A New Frog of the Genus Ctenophryne (Microhylidae) from the Pacific Lowlands of Northwestern South America
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AMERICAN MUSEUM Noviltates PUBLISHED BY THE AMERICAN MUSEUM OF NATURAL HISTORY CENTRAL PARK WEST AT 79TH STREET, NEW YORK, N.Y. 10024 Number 2947, 16 pp., 9 figs. August 8, 1989 A New Frog of the Genus Ctenophryne (Microhylidae) from the Pacific Lowlands of Northwestern South America RICHARD G. ZWEIFEL' AND CHARLES W. MYERS' ABSTRACT A single specimen of narrow-mouth frog (Mi- Specimens from northern and western populations crohylidae), from lowland rain forest in south- of C. geayi (including the holotype)-from Guyana western Colombia, is assigned to the genus Cten- to Ecuador and south to central Peru-have pale- ophryne on the basis of radiographic data and flecked venters. Specimens from most of the re- external resemblance. It appears to represent a gion south of the east-west axis of the Amazon smaller and differently proportioned species than River, however, have the venter marked with larg- the only other member of this genus, C. geayi, er spots. A call from a northern population is con- which is widespread in Amazonian and north- trasted with one from a southwestern population eastern South America. Even with the addition of (ventral pattern unknown); the latter shows a faster Ctenophryne minor, new species, microhylids re- pulse rate at a lower temperature. main an insignificant part of the richly endemic Although lacking corroboration, these differ- anuran fauna on the Pacific versant of northwest- ences suggest a possibility that northern and south- ern South America, although the family is well ern Ctenophryne geayi might represent different represented east of the Andes. species. The new trans-Andean species, C. minor, The distribution and variation of Ctenophryne is geographically closer to northern C. geayi (sensu geayi are briefly reviewed in order to help deter- stricto), but its ventral color pattern is closer to mine the status of the trans-Andean C. minor. that of southern geayi. RESUMEN Un ejemplar de la "rana boca angosta" (Micro- de Colombia ha sido asignado al genero Cteno- hylidae) de la selva pluvial baja del suroccidente phryne, bas'andose en datos radiogrfaficos y de I Curators, Department of Herpetology and Ichthyology, American Museum of Natural History. Copyright ©3 American Museum of Natural History 1989 ISSN 0003-0082 / Price $1.90 2 AMERICAN MUSEUM NOVITATES NO. 2947 apariencia extema. El ejemplar parece mias pe- el sur hasta Per'u central-poseen vientre de man- queiio y de proporciones diferentes de las del 'unico chas p'alidas. Sin embargo, ejemplares de la mayor miembro de este genero, C. geayi, ampliamente parte de la region al sur del eje este-oeste del Rio distribuido en Amazonia y noreste de Suramerica. Amazonas poseen vientres marcados con manchas A(un con la adicion de Ctenophryne minor, nueva mas grandes. Se compara el canto de una pobla- especie, los microhilidos representan una parte in- cion septentrional con el de una poblacion mas al significante de la rica fauna endemica de los anuros sudoeste (con la coloracion ventral desconocida). de la vertiente Pacifica al noroeste de Suramerica, Este uiltimo muestra la tasa del pulso mas aceler- aun asi, la familia esta bien representada al este ada a mas baja temperatura. de los Andes. A(un cuando falta corroboracion, estas diferen- Se hace una breve revision de la distribucion y cias sugieren la posibilidad de que Ctenophryne variacion de Ctenophryne geayi con el fin de ayu- geayi septentrional y meridional representen es- dar a determinar la posicion sistemitica de C. mi- pecies diferentes. La nueva especie transandina, nor transandina. Ejemplares proveniente del norte C. minor, geogrfaficamente est'a mias cercana al C. y occidente de poblaciones de C. geayi (incluyendo geayi (sensu stricto), pero su patrono de coloracion el holotipo)-desde Guyana hasta Ecuador y hacia ventral esta mas cercano al del geayi meridional. INTRODUCTION The 34 currently recognized species of The new species was discovered in western South American narrow-mouth frogs (Mi- Colombia in 1973, during fieldwork con- crohylidae) are distributed mostly east of ducted under the auspices ofthe late F. Carlos the Andes. Exceptions include species ofEla- Lehmann Valencia, then director of the Mu- chistocleis (and the questionably distinct Re- seo Departamental de Historia Natural, in lictovomer), which occur in northern Colom- Cali. For courtesies rendered in support of bia and Panama, and Nelsonophryne, found this program of fieldwork, grateful acknowl- in Costa Rica, Panama, Colombia, and Ec- edgment is due also to authorities in the Sec- uador. Nelsonophryne aequatorialis (Peracca) cion de Recursos Naturales, CVC (Corpo- is a high-elevation species of the Ecuadorian racion Autonoma Regional del Cauca). Andes. The other species of this genus, N. aterrima (Gunther), is the only microhylid ABBREVIATIONS reported from the