Бронзовая лягушка Шри-Ланки (Indosylvirana temporalis)

Species of amphibian

Indosylvirana temporalis, commonly known as the bronzed frog or Günther's golden backed frog, is a species of true frog found in the riparian evergreen forests of the highlands of southwestern Sri Lanka. They are found abundantly on or close to the ground near 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. Some related species found in the Western Ghats of India were formerly included in this species but were separated in a 2014 study.

Its vomerine teeth are present in two oblique series that extend beyond the level of the hind edge of the choanae. Its head is depressed and triangular; the snout is subacuminate and prominent. The canthus rostralis is angular and the loreal region is nearly vertical and strongly concave. The interorbital space is as broad as the upper eyelid or rather broader in some cases. The tympanum is very distinct and is as large as the eye, but sometimes a little smaller. The digits are moderate wherein the first extends beyond the second. The toes are almost entirely webbed. The tips of the fingers and toes are dilated into well developed disks. Its subarticular tubercles are well developed, while the inner metatarsal tubercle is oval and blunt with a small, round, outer metatarsal tubercle and no tarsal fold. The tibiotarsal articulation reaches from the nostril to the tip of the snout and sometimes a little beyond it. The skin of these frogs is smooth or finely granulate above, with a narrow glandular lateral fold. While the dorsal regions are brown coloured, the loreal and temporal regions, and sometimes also the sides of the body are dark brown in colour. A white labial band can also be seen. Its limbs have dark cross bands. The ventral parts are typically white, with the throat and breast more or less speckled with brown spots. Males have internal vocal sacs and oval flat glands on the inner side of their arms. Males also have a strong pad on the inner side of the first finger, covered during the breeding season with a greyish brown velvet like horny layer.

The frogs' common name is derived from the small bronze coloured 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 several names, including Hylarana malabarica (incorrectly), Rana flavascens, Rana malabarica, Hylorana malabarica, Hylorana temporalis, Hylorana flavescens, Rana temporalis, Sylvirana temporalis, and Hylarana temporalis.

The bronzed frog is found only in Sri Lanka. They are chiefly found on edges of rocky streams at low altitude. They sit exposed on flat rocks and stones, and leap, often to a considerable distance, into the water when disturbed.

Following the south west monsoon rains that lash the Indian west coast from the first week of June, innumerable anuran species breed in ephemeral ponds and puddles. This incidentally puts the individuals in severe intra and interspecific competition for food and space, and also to predation pressures. Microhabitat selection is, therefore, an important strategy employed by the anuran species including the bronzed frog. Tadpoles of bronzed frogs, which possess ventral mouths, predominantly occupy the substrate zone, and in greater numbers at the night than in daytime.

Tadpoles of bronzed frogs show a social aggregation phenomenon. However, the nature and significance of this behaviour is yet to be understood.

Kin recognition is widespread in organisms as diverse as social insects, fishes, amphibians, birds, and mammals, and even plants. Kin recognition behaviour in bronzed frog seems to be associated with growth regulation as their growth and metamorphosis is enhanced when reared with siblings than with nonsiblings. Tadpoles of bronzed frog exhibit IFD behaviour while foraging, regardless of whether they are siblings or nonsiblings in a group, which correlates well with their group living strategy in nature.

Tadpoles of bronzed frogs detect food based on chemical cues and not visually, indicating that chemical perception predominates visual senses in I. temporalis tadpoles.