ABSTRACT
Crawfish Frogs and Gopher Frogs are so secretive that they are generally only encountered, and therefore collected, as noisy breeding adults. The major distinction is between Pickerel Frogs and the Gopher Frog/Crawfish Frog group. Pickerel Frogs are more slender and have relatively narrower heads and longer legs than either Gopher Frogs or Crawfish Frogs. In Crawfish Frogs, this growth zone slows down even more, presenting—as with all Nenirana species—a negative allometry in head length, but producing a positive allometric change in head width—a reversal of the ancestral pattern. A rounded snout offers the opportunity for Crawfish Frogs to seal a cylindrical burrow with their heads. In effect, when a Crawfish Frog is in its burrow facing up, toward the opening of the burrow, and lowers its head at the approach of a predator, its bony, rounded head acts as a hatch that seals the frog’s soft body from a potential predator.
