MYRIAPODOLOGICA Virginia Museum of Natural History Vol. 8, No. I ISSN 0163-5395 April 15, 2004 A synopsis of Phaeodesmus, an East African genus of paradoxosomatid millipeds (Diplopoda: Polydesmida) By Richard L, Hoffman ABSTRACT Phaeodesmus is defined on the basis of gonopod structure to include the established species aculeatus Peters, alatus Attems, flavocinctus Pocock, and the new species orestes, described from the Nyika Plateau. Malawi- The genus extends from Mozambique to southeastern Kenya with one disjunct locality in upland Malawi; the very few records even in well-collected areas suggest a contracting, relictual stage in the generic history. Within the tribe Cnemodesmini, Pheodesmus is clearly most closely related to Podochresimus, although the two taxa are at present separated by the entire width of South Africa. INTRODUCTION Like most genera of tropical millipeds, Phaeodesmus has undergone the usual progression from monotypy into polytypic heterogeneity and finally into preliminary revision and clarification of its status vis-a-vis related taxa. It is now possible to advance our knowledge of this genus of strikingly colored animals with the description of a new species from Malawi and the assignment hereto of a poorly- known congener from Kenya. These taxa extend the known range of the genus appreciably northward from Mozambique, and the availability of fresh material provides the opportunity for a detailed account of gonopod structure. Historical summary The first species definitely referable to this genus was named Strongyiosoma aculeatum by Peters in 1855, from a female specimen he collected in southern Mozambique. In 1 896, Attems described Orthomorpha longipes from a nearby Scanned with permission by the Virginia Tech Insect Systematics Group 2014 (www.jointedlegs.org) 2 Myriapodologtca locality in Mozambique and in the same year, Pocock published the name Tetracentroslernus flavocincins for specimens from southeast Kenya. Several years later, O. F. Cook ( 1 898) redescribed longipes from type material and set up the genus Phaeodesmus for it, but like Attems before him, failed to provide drawings of the gonopods. This omission w-as finally corrected in the same year by Attems in the first part of his "System der Polydesmiden" but unfortunately the illustration was made from a distorted microscopic preparation and gave a very misleading impression of the structure. In the "Nachtrag" to this work, Attems (1899: 175) mentioned Cook's paper, but rejected the genus Phaeodesmiis and continued to refer longipes to Orthomorpha. Not long afterward, however, Attems changed his opinion about Cook's proposal, and in 1914 listed Phaeodesmus amongst the 35 genera recognized in his family "Strongylosomidae". Moreover he greatly enlarged the scope of the genus by adding five more African species to it: an unfortunate action since none of the five is congeneric either with longipes or each other. Podochresimus alaius, described by Attems in 1928 from Mozambique, actually is congeneric with longipes, but Phaeo- desmus niger, named in the same paper, is not, despite their respective generic placements. In 1934 Attems named Phaeodesmus miles and P, neglectus from Angola. In his 1937 synopsis of the Strongylosomidae, Attems recognized five species in the genus, adding Cnemodesmus thysanopus and relocating several of the 1914 members. One year later he defined still another new species, Phaeodesmus convolutus, from material taken in Zaire. More recently, Schubart (1956) nasnod Phaeodesmus cataractae from Victoria Falls, and Lawrence (1966) described/*, subtropicus from the Kruger National Park, Transvaal. As shown by the foregoing account, Phaeodesmus acquired over the years a very unsatisfactory composition, notable for its heterogeneity. Coincidentally, two papers appeared in 1968 that essentially imposed a rational taxonomic context on the genus, one of them being Jeekefs classification of the Paradoxosomatidae (the correct name for the erstwhile Strongylosomidae), the other a brief synopsis of South African genera of that family by the author of the present account. Both of these papers admitted the species longipes and alatus to Phaeodesmus, and excluded the species cataractae as referable to Congolina (=Ectodesmus), Jeekel, however, also recognized Pocock's enigmatic