''Acanthogobius flavimanus'' is a species of

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...

in the goby family known by the common name yellowfin goby. Other common names include mahaze, Japanese river goby, Oriental goby, and spotted goby. It is native to Asia, where its range includes

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

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 ...

Korea 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 ...

, parts of

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

Vietnam Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making i ...

, and

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 ...

. It has spread beyond its native range to become an introduced, and often

invasive Invasive may refer to: *Invasive (medical) procedure *Invasive species *Invasive observation, especially in reference to surveillance *Invasively progressive spread of disease from one organ in the body to another, especially in reference to cancer ...

, species. It has been recorded in

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

, and

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...

and

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

.CABI, 2013
''Acanthogobius flavimanus''.
In: ''Invasive Species Compendium''. Wallingford, UK: CAB International.

Description

This fish reaches in length. It is light brown with darker saddle-marks and spots. The ventral fins are yellow. These fins are fused to form a cup. There are two dorsal fins. The species can be identified by the arrangement of pores on its head, the spines and rays in the dorsal fins, and the scales and papillae on the head and face. The yellow ventral fins also distinguish it from other gobies. The lifespan is generally up to 3 years, but some individuals may get older.''Acanthogobius flavimanus''.
California Fish Website. University of California.

Biology

This fish spends most of the year in rivers and streams. During the winter it descends to more saline environments, such as bays and

estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environment ...

, where it breeds. There it is a bottom-dweller, living on the muddy or sandy beds. Spawning only occurs when the temperature is between about 7 °C and 13 °C (44.6 and 55.4 ºF). One fish may produce up to 37,000 eggs. Each egg is about 5.5 millimeters long. The eggs are deposited in a nest, which is a burrow up to deep, constructed by the male. The nest may be guarded by both male and female. In optimal conditions the eggs hatch in about 28 days. The fish tolerates fresh and saline waters, and rapid movements between them. It can live in a wide variety of water habitat types. The adult can spend its whole life in freshwater, but the

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The ...

e generally develop in saltwater. The diet of the goby includes many kinds of small organisms, such as

copepod Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (inhabiting sea waters), some are benthos, benthic (living on the ocean floor) ...

s, amphipods,

mantis shrimp Mantis shrimp, or stomatopods, are carnivorous marine crustaceans of the order Stomatopoda (). Stomatopods branched off from other members of the class Malacostraca around 340 million years ago. Mantis shrimp typically grow to around in lengt ...

mysids Mysida is an order of small, shrimp-like crustaceans in the malacostracan superorder Peracarida. Their common name opossum shrimps stems from the presence of a brood pouch or "marsupium" in females. The fact that the larvae are reared in this ...

, small fish, and polychaetes. It has also been known to consume fly larvae,

bivalves Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...

such as the

Asian clam ''Corbicula fluminea'' is a species of freshwater clam native to eastern Asia which has become a successful invasive species throughout North America, South America, and Europe. ''Corbicula fluminea'' is commonly known in the west as the Asian cl ...

ostracod Ostracods, or ostracodes, are a class of the Crustacea (class Ostracoda), sometimes known as seed shrimp. Some 70,000 species (only 13,000 of which are extant) have been identified, grouped into several orders. They are small crustaceans, typic ...

s, and various detritus.Workman, M. L. and J. E. Merz. (2007)
Introduced yellowfin goby, ''Acanthogobius flavimanus'': Diet and habitat use in the Lower Mokelumne River, California.
''San Francisco Estuary and Watershed Science'' 5(1). Natural predators of the goby include yellow goosefish (''Lophius litulon''),

ocellate spot skate The ocellate spot skate (''Okamejei kenojei''), also known as the spiny rasp skate or swarthy skate, is a species of skate Skate or Skates may refer to: Fish *Skate (fish), several genera of fish belonging to the family Rajidae * Pygmy skates ...

(''Okamejei kenojei''), Japanese whiting (''Sillago japonica''), leopard shark (''Triakis semifasciata''), ashishirohaze (''Acanthogobius lactipes''), and

suzuki is a Japan, Japanese multinational corporation headquartered in Minami-ku, Hamamatsu, Japan. Suzuki manufactures automobiles, motorcycles, All-terrain vehicle, all-terrain vehicles (ATVs), outboard motor, outboard marine engines, wheelchairs ...

(''Lateolabrax japonicus''). Fish of this species are often found to carry heavy

parasite Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...

loads. They play host to the metacercariae of flukes, including '' Echinostoma hortense'', ''

Heterophyes nocens ''Heterophyes nocens'' is a species of trematodes, or fluke worms, in the family Heterophyidae. Distribution This species occurs in: * southwestern Korea in coastal regions * Kōchi Prefecture, Chiba Prefecture, Yamaguchi Prefecture, Chūgoku re ...

