Indirana semipalmata

Indirana semipalmata is a species of frog native to the Western Ghats region of southern India. They are frogs of small size, reaching lengths of about 1.4 inches from snout to vent. The species breeds during the monsoons. They lay their eggs on moist rocks and tree bark. Their tadpoles are terrestrial; they hatch, feed, and undergo metamorphosis without ever entering any standing bodies of water.

The snout is rounded with moderate canthal ridges. The space between the eyes is around the same width as each of the upper eyelids. The tympanum and the eyes are the same diameter. It has vomerine teeth with two slightly oblique oval groups located just behind the level of the rear edge of the choanae. The males lack vocal sacs.

The first fingers of the forelimbs stretch slightly beyond the second. At the ventral surface of each joint are well-developed tubercles and there is a single oval tubercle along the inner metatarsals. If the hind limbs are stretched forwards the length of the body, the tibiotarsal articulation reaches the snout.

The skin of this species has short and longitudinal glandular folds on the back; while on the bottom surface, it is smooth. It is mostly brown in coloration with the throat and chest mottled and lighter in color. The temples and the sides of the eyes are black. A dark colored bank is also present between the eyes at the top of the head. The limbs have dark stripes running across them.

The tadpoles have finless tails and strongly hooked beaks that make them able to skip along hard surfaces rather than to swim. Partially metamorphosed tadpoles can leap with their hind limbs. Observations on the feeding behaviors on the tadpoles also reveal that they consume bark substrate, the first known instance of any tadpoles to do so. It is presumed that they feed on the plankton growing on the bark.

Image Caption: Indirana semipalmata – ID by K V Gururaja. Frog found in Shola at Talakaveri, Coorg, India. Credit: L. Shyamal/Wikipedia (CC BY 2.5)