Body size variation and sexual dimorphism in eleven species of Venezuelan anurans
DOI:
https://doi.org/10.11606/issn.2316-9079.v25i1p3-27Keywords:
Anurans, Body Index, Body size, Cordillera de la Costa, MorphometryAbstract
This study examines intraspecific variation in linear morphometric traits—snout–vent length (SVL) and abdominal width (AW)—and sexual size dimorphism (SSD) of 11 Venezuelan anuran species, providing novel insights into their ecological and evolutionary dynamics. Seven species (Atelopus cruciger, Boana xerophylla, Dendropsophus luteoocellatus, D. microcephalus, Engystomops pustulosus, Phyllomedusa trinitatis, and Scarthyla vigilans) displayed significant female-biased SSD, with percentage differences in SVL ranging from 6.01% to 25.71%. This pattern was evident in A. cruciger, which exhibited an absolute SVL difference of 9.95 mm between sexes, and in P. trinitatis, with a difference of 12.55 mm. In contrast, Boana punctata, Leptodactylus fuscus, Rhinella marina, and Scinax rostratus showed no significant SSD, with values within ± 5% or nonsignificant t-test results (e.g., L. fuscus: t = 0.844, p = 0.595). These results align with the common pattern of female-biased SSD in anurans, where larger female size supports increased fecundity, while also revealing context-dependent variations influenced by ecological pressures and life history traits. The novel metric AW showed higher values in female-biased species, suggesting a morphology adapted for reproductive investment, particularly in A. cruciger. Geographic variation in SVL was apparent when compared to prior studies, emphasizing the need for broader sampling. Activity patterns significantly influenced SSD (F3,40 = 6.301, p = 0.001), with nocturnal species exhibiting stronger female bias, possibly due to reduced predation risk. Measurements on preserved specimens ensured consistency, though small sample sizes (e.g., N = 3 for D. luteoocellatus females) warrant caution. This study underscores the complexity of SSD, influenced by ecological, behavioral, and geographic factors. Morphometric indices validated here offer practical tools for future studies, requiring careful application across species, populations, and developmental stages. The results emphasize the ecological and evolutionary importance of body size variation and provide critical data for conservation efforts in Venezuelan anurans.
Downloads
References
Acevedo, A. A., M. Lampo, and R. Cipriani. 2016. The cane or marine toad, Rhinella marina (Anura, Bufonidae): two genetically and morphologically distinct species. Zootaxa 4103: 574–586.
Angel, L. P., M. R. Wells, M. A. Rodríguez-Malagón, E. Tew, J. R. Speakman, and J. P. Y. 2015. Sexual size dimorphism and body condition in the Australasian Gannet. PLoS ONE 10: e0142653.
Angilletta, M. J., T. D. Steury, and M. W. Sears. 2004. Temperature, growth rate, and body size in ectotherms: fitting pieces of a life-history puzzle Integrative and Comparative Biology 44: 498–509. Angulo, A. 2006. Fundamentals of bioacoustics and practical aspects of recordings and analysis of songs. Pp. 93–134
in A. Angulo, J. V. Rueda- Almondacid, J. V. Rodriguez-Mahecha, J. V., and E. La Marca (eds.), Inventory and Monitoring Techniques for Amphibians in the Andean Tropical Region. Bogotá. Conservation International. Serie Manuales de Campo, No. 2. Panamericana Formas e Impresos S.A.
Arantes, I., M. M. Vasconcellos, T. C. V. Boas, L. B. A. Veludo, and G. R. Colli. 2015. Sexual dimorphism, growth, and longevity of two Toad Species (Anura, Bufonidae) in a Neotropical Savanna. Copeia 103: 329–342.
Arak, A. 1988. Sexual dimorphism in body size: a model and test. Evolution 42: 820–825.
Ashton, K. G. 2002. Patterns of within-species body size variation of birds: strong evidence for Bergmann’s rule. Global Ecology and Biogeography 11: 505–523.
Atencia G., P. L., L. Solano, and J. Liria. 2020. Morphometric differentiation and diet of Engystomops pustulosus (Amphibia: Leptodactylidae) in three populations from Colombia. Russian Journal of Herpetology 27: 156–164.
