''Kaloula'' is a genus of

microhylid The Microhylidae, commonly known as narrow-mouthed frogs, are a geographically widespread family of frogs. The 683 species are in 57 genera and 11 subfamilies. Evolution A molecular phylogenetic study by van der Meijden, et al. (2007) has estima ...

frog A frog is any member of a diverse and largely semiaquatic group of short-bodied, tailless amphibian vertebrates composing the order (biology), order Anura (coming from the Ancient Greek , literally 'without tail'). Frog species with rough ski ...

s found in southern and eastern Asia. They are sometimes known as the Asian narrowmouth toads.

Species

The genus currently has at least 19 species. Some sources also recognize ''Kaloula macrocephala'' Bourret, 1942 as a valid species, whereas the

Amphibian Species of the World ''Amphibian Species of the World 6.2: An Online Reference'' (ASW) is a herpetology database. It lists the names of frogs, salamanders and other amphibians, which scientists first described each species and what year, and the animal's known range ...

treats it as a synonym of ''

Kaloula pulchra ''Kaloula'' is a genus of microhylid frogs found in southern and eastern Asia. They are sometimes known as the Asian narrowmouth toads. Species The genus currently has at least 19 species. Some sources also recognize ''Kaloula macrocephala'' Bou ...

''. 5 new species have been described since 2000, and there are unnamed species yet to be described. ''

'', ''

Kaloula picta The painted narrowmouth toad (''Kaloula picta''), or slender-digit chorus frog, is a species of frog in the family Microhylidae. It is endemic to the Philippines, where it is found throughout the archipelago, including Palawan. Habitat Its natu ...

'', and '' Kaloula borealis'' are the most widespread and commonly found varieties, often living near human settlements. Blackburn, et al. (2013) lists several ''Kaloula'' varieties that are likely to be new, previously undescribed species. *''Kaloula sp. nov. Palawan'': Closely related to '' Kaloula baleata''. Recorded in

Palawan Palawan (, ), officially the Province of Palawan (; ), is an archipelagic province of the Philippines that is located in the region of Mimaropa. It is the largest province in the country in terms of total area of . The capital and largest c ...

. *''Kaloula sp. nov. Sulawesi'': Closely related to '' Kaloula baleata''. Recorded in the

Togian Islands The Togian (or Togean) Islands are an archipelago of 56 islands and many offshore islets, situated in the Gulf of Tomini, off the coast of Central Sulawesi, in Indonesia. The largest islands are Batudaka Island, Batudaka, Togean Island, Togea ...

(

Batudaka Island Batudaka is an island of the Central Sulawesi province, located in the Gulf of Tomini. The largest island in the Togian archipelago, it has a land area of over 110 square kilometers with smaller islands) and is divided administratively into villa ...

Central Sulawesi Central Sulawesi (Indonesian language, Indonesian: ''Sulawesi Tengah'') is a Provinces of Indonesia, province of Indonesia located at the centre of the island of Sulawesi. The administrative capital and largest city is located in Palu. The provin ...

, and

North Sulawesi North Sulawesi () is a Provinces of Indonesia, province of Indonesia. It is mainly located on the Minahasa Peninsula of the island of Sulawesi, south of the Philippines and southeast of Sabah, Malaysia, but also includes various small archipel ...

(

Bogani Nani Wartabone National Park Bogani Nani Wartabone National Park is a 2,871 km2 (1,108 mi2) national park on Minahassa Peninsula on Sulawesi island, Indonesia. Formerly known as Dumoga Bone National Park, it was established in 1991 and was renamed in honour of Na ...

). *''Kaloula sp. nov. Sibuyan'': Closely related to '' Kaloula conjuncta''. Recorded on

Sibuyan Island Sibuyan is a crescent-shaped island, the second largest in an archipelago comprising Romblon Province, Philippines. Located in the namesake Sibuyan Sea, it has an area of and has a total population of 62,815, as of the 2020 census. The island ...

and

Mount Baloy Mount is often used as part of the name of specific mountains, e.g. Mount Everest. Mount or Mounts may also refer to: Places * Mount, Cornwall, a village in Warleggan parish, England * Mount, Perranzabuloe, a hamlet in Perranzabuloe parish, ...

