aichinger. 1991. a new species of poison-dart frog (anura dendrobatidae) from the serranía de sira,...

7/30/2019 Aichinger. 1991. A new species of poison-dart frog (Anura Dendrobatidae) from the Serrana de Sira, Peru

1/6

FIG. l.-Holotype of Dendrobates sirensis, NHMW 31892, SVL = 16.8 mm .


2/6

VOL. 47HERPETOLOGICA

MARCH 1991 NO .1

Herpetologica , 47(1), 1991, 1- 5 1991by The Herpetologis ts League, Inc.

A NEW SPECIES OF POISON-DART FROG(ANURA: DENDROBATIDAE) FROMTHE SERRANiA DE SIRA, PERU

MANFRED AICHINGERZoologisches lnstitut , Univ ersitiit Wien ,Althanstraj3e 14, A-1090 Wien, Austria

ABSTRACT: A new species of poison-dart frog, Dendrobates sirensis, is descri bed from theSerrania de Sira , an isolated mountain range in east-central Peru, Departamento Huanuco, at anelevation from 750-1560 m. Adult specimens have a snout-vent length of 15-17 mm . The speciesis easily diagnosed from all dendrobatids by the uni fo rm red coloration of the dorsum and theturquoise-green limbs.Key words: Anura; Dendrobatidae; Dendrobates sirensis; Peru

THE Serrania de Sira is an isolatedmountain range in the upper Amazon basin between the Rio Pachitea and the RioUcayali in east-central Peru . The highestelevations are about 2400-2500 m (Terborgh and Weske, 1975) . For an approximate location of this mountain range, seeDuellman and Toft (1979) .Our expeditionfollowed the same route to the Serrania deSira as described by Terborgh and Weske(1975) . Duellman and Toft (1979) first reported on a collection of anurans from thisregion, including the dendrobatids Colostethus marchesianus, Phyllobates (nowEpipedobates) petersi, and P. (now Epi-pedobates)pictus. During a herpetologicalsurvey from September 1987 to October1988, fivespecimens of the poison-dart frogwere captured . This new species was collected first in the Serrania de Sira in 1976byWerner Hanagarth.

METHODSNineteen different measurements (to thenearest 0.1 mm) were made following Myers (1982). The condition of the omoster-

1

num was judged by dissection. Specimensare deposited in Naturhistorisches Museum Wien (NHMW) and Museo de HistoriaNatural "Javier Prado" in Lima (MHNJP).One paratype is in the collection of Staatliches Museum fiir Naturkunde Stuttgart(SMNS). Museum abbreviations followFrost (1985).

Dendrobates sirensis sp. nov .Fig. I-FrontispieceHolotype.-NHMW 31892 (Fig. 1), an

adult female, collected on a horizontal tree1.2 m above a stream in the Serrania deSira, Rio Llullapichis drainage, 750 m, Departamento Huanuco, Peru (928' S, 7447'W), on 10 September 1987, at 0910 h byM. Aichinger.Paratypes.-MHNJP 11518 and MHNJP 11519, adult males, same location asholotype, 780 m, on the ground , on 20March 1988, at 1530 h and at 1250 m, inSeptember 1988, both by B. Wallnofer ,SMNS 07092, adult male, same location,at 1560 m, on the ground , on 23 January1976, by W. Hanagarth.


3/6

2 HERPETOLOGICA [Vol . 47, No.1Diagnosis.-A very small dendrobatid

having an adult snout-vent length (SVL)of about 15-17 mm (three males 14.7-15 .4mm , 1 female 16.8 mm). Skin on backslightly granular, moderately granular onventer, and smooth on limbs; dorsum uniform dark red, a rms and legs turquoisegreen , venter turquoise-green with a rectangular red patch on the belly, chin red;neither spots nor reticulation present dorsally; teeth absent; first finger much shorterthan second; finger discs very conspicuous,enlarged to at least twice finger width ;omosternum absent ; tympanum visiblyconcealed posterodorsally.D. sirensis is tentatively assigned to thequinquevittatus group as characterized bySchulte (1981) , Myers (1982), and Zimmermann and Zimmermann (1988). I t differs from all members of this group (D.captivus, D. fantasticus, D . imitator, D.mysteriosus, D. quinquevittatus, D . retic-ulatus, D. vanzolinii, D. variabilis) by itsuniform red dorsum, its unreticulated feetand venter, and its turquoise-green limbs.Dendrobates sirensis may be confused withother small poison-dart frogs of the genusDendrobates or Minyobates, like D. gran-uliferus, D. pumilio, D . speciosus, M.opisthomelas, and M. steyermarki, whichall have a bright red dorsal coloration.Dendrobates sirensis differs from D. spe-ciosus, M. opisthomelas, and M. steyer-marki in having turquoise-green l imbs ,from D. granuliferus in having only aslightly granular skin, and from D. pumilioin having a rectangular red patch on theturquoise-green belly .Description.-Size small , SVL of adults14.7-16.8 mm; (three males 14.7-15.4 mm;one female 16.8 mm): head narrower thanbody; in all specimens, greatest head width32-34% of SVL. Males lacking vocal slitsand vocal sacs. Teeth absent, omosternumabsent.Skin on the back is slightly granular inlife, moderately granular on venter, andsmooth on limbs. Snout subtruncate in dorsal aspect and sloping in lateral aspect (Fig.2). Naris situated near t ip of the snout anddirected laterally; both nares visible fromfront and from below bu t not from above.Canthus rostralis rounded; loreal region

