Arquivos de Zoologia MUSEU DE ZOOLOGIA DA UNIVERSIDADE DE SÃO PAULO ISSN 0066-7870 ARQ. ZOOL. S. PAULO 37(3):269-348 30.11.2005 VARIATION AND TAXONOMIC CLARIFICATION OF THE LARGE SPECIES OF THE LEPTODACTYLUS PENTADACTYLUS SPECIES GROUP (AMPHIBIA: LEPTODACTYLIDAE) FROM MIDDLE AMERICA, NORTHERN SOUTH AMERICA, AND AMAZONIA W. R ONALD HEYER1 ABSTRACT Variation of external morphology features and advertisement calls are analyzed for species currently identified as Leptodactylus knudseni, L. labyrinthicus, L. myersi, and L. pentadactylus from Middle America, the Pacific versants of Colombia and Ecuador, northern South America, greater Amazonia, and the corridor of open formations from Argentina to northeastern Brazil. Although there is noticeable geographic variation between eastern and western samples of L. knudseni, the variation is considered to be intraspecific in nature. Geographic variation within L. labyrinthicus is more pronounced and most consistent with recognizing three species: L. labyrinthicus (Spix, 1824), L. turimiquensis new species, and L. vastus A. Lutz, 1930. No new data are available for variation within L. myersi, which had previously been noted as possibly containing two species. Variation within L. pentadactylus is also pronounced and most consistent with recognizing four species: L. pentadactylus (Laurenti, 1768), L. peritoaktites new species, L. rhodomerus new species, and L. savagei new species. Some specimens that had been identified in collections as either L. knudseni or L. labyrinthicus from the Brazilian State of Pará are considered to represent an undescribed species, herein described as L. paraensis new species. Standard simple statistical tests of significance for sexual dimorphism in members of the study group may not indicate biological significance. Adult morphological and advertisement call differentiation patterns among the species recognized in this paper do not provide completely reliable information for identifying the species involved, suggesting a different pattern of differentiation than occurs in the Leptodactylus fuscus species group. Larval morphological variation and habitat differentiation may be important in the evolution of species differentiation in the taxa dealt with in this paper. Key words: Variation, taxonomy, Leptodactylus, Middle America, northern South America, Amazonia. 1 Amphibians and Reptiles, Department of Vertebrate Zoology, National Museum of Natural History, PO Box 37012, Smithsonian Institution, Washington, DC 20013-7012, USA. E-mail: [email protected] Recebido para publicação em 26.01.2004 e aceito em 12.11.2004. 270 Arquivos de Zoologia INTRODUCTION due to problems of storage of large specimens in museum collections. Ulisses Galatti (unpublished manuscript) The limited storage space available did not undertook comparative studies of the reproductive allow me to evaluate variation in the way I have biology of Leptodactylus pentadactylus just north found works most effectively. My optimum method of Manaus in Brazilian Amazonia and central is to borrow all available materials so that as data- Panama. He found striking differences in his studies taking and analysis proceed, specimens can be re- of the organisms at the two sites and convincingly examined when questions arise. For example, concluded that the two populations studied should during data-taking, pattern standards are continually be recognized as distinct species. This conclusion added and specimens evaluated early in the study is supported by the available genetic differentiation often should be re-inspected against the newer data (Maxson and Heyer, 1988). After receiving a standards. draft of Galatti’s unpublished manuscript for The generally small sample sizes of adults comment, I re-examined the data I had taken on available for most localities do not allow a rigorous specimens of L. pentadactylus (Heyer, 1979) to analysis of variation of specimens from single determine whether they were adequate to separate localities, a critical measuring stick for evaluating the specimens I had examined into two taxa; they inter-population variation. were not. Given the nature of the above two problems, At the same time, examination of certain the following approach was used. specimens of large Leptodactylus from the State of Variation in Leptodactylus myersi has been Pará in Brazil indicated that they were neither evaluated relatively recently (Heyer, 1995); L. knudseni nor L. labyrinthicus. I therefore began consequently data for this species are used only to taking more extensive data on large species of compare with data from the other taxa. As noted Leptodactylus in an attempt to define the taxa previously (Heyer, 1995), there is significant involved and to determine their geographic variation