Băncilă, R. I., T. Hartel, R. Plăiaşu, J. Smets, and D. Cogălniceanu. 2010. Comparing three body condition indices in amphibians: a case study of yellow-bellied toad Bombina variegata. Amphibia-Reptilia 31: 558– 562.
Baraquet, M., P. R. Grenat, N. Salas, and A. L. Martino. 2012. Morphometric and geographic variation among populations of Hypsiboas cordobae (Anura: Hylidae) in Argentina. UNED Research Journal 4: 147–155.
Baraquet, M., M. Alejandro Otero, P. R. Grenat, M. S. Babini, and A. L. Martino. 2018. Effect to age on the geographic variation in morphometric traits among populations of Boana cordobae (Anura: Hylidae). Journal of Tropical Biology 66: 1401–1411.
Barrio-Amorós, C. L. 1998. Systematics and biogeography of the amphibians (Amphibia) of Venezuela. Acta Biologica Venezuelica 18: 1–93.
Barrio-Amorós, C. L., F. J. M. Rojas-Runjaic, and J. C. Señaris. 2019. Catalogue of the amphibians of Venezuela: illustrated and annotated species list, distribution, and conservation. Amphibian and Reptile Conservation 13: 1–198.
Bergmann, C. 1847. Über die Verhältnisse der Wärmeökonomie der Thiere zu ihrer Grösse. Göttinger Studien 3: 595–708.
Bernal, M. H. and J. A. Clavijo. 2009. An essay on precision in morphometric measurements in anurans: interindividual, intraindividual and temporal comparisons. Zootaxa 2246: 32–44.
Bickford, D., D. J. Lohman, N. S. Sodhi, P. K. L. Ng, R. Meier, K. Winker, K. K Ingram, and I. Das. 2007. Cryptic species as a window on diversity and conservation. Trends in Ecology and Evolution 22: 148–155.
Bijma, N. N., S. N. Gorb, and T. Kleinteich. 2016. Landing on branches in the frog Trachycephalus resinifictrix (Anura: Hylidae). Journal of Comparative Physiology A, Neuroethology, Sensory, Neural, and Behavioral Physiology 202: 267–276.
Bosch, J. and R. Márquez. 1996. Discriminant functions for sex identification in two midwife toads (Alytes obstetricans and A. cisternasii). Herpetology Journal 6: 105–109.
Castro, N. 2015. Ecology of the Rancho Grande Harlequin Toad Atelopus cruciger (Anura: Bufonidae) in the Cuyagua river, Aragua state. Unpublished M.Sc. Dissertation. Universidad Central de Venezuela, Venezuela.
Chiapero, F., S. Flores Mariscal, D. E. Panigo, and F. Carezzano. 2019. Morphometry of Physalaemus biligonigerus (Anura: Leptodactylidae) in two environments with different perturbation. The Biologist 17: 51–59.
Cohen, M. and R. Alford. 1993. Growth, survival and activity patterns of recently metamorphosed Bufo marinus. Wildlife Research 20: 1–13.
Costa, T. B., L. D. A. Guimaraes, and R. P. Bastos. 2010. Territorial and mating behavior in Phyllomedusa azurea (Anura: Hylidae) at a temporary pond in west-central Brazil. Phyllomedusa 9: 99–108.
Duellman, W. and L. Trueb. 1994. Biology of Amphibians. Baltimore and London. The Johns Hopkins University Press. 670 pp.
Fairbairn, D. J. 1997. Allometry for sexual size dimorphism: pattern and process in the coevolution of body size in males and females. Annual Review of Ecology and Systematics 28: 659–687.
Feng, X., W. Chen, J. Hu, and J. Jiang. 2015. Variation and sexual dimorphism of body size in the Plateau Brown Frog along an altitudinal gradient. Asian Herpetological Research 6: 291–297.
Fonseca-Pérez, K. A., C. Molina, and Z. Tárano. 2017. Diet of Dendropsophus microcephalus and Scarthyla vigilans (Anura: Hylidae) at a locality in northwestern Venezuela with notes on microhabitat occupation. Papéis Avulsos de Zoologia 57: 93–104.
Frost, D. R. 2024. Amphibian Species of the World: an Online Reference. Version 6.2 (22 May 2024). Electronic Database accessible at https://amphibiansoftheworld. amnh.org/index.php. American Museum of Natural History, New York, USA. Captured on 20 January 2025.