more or less flat. Interorbital area widerthan upper eyelid. Center of naris to edgeof eye /eye length = 0 .75-0.86 . Tympanum seemingly vertically elliptical, butconcealed posterodorsally; its approximated diameter 56-64% of the eye length .Hand relatively large (Fig . 3); its length(proximal edge of metacarpal tubercle to

tip of longest finger) 78-87% of greatesthead wid th ; relative length of ad pressedfingers 3 > 4 > 2 > 1; adpressed first fingerroughly three-fourths the length of secondfinger. Discs conspicuously expanded onall but first finger . Disc of third f inger 22% times wider than distal end of adjacentphalanx; widths of discs without apparentsexual dimorphism. A circular metacarpaltubercle at base of palm, a smaller innermetacarpal tubercle at base of first finger,and one or two usually prominent subarticular tubercles on fingers (one each onfingers 1, 2, 4, two on finger 3). Distalsubarticular tubercle on finger 3 small andinconspicuous, but all other tubercles onhand prominently raised; surfaces of discsrounded; lack of pigment contributing toprominent appearance of tubercles.Hind limbs of moderate length, withheel of adpressed l imb reaching tympanum. Tibia 36-39% of SVL. Relative lengthof adpressed toes 4 > 5 > 3 > 2 > 1; firsttoe short, reaching bottom of subarticulartubercle on base of second toe, and withunexpanded disc; other toes with discs distinctly expanded (but smaller than fingerdiscs) .Moderate-sized inner and small outer metatarsal tubercles, somewhat protuberant but with rounded surfaces . One tothree subarticular tubercles (slightly protuberant tubercles, one each on toes 1, 2,two each on 3, 5; nonprotuberant tubercles, one each on toes 3, 5, three on toe 3).Hands and feet lack webbing, supernumerary tubercles , or a lateral fringe (Fig .3).Measurements (in m m ) o f holotype. The holotype is a female containing twomature ovarian eggs in both ovaries. Measurements of paratypes are given in Table l.Length from snout-vent 16.8; tibialength from heel to fold of skin on knee6.4; greatest head wid th (between anglesof jaws) 5.4; head wid th at level of eyes


4/6

March 1991] HERPETOLOGICA

oI

5m m

3

FIG. 2.- Dorsal and lateral view of the head of th eholotype of Dendrobates sirensis, NHMW 31892.

5.3;approximate width of in terorbital area2.1; head length from t ip of snout to angleof jaw 4.0; tip of snout to center of naris0.8; center of naris to anterior corner ofeye 1.5; distance between center of nares2.0; eye length from an terior to posteriorcorner 1.8; approximated horizontal diameter of tympanum because tympanumposteriorly indistinct 1.0 ; corner of mouthto lower edge of tympanic rin g 0.6.Length from pr oximal edge of large medial palmar tubercle to tip of longest (third)finger 4.7; width of third finger disc 1.1;width of third finger (penultima te pha-lanx) below disc 0.5.Wid th of di sc of third toe 0.7; width ofthird toe proximal to d isc 0 .5; width ofdisc of fourth toe 1.0; width of fourth toe(penultimate phalanx) pr oximal to disc 0.5.

o 5mm

F IG . 3.-P a lma r an d plan tar surfaces of right handand foot of holotype of Dendroba t es sirensis , NHMW31892.

Coloration in life.-H ead and dorsumdark red , no di stinct spots or str ipes; tym-panum dark brown ; iris black . Arms andlegs turquoise-green ; turquoise colora tionlighter on th e anterodorsal side of proximalhalf of upper arm and in groin an teroventrally on proxim al part of th igh extendingonto th e body. Venter turquoise-gr een witha rectan gular red pat ch on th e belly (approximately 5 x 3 mrn ): chin dark red ;vente r below rectangular patch and th eventral surfaces of th e legs dark tu rquoise .Surfaces of palms and soles black.Parat ype MH NJP 11519 had an indistinct brown spot in th e in terorbital area.One individual which escaped from captivity (sex unknown) showed a di spositionof a rather wide , ill-defined red lateralstripe extending horizontally from th egroin one-third of the dorsum to th e head(M. Henzl , personal communicat ion) . Acolor tran sparency of this specimen suggests that this stripe is not homologous withth e incomplet e oblique lat eral lin e thatchar acterizes man y dendrobat ids.In preservative, th e red coloration appears pal e gray; turquoise changes to black.The red colora tio n of parat yp e MHNJP11519 changed to black. Paratype SMNS07092 becam e pale brown but the coloration in life was as described above (W.Hanaga rth , personal communication).Life history notes.-The holot ype con tained two we ll-developed eggs in bothovaries (d iameter 2.0, 2.1 mrn) as we ll as


