Research Article |
Corresponding author: Armand Richard Nzoko Fiemapong ( armandnzoko@gmail.com ) Corresponding author: Didier VandenSpiegel ( dvdspiegel@africamuseum.be ) Academic editor: Pavel Stoev
© 2017 Armand Richard Nzoko Fiemapong, Paul Serge Mbenoun Masse, Joseph Lebel Tamesse, Sergei Ilyich Golovatch, Didier VandenSpiegel.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Fiemapong ARN, Masse PSM, Tamesse, JL Golovatch SI, VandenSpiegel D (2017) The millipede genus Stemmiulus Gervais, 1844 in Cameroon, with descriptions of three new species (Diplopoda, Stemmiulida, Stemmiulidae). ZooKeys 708: 11-23. https://doi.org/10.3897/zookeys.708.14072
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The large pantropical millipede genus Stemmiulus, which currently encompasses more than 150 species, i.e. the bulk of the species diversity of the family Stemmiulidae and entire order Stemmiulida, is shown to comprise seven species in Cameroon, including three new ones: S. ongot Nzoko Fiemapong & VandenSpiegel, sp. n., S. uncus Nzoko Fiemapong & VandenSpiegel, sp. n., and S. mbalmayoensis Nzoko Fiemapong & VandenSpiegel, sp. n. In addition, S. beroni Mauriès, 1989, previously known only from the type locality in Nigeria, is recorded from Cameroon for the first time, also being redescribed based on new samples. A key is given to all species of the genus encountered in the country, based on male gonopodal conformation, except for S. camerunensis (Silvestri, 1916), which was described only from female and juvenile material.
Cameroon, key, new species, Stemmiulus , taxonomy
The Stemmiulida is a small pantropical order of Diplopoda which contains only three genera in a single family, Stemmiulidae. According to the latest classification (
At present, Stemmiulus in Africa is comprised of 51 species or subspecies (Table
Checklist of the African species of Stemmiulus with locality or country records.
1. S. albicephalus Mauriès, 1989; Tanzania | 27. S. mauriesi VandenSpiegel, 2001; Kenya |
2. S. albicollis Demange & Mauriès, 1975; Guinea and Ivory Coast (Mts Nimba) | 28. S. morbosus (Demange & Mauriès, 1975); Guinea and Ivory Coast (Mts Nimba) |
3. S. altipratensis (Demange & Mauriès, 1975); Guinea and Ivory Coast (Mts Nimba and Tonkoui) | 29. S. nigricollis (Porat, 1894), sensu |
4. S. aoutii (Demange & Mauriès, 1975); Guinea and Ivory Coast (Mts Nimba) | 30. S. nimbanus (Demange & Mauriès, 1975); Guinea and Ivory Coast (Mts Nimba) |
5. S. badonneli (Demange & Mauriès, 1975); Guinea and Ivory Coast (Mts Nimba) | 31. S. nimbanus altipratensis (Demange & Mauriès, 1975); Mt Nimba |
6. S. bellus (Cook, 1895); Liberia, Mt Nimba | 32. S. oculiscaptus Demange & Mauriès, 1975; Mt Nimba |
7. S. beroni Mauriès, 1989; Nigeria (and Cameroon, first record) | 33. S. pencillatus (Cook, 1895); Liberia |
8. S. calcarifer (Demange & Mauriès, 1975); Guinea and Ivory Coast (Mts Nimba) | 34. S. perexiguus (Demange & Mauriès, 1975); Guinea and Ivory Coast (Mts Nimba) |
9. S. camerunensis (Silvestri, 1916); Cameroon | 35. S. perparvus (Silvestri, 1916); Guinea |
10. S. calvus (Cook, 1895); Liberia and Guinea (Mt Nimba) | 36. S. proximatus (Silvestri, 1916); Cameroon |
