''Rana ulma'' 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 Ranidae. It is

endemic Endemism is the state of a species being found 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 found elsew ...

Okinawa Islands The Okinawa Islands ( or ) are an island group in Okinawa Prefecture, Japan and are the principal island group of the prefecture. The Okinawa Islands are part of the larger Ryukyu Islands group and are located between the Amami Islands of Kagoshi ...

, in the central

Ryukyu Islands 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 ...

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

. It is currently only known from northern

Okinawa Island is the largest of the Okinawa Islands and the Ryukyu (''Nansei'') Islands of Japan in the Kyushu region. It is the smallest and least populated of the five main islands of Japan. The island is approximately long, an average wide, and has an ...

and from

Kume Island is an island, part of the Okinawa Islands and administratively part of the town of Kumejima, Okinawa Prefecture, Japan. It has an area of . The island had a population of 8,713 (2010). Kume Island is a volcanic island. Its principal economic ac ...

. Common names Okinawa frog and Ryukyu brown frog have been used for this species; the latter can refer to this species or to ''

Rana kobai Rana may refer to: Astronomy * Rana (crater), a crater on Mars * Delta Eridani or Rana, a star People, groups and titles * Rana (name), a given name and surname (including a list of people and characters with the name) * Rana (title), a historica ...

''. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

''ulma'' means "coral island" in

Uruma is a city located in Okinawa Prefecture, Japan. The modern city of Uruma was established on April 1, 2005, when the cities of Gushikawa and Ishikawa were merged with the towns of Katsuren and Yonashiro (both from Nakagami District). As of M ...

dialect of Okinawa.

Taxonomy

Before 2011, frogs now known as ''Rana ulma'', together with those of its close relative ''Rana kobai'' from the neighboring

Amami Islands The The name ''Amami-guntō'' was standardized on February 15, 2010. Prior to that, another name, ''Amami shotō'' (奄美諸島), was also used. is an archipelago in the Satsunan Islands, which is part of the Ryukyu Islands, and is southwest o ...

, had been misidentified as '' Rana okinavana''. ''Rana ulma'' and ''R. kobai'' form a

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

that is the

sister group In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and t ...

for ''

Rana tsushimensis The Tsushima brown frog or Tsushima leopard frog (''Rana tsushimensis'') is a species of frog in the family Ranidae. It is endemic to the Tsushima Island is an island of the Japanese archipelago situated in-between the Tsushima Strait and K ...

''. All three species share similar general appearance.

Description

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 ...

(SVL). The snout is low and fairly pointed. The tympanum is distinct and relatively large (more so in males than in females). A supratympanic fold is present. The forelimbs are rather stout whereas the hindlimbs are long. The fingers are slender and have no webbing. The toes are moderately webbed. Alcohol-preserved specimens are dorsally light gray brown. A distinct dark brown marking runs over the eye and tympanum towards the arm insertion. Males have no vocal sack. Males aggregate for breeding and form a chorus where they call synchronously. The call resembles that of chickens.

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 of

Gosner stage Gosner stage is a generalized system of describing stages of embryonal and larval development in anurans (frogs and toads). The Gosner system includes 46 numbered stages, from fertilized embryo (stage 1) to the completion of metamorphosis (stage ...

s 33–39 measure in total length. SVL at metamorphosis is about .

Habitat, ecology, and conservation

''Rana ulma'' occurs in lowland to montane forests at elevations of

above sea level Height above mean sea level is a measure of the vertical distance (height, elevation or altitude) of a location in reference to a historic mean sea level taken as a vertical datum. In geodesy, it is formalized as ''orthometric heights''. The comb ...

. During the breeding season that takes place in December, adults congregate around small montane streams. The eggs are deposited in the shallows of headwaters, sometimes in small pools. The egg masses are loose and contain only about ten eggs; the total clutch size is about 320 eggs. Outside the breeding season, this species is terrestrial. Predators of this frog include the pitviper '' Ovophis okinavensis'', which prey upon breeding adults. Also the frog '' Limnonectes namiyei'' is a potential predator. This species is suffering from

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 human settlements. It is not know from protected areas, but the Kume Island population enjoys the status of "a locally protected population".

References

{{Taxonbar, from=Q3418764 ulma Endemic amphibians of Japan Endemic fauna of the Ryukyu Islands Amphibians described in 2011 Taxa named by Masafumi Matsui