Both specics of Pycnotropis hitherto known from Amapá state, Brazil, i.e. P .subareata (JEEKEL, 1963) and P. goeldii GOLOVATCH, VOHLAND & HOFFMANN, 1998, are revised based on type material. Both appear quite similar but superficially "good" species differing in a number of peripheral and gonopod characters such as outline of some metaterga as well as the degree of development of both certain sternal structures and gonotelopodite branches. An improved key is provided to these two species to facilitate their recognition

Golovatch, S.

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AMAZONIANA XVII (ll2): 173-176 Dezerrrber Kiel,2002On two species of the millipede genus Pycnotropis CARL, 19I4from Amapá state, Brazil (Diplopoda, Polydesmida,Aphelidesmidae)byS.l. GolovatchProf. Dr. Sergei l, Golovatch, lnstitute fol Problerns of Ecology arrd Evolution. RussianAcaderny of Sciences, Leninsky prospekt 33, Moscow l1707l (V-71). Russia; e-rrrail:sgol(rÐ,orc.rulAccepted f'or publication: January. 2001).AbstractBoth spccìcs of Pvtnr¡tt'oÌti.s hitherto known {iorr Anrapá state. Brazil. t.e. P .¡ul¡orcola (.lEEKEL.. l9(r3)and P. goeldii GOLOVATCH. VOH LAN D & l lOtilrl\4 4 N. l 99tl. are rçviscd based on type nlaterial. IJothappear quite sirnilar bt¡t superficially "good" specics tliffering in a nurnbcr of peripheral and gonopoclcbaracters sL¡ch as outline ofsome nletaterga as well as the clegree ofclevelopment ofboth certain slernalstructures and gonotelopodite branches. An inrproved key is providcd to these two species to facilitate thcir'lecogni tion.Keywords: Diplopoda, Polydesmida, Aphelidesmidae, P¡'c¡1¡¡ron¡t. key, Antapá, Brazil.ResumoDuas espécics tle P.vcnotropi.s conhecidas até agora do estado do Amapá. P. sul¡art:utu (JEEKEL. 1963) cP. goaldiiGOLOVATCH, VOHLAND & HOFFi\44N. 1998, são rcvidadas baseando-se enr nraterial tipo.Ambas parcem bastante similar mas superficialmente sào "boas" espécies, diferintlas em vários carateresperiferais e gonopodais como o contoríìo de alguns rnetatergos como tambérrr o grau de desenvolvinrentotlc ccrtas estruturas sternais e da ranrificação clo gonotelopotlito. Urna chave melhorada é providencradapara estas duas cspécies para facilitar o seu reconhecimento.lntroductionAccording to the latest review (GOLOVATCH et al. 1998), the prolific rnillipede gerrusP),cnotropi.s CARL, l9l4 is not only the largest arnor.rgst Aphelidesuridae but also oneof the lnost cornnìon and diverse among Neotropical Diplopoda in gcneral. This familyis very likely to be Norlh Andean in origin, with only a few rnembers that have l'eachedas far nofth as Mexico and as far south as Amazonia (VOHLAND 1998). In factPycntropis is about the sole aphelidesrnid genus that has managed to colonize viltuallyentire Alrazonia and is definitely still at a stage of active speciation.While rnany of the cumently known 26 valid specics of Pycnotrop¡,ç sceur quite localin distribution, being restricted to the Andes of Peru, Ecuaclor or Colombia, at thcopposite extrelne a few floodplain congeners appear confined to seasonally inundatedforests of Amazonia. It is this handful that irrcludes the particularly widespread arrclISSN 0065-67551200211'731 O MPI ftir Linrnologie. AG TroperrökoloË.ic. Plörr; INPA. Manausn3ecologically plastic P. tida (CHAMBERLIN, I94l) that ranges fiom the upper reachesof Rio Marañon, Peru to the environs olManaus, Brazil (GoLovATCH et al. l99g;VOHLAND & ADIS 1999). Probably not only because of an especially intensiye anddiligent collecting effort but also due to the proximity to the presumed generic centre oforigin, rather lìumerous species of Pycnotrop¡¡ seeln endemic to the environs of Iquitos"Peru, largely tera firme sites. A few localities, mostly terra firme as well, lying firrtherdownstrearr in Brazil likewise appear to