Goldberg, J., D. Cardozo, F. Brusquetti, D. Bueno-Villafañe, A. Caballero-Gini, and C. Bianchi. 2018. Body size variation and sexual size dimorphism across climatic gradients in the widespread treefrog Scinax fuscovarius (Anura, Hylidae). Austral Ecology 43: 35–45.
Haddad, C. F. B. 1991. Satellite behavior in the Neotropical treefrog Hyla minuta. Journal of Herpetology 25: 226–229.
Han, X. and J. Fu. 2013. Does life history shape sexual size dimorphism in anurans? A comparative analysis. BMC Evolutionary Biology 13: 27.
Hammer, O., D. A. T. Harper, and P. D. Ryan. 2001. PAST: Paleontological Statistic Software Package for Education and Data Analysis. Version 4.04. URL: http:// palaeoelectronica.org/2001_1/past/issue1_01.htm.
Hayek, L. C. and W. R. Heyer. 2005. Determining sexual dimorphism in frog measurement data: integration of statistical significance, measurement error, effect size and biological significance. Anais da AcademiaBrasileira de Ciências 77: 45–76.
Heyer, W. R. 1978. Systematics of the fuscus group of the frog genus Leptodactylus (Amphibia, Leptodactylidae). Natural History Museum 29: 1–85.
Howard, R. D. 1981. Sexual dimorphism in bullfrogs. Ecology 62: 303–310.
INAMEH (Instituto Nacional de Meteorología e Hidrología). 2021. Climograma. Carretera Nacional Baruta Hoyo de la Puerta Parque Tecnológico Sartenejas Baruta. Estado Miranda. Electronic Database accessible at http: //www.inameh.gob.ve/web/climogra.php. Captured on 12 July 2021.
Iturra-Cid, M., J. M. Ortíz, and N. R. Ibargüengoytía. 2010. Age, size, and growth of the Chilean Frog Pleurodema thaul (Anura: Leiuperidae): latitudinal and altitudinal effects. Copeia 4: 609–617.
Katsikaros, K. and R. Shine. 1997. Sexual dimorphism in the tusked frog, Adelotus brevis (Anura: Myobatrachidae): the roles of natural and sexual selection. Biological Journal of the Linnean Society 60: 39–51.
Kok, P. J. R. and M. Kalamandeen. 2008. Introduction to the Taxonomy of the Amphibians of Kaieteur National Park, Guyana. ABC Taxa Volume 5. Brussels. Belgian Development Cooperation, Royal Belgian Institute of Natural Sciences. 278 pp.
Lee, J. C. 1982. Accuracy and precision in anuran morphometrics: artifacts of preservation. Systematic Zoology 31: 266–281.
Lee, J. C. 2001. Evolution of a secondary sexual dimorphism in the toad, Bufo marinus. Copeia 4: 928–935.
Liao, W. B. and X. Lu. 2010. Age structure and body size of the Chuanxi Tree Frog Hyla annectans chuanxiensis from two different elevations in Sichuan (China). Zoologischer Anzeiger, Journal of Comparative Zoology 248: 255–263.
López-Juri, G., M. Chiaraviglio, and G. Cardozo. 2018. Macroevolution of sexual size dimorphism and reproduction-related phenotypic traits in lizards of the Chaco Domain. BMC Ecology and Evolution 18: 186.
Lovich, J. E. and J. W. Gibbons. 1992. A review of techniques for quantifying sexual size dimorphism. Growth, Development, and Aging 56: 269–281.
Martins, M. and Haddad, C. F. B. 1988. Vocalizations and reproductive behaviour in the smith frog Hyla faber Wied (Amphibia: Hylidae). Amphibia-Reptilia 9: 49–60.
Molina, C. 2004. Reproduction of Pleurodema brachyops (Anura, Lectodactylidae) in the plains of the State of Apure, Venezuela. Memoria de la Fundación La Salle Ciencias Naturales 2004 158: 117–125.
Monnet, J. M. and M. I. Cherry. 2002. Sexual size dimorphism in anurans. Proceedings of the Royal Society of London Series B 269: 2301–2307.
Morrison, C. and J. M. Hero. 2003. Geographic variation in life history characteristics of amphibians: a review. Journal of Animal Ecology 72: 270–279.
