''Acanthogobius flavimanus'' is a species of

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

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. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

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 ...

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 ...

, parts of

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

Vietnam Vietnam, officially the Socialist Republic of Vietnam (SRV), is a country at the eastern edge of mainland Southeast Asia, with an area of about and a population of over 100 million, making it the world's List of countries and depende ...

, and

Malaysia Malaysia is a country in Southeast Asia. Featuring the Tanjung Piai, southernmost point of continental Eurasia, it is a federation, federal constitutional monarchy consisting of States and federal territories of Malaysia, 13 states and thre ...

. It has spread beyond its native range to become an introduced, and often invasive, species. It has been recorded in

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

, and

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

and

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 ...

in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

.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 environm ...

, 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 . 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 (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

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 (living in the water column), some are benthos, benthic (living on the sedimen ...

amphipods Amphipoda () is an order (biology), order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. Amphipods () range in size from and are mostly detritivores or scavengers. There are more than 10,700 amphip ...

mantis shrimp Mantis shrimp are carnivorous marine crustaceans of the order Stomatopoda (). Stomatopods branched off from other members of the class Malacostraca around 400 million years ago, with more than 520 extant species of mantis shrimp known. All li ...

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 p ...

, small fish, and

polychaete Polychaeta () is a paraphyletic class of generally marine Annelid, annelid worms, common name, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called c ...

s. It has also been known to consume

fly larvae A maggot is the larva of a fly (order Diptera); it is applied in particular to the larvae of Brachycera flies, such as houseflies, cheese flies, hoverflies, and blowflies, rather than larvae of the Nematocera, such as mosquitoes and crane ...

bivalves Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed by a calcified exoskeleton consis ...

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 the world, including North America, South America, Europe, and New Zealand. It is native to freshwater enviro ...

ostracod Ostracods, or ostracodes, are a Class (biology), class of the crustacean, Crustacea (class Ostracoda), sometimes known as seed shrimp. Some 33,000 species (only 13,000 of which are extant taxon, extant) have been identified,Brandão, S.N.; Antoni ...

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 The Japanese whiting (''Sillago japonica''), also known as the Japanese sillago or Shiro-gisu, is a common species of coastal marine fish belonging to the smelt-whiting family, Sillaginidae. As suggested by its name, the Japanese whiting was fi ...

(''Sillago japonica''),

leopard shark The leopard shark (''Triakis semifasciata'') is a species of houndshark, in the family (biology), family Houndshark, Triakidae. It is found along the Pacific coast of North America, from the U.S. state of Oregon to Mazatlán in Mexico. Typically ...

(''Triakis semifasciata''), ashishirohaze (''Acanthogobius lactipes''), and

suzuki is a Japanese multinational mobility manufacturer headquartered in Hamamatsu, Shizuoka Prefecture, Shizuoka. It manufactures automobiles, motorcycles, all-terrain vehicles (ATVs), outboard motor, outboard marine engines, wheelchairs and a va ...

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

parasite Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted str ...

loads. They play host to the

metacercariae Trematodes are parasitic flatworms of the class ''Trematoda'', specifically parasitic flukes with two Sucker (zoology), suckers: one ventral and the other Mouth, oral. Trematodes are covered by a Tegument (helminth), tegument, that protects the o ...

of flukes, including '' Echinostoma hortense'', '' Heterophyes nocens'', '' 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 environm ...

, was first discovered in the

Sacramento Sacramento ( or ; ; ) is the capital city of the U.S. state of California and the seat of Sacramento County. Located at the confluence of the Sacramento and American Rivers in Northern California's Sacramento Valley, Sacramento's 2020 p ...

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 ...

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 Ballast is dense material used as a weight to provide stability to a vehicle or structure. Ballast, other than cargo, may be placed in a vehicle, often a ship or the gondola of a balloon or airship, to provide stability. A compartment within ...

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 no ...

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), the fourth letter of the Greek alphabet * D (NATO phonetic alphabet: "Delta"), the fourth letter in the Latin alphabet * River delta, at a river mouth * Delta Air Lines, a major US carrier ...

, as well as

San Francisco Bay San Francisco Bay (Chochenyo language, Chochenyo: 'ommu) is a large tidal estuary in the United States, U.S. state of California, and gives its name to the San Francisco Bay Area. It is dominated by the cities of San Francisco, California, San ...

. 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) is a system formed by Organism, organisms in interaction with their Biophysical environment, environment. The Biotic material, biotic and abiotic components are linked together through nutrient cycles and en ...

. It may compete with native fish such as the

tidewater goby ''Eucyclogobius newberryi'', the northern tidewater goby, is a species of goby native to lagoons of streams, marshes, and creeks along the coast of California, United States. The northern tidewater goby is one of six native goby species of Califo ...

(''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 coast of Southern California, adjacent to the Mexico–United States border. With a population of over 1.4 million, it is the List of United States cities by population, eighth-most populous city in t ...

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 New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

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