rainforested lowlands of COLLECTION western Colombia and northwestern Ecuador AMNH American Museum of Natural (Boulenger, 1913); it occurs also in Costa Rica History, New York and Panama (often at elevations above 1000 KU Museum of Natural History, Uni- m). Given this context, the discovery of an versity of Kansas, Lawrence undescribed species of microhylid in south- MNHN Museum National d'Histoire Na- western Colombia is of both systematic and turelle, Paris zoogeographic interest. The purposes of this USNM National Museum of Natural His- contribution are to describe the new species tory, Smithsonian Institution, found west of the Andes and to summarize Washington, D.C. the variation and distribution of its probable sister species, Ctenophryne geayi Mocquard, GENERIC ASSIGNMENT which occurs east of the Andes. OF A NEW MICROHYLID This paper had its genesis when we tried ACKNOWLEDGMENTS to identify a specimen (fig. 1) of microhylid We thank Drs. Darrel Frost and John D. frog from the Pacific lowlands of western Co- Lynch for commenting on the manuscript. lombia. South American Microhylidae are We are grateful to Drs. William E. Duellman placed in 16 genera, 11 of them monotypic (KU) and W. Ronald Heyer (USNM) for ac- (Nelson, 1985; Zweifel, 1986; Frost, 1987). cess to specimens in their care, and to Dr. The similarity of the new specimen to Cten- Janis A. Roze for the Spanish abstract. ophryne geayi in color pattern suggested its 1989 ZWEIFEL AND MYERS: NEW CTENOPHRYNE 3 status as a member of this currently mono- typic genus.2 Confirmation of this generic as- signment must await availability ofaddition- al specimens that can be used for osteological preparation, inasmuch as genera of micro- hylid frogs are defined largely on characters of the skeleton. However, details that can be observed through radiography (see Osteolo- gy) are consonant with assignment to Cten- ophryne. Four South American microhylid genera additional to Ctenophryne lack the clavicle and procoracoid and so are appropriate to consider with regard to the generic placement Fig. 1. Ctenophryne minor, new species. The ofthe Colombian specimen: Adelastes, Myer- holotype (AMNH 88977) shown about 2.2 times siella, Synapturanus, and Nelsonophryne. life size. Among other differences from Ctenophryne, the first three genera agree in lacking contact between the quadratojugal and maxilla. This adjective meaning smaller, in comparison contact is clearly visible in the radiograph of with the apparently larger C. geayi. our new specimen. The fourth genus, Nel- DiAGNOsIs: Ctenophryne minor differs from sonophryne (formerly Glossostoma, see Frost, its only congener, C. geayi, in size, certain 1987) possesses a full complement of palatal aspects of color pattern, and in most pro- bones (Zweifel, 1986: fig. 1OA), whereas our portions. The female holotype appears to be resembles C. l near maturity at 30 mm SVL (see Description specimen geayi (op. cit.: fig. OB) following), whereas a female geayi of 39 mm in lacking posterior elements of the vomer- is immature and the smallest mature female opalatine complex. Thus, the Pacific lowland measures 42 mm SVL (Lynch, 1988, men- specimen is most comfortably accommodat- tioned a juvenile female geayi of 41.8 mm). ed within Ctenophryne, but it appears spe- A continuous light line from nose to groin in cifically distinct from the widespread C. geayi minor is nearly straight, passing well above that occurs east of the Andes. the arm insertion so that the dark area below this line is neither broken nor appreciably Ctenophryne minor, new species narrowed above the arm (fig. 1). The hom- Figures 1, 2A, B, 4 olog of this line in geayi dips down behind HoLoTYPE: AMNH 88977 (field no. CWM the eye, closely approaching or reaching the 11893), a subadult female brought into camp arm before elevating again behind it. Thus, by Embera Choco Indians for C. W. Myers the dark lateral area of geayi is broken or and J. W. Daly on February 17, 1973, at greatly narrowed above the arm (Schliiter, Quebrada Guangui, about 0.5 km above its 1980, fig. 9). Black diagonal marks dorsally junction with Rio Patia,3 100-200 m elev., on the femur, shank, and foot of minor are in upper Rio Saija drainage, Department of absent or infrequent in geayi (cf., figs. 2A, Cauca, Colombia. The type locality is rough- 2C). The pale ventral spots in minor are larger ly 2° 50'N, 77° 25'W. than in northern populations of geayi and ETYMOLOGY: The name minor is a Latin also seem to differ in color in life (pale blue in minor, white in geayi). Among various 2 See Zweifel ( 1989) for the disposition of Ctenophryne proportional differences (fig. 5), the eye is marmorata Ahl 1935, an African Phrynomerus erro- larger in minor (Eye/SVL 0.083 vs. maxi- neously attributed South American provenance. mum of 0.075 in geayi), head narrower (HW/ 3This is the same as "Rio Patia del Norte," a carto- SVL 0.353 vs. minimum of 0.360), and legs graphic invention. Not to be confused with the Rio Patia; longer (TL/SVL 0.443 vs.