FAMILY PTYCHADENIDAE – Grass frogs

Ptychadena anchietae (Rooiruggraspadda)

Very prominent tympanum. The snout is paler than the rest of the body, forming a pale triangle

I have found the same individual at the same place night after night

Their hearing or detection of vibrations must be very well developed. They will stop calling when I approach them when I’m about 50-75 meters away.

These grass frogs can jump several meters at the slightest disturbance

Black markings on the back of the thighs tend to fuse to form bands on a yellowish background

Males have two vocal sacs, tucked into lateral pouches oblique to the jaw-line, clearly visible in this individual

Amplexus *

The mating call of Ptychadena anchietae can go on and on through the night. The males have two vocal sacs that are tucked into pouches oblique to the jaw-line.

I have been lucky a few times to capture the calls. This is a view from the top, with both vocal sacs visible.

TERMINOLOGY:

Amplexus is a term used to define mating in frogs. It is a reproductive position used by frogs to replicate externally. The male frog will clasp the female from the back, stimulating the release of eggs. After the egg has been released, the male frog fertilizes each egg with the sperm cells.

Tympanum: The tympanic membrane is a thin membrane that separates the frog’s outer and inner ear. It is located behind the eyes. It allows it to hear both in the air and below the water.

Please contact me should you find a species that I have misidentified.

For more information:

1. Frogs Of Southern Africa, A Complete Guide, Louis du Preez & Vincent Carruthers. Struik Nature 2017