Description
Microhyla karunaratnei is a small sized frog with snout vent length of 15.8 – 19.1 mm in males and 19.1 mm in females. It is distinguished from all other Microhyla species known from Sri Lanka, western and southern India and the Andaman Islands by the combination of the following characters: median cleft on dorsal side of digits (vs. digits entire); venter marbled in black and white in living specimens and grey-brown and white in alcohol-preserved specimens (vs. venter uniformly coloured) (Fernando and Siriwardhane 1996).

Colour in life: pinkish grey-brown with a blackish lateral stripe extending from the eye to the groin,uninterrupted above the shoulder; the dorsal margin of this strip is distinct, but ventrally it breaks up and becomes indistinguishable from the ventral pattern. There is a dark brown mid-dorsal marking that commences between the eyes (connecting the upper eyelids), narrowing behind the occiput, broadening between the shoulders, narrowing and broadening again, giving rise to two posteriorly-directed bands of variable length. In some specimens, the marking continues on narrowing and broadening again, and in others, it is interrupted between the broad patches. Among the other dorsal colour pattern variations observed were the absence of the retrorse markings and an indistinct pattern with the whole of the dorsum in a reddish-brown tint. There are a few indistinct, narrow, wavy bands parallel with the edges of the dorsal marking. Ventrally white with black (grey-brown in alcohol-preserved specimens) marbling. The pattern varies from one individual to another, but the marbling was observed in all specimens. Gular region blackish (grey-brown in alcohol-preserved specimens) with fine, white stippling. A black mark on the anterior side of the thigh, and an incomplete bar on its dorsal side. Vent enclosed in a black patch. Limbs with dark cross-bars (Fernando and Siriwardhane 1996).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Sri Lanka

View distribution map in BerkeleyMapper.

Microhyla kamnaratnei is found in the Morningside Estate, Sinharaja World Heritage Site at around 1100m elevation (Fernando and Siriwardhane 1996; Batuwita et al. 2019).

Life History, Abundance, Activity, and Special Behaviors
The vegetation in the Morningside estate area is regenerated submontane scrub. Microhyla karunaratnei has been observed only in and around the margins of disused "gem pits," now filled with water. These pits are scattered throughout the Morningside Plain, covered with a dense growth of grass, Hedyotis sp. (Rubiaceae) and the fern Gleichenia linearis (Gleichenaceae). Adults were usually found in the tangled roots and stems of grass surrounding small pools of water (Fernando and Siriwardhane 1996).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Intensified agriculture or grazing
Habitat fragmentation

Comments
Microhyla kamnaratnei is named after P.B. Karunaratne, the Sri Lankan naturalist (Fernando and Siriwardhane 1996).

Molecular phylogenetic evidence suggests that M. karunaratnei is closely related to M. zeylanica (Garg et al. 2018)

References

Batuwita S, Udugampala S, DeSilva M, Diao J and Edirisinghe U. (2019). "A review of amphibian fauna of Sri Lanka: distribution, recent taxonomic changes and conservation." Journal of Animal Diversity, 1(2), 44-82. [link]

Fernando P and Siriwardhane M (1996). "Microhyla karunaratnei (Anura: Microhylidae), a new species of frog endemic to Sri Lanka." Journal of South Asian Natural History. Colombo, 2, 135-142.

Garg S., Suyesh R., Das A., Jiang J., Wijayathilaka N., Amarasinghe A.A.T., Alhadi F., Vineeth K.K., Aravind N.A., Senevirathne G., Meegaskumbura M. and Biju S.D. (2019). "Systematic revision of Microhyla (Microhylidae) frogs of South Asia: a molecular, morphological, and acoustic assessment." Vertebrate Zoology, 69(1), 1-71. [link]

Species Account Citation: AmphibiaWeb 2021 Microhyla karunaratnei: Karunaratne's Narrow-mouthed Frog <https://amphibiaweb.org/species/2176> University of California, Berkeley, CA, USA. Accessed Feb 5, 2025.

Citation: AmphibiaWeb. 2025. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 5 Feb 2025.

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