species T. flavocinctus, and expressed the view that subtropicus was probably a true Phaeodesmus related to alatus. Both authors restored Cnemodesmus to generic rank, with C. thysanopus as its type species, and recognized Campsogon (Chamberlin, 1951) as a valid genus containing the nominal species laquifer Chamb., iugans Chamb., miles Attems, and convolutus Attems. Lastly, having studied the male characters of P. neglectus, Hoffrnan (1982) established the new genus Anaclastopus to accomodate this single disjunct species. The genus is here considered to contain four nominal species, two of which {flavocinctus and aculeatus) are probably subspecifically related Scanned with permission by the Virginia Tech Insect Systematics Group 2014 (www.jointedlegs.org) Hoffinan; Phaeodesmus 3 ACKNOWLEEXjMENTS The material upon which the following account is based w^as made available by my colleagues Manfred Moritz (Zoologisches Museum des Humboldt Universitats, Berlin), Rudy Joeque (Museum Royal de f Afrique Central, Tervuren), Gisela Rack (Zoologisches Museum, Universitat Hamburg), and Paul Hillyard (British Museum - Natural History , London), to whom I express my thanks. SYSTEMATICS FAMILY PARADOXOSOMATIDAE Tribe Cnemodesmini Cnemodesmini Jeekel, 1968, Paradoxosomatidae, p. 104. - Hoffman. 1980, Classification of Uie Diplopoda, p. 168. Phaeodesmus Phaeodesmus Cook, 1898, Proc. U. S. Nat. Mus, 20: 706. Tjpe species, Orthomorpha longipes Attems. 1896, by original designation and monot}T>y.“Atlems, 1937, Tierreich 68:. 218. - Jeekel, 1968, Paradoxosomatidae, p. 105. - Hoffinan, 1968, Wasinann Jnl Biol. 26: 218. Diagnosis: A cnemodesmine genus characterized by a row of 3-6 setae along inner margin of antennal sockets; presence of parantennal organ; moderately well developed paranoia; very^ long and slender legs with tarsi longer than femora and, on anterior legs, provided with a ventral brush of modified setae; femora of 3rd-5th legs of males provided with a ventrodistal adenostyle (one exception); sternum of 5th segment of males with prominent transverse process; and sternum of 6th segment with a median macroseta or cluster of hairs betw^een both pairs of legs. Coxa of gonopods long, cylindrical, moderately constricted at distal third, with small field of short setae on dorsal side; femur set off from prefemur by distinct cingulum visible on lateral side, median surface of femur with central membranous area bounded on its dorsal edge by a promment laminate process; distal part of femur prolonged on dorsal side into a large, long, falcate process curved parallel to the arcuate tibiotarsal region; posttemur set off basally by an indistinct cingulum on lateral side, merging gradually into tibiotarsus which extends mesad as an intricately folded, apically expanded blade enveloping solenomere for most of its length; postfemur with a large digitiform medially directed process (e) from its ventral surface. Relationships: Insofar as can be determined with insufficient reference material and often inadequate published illustrations, I believe that the nearest relative of Phaeodesmus must be Podochresimus, a view already expressed (Hoffinan, 1968). In addition to the synapomorphy of femoral adenostyles on the 3 -5th legs of males, the gonopods of these nominal taxa are very’ similar, distinguished only by the presence of an additional tibiotarsal process (labeled “c” on Attems’ drawings) in the Scanned with permission by the Virginia Tech Insect Systematics Group 2014 (www.jointedlegs.org) 4 Myhapodologica species of Podochresimus . The broad geographic separation of these adelphotaxa on the cast and west coasts of South Africa is quite likely due to the “relatively recent desiccation of South-West Africa’’ invoked by Jeekel (1968: 138). Distribution: East Africa, from southern Mozambique (Inhambane) north to eastern Kenya; with one exception (in northern Malawi) the species occur in coastal lowlands and arc thus largely allopatric with those of the related cnemodesmine goms Aklerobunus (see map. Fig. 12). Species: Four, one of them new, separable as follows: 1. Femora of anterior legs of males without apicoventral adenosfrie; tibiotarsus of gonopod only slightly curved, with a small acicular basal spine on mesal side orestes - Femora of legs 4-6 of males with small acute apicoventral adenostyle 