FOUR-EYED WEEPING FROG Physalaemus biligonigerus
Frogs of the genus Physalaemus are widespread and common and are locally nicknamed "racing car frogs" on account of their strange songs which sound just like a racing car speeding past! Males croak whilst floating in shallow water, tilting backwards and forwards as they pound out their rhythm! They are burrowing frogs and possess a tubercle on the foot which acts as a sort of "spade". The two black spots at the base of the legs are used as a defence against predators, the frogs raising up the hind parts so that they look like two eyes, hence the alternative name "False-eyed Frog". Note the shortened snout of this species, a useful identification character when separating from other members of the genus - it is otherwise extremely variable!
Click on the images to enlarge them.
Gallery 1 - Dark adult
FIGURE 1a - (FPANF97PH) Dark adult, Fortín Boquerón, Departamento Presidente Hayes (Paul Smith November 2008).
FIGURE 1b - (FPANF98PH) Same individual dorsal view (Paul Smith November 2008).
FIGURE 1c - (FPANF99PH) Same individual flash colours (Paul Smith November 2008).
FIGURE 1d - (FPANF100PH) Same individual ventral view (Paul Smith November 2008).
FIGURE 1e - (FPANF101PH) Same individual forefoot (Paul Smith November 2008).
FIGURE 1f - (FPANF102PH) Same individual hindfoot (Paul Smith November 2008).
FIGURE 1a

FIGURE 1a
FIGURE 1b

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FIGURE 1c

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FIGURE 1d

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FIGURE 1f
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Gallery 3 - Variants
FIGURE 3a - (FPANF625PH) Adult black striped, Fortín Toledo, Departamento Boquerón (Paul Smith October 2013).
FIGURE 3b - (FPANF626PH) Same individual as (FPANF625PH) dorsal (Paul Smith October 2013).
FIGURE 3c - (FPANF627PH) Same individual as (FPANF625PH) flash colours (Paul Smith October 2013).
FIGURE 3d - (FPANF628PH) Same individual as (FPANF625PH) ventral (Paul Smith October 2013).
FIGURE 3e - (FPANF629PH) Adult red marbled, Fortín Toledo, Departamento Boquerón (Paul Smith October 2013).
FIGURE 3f - (FPANF630PH) Same individual as (FPANF629PH) dorsal (Paul Smith October 2013).
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FIGURE 3f
Gallery 2 Uniform Adult
FIGURE 2a - (FPANF568PH) Uniform adult lateral view, Cerro León, Departamento Alto Paraguay (Paul Smith July 2012).
FIGURE 2b - (FPANF569PH) Same individual as (FPANF569PH) dorsal (Paul Smith July 2012).
FIGURE 2c - (FPANF570PH) Same individual as (FPANF569PH) showing flash colours (Paul Smith July 2012).
FIGURE 2d - (FPANF571PH) Same individual as (FPANF569PH) ventral (Paul Smith July 2012).
FIGURE 2e - (FPANF103PH) Uniform adult lateral view, Laguna Capitán, Cuenca Upper Yacaré Sur (Paul Smith September 2006).
FIGURE 2f - (FPANF104PH) Dorsal view of same individual (Paul Smith September 2006).
FIGURE 2g - (FPANF105PH) Male singing, PN Tte Enciso, Departamento Boquerón (Paul Smith October 2009).
VIDEO - (FPANF109VI) Male singing and female, PN Tte Enciso, Departamento Boquerón (Paul Smith October 2009).
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FIGURE 2g

FIGURE 2g
Physalaemus biligonijerus Click the links to hear the calls.
1 (FPANF110RE) Song Recorded Cuenca Upper Yacaré Sur, Departamento Boquerón (Paul Smith October 2008)
2 (FPANF653RE) Chorus Recorded Fortín Boquerón, Departamento Boquerón (Paul Smith October 2013)