Panay Panay is the sixth-largest and fourth-most populous island in the Philippines, with a total land area of and a total population of 4,542,926, as of 2020 census. Panay comprises 4.4 percent of the entire population of the country. The City of Il ...

. *''Kaloula sp. nov. Samar & Leyte'': Related to '' Kaloula conjuncta'' and ''

''. Recorded in Taft, Eastern Samar, and Danao and

Baybay Baybay (IPA: aɪ'baɪ, officially the City of Baybay (; ), is a component city in the province of Leyte, Philippines. It has a population of 111,848 people. With an area of , it is the second largest city in the province after Ormoc. Former ...

Leyte Leyte ( ) is an island in the Visayas group of islands in the Philippines. It is eighth-largest and sixth-most populous island in the Philippines, with a total population of 2,626,970 as of 2020 census. Since the accessibility of land has been ...

. *''Kaloula sp. nov. Panay'': Related to ''

Kaloula kalingensis The Kalinga narrowmouth toad (''Kaloula kalingensis'') is a species of frog in the family Microhylidae. It is endemic to the Philippines. Its natural habitats are subtropical or tropical moist lowland forests, subtropical or tropical moist montan ...

'' and '' Kaloula kokacii''. Recorded in

Sibalom Sibalom, officially the Municipality of Sibalom, (; ; ), is a municipality in the province of Antique, Philippines. According to the 2020 census, it has a population of 63,833 people. Thus, making it a suburb of San Jose (the provincial capi ...

Antique Province Antique (), officially the Province of Antique, is a Provinces of the Philippines, province in the Philippines located in the Western Visayas Regions of the Philippines, region. Its capital and most populous town is San Jose de Buenavista, Antique ...

, Panay. *''Kaloula sp. nov. East Luzon'': Related to ''

'' and '' Kaloula kokacii''. Recorded on

Mount Makiling Mount Makiling (also spelled Maquiling) is an inactive stratovolcano located in the provinces of Laguna and Batangas on the island of Luzon in the Philippines. The mountain rises to an elevation of above mean sea level and is the highest feat ...

, Sierra Madres, and

Aurora Memorial National Park Aurora Memorial National Park is a protected area of the Philippines located within the Sierra Madre mountain range between the provinces of Nueva Ecija and Aurora in Central Luzon. History Established in 1937 by virtue of ''Proclamation No. 2 ...

Phylogeny

molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

study by Mo et al. (2013) suggests that the only four ''Kaloula'' species found in China, namely '' Kaloula borealis'', ''

Kaloula nonggangensis ''Kaloula nonggangensis'' is a species of frog in the family Microhylidae. It is endemic to China, where it is so far only known from the vicinity of its type locality in Nonggang National Nature Reserve in Longzhou County, southwestern Guangxi ...

'', ''

Kaloula rugifera ''Kaloula rugifera'', the Sichuan digging frog or Szechwan narrowmouth toad, is a species of frog in the family Microhylidae found in China. Range It is endemic to China where it is found in Sichuan and extreme southern Gansu. Habitat Its habit ...

'', and ''

Kaloula verrucosa ''Kaloula verrucosa'', the verrucous digging frog or Chinese narrowmouth toad, is a species of frog in the family Microhylidae. It is only known from the Yunnan–Guizhou Plateau of southwestern China in Sichuan, Yunnan, and Guizhou provinces, bu ...

'', belong to a

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

group, termed the ''K. verrucosa'' group. Blackburn, et al. (2013) consider ''Kaloula'' species

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the

Philippines The Philippines, officially the Republic of the Philippines, is an Archipelagic state, archipelagic country in Southeast Asia. Located in the western Pacific Ocean, it consists of List of islands of the Philippines, 7,641 islands, with a tot ...

to form a

group, containing the species ''

Kaloula walteri ''Kaloula walteri'' is a species of frog in the family Microhylidae. . The specific name ''walteri'' honors , an American herpetologist. Common name Walter's narrow-mouthed frog has been proposed for it. ''Kaloula walteri'' is most closely relate ...

