Bufonidae

Guayasamin, Juan M. & Funk, Chris, 2009, The amphibian community at Yanayacu Biological Station, Ecuador, with a comparison of vertical microhabitat use among Pristimantis species and the description of a new species of the Pristimantis myersi group, Zootaxa 2220, pp. 41-66 : 43

Family: Bufonidae

This group of toads contains some of the most familiar anurans, including the cane toad ( Rhinella marina ; previously Bufo marinus ) and the jambato ( Atelopus ignescens ). Most of them have a warty appearance and are diurnal, terrestrial, and have aquatic larvae (e.g., Rhinella , Atelopus ), but others are nocturnal, arboreal, and undergo direct development (e.g., Osornophryne ). Bufonids are found natively in all continents, except Australia (where it has been introduced) and Antarctica. The family Bufonidae contains 538 species (AmphibiaWeb 2009). The taxonomy of amphibians has undergone several recent changes and there is debate on which names should be used. For bufonids, we follow the general proposal by Frost et al. (2006), as modified by Chaparro et al. (2007). In YBS, there are two species of bufonids, Osornophryne guacamayo and Rhinella margaritifera (previously Bufo margaritifer ).

Osornophryne guacamayo (Plate 1). Described by Hoogmoed (1987). This species can be easily recognized by having a blackish dorsal coloration with, usually, two yellow-gray dorsolateral lines, which are not clearly differentiated from the rest of the dorsum; yellow venter with dark brown to black spots; dorsal skin of body and limbs with numerous tubercles of different sizes; limbs long and slender; fingers connected by a thick web; feet heavily webbed with Toe IV and V much longer than Toes I, II, and III; and by lacking parotoid glands and tympanum ( Hoogmoed 1987). At YBS, SVL in adult females is 36.1–39.3 mm (n = 3) and 22.7 mm in one adult male. Osornophryne guacamayo has been found on leaves during the night ( Table 1). Although most bufonids reproduce in water, O. guacamayo places its eggs on the ground, where they undergo direct development into froglets. At YBS, the only species that is likely to be confused with O. guacamayo is Rhinella margaritifera , which has a visible tympanum, parotoid glands, dorsolateral row of red tubercles (traits absent in O. guacamayo ), and lacks conspicuous webbing among fingers (present in O. guacamayo ). Additionally, in R. margaritifera , only Toe IV is elongated, whereas in O. guacamayo Toes IV and V are conspicuously longer that the rest of the toes.

Rhinella margaritifera (Plate 1). Described by Laurenti (1768). A moderate-sized toad distinguished by having dorsal skin scattered with tubercles, and a row of red conical tubercles that begins on the posterior edge of the parotoid gland and ends on the groin. The fingers lack webbing, whereas the toes are about onehalf webbed. This is a terrestrial and diurnal species that has a dorsal coloration that mimics leaf litter. At YBS, SVL in adult females is 57.4–68.7 mm (n = 4) and 40.9–46.1 mm (n = 5) in adult males. Within YBS, Rhinella margaritifera can only be confused with Osornophryne guacamayo (see previous species account).

Remarks: One of the oldest problem in the taxonomy of South American amphibians is the Rhinella margaritifera species complex. Hoogmoed (1986, 1989) recognized several species within this complex (previously referred to as the Bufo typhonius complex), but he did not formally recognize most of them. More recently, Fouquet et al. (2007) suggested that R. margaritifera might be composed of as many as 11 species. Herein, we use the name R. margaritifera realizing that it represents a species complex until the systematics of this group of toads is resolved.