''Ponticola kessleri'', the bighead goby or Kessler's goby, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

goby Goby is a common name for many species of small to medium sized ray-finned fish, normally with large heads and tapered bodies, which are found in marine, brackish and freshwater environments. Traditionally most of the species called gobies have b ...

native to

Eurasia Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago a ...

. The bighead goby is a Ponto-Caspian

relict A relict is a surviving remnant of a natural phenomenon. Biology A relict (or relic) is an organism that at an earlier time was abundant in a large area but now occurs at only one or a few small areas. Geology and geomorphology In geology, a r ...

species. It inhabits the

fresh Fresh or FRESH may refer to: People *DJ Fresh (born 1977), UK-based drum and bass artist *DJ Fresh (producer), US-based R&B producer born Marqus Brown Arts, entertainment, and media Films * ''Fresh'' (1994 film), a crime film * ''Fresh'' (200 ...

and oligohaline waters, with mineralisation from 0-0.5‰ up to 1.5-3.0‰.

Characteristics

This species has a big flattened

head A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may ...

, strongly expended upper

lip The lips are the visible body part at the mouth of many animals, including humans. Lips are soft, movable, and serve as the opening for food intake and in the articulation of sound and speech. Human lips are a tactile sensory organ, and can be ...

, prolonged-conical body and thickened anterior. The

mandibula In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone ...

is longer than

maxilla The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The t ...

. It reaches . A triangular dark spot is visible near the

caudal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

. The collar of its abdominal

sucker Sucker may refer to: General use * Lollipop or sucker, a type of confection * Sucker (slang), a slang term for a very gullible person * Hard candy ** Cough drop ** Mint (candy) Biology * Sucker (botany), a term for a shoot that arises undergro ...

has blades. The

does not reach the

anus The anus (Latin, 'ring' or 'circle') is an opening at the opposite end of an animal's digestive tract from the mouth. Its function is to control the expulsion of feces, the residual semi-solid waste that remains after food digestion, which, d ...

. It is red- or grey-brown with 5 transverse lines on the back, one of which is on the basis of the

. The head has light round spots with a white margin on sides. The basis of the

pectoral fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...

has wave-shaped brown spots, odd

fin A fin is a thin component or appendage attached to a larger body or structure. Fins typically function as foils that produce lift or thrust, or provide the ability to steer or stabilize motion while traveling in water, air, or other fluids. Fin ...

s have lines of black spots. This species is distinguished from related Black Sea basin inhabitants by the following: 75-95% of its length is between its origin and anus;

ctenoid A fish scale is a small rigid plate that grows out of the skin of a fish. The skin of most jawed fishes is covered with these protective scales, which can also provide effective camouflage through the use of reflection and colouration, as ...

scales completely cover the predorsal area and nape; pelvic disc fraenum with angular lobes, Distinguishing characteristics include a fraenum with length 1/6-1/2 of its width at base, midlateral series

scales Scale or scales may refer to: Mathematics * Scale (descriptive set theory), an object defined on a set of points * Scale (ratio), the ratio of a linear dimension of a model to the corresponding dimension of the original * Scale factor, a number w ...

68-72 +3-4, a snout length 1.5-2.0 times its eye diameter, that its first branched ray of second dorsal is about as long as penultimate ray and that the posterior part of first dorsal is without a black spot.

Ecology

Range

It is present in

lagoons A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into ''coastal lagoons'' (or ''barrier lagoons'') an ...

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 ...

of the north-western

Black Sea The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Roma ...

, near the

Bulgaria Bulgaria (; bg, България, Bǎlgariya), officially the Republic of Bulgaria,, ) is a country in Southeast Europe. It is situated on the eastern flank of the Balkans, and is bordered by Romania to the north, Serbia and North Macedon ...

coast The coast, also known as the coastline or seashore, is defined as the area where land meets the ocean, or as a line that forms the boundary between the land and the coastline. The Earth has around of coastline. Coasts are important zones in n ...

, especially in lakes

Mandra Mandra ( el, Μάνδρα), is a town and former municipality in West Attica, Greece. Since the 2011 local government reform it is part of the municipality Mandra-Eidyllia, of which it is the seat and a municipal unit. The municipal unit has an ...

, Vaya,

Varna Varna may refer to: Places Europe *Varna, Bulgaria, a city in Bulgaria **Varna Province **Varna Municipality ** Gulf of Varna **Lake Varna **Varna Necropolis *Vahrn, or Varna, a municipality in Italy *Varniai, a city in Lithuania * Varna (Šaba ...

, Beloslavsko. In the

Danube The Danube ( ; ) is a river that was once a long-standing frontier of the Roman Empire and today connects 10 European countries, running through their territories or being a border. Originating in Germany, the Danube flows southeast for , pa ...