Olalla-Tárraga, M. A. and M. A. Rodríguez. 2007. Energy and interspecific body size patterns of amphibian faunas in Europe and North America: anurans follow Bergmann’s rule, urodeles its converse. Global Ecology and Biogeography 16: 606–617.
Özdemir, N., A. Altunışık, T. Ergül, S. Gül, M. Tosunoğlu, G. Cadeddu, and C. Giacoma. 2012. Variation in body size and age structure among three Turkish populations of the treefrog Hyla arborea. Amphibia-reptilia 33: 25–35.
Pesarakloo, A., M. Najibzadeh, A. Gharzi, N. Rastegar-Pouyani, and E. Rastegar-Pouyani. 2018. Sexual dimorphism and geographic variation of body size in the Mountain Brown Frog (Rana macrocnemis Boulenger, 1885) in Iran. South-Western Journal of Horticulture, Biology, and Environment 9: 1–13.
Ponssa, M. L. and J. S. Barrionuevo. 2012. Sexual dimorphism in Leptodactylus latinasus (Anura, Leptodactylidae): nasal capsule anatomy, morphometric characters and performance associated with burrowing behavior. Acta Zoologica 93: 57–67.
Prado, C. P. A., M. Uetanabaro, and C. F. B. Haddad. 2002. Description of a new reproductive mode in Leptodactylus (Anura, Leptodactylidae), with a review of the reproductive specialization toward terrestriality in the genus. Copeia 4: 1128–1133.
Reading, C. J. and G. M. Jofre. 2003. Reproduction in the nest building vizcacheras frog Leptodactylus bufonius in central Argentina. Amphibia-Reptilia 24: 415–427.
Rohlf, F. J. 1990. Morphometrics. Annual Review Ecology Systematics 21: 299–316.
Rojas-Runjaic, F. J. M., E. E. Infante-Rivero, and C. L. Barrio-Amorós. 2011. A new frog of the genus Aromobates (Anura, Dendrobatidae) from Sierra de Perijá, Venezuela. Zootaxa 2919: 37–50.
Rojas-Runjaic, F. J. M., E. E. Infante-Rivero, P. E. Salerno, and F. L. Meza-Joya. 2018. A new species of Hyloscirtus (Anura, Hylidae) from the Colombian and Venezuelan slopes of Sierra de Perijá, and the phylogenetic position of Hyloscirtus jahni (Rivero, 1961). Zootaxa 4382: 121–146.
Rojas-Runjaic, F. J. M., C. L. Barrio-Amorós, C. Molina, J. C. Señaris, and I. Fedón. 2008. Amphibia, Anura, Hylidae, Scarthyla vigilans: range extensions and new state records from Delta Amacuro and Miranda states, Venezuela. Check List 4: 507–511.
Salthe, S. N. and J. S. Mecham. 1974. Reproductive and courtship patterns. Pp. 309–521 in B. Lofts (ed.), Physiology of the Amphibia. Vol. II. New York. Academic Press Inc.
Sánchez-Dávila, G. 2017. Mapa de Ubicación Relativa de la Cordillera de la Costa [Mapa]. Wikimedia Commons.Electronic Database accessible at https://commons.wikimedia.org/wiki/File:Cordillera_de_la_Costa_en_Venezuela.svg Licencia: Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0). Captured on 20 January 2025.
Santini, L., A. Benítez López, G. F. Ficetola, and M. A. J. Huijbregts. 2018. Length-mass allometries in amphibians. Integrative Zoology 13: 2–45.
Schäuble, C. S. 2004. Variation in body size and sexual dimorphism across geographical and environmental space in the frogs Limnodynastes tasmaniensis and L. peronii. Biological Journal of the Linnean Society 82: 39–56.
Señaris, J. C., M. Lampo, F. J. M. Rojas-Runjaic, and C. L. Barrio-Amorós. 2014. Illustrated Guide to the Amphibians of Canaima National Park, Venezuela. Caracas. Ediciones Instituto Venezolano de Investigaciones Científicas (IVIC). 264 pp.
Señaris, J. C., M. M. Aristeguieta Padrón, H. Rojas Gil, and F. J. M. Rojas-Runjaic. 2018. Illustrated Guide to the Amphibians and Reptiles of the Caracas Valley, Venezuela. Caracas. Ediciones Instituto Venezolano de Investigaciones Científicas (IVIC). 348 pp.
