The deepwater sculpin (''Myoxocephalus thompsonii'') 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 ...
of
freshwater
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...
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
family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
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 ...
of
order Scorpaeniformes
The Scorpaeniformes are a diverse order of ray-finned fish, including the lionfishes and sculpins, but have also been called the Scleroparei. It is one of the five largest orders of bony fishes by number of species, with over 1,320.
They are ...
.
It is a
glacial relict
A glacial relict is a population of a cold-adapted species that has been left behind as the range of the species changed after an ice age ended. Glacial relicts are usually found in enclaves "under relatively benign conditions".
Examples:
*The bi ...
, native to a limited number of deep, cold lakes in
Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
and 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 ...
.
The deepwater sculpin was first described in 1851 by
Charles Frédéric Girard
Charles Frédéric Girard (8 March 1822 – 29 January 1895) was a French biologist specializing in ichthyology and herpetology.
Born in Mulhouse, France, he studied at the College of Neuchâtel, Switzerland, as a student of Louis Agassiz. In ...
under the name ''Triglopsis thompsonii''.
The description was based on specimens obtained by
Spencer Fullerton Baird
Spencer Fullerton Baird (; February 3, 1823 – August 19, 1887) was an American naturalist, ornithologist, ichthyologist, Herpetology, herpetologist, and museum curator. Baird was the first curator to be named at the Smithsonian Institution. He ...
for the
Smithsonian Institution
The Smithsonian Institution ( ), or simply the Smithsonian, is a group of museums and education and research centers, the largest such complex in the world, created by the U.S. government "for the increase and diffusion of knowledge". Founded ...
from the stomachs of
Burbot
The burbot (''Lota lota'') is the only gadiform (cod-like) 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 di ...
caught by fishermen on
Lake Ontario
Lake Ontario is one of the five Great Lakes of North America. It is bounded on the north, west, and southwest by the Canadian province of Ontario, and on the south and east by the U.S. state of New York. The Canada–United States border sp ...
.
The name ''Triglopsis'' referred to its resemblance to the
Piper gurnard
The piper gurnard (''Trigla lyra''), also known as the piper or the lyre gurnard, is a species of marine, demersal ray-finned fish from the family Triglidae, the gurnards and sea robins. It is found in the eastern Atlantic Ocean and the Mediterran ...
.
The specific epithet honored fellow
naturalist Rev.
Zadock Thompson of
Burlington, Vermont
Burlington is the most populous city in the U.S. state of Vermont and the seat of Chittenden County. It is located south of the Canada–United States border and south of Montreal. As of the 2020 U.S. census, the population was 44,743. It ...
.
The similarity between this species and the
Fourhorn sculpin
The fourhorn sculpin (''Myoxocephalus quadricornis'') is a species of fish in the family Cottidae. It is a demersal fish distributed mainly in brackish arctic coastal waters in Canada, Greenland, Russia, and Alaska, and also as a relict in the bo ...
led to some taxonomic discussion. Some authors considered it a
subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...
(''Myoxocephalus quadricornis thompsonii''), while other authors maintained it as a species within the same
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 ...
(''Myoxocephalus thompsonii'').
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 ...
analysis was able to establish that the two species were distinct while providing additional support for the proposal that the deepwater sculpin evolved from the fourhorn sculpin during the early
Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...
era.
The deepwater sculpin is a small fish on average between in length
Its body is generally flattened in shape and tapers from the head to the tail.
It does not have true scales.
Spines are present on the body and fins.
The skin is mottled green, gray and brown on the back and whitish underneath.
The deepwater sculpin can be distinguished from other freshwater sculpins in its range by a distinct gap between the two dorsal fins.
It is most similar in appearance to the fourhorn sculpin, a fish found in salt and
brackish water
Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estua ...
in the
arctic
The Arctic ( or ) is a polar regions of Earth, polar region located at the northernmost part of Earth. The Arctic consists of the Arctic Ocean, adjacent seas, and parts of Canada (Yukon, Northwest Territories, Nunavut), Danish Realm (Greenla ...
but lacks the four bony spines found on the head of that species.
The deepwater sculpin is found from the
Gatineau
Gatineau ( ; ) is a city in western Quebec, Canada. It is located on the northern bank of the Ottawa River, immediately across from Ottawa, Ontario. Gatineau is the largest city in the Outaouais administrative region and is part of Canada's N ...
through the
Great Lakes
The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the mid-east region of North America that connect to the Atlantic Ocean via the Saint Lawrence River. There are five lakes ...
,
Manitoba
Manitoba ( ) is a Provinces and territories of Canada, province of Canada at the Centre of Canada, longitudinal centre of the country. It is Canada's Population of Canada by province and territory, fifth-most populous province, with a population o ...
, and
Saskatchewan
Saskatchewan ( ; ) is a Provinces and territories of Canada, province in Western Canada, western Canada, bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and on t ...
to the
Great Slave
Great Slave is a territorial electoral district for the Legislative Assembly of the Northwest Territories, Canada.
