Bronzed Frog, Hylarana temporalis

The Bronzed Frog (Hylarana temporalis) is a species of true frog located in the riparian evergreen forests of the Western Ghats, India, and the highlands of southwestern Sri Lanka. They are found abundantly on or close to the ground near the water. Individuals are not shy and react by jumping only when provoked. They are important prey of many species of snakes, including the vine snake and the Malabar pit viper.

The vomerine teeth are in two oblique series that stretch beyond the level of the hind edge of the choanae. Its head is depressed and triangular and the snout is subacuminate and prominent.

The fingers are moderately sized wherein the first extends beyond the second. The toes are nearly entirely webbed. The tips of the fingers and toes are dilated into well-developed disks. Its subarticular tubercles are well developed as well, while the inner metatarsal tubercle is oval shaped and blunt with a small and round outer metatarsal tubercle and no tarsal fold.

The skin of the frog is smooth or finely granulate above, with a narrow glandular lateral fold. While the dorsal regions are a brown color, the loreal and temporal regions, and occasionally the sides of the body are a dark brown color. A white colored labial band can be seen as well. The limbs of this frog have dark cross bands. The males have internal vocal sacs and oval flat glands on the inner side of their arms. The males also have a strong pad on the inner side of the first finger, covered during the breeding season with a greyish brown and velvet-like horny layer.

The common name of this species comes from the small bronze-colored strips that appear on either side of the lower jaw, between the snout and the posterior point of the forelimbs, within a week after metamorphosis. The species has been referred to by a number of names, including Hylarana Malabarica, Rana Flavescens, Rana Malabarica, Hylorana Malabarica, Hylorana Temporalis, Hylorana Flavescens, Rana Temporalis, and Sylvirana Temporalis.

This frog is distributed throughout the Western Ghat Mountains of South India, along Kerala, Tamil Nadu, Karnataka, and Maharashtra. They are primarily found on edges of rocky streams at low altitudes. They sit out in the open on flat rocks and stones, and leap, frequently to a considerable distance, into the water when they are disturbed.

It typically breeds along the edges of gently flowing and/or in pockets of still water along streams. The muddy color of the tadpoles matches well with the substratum of the streams. The oral armature is well-suited for grazing at the bottom of the water. In near permanent water, the tadpoles might have longer metamorphic duration, around three to four months, to enable body growth and emergence of larger and stronger froglets.

Image Caption: Bronzed Frog, Rana temporalis at Wynaad, India. Credit: L. Shyamal/Wikipedia (CC BY-SA 2.5)