''Nanohyla petrigena'' is a species of

frog A frog is any member of a diverse and largely Carnivore, carnivorous group of short-bodied, tailless amphibians composing the order (biology), order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-f ...

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 is found in northern and central

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 ...

(

Brunei Brunei ( , ), formally Brunei Darussalam ( ms, Negara Brunei Darussalam, Jawi alphabet, Jawi: , ), is a country located on the north coast of the island of Borneo in Southeast Asia. Apart from its South China Sea coast, it is completely sur ...

, southeastern

Sabah Sabah () is a States and federal territories of Malaysia, state of Malaysia located in northern Borneo, in the region of East Malaysia. Sabah borders the Malaysian state of Sarawak to the southwest and the North Kalimantan province of Indone ...

and central

Sarawak Sarawak (; ) is a States and federal territories of Malaysia, state of Malaysia. The largest among the 13 states, with an area almost equal to that of Peninsular Malaysia, Sarawak is located in northwest Borneo Island, and is bordered by the M ...

Malaysia Malaysia ( ; ) is a country in Southeast Asia. The federation, federal constitutional monarchy consists of States and federal territories of Malaysia, thirteen states and three federal territories, separated by the South China Sea into two r ...

, and central

Kalimantan Kalimantan () is the Indonesian portion of the island of Borneo. It constitutes 73% of the island's area. The non-Indonesian parts of Borneo are Brunei and East Malaysia. In Indonesia, "Kalimantan" refers to the whole island of Borneo. In 2019, ...

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

) and in the Sulu Archipelago of the

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

. The common names pothole narrow-mouthed frog and Kapit rice frog have been coined for the species.

Taxonomy

''N. petrigena'' was formerly placed in the genus '' Microhyla'', but a 2021 study using morphological and phylogenetic evidence moved nine species (including ''N. petrigena)'' to a new genus, '' Nanohyla''.

Description

''Nanohyla petrigena'' is a small frog: adult males measure and adult females in

snout–vent length Snout–vent length (SVL) is a morphometric measurement taken in herpetology from the tip of the snout to the most posterior opening of the cloacal slit (vent)."direct line distance from tip of snout to posterior margin of vent" It is the most c ...

. Its hands have only three fingers. The dorsum is colored in shades of brown. There are dark markings on the shoulder and a light band on the flank. The venter is dark with an irregular white blotch. The male advertisement call is a single, pulsed note, emitted in series consisting of maximally 15 notes. Call repetition rate is about 0.7 per second, declining towards the end of the series.

Habitat and conservation

''Nanohyla petrigena'' occurs in lowland primary rainforests at elevations below . It lives in leaf litter. Breeding takes place in small pot-holes on rocky banks of clear streams and rivers and appears to be restricted to certain nights. The egg masses float on the surface of these pools. The

tadpole A tadpole is the larval stage in the biological life cycle of an amphibian. Most tadpoles are fully aquatic, though some species of amphibians have tadpoles that are terrestrial. Tadpoles have some fish-like features that may not be found i ...

s feed in mid-water. This species appears not to be able to adapt to modified habitats. It is threatened by

habitat loss Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

caused by logging and conversion in palm oil plantations; the type locality has already been destroyed and species has likely disappeared from there. However, the species occurs in several protected areas.

References

{{Taxonbar, from=Q104835856, from2=Q2242259 petrigena Amphibians of Borneo Amphibians of Brunei Amphibians of Indonesia Amphibians of Malaysia Amphibians of the Philippines Taxa named by Robert F. Inger Amphibians described in 1979 Taxonomy articles created by Polbot