Herpetology Notes, volume 5: 9-10 (2012) (published online on 14 January 2012)
On the occurrence of thanatosis in Elachistocleis piauiensis Caramaschi and Jim, 1983 (Anura: Microhylidae) Maria Juliana Borges-Leite¹*, Diva Maria Borges-Nojosa¹, João Fabrício Mota Rodrigues¹ and Flávia Michele Vasconcelos do Prado²
Amongst the large variety of amphibian defensive behaviors, thanatosis (also known as death feigning) is a common survival strategy (Lutz and Lutz, 1939; Sazima, 1974; Haddad and Sazima, 1992). The onset of thanatosis is usually stimulated by direct contact of a predator with the amphibian. Initially, the individual swells or retracts the body and stays motionless, pretending to be dead, in order to make the predator lose interest. Probably, this type of behavior has evolved as a reaction to general slow amphibian movement, which does not permit effective escape during predation (Duellman and Trueb, 1986; Stebbins and Cohen, 1995). Currently, the genus Elachistocleis Parker, 1927 from the subfamily Gastrophryninae comprises thirteen known species. The members of the genus range east of the Andes mountain chain from Panama and Colombia southward to southern Paraguay, southeastern Bolivia, central Argentina, Brazil and Uruguay. Eleven species occur in Brazil: E. bicolor, E. bumbameuboi, E. carvalhoi, E. cesarii, E. erythrogaster, E. helianneae, E. magnus, E. matogrosso, E. ovalis, E. piauiensis and E. surumu (Frost, 2011). Elachistocleis piauiensis 1 Programa de Pós-Graduação em Ecologia e Recursos Naturais, Universidade Federal do Ceará. Núcleo Regional de Ofiologia, Universidade Federal do Ceará (NUROF-UFC) Campus do Pici, Bloco 905, CEP 60.455-760, Fortaleza - CE, Brazil. 2 Superintendência Estadual do Meio Ambiente (SEMACE). Rua Jaime Benévolo, 1400, Bairro de Fátima, CEP 60050081, Fortaleza, CE, Brazil. *Corresponding author; e-mail:
[email protected]
Caramaschi and Jim, 1983 (also known as the common oval frog) is restricted to the states of Piauí, Maranhão and Ceará (Frost, 2011). This species is characterized by a ovoid body shape, triangular head, pointed snout, short and robust legs and a snout vent length of approximately 35 mm (Caramaschi and Jim, 1983). Observations of thanatosis in E. piauiensis reported herein took place during January-May 2009 within the municipality of São Gonçalo do Amarante, west coast of Ceará State, Brazil (S 03º30’54,9” / W 38º55’07,7”). On four different occasions we captured one individual adult E. piauiensis (27, 34, 26, 25 mm SVL, respectively) during pitfall traps checks located on fixed dunes with mata de tabuleiro vegetation which is mainly composed of the families Cactaceae, Rhamnaceae, Poligonaceae and Anacardiaceae (Figueiredo, 1997). All four E. piauiensis displayed death feigning while being manipulated for photographs and measurements (i.e. during fixation by the hind limbs or mid-body) following a failed escape attempt. While exposing their abdomen, individuals stretched their front legs and retracted their hind limbs close to the body (Fig. 1 and 2). The behavior lasted for approximately five minutes, after which each individual returned to a normal body position. Thanatosis has been reported to occur in several families of amphibians including the Bufonidae (Zamprogno, Zamprogno and Teixeira, 1998), Cycloramphidae (Hartmann et al., 2002), Leptodactylidae (Toledo, Tozetti and Zina, 2005), Ranidae (Gramapurohit, Shanbhag and Saidapur, 2001) and especially
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Figure 1. Adult Elachistocleis piauiensis displaying thanatosis during handling.
Figure 2. Elachistocleis piauiensis feigning death after being handled.
Hylidae (Sazima, 1974; Azevedo-Ramos, 1995) indicating that it is a common defensive behavior. Records of death feigning within the family Microhylidae have only been reported for the species Elachistocleis erythrogaster (Kwet and Solé, 2002) and E. cf. ovalis (Kokubum and Menin, 2002; Toledo, 2004). This paper presents a new record for a third species of this genus, providing unique information for E. piauiensis.
Frost, D.R. (2011): Amphibians Species of the World: an online reference. Version 5.5 (31 January, 2011). Electronic Database accessible at http://research.amnh.org/vz/herpetology/amphibia. Visited on 10 October 2011. Gramapurohit, N.P., Shanbhag, B.A., Saidapur, S.K. (2001): Rana curtipes (Jerdon): Death feigning. Herp. Rev. 32: 103. Haddad, C.F.B., Sazima, I. (1992): Anfíbios Anuros da Serra do Japi. In: Historia Natural da Serra do Japi: Ecologia e preservação de uma área florestal no sudeste do Brasil, p.88-211. Morellato, L.P.C., Ed., UNICAMP/FAPESP, Campinas, Brasil. Hartmann, M.T., Hartmann P.A., Prado C.P.A., Garcia P.C.A. (2003): Cycloramphus boraceiensis (Flattened Waterfall Frog). Defensive behavior. Herp. Rev. 34 (1): 50. Kokubum, M.N.C., Menin, M. (2002): Elachistocleis ovalis (NCN). Defensive behavior. Herp. Rev. 33: 198. Kwet, A., Sole, M. (2002): Elachistocleis erythrogaster. Defensive behavior. Herp. Rev. 35(1): 46. Lutz, A., Lutz, B. (1939): Notes on the genus Phyllomedusa Wagler. An. Acad. Bras. Ciênc. 11(3): 219-263. Sazima, I. (1974): Experimental predation on the leaf-frog Phyllomedusa rohdei by the water snake Liophis miliaris. J. Herp. 8(4): 376-377. Stebbins, R.C., Cohen, N.W. (1995): A Natural History of Amphibians. Princeton University Press. Toledo, L.F. (2004): Elachistocleis cf. ovalis (Common Oval Frog). Death feigning. Herp. Rev. 35(4): 371-372. Toledo, L.F., Tozetti, A., Zina, J. (2005): Leptodactylus labyrinthicus (Pepper Frog): Repertoire of defensive behaviours. Herp. Bull. 91: 29-31. Zamprogno, C., Zamprogno, M.G.F., Teixeira, R.L. (1998): Bufo paracnemis (Sapo-boi). Death feigning. Herp. Rev. 29: 96-97.
Acknowledgements. We thank Ana Paula Marques for the English review; Wouter Beukema for a critical review of the manuscript; and IBAMA (Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis) for the collection permit.
References Azevedo-Ramos, C. (1995): Defense behaviors of the Neotropical treefrog Hyla geographica (Anura, Hylidae). Rev. Bras. de Biol. 55: 45-47. Caramaschi, U., Jim, J. (1983): A new microhylid frog, genus Elachistocleis (Amphibia, Anura) from northeastern Brazil. Herpetologica 39(4): 390-394. Duellmann, W.E., Trueb, L. (1986): Biology of Amphibians. McGraw-Hill Book Company, New York, USA. Figueiredo, M.A. (1997): Unidades Fitoecológicas. In: Atlas do Ceará, p.28-29. Iplance, Ed., Fundação Instituto de Planejamento do Ceará/Governo do Estado do Ceará, Fortaleza, Brasil.
Accepted by Wouter Beukema