2 2. Apex of tibiotarsus strongly recurved dorsad, with several small marginal denticulations alatus - Apex of tibiotarsus recurved ventrad then laterad 3 3. Subapical lobe of tibiotarsus (ventral aspect) relatively small; postfemoral process e without a rounded lobe at midlength (Fig. 9); adenosfrie of 3*^^ leg of male (Fig. 3) aculeatus - Subapical lobe of tibiotarsus relatively large; postfemoral process e conspic- uously broadened at midlength (Fig. 1 1); adenostyle of 3'^'^ leg of male (Fig. 4) flavocinctus Phaeodesmus aculeatus (Peters), new combination (Figs. 3, 7, 8, 9) Strongylosoma aculeatum Peters, 1855, Monatsber. Akad. Berlin: 81. Female holotype (Zool. Mus. Berlin) from "Terra horror, 18'’ lat. aust.", Mozambique (W, C. H. Peters). Strongylosoma aculeatum: Peters, 1862, Reise nach Mossambique, Zool., 5: 532, pi, 33, fig. 7. Hahrodesmus aculeatus: Cook, 1896, Proc. U. S. Nat. Mus., 18; 98, pi. 5, figs. 6, 7. Orthomorpha longipes Attems, 1896, Mitt. Naturh. Mus. Hamburg 13; 25. Male and female syntjpes (Zool. Mus. Hamburg) from Quelimane, Mozambique (Franz Stuhlmann).- Attems, 1898, Denks Akad. Wien 67; 332, figs. 87, 88. New Synonymy! Phaeodesmus longipes: Cook, 1898, Proc. U. S. Nat. Mus. 20: 707.— Attems, 1928, Ann. S. Afr. Mus. 26: 249.- Attems, 1937, Das Tierreich 68: 219. - Jeekel, 1968, Para- doxosomatidac, p. 105. Cnemodesmus longipes: Hoffman, 1953, Proc. Biol. Soc. Wasliington, 66; 81. Material: Female holotype of aculeatum; male and female syntypes of longipes. Scanned with permission by the Virginia Tech Insect Systematics Group 2014 (www.jointedlegs.org) Hofifinan: Phaeodesmus 5 Figs. 1-7. Phaeodesmus species, structural features. 1. P. orestes, left side of segments 1-4, dorsal aspect. 2. P. orestes, left side of segments 10 and 11, dorsal aspect. 3. P. aculeatusjQmuroi3^ leg of male. 4 . P./?^ivoc/nctM.s,femurof3rdlegofmale. 5. Sternal process of 5*^ segment, P. orestes. 6. The same, P.flavocinctus. 7. The same, P, aculeatus. Scanned with permission by the Virginia Tech Insect Systematics Group 2014 (www.jointedlegs.org) 6 Mynapodologjca As already remarked by Cook (1898: 704) it is highly probable that Peters' earlier name aculeatum is a senior synonym of longipes even though the species was based upon a female. There is close agreement in all external details, and the type localities are only 80 km (48 miles) apart (details on the identity and location of ‘"Borror” from Bauer et al, 1995). Attems' illustration of the gonopod in his "System der Polydesmiden" is inaccurate, drawn from a distorted slide preparation. In 1937 he gave a much better drawing which shows longipes to be very similar to flavocinctus in gonopod stnicture, but with the dorsal femoral process shorter and deltoidally expanded apically. Examination of Attems' type series gave the opportunity to make more precise drawings (Figs. 8 and 9) of gonopod structure which show^ the characters of longipes more clearly and permit comparison with other members of the genus. Cook's 1898 account of longipes contained an inadvertent contradiction: in the generic diagnosis he alluded to ventral processes from the femora of the 5th and 6th pairs of legs, whereas in the specific description the 4th and 5th legpairs are correctly so specified, I provide here (Fig. 3) a drawing of the 5th femur of a lectoparatype for comparison with the same structure 'm flavocinctus. Phaeodesmus fJavocinclus (Pocock) (Figs. 4, 6, 10, 11) Tetracentrosternus JIm’ocinctus Pocock, 1896, Ann. &. Mag. Nat. Hist. (6) 17: 438, fig. 5. Male holotype (Brit. Mus. Nat, Hisl.1893.1 1.9,44) labeled "Leikipia and Ngatana" [Kenya] (J. W. Gregory). Habrodesmus flavocinctus: Cook, 1898, Proc. U. S. Nat. Mus. 20: 702. --Attems, 1937, Tierreich 68: 182. Phaeodesmus flavocinctus: Jeckel, 1968, Paradoxosomatidae: 105. MATERIAL: The holotype (BMNH); also Tanzania: Rufiji District: Mafia Island, evergreen forest on coral, near Mrora village , W. A. Rodgers and J. B. Hall leg. 19- 20 February 1983 (VMNH Id', 3? ?). Pocock's illustration of a gonopod from his type specimen was made from the appendage in situ, and despite its small size is quite accurate. It is curious that neither Cook nor Attems, working later with material of ‘longipes " and alatus, did not compare their specimens from the same orientation, a measure which would