''Misgurnus dabryanus'', the large-scale loach is a species of

true loach Cobitidae, also known as the true loaches, is a family of Old World freshwater fish. They occur throughout Eurasia and in Morocco, and inhabit riverine ecosystems. Today, most "loaches" are placed in other families (see below). The family includes ...

that is native to

Mainland China "Mainland China", also referred to as "the Chinese mainland", is a Geopolitics, geopolitical term defined as the territory under direct administration of the People's Republic of China (PRC) in the aftermath of the Chinese Civil War. In addit ...

Hainan Hainan is an island provinces of China, province and the southernmost province of China. It consists of the eponymous Hainan Island and various smaller islands in the South China Sea under the province's administration. The name literally mean ...

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia. The main geography of Taiwan, island of Taiwan, also known as ''Formosa'', lies between the East China Sea, East and South China Seas in the northwestern Pacific Ocea ...

Korea Korea is a peninsular region in East Asia consisting of the Korean Peninsula, Jeju Island, and smaller islands. Since the end of World War II in 1945, it has been politically Division of Korea, divided at or near the 38th parallel north, 3 ...

, and the

Russian Far East The Russian Far East ( rus, Дальний Восток России, p=ˈdalʲnʲɪj vɐˈstok rɐˈsʲiɪ) is a region in North Asia. It is the easternmost part of Russia and the Asia, Asian continent, and is coextensive with the Far Easte ...

. It can be found in water bodies such as the

Yangtze Basin The Yangtze or Yangzi ( or ) is the longest river in Eurasia and the third-longest in the world. It rises at Jari Hill in the Tanggula Mountains of the Tibetan Plateau and flows including Dam Qu River the longest source of the Yangtze, in ...

Pearl River The Pearl River (, or ) is an extensive river system in southern China. "Pearl River" is often also used as a catch-all for the watersheds of the Pearl tributaries within Guangdong, specifically the Xi ('west'), Bei ('north'), and Dong ( ...

Amur River The Amur River () or Heilong River ( zh, s=黑龙江) is a perennial river in Northeast Asia, forming the natural border between the Russian Far East and Northeast China (historically the Outer and Inner Manchuria). The Amur ''proper'' is ...

, and various other drainages. There are several known invasive populations in places such as

Barcelona Barcelona ( ; ; ) is a city on the northeastern coast of Spain. It is the capital and largest city of the autonomous community of Catalonia, as well as the second-most populous municipality of Spain. With a population of 1.6 million within c ...

, the

San Joaquin River The San Joaquin River ( ; ) is the longest river of Central California. The long river starts in the high Sierra Nevada and flows through the rich agricultural region of the northern San Joaquin Valley before reaching Suisun Bay, San Francis ...

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

, and the majority of

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

. The large-scale loach is typically brown, grey, or golden in color with mottled or speckled black dots, which leads to it sometimes called a "peppered loach" when sold at pet stores (though it is more often misidentified as the

pond loach The pond loach (''Misgurnus anguillicaudatus''), also known as the Dojo loach, oriental weatherloachGomon, M.F. & Bray, D.J. (2020)Oriental Weatherloach, ''Misgurnus anguillicaudatus'' (Cantor 1842) ''Fishes of Australia'', Museums Victoria. Ret ...

instead). It is a small loach, growing between TL. The diet and behaviors of the large-scaled loach are just about the same as other true loaches. This loach is an

omnivorous An omnivore () is an animal that regularly consumes significant quantities of both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize ...

scavenging Scavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a herbivorous feeding be ...

bottom feeder A bottom feeder is an aquatic animal that feeds on or near the bottom of a body of water. Biologists often use the terms ''benthos''—particularly for invertebrates such as shellfish, crabs, crayfish, sea anemones, starfish, snails, bristlew ...

, and is equipped with three pairs of

barbels In fish anatomy and turtle anatomy, a barbel is a slender, whisker like sensory organ near the mouth (sometimes called whiskers or tendrils). Fish that have barbels include the catfish, the carp, the goatfish, the hagfish, the sturgeon, the z ...

used to detect edible items. They are able to breathe atmospheric oxygen, which allows it to survive in poor quality water or even on land for extended periods of time. Females develop eggs over the winter and reproduction occurs during the spring. The male wraps around the female in order to fertilize the eggs, which are laid in cover such as aquatic vegetation with no further parental care provided. The large-scale loach looks very similar to another species of

, the

(''Misgurnus anguillicaudatus''), so it is possible that invasive populations of the pond loach might actually consist either partially or entirely of large-scale loaches. The large-scale loach can be told apart from the pond loach by the presence of higher

adipose Adipose tissue (also known as body fat or simply fat) is a loose connective tissue composed mostly of adipocytes. It also contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, Blood vessel, vascular endothel ...

crests on the caudal peduncle, a thinner lamina circularis (enlarged bony scale at the base of the first and second pectoral fin ray), and the lack of a dark spot near the caudal base in the upper corner on the tail fin. The large-scale loach also grows to a smaller size than the pond loach, which reaches TL. Both species are able to hybridize together, so identification may be difficult in mixed populations.

References

dabryanus Taxa named by Alphonse Guichenot Freshwater fish of China Fish of Russia Freshwater fish of Taiwan Fish described in 1872 {{Cobitidae-stub