The Japanese brown frog (''Rana japonica'') 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,
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 ...
to
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 ...
. Its natural
habitat
In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...
s are temperate
grassland
A grassland is an area where the vegetation is dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur natur ...
,
river
A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of wate ...
s,
swamp
A swamp is a forested wetland.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Swamps are considered to be transition zones because both land and water play a role in ...
s, irrigated land, and seasonally flooded agricultural land.
Characteristics
Defining characteristics include a slender, reddish-brown body with a long, narrow head. The average snout-vent length is for males. Females are usually much larger than males, with lengths of about . Neither gender has a
vocal sac
The vocal sac is the flexible membrane of skin possessed by most male frogs and toads. The purpose of the vocal sac is usually as an amplification of their mating or advertisement call. The presence or development of the vocal sac is one way o ...
, but males develop yellowish-brown nuptial pads and sing during mating season (which lasts from January to March). Songs consist of 10 to 20 notes.
Habitat
''R. japonica'' occurs in Honshu, Shikoku, and Kyushu in Japan to the southern region of China. Within Japan, it inhabits mostly hillsides and plains and is rarely seen in mountain ranges. More specifically, the brown frog resides in temperate
grassland
A grassland is an area where the vegetation is dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur natur ...
s, hillsides, plains,
river
A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of wate ...
s,
swamp
A swamp is a forested wetland.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Swamps are considered to be transition zones because both land and water play a role in ...
s, irrigated land, and seasonally flooded agricultural land.
Translucent breed
By combining two types of recessive genes that cause frogs to become translucent, a breed of ''Rana japonica,'' popularly called "see-through frogs", was produced by Japanese scientists in 2007 to see the frog's organs,
blood
Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the c ...
cells, and eggs without
dissection
Dissection (from Latin ' "to cut to pieces"; also called anatomization) is the dismembering of the body of a deceased animal or plant to study its anatomical structure. Autopsy is used in pathology and forensic medicine to determine the cause o ...
. The skin is not clear, but translucent. Cancer growths can be seen more easily.
Predators
Tadpole larvae of ''R. japonica'' are known to be consumed by aquatic larvae of the
Ezo salamander
The Ezo salamander (''Hynobius retardatus''), also known as the Hokkaido salamander, Noboribetsu salamander, or Ezo Sanshouo in Japanese is a species of salamander in the family Hynobiidae. Prior to 1923 the species was also classified by the bin ...
, ''Hynobius retardatus''.
See also
*
European frog
References
Rana (genus)
Endemic amphibians of Japan
Amphibians described in 1879
Taxonomy articles created by Polbot
{{Ranidae-stub