have surely revealed the dose structural similarity. Inspection of the drawings (Figs. 10-11) made from the holotype will show that despite its somewhat distant geographic position, flavocinctus is closely related to aculeatus. It seems entirely possible that these nominal taxa arc only geographic races of a single species. But so long as they remain known only from very widely separated localities - with the implication of effectual reproductive isolation - a conservative non-judgmental posture seems warranted. The fact that only one collection of flavocinctus has been made in coastal Tanzania despite extensive collecting in recent decades is noteworthy, and may reflect a declining, fragmentary' range. Scanned with permission by the Virginia Tech Insect Systematics Group 2014 (www.jointedlegs.org) Figs. 8-11. Gonopod structure of Phaeodesmus species. 8, P. aculeatus, mesal aspect. 9. P. aculeatus, ventral aspect. 10. P. flavocinctus, mesal aspect. 11. P. flavocinctus, ventral aspect, f, g; dorsal femoral processes; e, postfemoral process. Scanned with permission by the Virginia Tech Insect Systematics Group 2014 (www.jointedlegs.org) 8 Myriapodologica Phaeodesmus orestes, new species (Figs. 1,2,5, 12-14) material: Male holotype (MRAC) from Malawi: Nyika Plateau: Chelinda, 2300 m. ASL, 7 December 1981, R. Jocque leg. NAME: The Greek word for "‘mountaineer”, in reference to the upland habitat of the species. diagnosis: Distinct by the absence of adenostyles on the 5*^ male legs, by the shorter, less curved gonopod telopoditc, with a basal spine on the tibiotarsus, and by the more proximal placement of femoral process f + g. holotype: Adult male, length not measureable owing to fragmentation, but about 22 mm, width over most of body 2. 1 mm. Color almost entirely bleached by preservative, but appearing to have been dark brown with legs, antennae, paranoia, and a broad transverse band on each metatergum yellow. Head without modifications, supra-antennal organ small; antennae long (4.3 mm) and slender, reaching back to 5^ segment, articles 2-6 about equal in length, 6^ slightly clavate distally; 7^ truncate-conic, about as long as its diameter. Segments smooth dorsally, metaterga with transverse sulcus evident on segments 4- 1 2, thereafter more obscure, no rows of setae visible; prozona telescoped about half their length at midbody, stricture without evident costulation or striation. Anterior segments convex, with paranoia set low on sides, largest on segment 2 wfrere both anterior and posterior comers are acutely produced; thereafter anterior comer replaced by an even curve (Fig. 1). Paranoia placed progressively higher on sides, dorsum at midbody thus nearly horizontal, generally only large enough to accomodate ozopores, latter placed near posterior end (Fig. 2). Epiproct conical, the apex not divided or bituberculate, sides without enlarged tubercles. Legs long and slender, nearly glabrous, attached to low, unmodified podostema, about as wide at midbody as adjacent prefemora; lengths of podomcres 3=6>5> 4>2>1, 2-5 each slightly clavate distally, 6*^ gradually attenuated, with sparse setation especially ventrally. Entire length of tarsi with brush of dense setae bek to legs of 9^^ segment; tibiae witli ventro-apical tuft of setae back to 7^ segment. Femora of anterior legs without adcnostyle. Sternum of 5* segment with median sternal process between anterior pair of legs (Fig. 5), slightly longer than wide, slightly emarginate mediodistally. Gonopods similar to those of other species, distinctive in the shorter, less arcuate tibiotarsal region with a small spiniform basal process on median side. Femoral process /+g more proximal: g basal to e (mesal aspect!) rather than distal to it. Phaeodesmus alatus (Attems) Podochresimus alatus Axioms, 1928, Aim. South African Mus,, 26: 244, figs. 513-515. T>pe material (S. Afr. Mus., Naturh. Mus. Wien) from Inhambane, Mozambique.. Phaeodesmus alatus: Attems, 1937, Tierreich 68: 220, fig. 111. - Jeekel, 1968, Paradoxo- somatidae, p. 105. Scanned with permission by the Virginia Tech Insect Systematics Group 2014 (www.jointedlegs.org) Hoffinan: Phaeodesmus 9 Figs. 12-14. Phaeodesmus orestes^ n. sp. leftgonopodof holotype. 12. Ventral aspect, “in situ”. 13. Mesal aspect. 