'', ''

Kaloula rigida The Luzon narrow-mouthed frog (''Kaloula rigida'') is a species of frogs in the family Microhylidae. It is endemic to the Central Cordilleras and Sierra Madres of northern Luzon, Philippines. The Baguio variety is divergent from the rest of ...

'', '' Kaloula conjuncta'', ''

'', ''

'', and '' Kaloula kokacii''. ''Kaloula'' likely colonized the Philippines from Southeast Asia during the

Late Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million ye ...

, and then radiated into different

ecotype Ecotypes are organisms which belong to the same species but possess different phenotypical features as a result of environmental factors such as elevation, climate and predation. Ecotypes can be seen in wide geographical distributions and may event ...

s. ''K. kalingensis'' and ''K. kokacii'' occupy niches as arboreal tree-hole frogs in northern and southern Luzon respectively, while ''K. rigida'' and ''K. walteri'' are ground frogs in northern and southern Luzon respectively. ''K. picta'', which is a terrestrial ground frog, and ''K. conjuncta'', which is

scansorial Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally (scansorial), but others are exclusively arboreal. The habi ...

(climbing) and prefers shrubs, have established themselves throughout the Philippine archipelago. ''K. picta'' as well as ''K. pulchra'' display the lowest internal genetic diversity, but also have widespread geographical distributions that may have likely occurred be due to human activity. Excluding '' Kaloula taprobanica'', the

most recent common ancestor A most recent common ancestor (MRCA), also known as a last common ancestor (LCA), is the most recent individual from which all organisms of a set are inferred to have descended. The most recent common ancestor of a higher taxon is generally assu ...

of ''Kaloula'' likely existed about 22.3 million years ago, around the

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

–

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

boundary. The

of the terrestrial species ''K. rigida'' and ''K. walteri'' likely lived 4.8 million years ago during the

Early Pliocene Early may refer to: Places in the United States * Early, Iowa, a city * Early, Texas, a city * Early Branch, a stream in Missouri * Early County, Georgia * Fort Early, Georgia, an early 19th century fort Music * Early B, stage name of Jamaican d ...

, while that of the arboreal species ''K. kalingensis'' and ''K. kokacii'' likely lived 9.1 million years ago. The

of ''K. conjuncta'', which currently has four recognized subspecies, likely lived 4.4 million years ago. Blackburn, et al. (2013) suggests that '' Kaloula taprobanica'' might not form a clade with the other ''Kaloula'' species, although it does clearly form a clade with ''

Metaphrynella ''Metaphrynella'' is a small genus of Microhylidae, microhylid frogs from the southern Malay Peninsula and Borneo. They are sometimes known as the Borneo treefrogs or tree hole frogs. The common name refers to the microhabitat of these frogs: mal ...

'', ''

Ramanella ''Uperodon'' is a genus of microhylid frogs. They occur in South Asia (Pakistan, India, Sri Lanka, Bhutan, Nepal, and Bangladesh) and Myanmar. ''Uperodon'' reached its current composition in 2016 when the genus Ramanella was brought into its syn ...

'', and the rest of ''Kaloula''. Other studies relating to ''Kaloula'' phylogeny include van Bocxlaer et al. (2007), Matsui et al. (2011), and Trueb et al. (2011).Trueb, L., R. Diaz, and D. C. Blackburn. 2011. Osteology and chondrocranial morphology of Gastrophryne carolinensis (Anura: Microhylidae), with a review of the osteological diversity of New World microhylids. Phyllomedusa 10:99–135. The following phylogeny has been adapted from Blackburn, et al. (2013). '' Kaloula assamensis'', '' Kaloula taprobanica'', and '' Kaloula aureata'' have not been included.

References

External links

AmphibiaWeb
Microhylidae Amphibians of Asia Amphibian genera Taxa named by John Edward Gray {{Microhylidae-stub