11. S. discotarsus VandenSpiegel, 2001; Kenya | 37. S. pullulus (Demange & Mauriès, 1975); Guinea and Ivory Coast (Mts Nimba) |
12. S. elegans (Silvestri, 1916); Dahomey | 38. S. ramifer (Demange & Mauriès, 1975); Guinea and Ivory Coast (Mts Nimba) |
13. S. feae (Silvestri, 1916); Guinea-Bissau | 39. S. recedens (Silvestri, 1916); Guinea |
14. S. furcosus (Demange, 1971); Sierra Leone | 40. S. regressus (Silvestri, 1916); Guinea |
15. S. genuinus (Silvestri, 1916); Nigeria | 41. S. royi (Demange & Mauriès, 1975); Guinea and Ivory Coast (Mts Nimba) |
16. S. giffardi (Silvestri, 1916) ; Ghana | 42. S. saloumensis Mauriès, 1989; Senegal |
17. S. gilloni (Mauriès, 1979); Senegal | 43. S. simpliciter (Demange & Mauriès, 1975); Guinea and Ivory Coast (Mts Nimba) |
18. S. howelli Mauriès, 1989; Tanzania | 44. S. schioetzae (Mauriès, 1979); Sierra Leone |
19. S. infuscatus Mauriès, 1989; Cameroon | 45. S. sjoestedti (Brolemann, 1920); Tanzania |
20. S. jocquei (Mauriès, 1985); Malawi | 46. S. spinogonus Mauriès, 1989; Tanzania |
21. S. keoulentanus (Demange & Mauriès, 1975); Guinea and Ivory Coast (Mts Nimba) | 47. S. tremblayi (Demange & Mauriès, 1975); Guinea and Ivory Coast (Mts Nimba) |
22. S. kivuensis Mauriès, 1989; Congo D. R. | 48. S. trilineatus (Demange, 1971); Sierra Leone |
23. S. lacustris (Hoffman, 1975); Rwanda | 49. S. uluguruensis Mauriès, 1989; Tanzania |
24. S. latens (Silvestri, 1916); Guinea-Bissau | 50. S. usambaranus Mauriès, 1989; Tanzania |
25. S. lavellei Mauriès, 1989; Côte d’Ivoire | 51. S. verus Silvestri, 1916; Ghana |
26. S. lejeunei Mauriès, 1989; Congo D. R. |
The material underlying the present contribution was collected in Cameroon in 2014–2016. All type specimens are housed in the collection of the Royal Museum for Central Africa, Tervuren, Belgium (
Iulus (recte: Julus) bioculatus Gervais & Goudot, 1844.
Species of the genus Stemmiulus are know from North America (one species introduced to Florida), Central America (Mexico, Honduras, Guatemala, Costa Rica and Panama), the Caribbean (Haiti, Dominican Republic, Puerto Rico, Cuba, Guadeloupe, Virgin Islands), South America (Colombia, Ecuador, Venezuela, Guyana, Suriname, Peru and Brazil), South Asia (India and Sri Lanka), the East Indies (New Guinea and Halmahera, Indonesia), as well as tropical Africa: East Africa (Tanzania, Kenya, Malawi, Rwanda), West Africa (Nigeria, Ivory Coast, Ghana, Senegal, Sierra Leone, Guinea, Liberia, Benin?, Guinea-Bissau) and Central Africa (Congo, Gabon, Cameroon).
Small to medium-sized stemmiulid millipedes, reaching up 50 mm in length. Body compressed laterally, tapering gradually towards telson, metaterga striated, eyes consisting of one or two large ommatidia on each side of head.
Holotype ♂ (MRAC 22734), Cameroon, Center Region, Ongot disturbed Forest, N 03°51', E 011°25', ca 810 m a.s.l., 30.I.2015, leg A. R. Nzoko Fiemapong.
Paratype: 1 ♂ (SEM, lost).
The species is named after Ongot, the type locality.
Stemmiulus ongot sp. n. is characterized by the first six pairs of male legs being densely setose, the lateral projection of the subterminal lobe of the gonopodal angiocoxites relatively short (Fig.