It is one of seven districts that represent Yellowknife
Yellowknife (; Dogrib: ) is the capital, largest community, and onl ...
and
Great Bear Lakes. It is also found in
Waterton Lake
Waterton Lake is a mountain lake in southern Alberta, Canada and northern Montana, United States. The lake is composed of two bodies of water, connected by a shallow channel known locally as the Bosporus. The two parts are referred to as Middle Wat ...
within
Waterton Lakes National Park
Waterton Lakes National Park is a national park located in the southwest corner of Alberta, Canada. It borders Glacier National Park in Montana, United States. Waterton was the fourth Canadian national park, formed in 1895 and named after Waterto ...
and
Glacier National Park.
Within its range, it is limited to deep, well oxygenated lakes with ties to former
Wisconsinan glacial lakes or the
Champlain Sea
The Champlain Sea (french: Mer de Champlain) was a prehistoric inlet of the Atlantic Ocean into the North American continent, created by the retreating ice sheets during the closure of the last glacial period. The inlet once included lands in ...
.
The deepwater sculpin inhabits the
demersal zone
The demersal zone is the part of the sea or ocean (or deep lake) consisting of the part of the water column near to (and significantly affected by) the seabed and the benthos. The demersal zone is just above the benthic zone and forms a layer of ...
.
It prefers water temperatures that remain less than .
In lakes in the southern part of its range, it has been observed only in deep water where the water temperature remains cold year round.
The deepwater sculpin feeds primarily on small crustaceans
''
Mysis diluviana
''Mysis diluviana'' is a mysid crustacean (opossum shrimp) found in freshwater lakes of northern North America.
Appearance
''Mysis'' is a small, transparent shrimp-like crustacean, less than in length. It has two pairs of relatively long anten ...
'' and ''
Diporeia''.
They will also take
chironomid
The Chironomidae (informally known as chironomids, nonbiting midges, or lake flies) comprise a family of nematoceran flies with a global distribution. They are closely related to the Ceratopogonidae, Simuliidae, and Thaumaleidae. Many species ...
larvae.
Zooplankton
Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...
are the likely food of the larval stage.
Deepwater sculpin eggs hatch from November to August, peaking in March. Larvae are initially
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 ...
, staying in the water column above the reach of their adults. Beginning in July, larvae that have grown to go through
metamorphosis
Metamorphosis is a biological process by which an animal physically develops including birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some inse ...
and settle to the bottom.
Fish are thought to reach maturity at three years for females and two years for males.
Deepwater sculpin are a significant food source for other fish including
lake trout
The lake trout (''Salvelinus namaycush'') is a freshwater char living mainly in lakes in northern North America. Other names for it include mackinaw, namaycush, lake char (or charr), touladi, togue, and grey trout. In Lake Superior, it can also ...
(Salvelinus namaycush) and burbot (Lota lota).
They are an intermediate host for the parasites
Bothriocephalus cuspidatus
''Bothriocephalus'' is a genus of flatworms belonging to the family Bothriocephalidae.
The genus has cosmopolitan distribution.
Species:
*'' Bothriocephalus alessandrinii''
*'' Bothriocephalus andresi''
*'' Bothriocephalus angustatus''
*'' ...
, and
Proteocephalus sp. which also are found in the crustaceans they eat and the fish species that prey on them.
The deepwater sculpin is an
indicator species
A bioindicator is any species (an indicator species) or group of species whose function, population, or status can reveal the qualitative status of the environment. The most common indicator species are animals. For example, copepods and other sma ...
for the health of the deepwater communities in the lakes where it occurs.
It is of special interest to those interested in
zoogeography
Zoogeography is the branch of the science of biogeography that is concerned with geographic distribution (present and past) of animal species.
As a multifaceted field of study, zoogeography incorporates methods of molecular biology, genetics, mo ...
.
The deepwater sculpin is classified as of
Least Concern
A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...
by the IUCN based on the apparent stability of the population.
In Canada, it is considered a species at risk under the
Species at Risk Act
The ''Species at Risk Act'' (SARA) (the ''Act'') is a piece of Canadian federal legislation which became law in Canada on December 12, 2002. It is designed to meet one of Canada's key commitments under the International Convention on Biological D ...
. Threats include
habitat loss
Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...
, lake
eutrophication
Eutrophication is the process by which an entire body of water, or parts of it, becomes progressively enriched with minerals and nutrients, particularly nitrogen and phosphorus. It has also been defined as "nutrient-induced increase in phytopla ...
,
invasive species
An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...
, and water
pollution
Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the ...
.
References
External Links
Deepwater sculpin (Myoxocephalus thompsonii) management plan, Species at Risk, Government of Canada
{{Taxonbar, from=Q2131245
Fish of the Great Lakes
Fish described in 1851
Myoxocephalus