Coregonus hoyi
Encyclopedia
The bloater is a species
of freshwater whitefish
in the family
Salmonidae
. It is a silvery-coloured herring
-like fish, 25.5 centimetres (10 in) long. It is found in most of the Great Lakes
and in Lake Nipigon
, where it inhabits underwater slopes.
, from which it may be distinguished by its lighter upper lip and smaller eye. Its body is deepest at its middle, it has small and pale fins, and it has 40–47 long gill raker
s. The discoverer of the bloater, P. R. Hoy, thought it to be "the most beautiful of the white fish". It reaches a maximum total length of 37 centimetres (14.6 in) and commonly is 25.5 centimetres (10 in).
except Lake Erie
, and in Lake Nipigon
. Across its range it is in decline, and it is listed as Vulnerable
to global extinction
by the IUCN Red List
. It is extirpated in Lakes Ontario
and Nipigon, is uncommon in Lake Michigan
and is in decline Lakes Superior and Huron. This decline is caused mostly by predation by the alewife
, and also by sea lamprey
predation and pollution.
. Dr. Hoy collected the first specimens of this species in 1870 while dredging in Lake Michigan at least 16 miles (25.7 km) off Racine, at depths of 50 to 70 fathoms (90–130 m). Hoy did not describe the fish himself, but had icthyologist James W. Milner name the species. Milner placed it in the genus
Argyrosomus, now considered a junior synonym of Coregonus
, the genus in which the bloater is now placed. The generic name Coregonus, given by Carl Linnaeus in his 1758 tenth edition
of Systema Naturæ
, is derived from Greek
and means "angled eye", referring to the tilted pupil of whitefishes. It is closely related to the cisco or lake herring, Coregonus artedi, and the shortjaw cisco
, both of which it is known to hybridise with. The common name
of the bloater comes from the swollen appearance it has after being brought up from the deep waters it inhabits. The same name is given to certain type of smoked herring
in Britain, which is swelled in its preparation.
expands, giving it a swollen appearance.
The bloater feeds mostly on animals living at the lake bottom (zoobenthos), but will sometimes eat small drifting animals, or zooplankton
. The shrimp Mysis diluviana
, and the amphipod Diporeia hoyi, also named after P. R. Hoy, are recorded as food items. The lake trout
, various species of introduced salmon
, and the burbot
all are known to prey on the bloater. In the nineteenth century it was abundant, and was often caught by fishermen, among whom it was known as the "moon-eye". It was considered a good panfish
, but too small to be marketable. Since most of the other "chubs" of the Great Lakes have become extinct, the average size of the bloater has increased, and it is caught and smoked in the United States. The bloater is ignored by sport fishermen, since it is small and found at great depths, and it has too small of a mouth to be used as bait.
Spawning occurs all year round, but is usually in the winter or autumn. Spawning occurs at depths of 37 to 92 m (121.4 to 301.8 ft). The amount of eggs produced by the female varies depending upon her size, and ranges between 3,230 and 18,768. Eggs incubate for 4 months, and bloaters are 1.01 centimetre (0.397637795275591 in) in length at hatching. Larval bloaters head to the cool bottom of lakes before becoming pelagic, and by their first summers they become bottom-dwellers. Larval bloaters have a high mortality until they become large enough to avoid predation by other bloaters and alewives. It is slow-growing, because of the scarcity of food in its habitat. The bloater's average length at maturity is 18.3 centimetres (7.2 in), and maximum age reported from otoliths is 10 years.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of freshwater whitefish
Freshwater whitefish
The freshwater whitefish are fish of the subfamily Coregoninae in the salmon family Salmonidae. Along with the freshwater whitefish, the Salmonidae includes the freshwater and anadromous trout and salmon species as well as graylings...
in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Salmonidae
Salmonidae
Salmonidae is a family of ray-finned fish, the only living family currently placed in the order Salmoniformes. It includes salmon, trout, chars, freshwater whitefishes and graylings...
. It is a silvery-coloured herring
Herring
Herring is an oily fish of the genus Clupea, found in the shallow, temperate waters of the North Pacific and the North Atlantic oceans, including the Baltic Sea. Three species of Clupea are recognized. The main taxa, the Atlantic herring and the Pacific herring may each be divided into subspecies...
-like fish, 25.5 centimetres (10 in) long. It is found in most of the Great Lakes
Great Lakes
The Great Lakes are a collection of freshwater lakes located in northeastern North America, on the Canada – United States border. Consisting of Lakes Superior, Michigan, Huron, Erie, and Ontario, they form the largest group of freshwater lakes on Earth by total surface, coming in second by volume...
and in Lake Nipigon
Lake Nipigon
Lake Nipigon is the largest lake entirely within the boundaries of the Canadian province of Ontario . It is sometimes described as the sixth Great Lake. Lying 260 metres above sea level, the lake drains into the Nipigon River and thence into Nipigon Bay of Lake Superior...