Stemmiulus ongot Nzoko Fiemapong & VandenSpiegel, sp. n. ♂ paratype (SEM). A head front view B first leg-pair (one); C detail of the spatulate setae on the first leg-pair D leg-pairs 9 (paragonopods) oral view E, F, G leg-pair two, caudal, oral and latero-caudal views, respectively H, I leg-pair 8 (gonopods) caudal and oral views, respectively. Abbreviations: ac: apicolateral cluster of elongated setae, An: angiocoxite, amc: apicomedial cluster of setae, bc: basal cluster of setae, cp: conical projection, Co: colpocoxite, f: flagella, lf: lateral fringe of setae, lp: subterminal process, vmc: ventromedial cluster of setae, Scale bars 200 µm (A, H, I), 100 µm (B, D–G), 10 µm (C).
Holotype: adult male, ca 15 mm in length, 1.7 mm in maximum diameter, body with 43 rings. Head and collum dark brown, other body rings brown with a light axial dorsal stripe, legs and antennae yellowish.
Head typical in shape, beset with numerous simple macrosetae (Fig.
Collum without any ornamentation. Body rings ovoid in transverse section, height/width ratio of midbody rings ca 0.41; no legless body rings in front of telson. Prozonites smooth, metazonites with oblique transverse striae.
First six pairs of legs covered with numerous plumose setae. First pair unmodified, tarsi with a fringe of ventral setae in basal 2/3, but forming no true brush, coxae, femora, postfemora and tibiae each with an apical cluster of prominently enlarged spatulate setae (Fig.
Second pair of legs with coxa enlarged and elongated, anterior face with traces of segmentation, setose over entire anterior surface, glabrous on posterior surface; laterally each produced into a prominent, elongated, conical projection (Fig.
Pair 7 similar to following ones, without specialized setae.
Gonopod structure (Fig.
Paragonopods small and 3-segmented, median segment carrying a short series of long setae on medial side, distal segment minute, conical, with a few apical setae (Fig.
By the relative complexity of the gonopodal structure S. ongot sp. n is closely related to S. albicephalus from Tanzania, but the striations of the lateral sides of prozonae remind of those observed in S. infuscatus from Cameroon. Nevertheless, the males of these species can easily be distinguished by the structure of the lateral projection of the colpocoxite which is small and apically setose in S. ongot sp. n., and relatively elongate without setae in S. albicephalus and S. infuscatus. On the other hand, the conformation of the second pair of legs of S. ongot sp. n. is unique in the entire genus Stemmiulus.
Known only from the type locality.
Holotype ♂ (MRAC 22727), Cameroon, South Region, Vallée du Ntem Division, Engout’Adjap, N02°42', E011°09', ca 2010 m a.s.l., slightly disturbed natural forest under dead leaves, forest, 13.IX.2014, leg. A. R. Nzoko Fiemapong.
Paratypes: 1 ♂ (MRAC 22728), same data, together with holotype; 1 ♂ (SEM, MRAC 22729), same locality, but 14.III.2015, all leg. A. R. Nzoko Fiemapong.
The species name emphasizes the characteristic apical part of the colpocoxite which is unciform and pointed at the apex.
A species of Stemmiulus characterized by the first six ambulatory legs being especially robust and covered with peculiar, spatulate setae, also showing a field of numerous simple setae on the inner side of the tarsus (Fig.
Stemmiulus uncus Nzoko Fiemapong & VandenSpiegel, sp. n. ♂ paratype (SEM). A head front view B, D 3 and 4 leg-pairs C detail of telopodite of 3 leg-pair; E detail of spatulate setae on the 3 leg-pair F, G leg-pair two, oral and caudal views, respectively H, I leg-pair 8 (gonopods) oral and caudal views respectively J apical part of right gonopod showing angiocoxite (An) surrounding colpocoxite (Co) Scale bars 500 µm (A), 100 µm (B, D, F, H, I), 50 µm (G, J), 20 µm (C).
Holotype: adult male, ca 20 mm in length, 1.8 mm in maximum diameter, body with 46 rings. Head and collum dark brown, other body rings brown with a light axial dorsal stripe, legs and antennae yellowish.
Head typical in shape, beset with numerous simple macrosetae; ommatidia 2+2, posterior ommatidia larger than anterior ones; antennae long and setose, apices reaching third body ring. Gnathochilarium concave, stipes densely and uniformly porose, pores surrounded by a field of minute setae.
