|Figure 1. Two male Espadarana prosoblepon as found grappling from the overhanging branch. Male A is on top, and male B is towards the bottom of the image. The white arrow indicates the blue humeral spine of male A|
There are currently about 150 species of glass frogs in the family Centrolenidae, which range throughout tropical rain forests in Central and South America (Frost, 2014). Some species of glass frog are known to engage male-male combat where males dangle by their toes and grapple venter to venter for extended periods of time (Jacobson, 1985; Bolivar et al., 1999; Hutter et al., 2013). Humeral spines, present in the males of some glass frog species, are thought to be involved in this ritualized combat behavior. Here we present photographic evidence that the spines are indeed used in this combat behavior in one species, Esapadarana prosoblepon (Guyasamin et al.,
|Figure 2. Two Espadarana prosoblepon immediately after separating from the grappling behavior. Male A is at the top of the image; Male B is at the bottom. The arrow indicates the humeral spine of Male A.|
Alexander R. Krohn and Jamie Voyles. 2014. A Short Note on the Use of Humeral Spines in Combat in Espadarana prosoblepon (Anura: Centrolenidae). Alytes. 31(3-4); 77-82.