support an endernic species each; two suchspecies have been encountered in Amapá state, i.e. quite close to the mouth of AmazonRiver, though we know nothing about their habitats. The latter region is thus thesoutheasternmost distribution limit not only of PycnoÍropis but of the entire farnilyAphelidesmidae.Thus the conclusion has been drarvn that the Amazon seems to have served as amajor pathway for repeated downstream dispersal of various biotic elements, includingPycnotropis, fro[r the Andes, Surinam Plateau ancl other highlands surrounding theAmazon catchment area. Indeed, p. tida provides u u"ry gooJexample of how down_stream gene drift and subsequent (re)colonization(s) by opportunists cóuld have operatedon a geological time scale to trigger off secondary speciation in Pycnotrop¡s at least incentraland Easter¡ A*azonia (GoLovATCH et al. l99g; VoHLAND & ADIS 1999).There can be no doubt that many more Pycnotroprs species ale still to be discoveredand described while what we currently know is but a iragrnent ol the real diversity ofthis remarkable genus.As an unfoftunate situation, both Amapá species of pycnotrop¡¡, i.e. p. subareata(JEEKEL, 1963) and P. goetdii coLovATCH, voHLANo ¿¿ uopF}ulAN, 1998,bei'g quite similar both externalry and in gonopod traits, appear to contain a fewlacunae in the description and/or the character marrix (cf. GOLOVATCH et al. l99g).Thus, the original, and sole, description of p. subareata, however detaired (JEEKEL1963), was incomplete in omitting several structnral peculiarities now known to beimportant for distinguishing species in this genus. These omissions concem certainmeasurements, the shape of the caudal corner of paraterga 16, the height of paraterga,the degree of development of some sternal cones and ofipinules below paraterga, andthe exact conformation of the gonopod telopodite. As regards p. goetdii, by sorneaccident data conceming the shape of paratergum l6 were ãmitted flom the charactermatrix, though clearly described in the main text.To refine the diagnosis of p. subareara, especially so vis-a-vis the nearly sympatricP' goeldii, type material of both these species was received for restudy. As both speciesare indeed very similar, it appears highly important to draw a better clistinction betweenthem.MaterialType material has been received for study from the foilowing museum coilections.(l) Amplinus .subareatus JEEKEL, 1963 - Muséum nationar d'Histoire natu¡eile, paris: cr holotype, l ?allotype, 2 ðð paratypes, Brazil, Amapá, "Guyane contesté franco-brésilien, placers de carsevenne,1899", leg. F. GEAY (cf. JEEKEL 1963).(2) Pvcnon'opis goeldii GoLoyATCH, VOHLAND & HOFFMAN, 1998 - Museu paraense EmírioGoeldi' Belém, Brazir: r cr paratype, Brazir. Arnapá, "Serra do Navio, Mata, r7.05.r9g9,,, reg. R. N.BITTENCOURT (cf. COLOVATCH et at. t998).174Taxonomic partAs a direct, side-by-sicle comparison shows, p. "suhareata seems quite similar to, yetapparently different from. P. goeldii. The main differences and sorne additional sinlilari-ties concem the following characters. Colour pattern seems virtually the sarne in bothspecies, though P. subareata uraterial seems lnore strongly fa¿eã. p. sLtbareqta issomewhat larger than p. goeldii, body length varying from ca. 55 to 5g (d) to 63 rnm(9) versus ca. 50 rnm (d only), body width from 5.0-,5.7 and g.7-9.0 (c¡), or g.0 and10.0 mm (?) versus 4.6-4.9 and 8.0 mm (d) on midbody pro- and metazona, respecri_vely. collum ahnost pointed in p. subareuta versus narrowly rounded ín p. gåeùii.Metatergal areation usually more strongly obliterated in P. subareala as colr1pared to p.goeldii, this being particularly evident on collum which remains fully howeuer faintlyareated over the dorsum. The same concerns a few postcollar rnetaterga as well. Caudalcorner in P. goeldii