Photo: N. Iwai
Are you a lover and not a fighter? Not this frog! Japanese researcher Noriko Iwai of the University of Tokyo discovered that the rare and endangered Japanese Otton frog (Babina subaspera) has a special spiked pseudo-thumb that helps it as both a lover and a fighter:
... field observations in southern Japan's Amami islands, the frog's only home, showed that the males indeed jab their spikes into the sides of the females to hold on during amplexus — a form of pseudocopulation in which the males mount the female and fertilize her eggs as, or soon after, she lays them.
But it appears the frogs also use the spikes for male-to-male combat over females and breeding nests. The researcher found they wrestle with each other in an embrace while stabbing at each other with the spines.
"While the pseudo-thumb may have evolved for mating, it is clear that they're now used for combat," Iwai explained in a statement. "The males demonstrated a jabbing response with the thumb when they were picked up, and the many scars on the male spines provided evidence of fighting."
Megan Gannon of LiveScience has more: Link
See also: 30 Strangest Animal Mating Habits