Ceratophrys stolzmanni (Steindachner, 1882)

Cuadrado, Stefania S., Loor, Yelsin A. & Narváez, Andrea E., 2020, Herpetofauna of Engabao, Playas Canton, Ecuador, with notes on the occurrence of Ceratoprhys stolzmanni (Steindachner, 1882), Check List 16 (3), pp. 665-674 : 670-671

Ceratophrys stolzmanni (Steindachner, 1882)

Figure 3A, B

Material examined. ECUADOR, province of Guayas, Playas Canton, Engabao • 1 specimen (sex undeter- mined), 49 mm; moderate vegetation near a waterbody;

02°36′24″S, 080°26′03″W; 12 m a.s.l; 1 Mar. 2019; Stefa- nia S. Cuadrado, Yelsin A. Loor leg.; UG-AN103. 1 indi- vidual (sex undetermined), 54 mm; moderate vegetation near a waterbody; 02°36′24″S, 080°26′03″W; 12 m a.s.l; 1 Mar. 2019; Stefania S. Cuadrado, Yelsin A. Loor leg.; UG-AN104.

Identification. Ceratophrys stolzmanni differs from all species which inhabit the Ecuadorian coast in having an extremely wide head and mouth, and in bearing dark markings on the backs. The SVL of this species ranges from 48 to 82 mm. The body color varies from brown to green, both dark and light. The soles of the feet have spadices, which these frogs use to bury themselves. It differs from Ceratophrys cornuta and Ceratophrys testudo in lacking horn-shaped dermal appendages on the eyes and having keratinized appendages on the feet ( Lynch 1982; Rodríguez and Duellman 1994).

In this study, we found only two individuals, and both were at the same site. These were in the remnant patches of dry thorn scrub on the farm. One individual exhibited a dark brown ( Fig. 3A) dorsal pattern, while the other exhibited a dark green dorsal pattern ( Fig. 3B). They were around small puddles after a rain. These individuals were in the same area, separated by 1 m, at 19:00. Previous studies have reported that this species is cannibalistic and that it also feeds on other frogs like Trachycephalus jordani and on snakes like Leptodeira septentrionalis . We commonly found L. septentriolis during our surveys, and this species could be a feeding resource for C. stolzmani ( Székely et al. 2019) .

Distribution notes. Ceratophrys stolzmani is known to occur in southwestern Ecuador, in the provinces of Manabí, Santa Elena, Guayas, and El Oro, and in Tumbes Department, northwestern Peru ( Frost 2016). The previously known localities, both in Ecuador, nearest to our site are Playas, Guayas, and Loma Alta, Santa Elena; these are 18 km southwest and 86 km northeast of our site, respectively. These earlier-reported localities are the sources of the paratypes used for the species’ description by Peters (1967), who mentioned that there was only the dark-brown (reddish brown or darker black) morph in Playas, but we report not only this brown morph but also the light-green morph with dark marks ( Fig. 3). The next closest localities are Cerecita, Guayaquil Canton, 35.4 km to the northeast, and Bosque Protector Cerro Blanco 67.5 km to the northeast. ( Figure 1). Ceratophrys stolzmanni has been previously recorded from three types of ecosystems: dry thorn scrub (Manabí, Guayas province; 123 km from Engabao), trop- ical dry forest (Cerro Blanco, Guayas province, 67.51 km from Engabao, and Reserva Ecológica Arenillas, El Oro province, 104 km from Engabao), and garua forest (Loma Alta, Santa Elena province; 86 km from Engabao) (Appendix, Table A1).