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 ...

the original distribution of the bighead goby reached

Vidin Vidin ( bg, Видин, ; Old Romanian: Diiu) is a port city on the southern bank of the Danube in north-western Bulgaria. It is close to the borders with Romania and Serbia, and is also the administrative centre of Vidin Province, as well as o ...

and was common in the

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...

s of the

Danube delta The Danube Delta ( ro, Delta Dunării, ; uk, Дельта Дунаю, Deľta Dunaju, ) is the second largest river delta in Europe, after the Volga Delta, and is the best preserved on the continent. The greater part of the Danube Delta lies in Ro ...

. It inhabits the rivers

Dniester The Dniester, ; rus, Дне́стр, links=1, Dnéstr, ˈdⁿʲestr; ro, Nistru; grc, Τύρᾱς, Tyrās, ; la, Tyrās, la, Danaster, label=none, ) ( ,) is a transboundary river in Eastern Europe. It runs first through Ukraine and th ...

up to

Kamianets-Podilskyi Kamianets-Podilskyi ( uk, Ка́м'яне́ць-Поді́льський, russian: Каменец-Подольский, Kamenets-Podolskiy, pl, Kamieniec Podolski, ro, Camenița, yi, קאַמענעץ־פּאָדאָלסק / קאַמעניץ, ...

, small rivers

Zbruch The Zbruch ( uk, Збруч, pl, Zbrucz) is a river in Western Ukraine, a left tributary of the Dniester.Збруч
...

and Bystrytsia.

Dnieper } The Dnieper () or Dnipro (); , ; . is one of the major transboundary rivers of Europe, rising in the Valdai Hills near Smolensk, Russia, before flowing through Belarus and Ukraine to the Black Sea. It is the longest river of Ukraine and B ...

up to

Dnipropetrovsk Dnipro, previously called Dnipropetrovsk from 1926 until May 2016, is Ukraine's fourth-largest city, with about one million inhabitants. It is located in the eastern part of Ukraine, southeast of the Ukrainian capital Kyiv on the Dnieper Rive ...

, also in the

Southern Bug , ''Pivdennyi Buh'' , name_etymology = , image = Sunset S Bug Vinnitsa 2007 G1.jpg , image_size = 270 , image_caption = Southern Bug River in the vicinity of Vinnytsia, Ukraine , map = PietinisBug ...

River. The bighead goby was recorded as

non-indigenous species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there ...

in the Slovak section of the

River in 1996, and until 2004, this species had the widest density and distribution among the four

Gobiidae Gobiidae or gobies is a family of bony fish in the order Gobiiformes, one of the largest fish families comprising more than 2,000 species in more than 200 genera. Most of gobiid fish are relatively small, typically less than in length, and the ...

species. In the Danube River basin, species is also mentioned as non-indigenous in the

Tisza River The Tisza, Tysa or Tisa, is one of the major rivers of Central and Eastern Europe. Once, it was called "the most Hungarian river" because it flowed entirely within the Kingdom of Hungary. Today, it crosses several national borders. The Tisza be ...

. In the Upper Danube it was registered in

Austria Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Europe, lying in the Eastern Alps. It is a federation of nine states, one of which is the capital, Vienna, the most populous ...

n and

German German(s) may refer to: * Germany (of or related to) ** Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ge ...

parts up to the City of Straubing. During 2000-2002 рр. this species was registered in small streams of the

coast of Eastern

Turkey Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a list of transcontinental countries, transcontinental country located mainly on the Anatolia, Anatolian Peninsula in Western Asia, with ...

Since March 2009 the fish is registered in the

North Sea The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian S ...

basin, in the

Waal River The Waal (Dutch name, ) is the main distributary branch of the river Rhine flowing approximately through the Netherlands. It is the major waterway connecting the port of Rotterdam to Germany. Before it reaches Rotterdam, it joins with the Afg ...

, the

Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...

. At the German part of the Lower

Rhine ), Surselva, Graubünden, Switzerland , source1_coordinates= , source1_elevation = , source2 = Rein Posteriur/Hinterrhein , source2_location = Paradies Glacier, Graubünden, Switzerland , source2_coordinates= , so ...

, between the cities of

Cologne Cologne ( ; german: Köln ; ksh, Kölle ) is the largest city of the German western States of Germany, state of North Rhine-Westphalia (NRW) and the List of cities in Germany by population, fourth-most populous city of Germany with 1.1 m ...

and Rees, this species consists of 52% of gobies catchments in 2009. In 2011, the range of this species comprised the

Rhine River ), Surselva, Graubünden, Switzerland , source1_coordinates= , source1_elevation = , source2 = Rein Posteriur/Hinterrhein , source2_location = Paradies Glacier, Graubünden, Switzerland , source2_coordinates= , sourc ...

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

, and

Switzerland ). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...

