First report of overwintering in tadpoles of Odontophrynus occidentalis (Anura: Odontophrynidae) from Argentina

Abstract

Fellers et al. (2001) defined overwintering in anuran larvae as spending the winter (i.e., JuneSeptember in the Southern Hemisphere) as tadpoles. Several environmental factors influence growth and development rates in larval anurans (Saha and Grupta 2011). Among them are temperature (Kaplan 1980, Saidapur and Hoque 1995), photoperiod (Saidapur 1989), rainfall (Lynch and Wilczynski 2005), food quality (Alvarez and Nicieza 2002), and hydroperiod (Ryan and Winne 2001). We know little about larval overwintering sites in anurans and this is one of the major gaps in our understanding of amphibian ecology. Because of this, it is not possible to make a universal statement about the physicochemical environmental requirements of overwintering amphibians. Two factors that should be important are temperature and dissolved oxygen (Glenn et al. 2008). Overwintering tadpoles have been reported in at least 17 genera and 40 species of frogs in the northern and southern hemispheres. Included are: Rana (= Lithobates), Ascaphus, Alytes, Alsodes, Atelognathus, Batrachyla, Hylorina, Calyptocephalella, Chaltenobatrachus, and Polypedates (Martof 1956, Bradford 1983, Díaz and Valencia 1985, Thiesmeier 1992, Úbeda 1998, Úbeda et al. 1999, Hulse et al. 2001, Logares and Úbeda 2004, 2006, Cuello and Perotti 2006, Tattersall and Ultsch 2008, Navas et al. 2010, Basso et al. 2011, Hsu et al. 2012). In South America, larval overwintering has only been reported for temperate species such as Alsodes gargola Gallardo, 1970 (Logares and Úbeda 2004, 2006), A. tumultuosus Veloso et al., 1979, and A. montanus (Lataste, 1902) (Díaz and Valencia 1985) and two species of Atelognathus [A. nitoi Barrio, 1973 (Úbeda et al. 1999) and A. patagonicus (Gallardo, 1963) (Cuello and Perotti 2006, Cuello et al. 2014)]. Basso et al. (2011) suggested that overwintering might occur in Chaltenobatrachus grandisonae (Lynch, 1975). Herein, we report the occurrence of overwintering in tadpoles of Odontophrynus occidentalis.