paraterga usually sornewhat better protnrding as compared to p.subareata, yet somite 16 in both species equally acute, almost pointed. pàraterga setequally low, mostly just a little above midheight on midbody somites, rather narrow inlateral view (Fig. 1), in P. subareald g set a bit lower than in d. Cones below paratergain both species similar, rather numerous but inconspicuous, never spinifonn, those closerto caudal edge just a bit larger than others. Sterna 5 and 6 in P. subareata d relativelylow but equally well separated as in P. goetdii (Fig. 2). Finally, in both species gonopodtelopodite very similar, yet outer branch sornewhat less strongly sigrnoid in p. .suharea14(Figs. 3-4) than in P. goeldii.AII these clifferences seeln to provide a reliable basis for treating these two speciesas distinct front one another. The following key can be offered for their easier separ-a-tion:Collum and a few postcollar metaterga fully however faintly areate across dorsurn.Body size slnaller: tnetaterga <8.0 wide (cl). Cones on d sterra 5 and 6 tnore conspicu-ous. Gonopod telopodite somewhat more strongly sigrnoid . . . . . p. goeklii- Dorsal parts of collum and of a few postcollar metaterga virtually without areation,Iatter retained only sublaterally. Body size larger: rnetaterga >8.5 mm wíde (d, ?).Cones on d stema 5 and 6 lower (Fig. 2). Gonopod telopodite branches straighrer,rather poorly sigmoid (Figs. 3 &. 4) . p. subareataAcknowledgmentsThe types of both specics concerned were received through the kind cooperation of Dr. J.-p. Mauriòs.Paris, France and Dra. A.Y. Harada, Belém, Brazil, both keepers oftheir respective llìuseunl collections.In addition, I am most grateful to both PD Dr. W. Junk and Prof. Dr. J. Adis who helped nre obtâin grantsfronl the Max-Planck-Society for regular visits to the MPIL in Plön and, once, to conduct a fìeld trip tcrAnlazonia, always in close collaboration with Prof. Dr. Adis. Iwish to acknowledgc the constant suppÕrtrendered to me by thc Max-Planck-Society as well as the great help and hospitality ofmy colleague andfriend Prof. Dr. Joachim Adis whose enthusiastic research in the Amazon region of llrazil has yielcletl veryirnportant nraterials. Also, I ¿m very grateful to Mrs. lrmgar<l Ailis, Miss Bethania Adis, and Miss BeritHansen for their technicai assistance. Prof. Dr. Richard L. Floffman (Martinsville, Virginia, U.S.A.) andalso Prof. Dr. Alessandro Minelli (Padua, Italy) have been kind enough to revise the final dralt ol themanuscript and suggested several irnportant improvements.t75ReferencesGOLOVATCH. S.I., VOHLAND, K.. HOFFMAN, R.L.. ADIS, J., MÁRMOL, A.. BACHMANN. L. & J.TOMIUK (199tì): Review of the Neotropical genus P.vcnotropis CARL, 1914 (Diplopoda. Polydesnri-da. Aphelidesmidae ). - Ar¡razoniana 15(ll2): 67-102.JEE.KEL, C.A.W. (1963): Diplopoda of Guyana. - In: GEIJSKES, D.A" & P.W. HUMMELINCK: Studieson the fauna of Suriname and other Guyanas 4: l-157.VOHLAND, K. (1998): Review of the millipede subfamily Arnplininae (Diplopoda" f'olydesmicla, Apheli-dcsnlidae) with rernarks on phylogeny and the description of some new South American gcnera andspecies. - Amazoniana l5(ll2\: 129-163.VOHLAND, K. & J. ADIS ( 1999): Life history of P-r,crotropi,t tido (Diplopoda: Polydesrnìda: Aphelides-nridae) from seasonally inundated forests in Amazonia (Brazil and Peru). - Pedobiologia 43: 231-244.4t 2Figs. l-4:P),cnotropis subareata (.lEEKEL, 1963), c¡ holotype (l) & d paratypes (2-4).l: somite 10, lateral;2: sternal cones between legs 5 and 6;3: right gonopod, subcaudal;4: left gonopod.lateral. Scale bar: 2.0 mm (l &.2\,0.5 ¡nm (3 & 4).176wI

On two species of the millipede genus Pycnotropis CARL, 1914 from Amapá state, Brazil (Diplopoda, Polydesmida, Aphelidesmidae)

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