The Abyssocottinae are a
subfamily
In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...
of
ray-finned fish
Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species.
The ray-finned fishes are so called because their fins are webs of skin supported by bony or hor ...
es in the family
Cottidae
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 ...
, the sculpins. They are known commonly as the deep-water sculpins.
[Froese, R. and D. Pauly. (Eds.]
Abyssocottidae.
FishBase. 2011. The entire family is
endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...
to
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 ...
in
Siberia
Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part of ...
.
[Hunt, D. M., et al. (1997)]
Molecular evolution of the cottoid fish endemic to Lake Baikal deduced from nuclear DNA evidence.
''Molecular Phylogenetics and Evolution'' 8(3), 415–22.
Sculpins of this subfamily mostly live in deep water, below .
[ There are 24 known species in seven genera.][ These include, for instance, '' Abyssocottus korotneffi'' and '']Cottinella boulengeri
The short-headed sculpin (''Cottinella boulengeri'') iray-finned fish belonging to the family Cottidae, the typical sculpins. This species is endemic to Lake Baikal in Russia. It lives at depths of from , and is not longer than TL. This specie ...
'' which are among the deepest-living freshwater fish
Freshwater fish are those that spend some or all of their lives in fresh water, such as rivers and lakes, with a salinity of less than 1.05%. These environments differ from marine conditions in many ways, especially the difference in levels of s ...
. Baikal is the deepest lake on Earth () and sculpins occupy even its greatest depths.[
]
Evolution and systematics
Molecular studies based on mitochondrial DNA
Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial D ...
suggest that the Abyssocottinae along with other Lake Baikal cottoid fishes, now attributed to the likewise endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...
Cottocomephorinae (Baikal sculpins) and Comephorinae
''Comephorus'', known as the golomyankas or Baikal oilfish, are a genus comprising two species of peculiar, sculpin fishes endemic to Lake Baikal in Russia. ''Comephorus'' is the only genus in the family Comephoridae. Golomyankas are pelagic fi ...
(Baikal oilfish), together make a monophyletic
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...
group that has originated and diversified within the lake relative recently, since the Pliocene
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58[species flock
In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...](_blank)
comprising more than 30 species belonged to the widespread freshwater sculpin genus '' Cottus'' (in Cottidae
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 ...
). The Abyssocottidae itself appears as a natural group within this radiation, except that also the genus ''Batrachocottus
''Batrachocottus'' is a genus of freshawater ray-finned fishes belonging to the family Cottidae, the typical sculpins. These fishes are endemic to the Lake Baikal watershed in Russia.
Taxonomy
''Batrachocottus'' was first proposed as a monospeci ...
'' should be included.[Tytti Kontula, Sergei V. Kirilchik, Risto Väinölä (2003]
Endemic diversification of the monophyletic cottoid fish species flock in Lake Baikal explored with mtDNA sequencing
'' Molecular Phylogenetics and Evolution'' 27, 1, 143–155.
References
{{Taxonbar, from=Q1789959
Fish of Russia
Cottoidea