5/6

4 HERPETOLOGICA [Vol . 47 , No.1TABLE I.-Measurements (in mm) from paratypes .

MHNJP MHNJP SMNS11518 11519 7092Characteristic Male Male Male

Length from snout to vent 14.7 14.8 15.4Tibia length from heel to fold of skin on knee 5.3 5.8 6.0Tibia/SVL 36 .1% 39 .2% 39 .0%Greatest head width (between angles of jaws) 5.0 4.8 4.7Head width /SVL 0.3 0.3 0.3Head width at level of eyes 4.8 4.7 5.1Width of interorbital area 1.6 1.7 2.0Head l ength f rom t ip of snout to angle of jaw 3.0 3.2 3.8Tip of snout to center of nar is 0.7 0.8 0.8Center of naris to anterior corner of eye 1.2 1.2 1.4Distance between center of nares 1.7 1.7 2.0Eye length from anterior to posterior corner 1.6 1.4 1.4Naris-edge of eye/eye length 75.0% 85.7% 100.0%Horizontal diameter of tympanum (posteriorly indistinct) 0.9 0.9 0.9Diameter tympanum /eye length 56.3% 64.3% 64.3%Corner of mouth to lower edge tympanic ring 0.6 0.6 0.6Length from proximal edge of large medial palmar tubercleto tip of longest (3rd) f inger 3.9 4.0 3.9Length hand/greatest head width 78.0% 83.3% 83.0%Width of third finger disc 0.9 0.9 1.0Width of third finger (penultimate phalanx proximal to disc) 0.4 0.4 0.5Third finger disc /width 3rd finger 2.3 2.3 2.0Width of disc of third toe 0.6 0.6 0.7Width of third toe (penultimate phalanx) below disc 0.4 0.4 0.4Width of disc of fourth toe 0.8 0.6 0.9Width of fourth toe below disc 0.4 0.4 0.4

three small eggs (diameter < 1 mm). Anun preserved female laid a single egg onthe surface of a leaf in a plastic box a fewdays afte r cap ture (M. Henzl, personalcommunication) . Individuals are very agile, jumping continuously.The species seems to be extremely rareor secretive. During one year of investi-

gation, only five individualswere observed(two escaped from captivity).Etymology.-The species is named afte r the type locality, the Serrania de Sira.

DISCUSSIONDendrobates sirensis is known only fromthe Serrania de Sira in east-central Peru at

an elevation from 750-1560 m and seemsto be endemic in this isolated mountainrange. There it lives in sympatry with D.quinquevittatus, which was found fromthe lowland rainforest at 260 m up to1080 m.Based on characters that were attributedto the genus by Silverstone (1975), the newspecies is assigned to Dendrobates. These

characters are first finger shorter than thesecond, well expanded finger discs, and abright coloration in l ife.Dendrobates sirensis may be highly ar-boreal, judging from the relatively longhand with the well developed discs. Oneindividual showed an indication of lightred lateral stripes. A female contained onlytwo mature ovarian eggs. Considering thesefacts, D. sirensis is tentatively assigned tothe D. quinqueoittatus group. Based oncharacteristic behavioral parameters , Zim-mermann and Zimmermann (1988) attrib-uted the following characters to the quin-quevittatus group: the arboreal frogs livein middle to upper strata in tropical rain-forest; females lay only few eggs; malescarry one or two tadpoles to bromeliads;larvae feed facultat ively on unferti lizedeggs laid by the female.Schulte (1981), Myers (1982), and Zim-mermann and Zimmermann (1988) placed

the following eight species in the quin-quevittatus group: D. captivus, D. fan-tasticus, D. imitator, D. mysteriosus, D.


