Journal of Natural History Vol. 46, Nos. 43–44, November 2012, 2725–2733 Population dynamics of tadpoles of Crossodactylus gaudichaudii (Anura: Hylodidae) in the Atlantic Rainforest of Ilha Grande, southeastern Brazil M. Almeida-Gomes a *, R.C. Laia a , F.H. Hatano b , M. Van Sluys c and C.F.D. Rocha c a Programa de Pós-Graduação em Ecologia e Evolução, Departamento de Ecologia, Universidade do Estado do Rio de Janeiro, Rua São Francisco Xavier, 524, CEP 20550-900, Rio de Janeiro, RJ, Brazil; b Departamento de Biologia Animal, Universidade Federal Rural da Amazônia, Rua AS/N quadra especial, Cidade Nova, CEP 68.515-000, Parauapebas, PA, Brazil; c Departamento de Ecologia, Universidade do Estado do Rio de Janeiro, Rua São Francisco Xavier, 524, CEP 20550-900, Rio de Janeiro, RJ, Brazil (Received 6 January August 2012; final version received 30 July 2012; printed 31 October 2012) We studied the temporal distribution of tadpoles of Crossodactylus gaudichaudii, and their relationship with rainfall, in a Brazilian Atlantic Rainforest area. There is no previous information about the population dynamics of tadpoles from this species. We sampled 60 m along streams between May 2002 and April 2005. Tadpoles in initial stages of development (up to stage 25) were present in all months of the year and represented 80.4% of those sampled. This indicates a continuous recruitment of new individuals in the aquatic environment. Tadpoles in final stages of development (stages 42–46) represented only 5% of those sampled, which may be the result of higher mortality in the early development stages. Body length of tadpoles varied among developmental stages and between seasons. Tadpole density was higher in the rainy season than in the dry season, and was significantly related to rainfall in the area. Keywords: Amphibia; density; rainfall; rocky streams; temporal distribution Introduction Anuran tadpoles grow and develop in a wide array of microhabitats, such as perma- nent or ephemeral ponds, rivers, streams, bromeliads and depressions in tree trunks (Duellman and Trueb 1986; Loman 2002; Haddad and Prado 2005; Eterovick and Barata 2006). In the Atlantic Forest Biome, which is one of the most threatened bio- diversity hotspots in the world, more than 480 species of amphibians are found and about 80% of them have aquatic larvae (Mittermeier et al. 2005; Becker et al. 2007). Approximately 30% of the reproductive modes of anurans in the Atlantic forest involve tadpoles associated with streams (Haddad and Prado 2005). Therefore studies address- ing aspects of the ecology of tadpoles in stream environments need to be urgently conducted. The limited amount of information on the ecology of tadpoles in tropical streams, indicates that tadpoles can influence the food web in these environments. Therefore, a decline of stream-dwelling amphibian populations could affect the structure and functioning of aquatic systems (Ranvestel et al. 2004; Iwai et al. 2009). Although most species of amphibians in tropical regions have reproductive activity restricted *Corresponding author. Email: almeida.gomes@yahoo.com.br ISSN 0022-2933 print/ISSN 1464-5262 online © 2012 Taylor & Francis http://dx.doi.org/10.1080/00222933.2012.717643 http://www.tandfonline.com