Kessler's sculpin (''Leocottus kesslerii'') 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 ...

Baikal sculpin The Cottidae are a family of fish in the superfamily Cottoidea, the sculpins. It is the largest sculpin family, with about 275 species in 70 genera.Kane, E. A. and T. E. Higham. (2012)Life in the flow lane: differences in pectoral fin morphology ...

, a freshwater fish native to

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 ...

and

Mongolia Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of , with a population of just 3.3 million, ...

where it occurs in

Lake Baikal Lake Baikal (, russian: Oзеро Байкал, Ozero Baykal ); mn, Байгал нуур, Baigal nuur) is a rift lake in Russia. It is situated in southern Siberia, between the federal subjects of Irkutsk Oblast to the northwest and the Repu ...

and surrounding lakes as well as the Selenga,

Angara The Angara ( Buryat and mn, Ангар, ''Angar'', "Cleft"; russian: Ангара́, ''Angará'') is a major river in Siberia, which traces a course through Russia's Irkutsk Oblast and Krasnoyarsk Krai. It drains out of Lake Baikal and is ...

and Bain Gol rivers. It is the only member of its

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

. In Lake Baikal it occurs on sandy, rocky-sandy or sandy-muddy bottoms, ranging from relatively shallow water to depths of . In rivers they mainly occur in slow-flowing channels and

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...

s. This species grows to a

total length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish ...

of , but typically is . Adults are

crepuscular In zoology, a crepuscular animal is one that is active primarily during the twilight period, being matutinal, vespertine, or both. This is distinguished from diurnal and nocturnal behavior, where an animal is active during the hours of daylig ...

, and feed on gammarids, chironomids, and young fish. Spawning takes place in May to June at depths. Eggs are deposited under stones, and the male stays guarding the eggs. The

pelagic The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or wa ...

larvae feed on

plankton Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankt ...

. The Kessler's sculpin is sometimes caught by commercial fishers, and it is eaten by the

Baikal seal The Baikal seal, Lake Baikal seal or (''Pusa sibirica''), is a species of earless seal endemic to Lake Baikal in Siberia, Russia. Like the Caspian seal, it is related to the Arctic ringed seal. The Baikal seal is one of the smallest true seals a ...

, comprising about 0.3% of its diet in the winter and spring, and significantly more in the autumn. Kessler’s sculpin was first formally described as ''Cottus kessleri'' in 1874 by the Polish

zoologist Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the Animal, animal kingdom, including the anatomy, structure, embryology, evolution, Biological clas ...

Benedykt Dybowski with its type locality given as Lake Baikal and the Angara, Irkut and Selenga rivers in Siberia. In 1955 the name ''Leocottus'' was posthumously published by

Dmitrii Nikolaevich Taliev Dmitrii Nikolaevich Taliev (28 May 1908 – 2 July 1952) was a Soviet Russian ichthyologist and limnologist, notable for his work on the Lake Baikal. Notable Dates (includes list of publications and short biography) * 1930 - Senior Assistant, Pac ...

, as a

subgenus In biology, a subgenus (plural: subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between t ...

of ''

Paracottus The stone sculpin (''Paracottus knerii'') is a species of cottoid fish endemic to Russia, where it is found in Lake Baikal and surrounding tributaries as well as the Gramninskie Lakes, Lake Verkhnaya Agata and the Enisei River and various lakes ...

'', but he did not designate a

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

so the name was unavailable under the

ICZN The International Code of Zoological Nomenclature (ICZN) is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals. It is also informally known as the ICZN Code, for its publisher, the I ...

. In 1961 the British

ichthyologist Ichthyology is the branch of zoology devoted to the study of fish, including bony fish ( Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha). According to FishBase, 33,400 species of fish had been described as of Octobe ...

Geoffrey Palmer Geoffrey Palmer may refer to: Politicians *Sir Geoffrey Palmer, 1st Baronet (1598–1670), English lawyer and politician *Sir Geoffrey Palmer, 3rd Baronet (1655–1732), English politician, Member of Parliament (MP) for Leicestershire *Geoffrey Pal ...

published the name in ''

The Zoological Record ''The Zoological Record'' (''ZR'') is an electronic index of zoological literature that also serves as the unofficial register of scientific names in zoology. It was started as a print publication in 1864 by the Zoological Society of London, a ...

''. It is now regarded as a valid monospecific genus which was classified in the family Cottocomephoridae but the 5th edition of ''

Fishes of the World ''Fishes of the World'' by the American ichthyologist Joseph S. Nelson (1937–2011) is a standard reference for fish systematics. Now in its fifth edition (2016), the work is a comprehensive overview of the diversity and classification of the ...

'' states that this taxon forms a

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

arising from within the genus '' Cottus''.

References

{{Taxonbar, from=Q2119250 Cottinae Fish described in 1874 Taxa named by Benedykt Dybowski