spines	2 apical	2 apical	2 apical	2 apical+1 lateral
Coxopleural pore- field widened anteriorly	Very slightly	No (oval)	Very slightly	No data
Legs with tarsal spurs	None	None	Some or None	None
Ultimate leg dorsal grooves	On prefemur, femur and tibia. Very we ak	On prefemur, femur and tibia. Weak or none	Absent	Absent
Ultimate leg prefemoral spine rows	3	3	3	3
Number of spines	6 or 7	8–9	7(8)	12 1
Note: 1 Corner spine prominent.