''Pelophylax nigromaculatus'' (formerly ''Rana nigromaculata''), is a species of true frog found in

East Asia East Asia is the eastern region of Asia, which is defined in both geographical and ethno-cultural terms. The modern states of East Asia include China, Japan, Mongolia, North Korea, South Korea, and Taiwan. China, North Korea, South Korea and ...

, first described in 1861. This widespread and common frog has many common names, including dark-spotted frog, black-spotted pond frog, and black-spotted frog.

Occurrence

It occurs across much of eastern and northeastern China, the

Amur River The Amur (russian: река́ Аму́р, ), or Heilong Jiang (, "Black Dragon River", ), is the world's List of longest rivers, tenth longest river, forming the border between the Russian Far East and Northeast China, Northeastern China (Inne ...

valley in Russia, the

Korean Peninsula Korea ( ko, 한국, or , ) is a peninsular region in East Asia. Since 1945, it has been divided at or near the 38th parallel, with North Korea (Democratic People's Republic of Korea) comprising its northern half and South Korea (Republic o ...

, and most of Japan, although it does not occur on

Hokkaidō is Japan's second largest island and comprises the largest and northernmost prefecture, making up its own region. The Tsugaru Strait separates Hokkaidō from Honshu; the two islands are connected by the undersea railway Seikan Tunnel. The la ...

. It has been considered the commonest of the true frogs on the Korean Peninsula, and has been hunted for food and used as an

experimental animal Animal testing, also known as animal experimentation, animal research, and ''in vivo'' testing, is the use of non-human animals in experiments that seek to control the variables that affect the behavior or biological system under study. This ...

. There are introduced populations in

Turkmenistan Turkmenistan ( or ; tk, Türkmenistan / Түркменистан, ) is a country located in Central Asia, bordered by Kazakhstan to the northwest, Uzbekistan to the north, east and northeast, Afghanistan to the southeast, Iran to the sout ...

Oahu Oahu () (Hawaiian language, Hawaiian: ''Oʻahu'' ()), also known as "The Gathering place#Island of Oʻahu as The Gathering Place, Gathering Place", is the third-largest of the Hawaiian Islands. It is home to roughly one million people—over t ...

, and

Saipan Saipan ( ch, Sa’ipan, cal, Seipél, formerly in es, Saipán, and in ja, 彩帆島, Saipan-tō) is the largest island of the Northern Mariana Islands, a Commonwealth (U.S. insular area), commonwealth of the United States in the western Pa ...

Habitat

The dark-spotted frog is a relatively low-altitude species, not being found above 2200 m. It ranges across a variety of habitats, from deserts and bushland to meadows and forests, and is typically found in or near stagnant or slow-moving water. Although relatively tolerant of human interference, it is increasingly threatened by hunting and water pollution.

Description

Adult males measure about and females in snout–vent length. The dorsal colouration varies from grey to greyish-olive, olive, and green. There are usually large dark spots, a light mid-dorsal line, and two lines on dorso-lateral folds. The belly is white. The toes are webbed. Males have a paired

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 ...

and nuptial pads on the first finger. Mating season occurs soon after hibernation. Maturation probably occurs at an age of two years, and the total life span may reach 13 years. The clutch size has been reported as 1800–3000 or 600–5000 eggs. The eggs are laid in shallow water.

Parasites

Parasites of this frog include the

opalinid The opalines are a small group of peculiar heterokonts, currently assigned to the family Opalinidae, in the order Slopalinida. Their name is derived from the opalescent appearance of these microscopic organisms when illuminated with full sunli ...

''Protoopalina pingi'' in the

rectum The rectum is the final straight portion of the large intestine in humans and some other mammals, and the Gastrointestinal tract, gut in others. The adult human rectum is about long, and begins at the rectosigmoid junction (the end of the s ...

References

{{Taxonbar, from=Q1072424 nigromaculatus Amphibians of China Amphibians of Japan Amphibians of Korea Amphibians of Russia Amphibians described in 1861 Taxa named by Edward Hallowell (herpetologist)