within L. myersi that may conform better distributions. The taxa included in this study involve to recognition of two species. There are no new the specimens that were or would be identified as data to address this issue. Leptodactylus knudseni, labyrinthicus, myersi, or Data were taken anew for the following pentadactylus in my previous studies (Heyer, 1979, characters of transformed juveniles and adults: sex; 1995). The large species of the Leptodactylus dorsal pattern; belly pattern; lip pattern; posterior pentadactylus group not included in this study are thigh pattern; upper shank pattern; body folds; male L. fallax, flavopictus, and laticeps, because there arm hypertrophy; male thumb spines; male chest is no evidence to suggest that there are taxonomic spines; male chin, throat, and chest tubercles; upper problems associated with them and they have shank texture; outer tarsal texture; foot texture; distributions largely or entirely apart from the taxa snout-vent length (SVL); head length; head width; included in this study. eye-nostril distance; maximum tympanum diameter including annulus; thigh length; shank length; foot length. MATERIALS AND METHODS Data were accumulated during the years 1994-2003. Evaluating variation to discern species limits Museum abbreviations follow Leviton et al., in the frogs included in this study is made difficult 1985 and Leviton and Gibbs, 1988 (for the two by two problems, both likely related to the large Swedish collections involved), with the exception size of the adults. First, due to space constraints in of OMNH, herein used for the Sam Noble the Division of Amphibians & Reptiles at the Oklahoma Museum of Natural History and the Smithsonian Institution, I could not borrow all of addition of CBF = Colección Boliviana de Fauna, the museum specimens even if the curators of the La Paz, CV-ULA = Collection of Vertebrates, collections involved were willing to loan the Universidad de Los Andes, Mérida, FHGO = specimens to me for study. Second, over much of Laboratorio de Anfibios & Reptiles, Universidad the geographic ranges of the taxa involved, sample San Francisco de Quito, Fundación Herpetológica sizes of adults are characteristically small, in general “G. Orces,” Quito, MECN = Museo Ecuatoriano Vol. 37(3), 2005 271 de Ciencias Naturales, Quito, and QCAZ = Museo to the groin region. These lateral folds are not de Zoología de la Pontificia Universidad Católica highlighted with darker pigment and thus much del Ecuador, Quito. Data on most specimens of the more difficult to evaluate in many of the specimens. taxa involved were taken from the MZUSP, OMNH, Information is now available that allows a and USNM collections. In addition, I took data on better understanding of the nature of male specimens from Colombia and Venezuela during secondary characteristics involving arm visits to several collections in those countries. Based hypertrophy and thumb and chest spines. Jaslow on my previous work on these taxa (Heyer, 1979), (1985) indicated that the dark keratinized thumb the data from these materials should be sufficient and chest spines were shed by Leptodactylus for the purpose of this study. pentadactylus from Panama during the non- Five categories were used for sex: (1) adult breeding season. He reported that the male arm, females were determined by having curly oviducts while larger than the female arm due to humeral or well-developed ova; (2) juvenile females were hypertrophy, also had additional muscle growth and determined by having straight oviducts – only larger diminution on a seasonal basis. Observations in individuals were dissected to make this captive breeding colonies support and extend determination; (3) adult males were determined as Jaslow’s findings. Richard Gibson (pers. comm.) having vocal slits; (4) juvenile males were observed that captive male L. fallax shed “… the determined as having testes or other secondary black keratinous sheath from their thumb spines. A characteristics such as a small thumb spine, but white hard cone is left in place.” (Leptodactylus lacking vocal slits – only larger individuals were fallax lack chest spines.) James Ellis (pers. comm.) dissected, if needed, to make this determination; found that specimens identified by St. Louis zoo (5) juveniles were small individuals, clearly not personnel as L. pentadactylus shed both thumb and adults, and were not dissected. chest spines on a regular annual cycle, but a marked For all the pattern characters, outline diminution of the arm when the spines were shed drawings of the body area involved were filled in was not observed in the captive colony. A smaller with patterns used previously or with new sketches. white core was still visible on the thumbs after the Each pattern was uniquely labeled.