14. Lateral aspect. Abbreviations as for Figs. 10 and 11. Scanned with permission by the Virginia Tech Insect Systematics Group 2014 (www.jointedlegs.org) 10 Myriapodologica Cnemodesmus alatus: Hoffinan, 1953, Proc. Biol Soc. Washington, 66: 81. Phaeodesmus subtropicus hs.'wxQnoQ, 1966, Zool Africana, 2(2); 244, figs. 5a-5f. Male hololype (NMP 8988) from confluence of the Le\ubu and Limpopo rivers, west of Pafuri, Northern Province, South Africa (R. F. LawTcnce), New Synonymy! stoonymy: Comparison of the published information shows a remarkable similarity in the descriptions and drawings for alatus and subtropicus^ as was indeed admitted by Lawrence when describing the latter. His distinction involving the position of the solenomere ( his “tibia! process") is clearly illusory, as that structure as shown in Attems’ drawing (1928: fig. 513) was obviously dislodged from its natural position, a common condition in specimens through this family. In fact the major feature cited to separate the two was the greatly elongated sternal process of the 5^ segment shown in Attems’ drawing (1928: fig. 515) for alatus. I am convinced this drawing is inaccurate, firstly because the shape of this process is so uniform in other members of the genus, secondly because Attems’ drawing shows the process as bipartite with a transverse, sinuous, subabasal line: if the part distad to that line be removed, the proximal remnant has exactly the size and shape seen in other species including ‘^subtmpicus'' Lastly, the t3^e localities are only 500 km apart, in this genus not a significant distance considering the more than 1500 km spanned by the range of aculeatus-flavocinctus . LawTence illustrated the gonopod of subtropicus from a lateral aspect, against the standard mcsal aspect employed by Attems for alatus^ making comparison of structures difficult. The drawings of neither author clearly indicated the several subdivisions of the telopodite. REFERENCES Attems, C. 1 896. Beschreibung der von Dr. Stuhlmann in Ost-Afrika gesammclten MyTiopoden. Mitt. Naturh. Mus. Hamburg, 13: 23-42. - 1898. System der Polydesmiden. I. Theil. Denks. Akad. Wien, 67: 221-482. - 1928. The Myxiopoda of South Africa. Aim. South African Mus., 26: 1-431. - 1937. Myriapoda 3. Polydesmoidea I, Fam. Strongylosomidae. Das Tierreich, 68: 1-300. Bauer, A.M., R. Gunther, and M. Klipfel. 1995. The herpetological contributions of Wilhelm C. H. Peters (1815-1883). Society for the Study of Amphibians and Reptiles, Ithaca, New York. 714 pp. Cook, O. F. 1 896. East African Diplopoda of tlic suborder Polydesmoidea, collected by Mr. William Astor Chanler. Proc. U. S. Nat. Mus., 18: 81-111. - 1898. A revision of tropical African Diploptxla of the family Strongylosomat- idae. Proc. U. S. Nat. Mus. 20: 695-708. Scanned with permission by the Virginia Tech Insect Systematics Group 2014 (www.jointedlegs.org) Hoffinan: Phaeodesmus 11 Fig. 12. Distribution of the four species oi Phaeodesmus in East Africa. Triangles, P. JIavocinctus; cross, P. orestes; inverted triangles, P. aculeatus; squares, P. alatus. The currently known range of the related genus Aklerobunus is indicated by tlie hea\y dashed line. Scanned with permission by the Virginia Tech Insect Systematics Group 2014 (www.jointedlegs.org) 12 Myriapodologica Hoffman, R. L. 1953. Scolodesmm and related African milliped genera (Polydesmida: Strongylosomatidae). Proc. Biol. Soc. Washington, 66: 75-84. - 1968. Millipeds of the genus Aklerobunus, with notes on some related South African genera of the family Paradoxosomatidae. Wasmann Joum. Biol., 26: 209-239. Jeekel, C. A. W. 1968. On the classification and geographic distribution of the family Paradoxosomatidae. Privately published dissertation, Amsterdam. 162 pp. Lawrence, R. F. 1966. The Myriapoda of the Kruger National Park. Zool. Africana, 2: 225-262. Peters, W. C. H. 1855. Uber die Myriapoden im allgemeinen und inbesondere iiber die in Mossambique beobachtenen Arten dieser Familie, Monatsb. Akad. Wiss. Berlin, 75: 75-79. Pocock , R. I. 1 896. On the scorpions, centipedes, and millipedes obtained by Prof Gregory on his expedition to Mount Kenia, East Africa. Ann. Mag. Nat. Hist. (6) 17: 425-444. Address of the author: Dr. Richard L. Hoffman Virginia Museum ofNatural History Martinsville, Virginia, 24112 USA Scanned with permission by the Virginia Tech Insect Systematics Group 2014 (www.jointedlegs.org)