A review of amphibian fauna of Sri Lanka: distribution, recent taxonomic changes and conservation

Abstract

The amphibian fauna of Sri Lanka comprises 120 species, including 107 (~90.0%) endemic species. They belong to five families: Bufonidae, Dicroglossidae, Ichthyophiidae, Microhylidae, and Rhacophoridae. Based on distribution, we recognized five zoogeographic zones for them, Central Hills, Dry Zone, Knuckles Range, Lowland Wet Zone, and Rakwana Hills. Fifty three species were reported from the Central Hills (48 endemics [90.6%] and 42 [79.2%] threatened species). 47 species were recorded from the Lowland Wet Zone, including 36 (76.6%) endemics and 28 (59.6%) threatened species. The Knuckles Range had 25 species, of which, 19 (76.0%) were endemics and 15 (60.0%) are threatened species. 19 species were reported from Dry Zone including seven endemics (36.8%) and four threatened species (21.1%). Out of 29 species, which inhabited in the Rakwana Hills, 26 were endemics (~89.7%) including 24 (82.8%) threatened species. Species diversity along the elevational gradient was also observed with the highest species richness in the mid-elevational localities. Family Ichthyophiidae can be considered as the least studied family. Recent rediscoveries and studies have helped to reduce the number of extinct species from 21 to 18. It is speculated that some of the other extinct species have to be rediscovered or probably were misidentified as other species. About 90% of Sri Lankan amphibians occur in the regions with the highest human populations where there are established agricultural lands. Loss of habitats, competition due to anthropogenic species and invasive species, pollution (cause for malformations, parasites, and other diseases), and climate change appear to be major threats.

Chytridiomycosis in Sri Lanka: Predicting the future of a global amphibian hotspot

“…Three different altitude classes for the distribution of Sri Lankan amphibians were identified, congruent with Batuwita et al (2019): A, 0–800 m a.s.l. ; B, >800–1,700 m a.s.l.…”

“…The high‐risk zone (Figure 1) comprises three out of the five amphibian zones of Sri Lanka (Batuwita et al, 2019; MoMD&E, 2019): the Central Highlands, the Knuckles Massif, and the Rakwana Hills. The importance of these regions as local amphibian hotspots is illustrated by the many new species described from them in the recent past (Manamendra‐Arachchi & Pethiyagoda, 2005; Meegaskumbura & Manamendra‐Arachchi, 2005; Meegaskumbura & Manamendra‐Arachchi, 2011; Wickramasinghe et al, 2013b; Senevirathne et al, 2018), as well as the rediscovery of species (Wickramasinghe et al, 2013a).…”

“…Of the 112 frog species recorded in Sri Lanka (Ellepola et al, 2021), the 93 extant species were considered in this study. The 18 extinct species were discounted as their distributional ranges have not been well documented (de Silva, Ukuwela & Chathuranga, 2022), whereas Hoplobatrachus tigerinus was discounted as its occurrence is now refuted (Dutta, 1997; Batuwita et al, 2019). Occurrence data over a 30‐year period (1990–2020) was collected and supplemented with data from the literature.…”

A new species of the genus Hoplobatrachus Peters, 1863 (Anura, Dicroglossidae) from northwestern Thailand

“…This species was introduced to Madagascar (Frost, 2022). Ongoing taxonomic research in Sri Lanka has revealed that H. tigerinus does not occur in this country, and frogs previously assigned to H. tigerinus are misidentifications of H. crassus (Dutta, 1997;Batuwita et al, 2019). However, the current authors recently collected some specimens from the herpetological survey at Salawin National Park, Mae Hong Son province, northwestern Thailand.…”

Morphometry and habitat selection of the Mountain Hourglass Treefrog [<em>Taruga eques</em> (Günther, 1858)] (Amphibia, Rhacophoridae) in the Horton Plains National Park, Sri Lanka

“…There are several threats to amphibians, even to extinction, such as climate change (Meegaskumbura et al, 2011a), predator attacks, parasite attacks (leach, dragonfly and damselfly larvae, and freshwater crabs), road kills (Karunarathna et al, 2017b), and humanrelated pressure (Batuwita et al, 2019). During the surveys, several threats were recorded that were detrimental to this species.…”