Sever, D. A., M. Herrboldt, and N. L. Staub. 2024. Hormones, sex accessory structures, and secondary sexual characteristics in amphibians: A focus on breeding glands. Pp. 105–119 in D. O. Norris and K. H. Lopez (eds.), Hormones and Reproduction of Vertebrates, Volume 2, Amphibians. 2nd Edition. New York. Academic Press Inc. 316 pp.
Sexton, O. 1958. Observations on the life history of a Venezuelan frog, Atelopus cruciger. Acta Biologica Venezuelica 2: 235–242.
Shine, R. 1979. Sexual selection and sexual dimorphism in the Amphibia. Copeia 1979: 297–306.
Solano, H. 1987. Some aspects of the reproductive biology of the whistling toad Leptodactylus fuscus (Schneider) (Amphibia: Leptodactylidae). Amphibia-Reptilia 8: 111–128.
Smith, R. J. 1999. Statistics of sexual size dimorphism. Journal of Human Evolution 36: 423–459.
Székely, T., R. B. Freckleton, and J. D. Reynolds. 2004. Sexual selection explains Rensch’s rule of size dimorphism in shorebirds. Proceedings of the National Academy of Sciences (PNAS) 101: 12224–12227.
Teder, T. and T. Tammaru. 2005. Sexual size dimorphism within species increases with body size in insects. Oikos 108: 321–334.
Tejedo, M. 1988. Fighting for females in the toad Bufo calamita is affected by the operational sex ratio. Animal Behaviour 36: 1765–1769.
Urbani, F. and J. Rodríguez. 2004. Atlas Geológico de la Cordillera de la Costa, Venezuela. Caracas. Fundación Venezolana de Investigaciones Sismólogicas, Fundación Geos. 156 pp.
Vargas-Salinas, F. 2006. Sexual size dimorphism in the Cuban tree frog Osteopilus septentrionalis. Amphibia- Reptilia 27: 419–426.
Vera-Candioti, J., M. F. D’andrea, and C. M. J. Brodeur. 2019. Body condition of Pseudis minuta Günther, 1858 (Anura: Hylidae) inhabiting an agroecosystem from south Santa Fe Province, Argentina. Herpetology Notes 12: 13–17.
Viña, J. L. 2015. Characterization of the diet of Engystomops pustulosus (Anura: Leptodactylidae) during the reproductive season at Hacienda La Guáquira, Yaracuy State, Venezuela. Unpublished M.Sc. Dissertation. Universidad Central de Venezuela, Venezuela.
Watters, J., S. Cummings, R. Flanagan, and C. Siler. 2016. Review of morphometric measurements used in anuran species descriptions and recommendations for a standardized approach. Zootaxa 4072: 477–495.
Wells, K. D. 1977. The social behaviour of anuran amphibians. Animal Behaviour 25: 666–693.
Wells, K. D. 1978. Territoriality in the green frog (Rana clamitans): vocalizations and agonistic behaviour. Animal Behaviour 26: 1051–1063.
Wells, K. D. 2007. The Ecology and Behavior of Amphibians. Chicago. University of Chicago. 1400 pp.
Woolbright, L. L. 1983. Sexual selection and size dimorphism in anuran Amphibia. American Naturalist 121: 110–119.
Zelditch, M. L., B. L. Lundrigan, and T. Garland. 2004. Developmental regulation of skull morphology. I. Ontogenetic dynamics of variance. Evolution and Development 6: 194–206.
Zhang, X., J. L. Xiong, Y. Y. Lv, L. Zhang, and Y. Y. Sun. 2014. Sexual size and shape dimorphism in the Wushan salamander, Liua shihi (Liu, 1950) (Urodela: Hynobiidae). Italian Journal of Zoology 81: 368–373
Downloads
Published
Issue
Section
License
Copyright (c) 2026 ESALQ-USP
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
All material originally published in Phyllomedusa belongs to Escola Superior de Agricultura Luiz de Queiroz - Universidade de São Paulo. All contents are under a license of Creative Commons BY-NC-ND.
Impact Factor (JCR): 0.600
CiteScore: 1.0