'', '' Heterophyopsis continua'', '' Pygidiopsis summa'', '' Strictodora fuscata'', '' S. lari'', and '' Acanthotrema felis''. These, particularly ''E. hortense'', pose a risk to humans. People in Korea catch and eat the yellowfin goby raw, and often become infected with flukes.Sohn, W., et al. (2009)
''Echinostoma hortense'' and heterophyid metacercariae encysted in yellowfin goby, ''Acanthogobius flavimanus'', from Shinan-gun and Muan-gun (Jeollanam-do), Korea.
''Korean J Parasitol'' 47(3) 307–10. The fish is also host to the copepods '' Acanthochondria yui'' and '' Anchistrotos kojimensis'',Bailly, N. (2013)
''Acanthogobius flavimanus'' (Temminck & Schlegel, 1845).
In: Froese, R. and D. Pauly. Editors. FishBase. Accessed through: World Register of Marine Species. the latter of which was first described from a yellowfin goby specimen.Do, T. T. and J. Ho. (1983)
''Anchistrotos kojimensis'' sp. nov. (Copepoda: Taeniacanthidae) parasitic on ''Acanthogobius flavimanus'' (Pisces: Teleostei) in Kojima Bay, Japan.
''Fish Pathology'' 18(1) 1-5.

As an introduced species

''A. flavimanus'', the largest species of goby found in

estuaries of California An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environment ...

, was first discovered in the

Sacramento ) , image_map = Sacramento County California Incorporated and Unincorporated areas Sacramento Highlighted.svg , mapsize = 250x200px , map_caption = Location within Sacramento ...

- San Joaquin River system of California in 1963. It had probably been introduced a few years earlier, around the same time as the chameleon goby (''Tridentiger trigonocephalus''). It may have arrived in ballast water or as eggs on

biofouling Biofouling or biological fouling is the accumulation of microorganisms, plants, algae, or small animals where it is not wanted on surfaces such as ship and submarine hulls, devices such as water inlets, pipework, grates, ponds, and rivers that ...

animals such as

oyster Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but not al ...

s on ship hulls. Anglers using the goby as bait in the local river system may have aided its dispersal.Nico, L., et al. 2013
''Acanthogobius flavimanus''.
USGS Nonindigenous Aquatic Species Database, Gainesville, FL. Now it is one of the most common bottom-dwelling fish in the rivers and the

Delta Delta commonly refers to: * Delta (letter) (Δ or δ), a letter of the Greek alphabet * River delta, at a river mouth * D (NATO phonetic alphabet: "Delta") * Delta Air Lines, US * Delta variant of SARS-CoV-2 that causes COVID-19 Delta may also re ...

, as well as

San Francisco Bay San Francisco Bay is a large tidal estuary in the U.S. state of California, and gives its name to the San Francisco Bay Area. It is dominated by the big cities of San Francisco, San Jose, and Oakland. San Francisco Bay drains water from a ...

. There it has become an important prey item for the

harbor seal The harbor (or harbour) seal (''Phoca vitulina''), also known as the common seal, is a true seal found along temperate and Arctic marine coastlines of the Northern Hemisphere. The most widely distributed species of pinniped (walruses, eared sea ...

(''Phoca vitulina''). On the other hand, it has negative effects on the local

ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syste ...

. It may compete with native fish such as the tidewater goby (''Eucyclogobius newberryi''). The fish was first encountered in Southern California in 1977, when it was found in Los Angeles Harbor; it was found in

San Diego San Diego ( , ; ) is a city on the Pacific Ocean coast of Southern California located immediately adjacent to the Mexico–United States border. With a 2020 population of 1,386,932, it is the List of United States cities by population, eigh ...

a few years later. This fish is thought to have been introduced to Australia in ballast or on imported oysters.''Acanthogobius flavimanus''.
Global Invasive Species Database. 2013. The species has been collected from the waters of

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

since 1971.Middleton, M. J. (1982)
The Oriental goby, ''Acanthogobius flavimanus'' (Temminck and Schlegel), an introduced fish in the coastal waters of New South Wales, Australia.
''Journal of Fish Biology'' 21(5) 513-23. It is a Class 1 noxious fish in the state, its sale or possession prohibited and punishable by fines.Yellowfin Goby (''Acanthogobius flavimanus'').
New South Wales Department of Primary Industries - Fishing and Aquaculture.

Other uses

This species is sometimes kept in aquaria as an ornamental fish.

References

{{Taxonbar, from=Q1073434 Gobionellinae Taxa named by Coenraad Jacob Temminck Taxa named by Hermann Schlegel Fish described in 1845