, also in the French part of the

Moselle River The Moselle ( , ; german: Mosel ; lb, Musel ) is a river that rises in the Vosges mountains and flows through north-eastern France and Luxembourg to western Germany. It is a left bank tributary of the Rhine, which it joins at Koblen ...

Ponticola kessleri with ruler, Dniester Estuary

Feeding

In the

Dniester Estuary Dniester Estuary, or Dniester Liman ( uk, Дністровський лиман; ro, Limanul Nistrului) is a liman, formed at the point where the river Dniester flows into the Black Sea. It is located in Ukraine, in Odessa Oblast, and connects B ...

the bighead mostly eats

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 ...

—up to 92% by weight. The

crustaceans Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

('' Corophium chelicorne'', '' Paramysis intermedia'') also provides up to 7% of its diet.

Molluscs Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant taxon, extant species of molluscs are recognized. The number of fossil sp ...

and

polychaetes Polychaeta () is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are mad ...

have less importance (2% each).

Predators and parasites

The bighead plays an important role in the diet of predatory

, such as

zander The zander (''Sander lucioperca''), sander or pikeperch, is a species of ray-finned fish from the family Percidae, which includes the perches, ruffes and darters. It is found in freshwater and brackish habitats in western Eurasia. It is a popul ...

. In the

the bighead goby

host A host is a person responsible for guests at an event or for providing hospitality during it. Host may also refer to: Places * Host, Pennsylvania, a village in Berks County People *Jim Host (born 1937), American businessman * Michel Host ...

parasites Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted structurally to this way of lif ...

such as

trematodes Trematoda is a class of flatworms known as flukes. They are obligate internal parasites with a complex life cycle requiring at least two hosts. The intermediate host, in which asexual reproduction occurs, is usually a snail. The definitive host ...

Nicolla skrjabini ''Nicolla skrjabini'' is a species of trematodes in the family Opecoelidae. Distribution The distribution of ''Nicolla skrjabini'' includes rivers of the Azov-Black Sea and rivers of the Baltic Sea. Expansion of its host species ''Lithoglyph ...

'' and

larvae 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 ...

nematode The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhab ...

s ''

Eustrongylides ''Eustrongylides'' is a genus of nematodes belonging to the family Dioctophymatidae. The species of this genus cause eustrongylidosis. The genus has almost cosmopolitan distribution. Species: *''Eustrongylides excisus'' *''Eustrongylides ig ...

excisus''. In the Middle

this goby species supports 33 species of

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 ...

s. The core of the parasitefauna are acanthocephalans ''

Pomphorhynchus laevis ''Pomphorhynchus laevis'' is an endo-parasitic acanthocephalan worm, with a complex life cycle, that can modify the behaviour of its intermediate host, the freshwater amphipod ''Gammarus pulex''. ''P. laevis'' does not contain a digestive tr ...

'',

glochidia The glochidium (plural glochidia) is a microscopic larval stage of some freshwater mussels, aquatic bivalve mollusks in the families Unionidae and Margaritiferidae, the river mussels and European freshwater pearl mussels. These larvae are ...

mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...

s ''Anadonta anatina'', and

s ''Raphidascaris acus''. The bighead goby

the

of invasive

Far East The ''Far East'' was a European term to refer to the geographical regions that includes East and Southeast Asia as well as the Russian Far East to a lesser extent. South Asia is sometimes also included for economic and cultural reasons. The ter ...

ern

'' Anguillicoloides crassus''. In the

n sector of the

, 5

are registered:Mühlegger J.M., Jirsa F., Konecny R., Frank C. (2010) Parasites of '' Apollonia melanostoma'' (Pallas 1814) and ''Neogobius kessleri'' (Guenther 1861) (Osteichthyes,

) from the Danube River in Austria. Journal of Helminthology, 84: 87–92.

infusoria Infusoria are minute freshwater life forms including ciliates, euglenoids, protozoa, unicellular algae and small invertebrates. Some authors (e.g., Bütschli) used the term as a synonym for Ciliophora. In modern formal classifications, the term i ...

'' Trichodina'' sp.,

parasitic 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 c ...

Ergasilus ''Ergasilus'' is a genus of copepod crustaceans occurring in both the ocean and fresh water, often called gill lice. The females are parasitic upon the gills of fishes. Being copepods, gill lice have a single median eye on their head. The second ...

sieboldi'',

''Diplostomum'' sp. and ''N. skrjabini'', and also acanthocephalans '' Acanthocephalus lucii''.

References

External links

Fishes of waters of Ukraine (in Russian)
{{Taxonbar, from=Q581610 Ponticola Freshwater fish of Europe Fish of Western Asia Fish of the Black Sea Fish described in 1861 Taxa named by Albert Günther Taxonomy articles created by Polbot