Collum with a single fold at anterior edge, this being better expressed at lateral margin.
Body rings ovoid (height/width ratio of midbody rings ca 0.31), telson short and upcurved. Both pro- and metazonites with transverse oblique striae better pronounced at pleurotergal margin.
First six pairs of legs as in S. ongot sp. n., but mostly with filiform and plumose setae (Fig.
Second pair of legs with enlarged coxae (Fig.
Gonopods (Fig.
Paragonopods small and 3-segmented, each of medial and distal segments carrying a small series of short setae.
Female unknown.
The peripheral characteristics and simple gonopods bring S. uncus sp. n. close to S. beroni, from Nigeria, and S. pullulus, from Mount Nimba. All these species share the simplicity of their second pairs of male legs, despite the fact that the basal segment of the telopodite in the new species is about twice as large and broad as the distal segment. Nevertheless, the males of this trio can easily be distinguished by the structure of the apical part of the colpocoxite. The latter ends up in a pointed curved hook in S. uncus, versus a pointed straight tip in S. beroni or a rounded tip in S. pullulus.
Known only from the type locality.
Holotype ♂ (MRAC 22730), Cameroon, Center Region Zamakoe near Mbalmayo Reserve Forest, N 03°33', E 011°31', 815 m a.s.l., forest, 19.IV.2014, leg. A. R. Nzoko Fiemapong.
Paratype: 1 ♂ (SEM, MRAC 22731), same locality, pitfall trap, 18.IV.2015, leg. A. R. Nzoko Fiemapong.
The species is named after the Mbalmayo Reserve Forest, the type locality.
A species close to the previous new one and to S. beroni by its external characters, but is easily distinguished by the structure of the colpocoxite whose apical part is axe-shaped.
Stemmiulus mbalmayoensis Nzoko Fiemapong & VandenSpiegel, sp. n. ♂ paratype (SEM). A first leg-pair oral view B, C leg-pair two, oral and caudal views, respectively D, E leg-pair 8 (gonopods) oral and caudal views, respectively F apical part of right gonopod showing angiocoxite (An) partly surrounding colpocoxite (Co). Scale bars 200 µm (A), 100 µm (B–E), 50 µm (F).
Holotype: adult male, ca 20 mm in length, 1.8 mm in maximum diameter, body with 46 rings. Head and collum dark brown, other body rings brown with a light axial dorsal stripe, legs and antennae yellowish.
Head typical in shape, beset with numerous simple macrosetae as in previous species; ommatidia 2+2, posterior ommatidia slightly larger than anterior ones. Antennae reaching the fourth body ring, and covered with minute setae.
Gnathochilarium concave, without special modification, stipes densely and uniformly porose, pores surrounded by a field of setae. Collum with a single fringe at anterior edge, this being best visible laterally. Body rings ovoid (height/width ratio of midbody rings ca 0.38), metazonites with transverse oblique striae better visible at pleurotergal margin. Striations on prozonites more weakly developed than on metazonites. Annal valves beset with numerous setae.
First pair of legs and legs 3 to 6 as in S. uncus (Fig.
Second pair of legs with enlarged and subquadrate coxae (Fig.
Gonopods (Fig.
Paragonopods small, 3-segmented, quite similar to those in most of the African congeners.
Female unknown.
Most of the peripheral characters and especially the simple gonopods seem to bring S. mbalmayoensis sp. n. close to S. uncus sp. n., S. beroni and S. pullulus. Nevertheless, the males of all these species can easily be distinguished by the structure of the colpocoxite, in which the apical part is axe-shaped in S. mbalmayoyensis sp. n., pointed and unciform in S. uncus sp. n., pointed and straight in S. beroni, but with a rounded tip in S. pullulus.
Known only from the type locality.
1 ♂, 1 ♀ (MRAC 22732), 1 ♂ (SEM, MRAC 22733), Cameroon, South Region, Kribi, road toward Bipindi, Bidou I, cocoa plantation, disturbed vegetation near secondary forest; N3°03'25", E10°06'02" 80 m a.s.l. collect by hand 14.X.2014, all leg. A. Henrard and VandenSpiegel.
