''Microhyla'', commonly known as the rice frogs or narrow-mouthed frogs, is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of frogs in the family

Microhylidae The Microhylidae, commonly known as narrow-mouthed frogs, are a geographically widespread family of frogs. The 683 species are in 63 genera and 11 subfamilies, which is the largest number of genera of any frog family. Evolution A molecular phylo ...

. It consists of 42 species of diminutive frogs. Members of this genus are widespread from

Ryukyu The , also known as the or the , are a chain of Japanese islands that stretch southwest from Kyushu to Taiwan: the Ōsumi, Tokara, Amami, Okinawa, and Sakishima Islands (further divided into the Miyako and Yaeyama Islands), with Yonaguni ...

Is. in Japan, and throughout South-east Asia, (China,

Sumatra Sumatra is one of the Sunda Islands of western Indonesia. It is the largest island that is fully within Indonesian territory, as well as the sixth-largest island in the world at 473,481 km2 (182,812 mi.2), not including adjacent i ...

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's List ...

Bali Bali () is a province of Indonesia and the westernmost of the Lesser Sunda Islands. East of Java and west of Lombok, the province includes the island of Bali and a few smaller neighbouring islands, notably Nusa Penida, Nusa Lembongan, and Nu ...

Borneo Borneo (; id, Kalimantan) is the third-largest island in the world and the largest in Asia. At the geographic centre of Maritime Southeast Asia, in relation to major Indonesian islands, it is located north of Java, west of Sulawesi, and eas ...

, India and Sri Lanka).Frost, Darrel R. 2016. Amphibian Species of the World: an Online Reference. Version 6.0 (Date of access). Electronic Database accessible at http://research.amnh.org/herpetology/amphibia/index.html. American Museum of Natural History, New York, USA.

Taxonomy

In 2021, nine species of ''Microhyla'' were moved to '' Nanohyla'' on the basis of morphological and phylogenetic differences. ''Microhyla pulverata'' was found to be a junior synonym of ''

Nanohyla marmorata ''Nanohyla marmorata'' is a species of frog in the family Microhylidae. It is found in Laos and Vietnam. It is not considered threatened by the IUCN. Taxonomy ''N. marmorata'' was formerly placed in the genus ''Microhyla'', but a 2021 study us ...

'' based on phylogenetic evidence.

Diagnosis

According to Seshadri et al. (2016), this genus can be diagnosed using the following set of criteria: Adult frogs are of small size; pupil circular; skin on dorsum smooth; lateral side of body with markings from back of eye to vent; supratympanic fold present in adults; paratoid glands are absent, fingers without webbing, finger tips may or may not be dilated; oval tongue, its margin is entire and free at the base; the diameter of eye is smaller than snout; a thin layer of skin hides the tympanum; tubercles on hand distinct; distinct oval shaped inner metatarsal tubercle and rounded outer metatarsal tubercle; webbing in feet, rudimentary.

Evolutionary relationships

The genus ''Microhyla'' is closely related to ''

Glyphoglossus ''Glyphoglossus'' is a genus of frogs in the family Microhylidae. The genus occurs in Southeastern Asia. Common name balloon frogs has been coined for it, whereas the common name squat frogs refers to the ''Calluella'' species that are now includ ...

'' within the family

. Members of the genus ''Microhyla'' began diversifying from the most common ancestor around 45 million years ago and this resulted in forming '' Metaphrynella'' and ''Microhyla''. However, ascertaining the

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

relationship of frogs within ''Microhyla'' has been difficult as many species are not

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...

. A 2021 study on the relationship between ''Microhyla'' and ''Glyphoglossus'' found that nine species within ''Microhyla'' actually belong to a separate lineage. They have been subsequently moved to the new genus, '' Nanohyla''.

Species

The following species are recognised in the genus ''Microhyla'': In

central Vietnam Central Vietnam ( vi, Trung Bộ or ), also known as Middle Vietnam or The Middle, formerly known as by South Vietnam, and Annam under French Indochina, is one of the three geographical regions within Vietnam. The name Trung Bộ was used by ...

, several new species of ''Microhyla'' have been described in the 2000s: *'' Microhyla darevskii'': Mount

Ngọc Linh Ngọc Linh (a Sino-Vietnamese name meaning "Jade Mountain") is a mountain of the Annamite Range in Vietnam. It straddles the two provinces of Quảng Nam and Kon Tum. It is considered "the roof of Southern Vietnam". ''Panax vietnamensis'' ( v ...

, Kon Tum Province *'' Microhyla minuta'': Đồng Nai Province *'' Microhyla pineticola'': Lâm Đồng Province and Đắk Lắk Province Several new species of ''Microhyla'' have been described since 2018.

Phylogeny

The following phylogeny of the genus ''Microhyla'' is from Khatiwada, et al. (2017). 27 species are listed, including various newly described species from South Asia. (Note: the chart below includes some species that have since been moved to '' Nanohyla'' including ''N. annectens'' and ''N. perparva''.)

References

External links

* {{Taxonbar, from=Q2108367 Microhylidae Amphibians of Asia Amphibian genera Taxa named by Johann Jakob von Tschudi