6/6

March 1991] HER PETOLOGICA 5quinqueoittaius, D. reticulatus, D. vanzolinii, and D . variabilis. Myers (1982)could not documen t a relationship of D .captivus and D. mysteriosus to th e quinquevittatus group and lef t th em as possibleclose relatives to th at group. Dendrobatesquinquevittatus is widespread throughoutthe Ama zon Basin, inhabiting primarilylowland rainforest (Lescure and Bechter ,1981; Silverstone, 1975). All other speciesof the quinquevittatus group occ ur onl yin comparatively small ar eas in the western Amazonian lowl ands (Kneller, 1983 ;Myers, 1982 ; Schulte , 1986; Zimmermannand Zimmermann , 1984, 1988). Dendrobates captivus, D . imitator, and D. mys-teriosus may be restricted to single localities in montane rainforest. Excep t for D .mysteriosus, which is known only from asingle specimen (Myers, 1982), D . quinquevittatus lives sympatrically with allother species.Like Minyobates abditus and M . steyermarki, which Myers and Daly (1976) assigned to the minutus group as defin ed bySilverstone (1975), and M . opisthomelas,Dendrobat es sirensis might be a terminalrelict of an ancestor whose range wa s fragmented by climatic vegetational changesthat occur re d in th e Andes dur ing Quaternary time. Further studies on skin al kaloids, knowledge of tadpoles, and th ereproductive biology of this spec ies will benecessary to define th e exact generic andgroup relationships of D . sirensis.

R ESUMENSe describe Dendrobates sirensis, unanueva espec ie de batracio venenoso de laSerrania de Sira , Departamento Hu anuco ,

Peru, a una elevacion de 750 a 1560 m. Esuna rana diminuta (15- 17 mm ) que sepuede facil d istinguir de otros dendrobatidos por su coloracion . La coloracion dorsal del cuerpo es roja y la de las extremidades, verde turqui.Acknowledgmen ts.-I thank B, Wallnof er for collecting specimens an d M. Henzl for observational

data. I am indebted to A. Schliiter (Stu ttgar t ) and N.Cari llo (Lima ) for the loan of specimens. Th anks area lso du e to M. Henzl, W . Hodl, K.-H. Jungfer , A.Schliite r, and E . Zimmermann for ca re fu llv reviewing th e manuscript and to th e Di reccion Ge'neral Fores ta l y de Fauna for permits (062-87-AG-DGFFDR FF-SDFF ). F ina ncial support was de rived from"os terreich ische r Fonds zur Fiirderung der wissenschaftlichen Forschung" (project P6399B) and "Bundesministerium Iu r Wissenschaft und Forschung , osterre ich".

LITERATURE CITEDDUELLMA:-I , W . E., AND C. A. TOFT. 1979. Anuransfro m the Serrania de Sira , Amazon ian Per u: Taxonomy an d biogeography . Herpetologica 35:60-70.FHOST, D. R. 1985 . Amphibian Species of the World .Allen Pr ess an d the Associati on of Systema tics Co llections, Lawrence, Kansas.KNELLER, M. 1983. Beobachtunge n an Dendrobates fantast icus im na tiirlichen Lebensraum un d imTerrarium . Herpetofauna 5 :15-18.LESCURE, J., Al':D R. BECHTER. 1982. Le comport ement de rep rodu c tio n en captivite et Ie pol ymorph isme de Dendrobates quinquevit tatus Steindachner. Revue froAquario!. 8:107 - 118.MYERS, C. W. 1982. Spo tt ed poison frogs: Description of th ree new Dendrobates from western Amazonia, and resurrection of a lost species from "Chir iqui" . Am. Mus. Nov it . 2721 :1-23.MYEHS, C.W., ANDJ. W . DALY. 1976. A new speciesof poison frog (Dendrobates) fr om Ande a n Ecuador including an analysis of its skin toxins . Occ.Pa p. Mus. Nat . H ist. Un iv. Kansas 59:1-12.

SCHULTE, R. 1981. Dendrobates quinqueoit tat us ;iikologie, Haltun g und Zucht. Herpetofauna 3:2428.---. 1986. E ine neu e Dend robates-Art aus Ostpe ru (Amphibia; Salientia; Den drobatidae ). Sauria8:11-20.SILVERSTONE, P. A. 1975 . A revis ion of the poisondar t fro gs of th e ge nus Dend robates Wagler. Nat.Hi st. Mu s. Los Ange les Co . Sci. Bull . 21:1-5 3 .T EHBORGH, J. , ANDJ. S. WESKE. 1975. Th e ro le ofcompe tit ion in the distributi on of Andean birds.Ecology 56:562-5 76.ZIMMERMANN, H. , AND E. ZIMMERMANI':. 1984.Durch Nachzucht er ha lten : Baumsteigerfr iischeDendrobat es quinqu evi ttatus und D. reticulatus.Aqu. Mag. 18:35-41.1988. Etho-Ta xon om ie und zoogeograph ische Ar tengruppenbildung bei Pfeilgiftfriisch en (Anur a: Dendrobatidae ). Salamandra 24 :125160.

Accep ted: 26 Apri l 1990Associate Editor: David Canna tella

aichinger. 1991. a new species of poison-dart frog (anura dendrobatidae) from the serranía de sira,...

Documents