Adult males ca 13 mm in length, 1.5 mm in maximum diameter (height/width ratio ca 1.36), body with 43–44 rings; female with 46 rings, including 2 apodous (height/width ratio ca 1.15). Body light brown with 2–3 marbled spots lying symmetrical to mid-dorsal region which is covered by a large yellowish band all along its extent (Fig.
Stemmiulus beroni Mauriès, 1989. A Habituses of ♂ (small specimen) and ♀ (large specimen) B head front view C gnathochilarium D leg-pairs 3 to 7 F first leg-pair (one) G, H leg-pair two, oral and caudal views, respectively I left paragonopod, oral view J, K leg-pair 8 (gonopods) oral and caudal views, respectively L, M apical part of right gonopod oral and caudal views, respectively. Abbreviations: f: flagella, fl: finger-like process. Scale bars 1 mm (A), 200 µm (B, D), 100 µm (C, F–H, J, K), 50 µm (L, M), 20 µm (E)
Head typical in shape, beset with numerous simple macrosetae (Fig.
First pair of male legs with short and globular coxae, telopoditomeres clothed with numerous plumose setae. First article of telopodite long and voluminous, nearly equal in length to all three other telopoditomeres combined, tarsal segment with a brush of setae on basal two-thirds of ventral surface.
Second pair of male legs relatively simple, with rounded coxae and 2-segmented telopodites, distal segment of the latter being relatively slender. Anterior side of proximal part of telopodite covered with long plumose setae (Fig.
Ventral surface of first six pairs 3 to 7 of male legs clothed with numerous plumose setae, tarsal segment with a fringe of setae in basal two-thirds of ventral surface but no true brush formed (Fig.
Legs 8 and following unmodified (Fig.
Gonopods (Fig.
This species is new to the fauna of Cameroon and is illustrated, based on new material taken from outside the type locality (Jos, Plateau State, Nigeria) for the first time. The fresh males from Cameroon are peculiar in the apical part of the colpocoxite being slightly curved (Fig.
Among the Stemmiulus species known to occur in Cameroon, S. nigricollis was the first to be described (
Since the key below is based on male characters alone, the female-based S. camerunensis is excluded from treatment. Silvestri (1916) described his S. camerunensis from a series of syntypes which included an adult female and two juveniles, all taken at Victoria, Cameroon. Only recollecting fresh topotypes, including male material, would finally allow us to clarify the identity of S. camerunensis and to incorporate this species into a key.
1 | Angiocoxite of gonopod with a subapicolateral projection (Fig. |
2 |
– | Angiocoxite of gonopod without a subapicolateral projection | 4 |
2 | Second pair of legs relatively complex in structure, coxa with a well pronounced subconical projection anterolaterally (Fig. |
3 |
– | Second pair of legs relatively simple in structure, coxa without projection | S. nigricollis |
3 | Basal segment of telopodite of second pair of legs forming laterally a subconical projection with a field of localized setae on the tip (Fig. |
S. ongot sp. n. |
– | Basal segment of telopodite of second pair of legs without subconical projection | S. infuscatus |
4 | Corolla of angiocoxite of gonopod with a well-pronounced constriction in subapical part (Fig. |
S. uncus sp. n. |
– | Corolla of angiocoxite of gonopod without a constriction in subapical part | 5 |
5 | Apical part of colpocoxite forming a stretched finger-like process (Fig. |
S. beroni |
– | Apex of colpocoxite axe-shaped (Fig. |
S. mbalmayoensis sp. n. |
The first author is greatly obliged to the Belgian Cooperation to Development programme, which funded this study through the ABIC programme and the Rufford Foundation (ref: 20687-1), as well as the Congo Basin Grant Program 2016 which made it possible to collect material. The last author thanks the “Fond Léopold III” for financial support. Special thanks go to Jonathan Brecko from the Museum for Central Africa for taking the colour pictures and to Christophe Allard for his technical assistance.