, where it inhabits underwater slopes.
Description
The bloater is a small silvery-coloured whitefish with a pink and purple iridescence. It has a greenish tinge above, and a whitish belly. It is very similar to the kiyiKiyi
The kiyi is a species of freshwater whitefish, a deepwater cisco, endemic to the Great Lakes of North America. It previously inhabited Lake Superior, Lake Michigan, Lake Huron and Lake Ontario, but is now believed to persist only in Lake Superior where it is common...
, from which it may be distinguished by its lighter upper lip and smaller eye. Its body is deepest at its middle, it has small and pale fins, and it has 40–47 long gill raker
Gill raker
Gill rakers in fish are bony or cartilaginous processes that project from the branchial arch and are involved with filter feeding tiny prey. They are not to be confused with the gill filaments that compose the bony part of the gill. Rakers are usually present in two rows, projecting from both the...
s. The discoverer of the bloater, P. R. Hoy, thought it to be "the most beautiful of the white fish". It reaches a maximum total length of 37 centimetres (14.6 in) and commonly is 25.5 centimetres (10 in).
Distribution
The bloater is native to all of the Great LakesGreat Lakes
The Great Lakes are a collection of freshwater lakes located in northeastern North America, on the Canada – United States border. Consisting of Lakes Superior, Michigan, Huron, Erie, and Ontario, they form the largest group of freshwater lakes on Earth by total surface, coming in second by volume...
except Lake Erie
Lake Erie
Lake Erie is the fourth largest lake of the five Great Lakes in North America, and the tenth largest globally. It is the southernmost, shallowest, and smallest by volume of the Great Lakes and therefore also has the shortest average water residence time. It is bounded on the north by the...
, and in Lake Nipigon
Lake Nipigon
Lake Nipigon is the largest lake entirely within the boundaries of the Canadian province of Ontario . It is sometimes described as the sixth Great Lake. Lying 260 metres above sea level, the lake drains into the Nipigon River and thence into Nipigon Bay of Lake Superior...
. Across its range it is in decline, and it is listed as Vulnerable
Vulnerable species
On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...
to global extinction
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...
by the IUCN Red List
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
. It is extirpated in Lakes Ontario
Lake Ontario
Lake Ontario is one of the five Great Lakes of North America. It is bounded on the north and southwest by the Canadian province of Ontario, and on the south by the American state of New York. Ontario, Canada's most populous province, was named for the lake. In the Wyandot language, ontarío means...
and Nipigon, is uncommon in Lake Michigan
Lake Michigan
Lake Michigan is one of the five Great Lakes of North America and the only one located entirely within the United States. It is the second largest of the Great Lakes by volume and the third largest by surface area, after Lake Superior and Lake Huron...
and is in decline Lakes Superior and Huron. This decline is caused mostly by predation by the alewife
Alewife
The alewife is a species of herring. There are anadromous and landlocked forms. The landlocked form is also called a sawbelly or mooneye...
, and also by sea lamprey
Sea lamprey
The sea lamprey is a parasitic lamprey found on the Atlantic coasts of Europe and North America, in the western Mediterranean Sea, and in the Great Lakes. It is brown, gray, or black on its back and white or gray on the underside and can grow up to 90 cm long. Sea lampreys prey on a wide...
predation and pollution.
Taxonomy and etymology
The specific epithet of the bloater is given after Dr. P. R. Hoy of Racine, WisconsinRacine, Wisconsin
Racine is a city in and the county seat of Racine County, Wisconsin, United States. According to 2008 U.S. Census Bureau estimates, the city had a population of 82,196...
. Dr. Hoy collected the first specimens of this species in 1870 while dredging in Lake Michigan at least 16 miles (25.7 km) off Racine, at depths of 50 to 70 fathoms (90–130 m). Hoy did not describe the fish himself, but had icthyologist James W. Milner name the species. Milner placed it in the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Argyrosomus, now considered a junior synonym of Coregonus
Coregonus
Coregonus is a diverse genus of fish in the salmon family . The type species is the common whitefish . The Coregonus species are known as whitefishes...
, the genus in which the bloater is now placed. The generic name Coregonus, given by Carl Linnaeus in his 1758 tenth edition
10th edition of Systema Naturae
The 10th edition of Systema Naturae was a book written by Carl Linnaeus and published in two volumes in 1758 and 1759, which marks the starting point of zoological nomenclature...
of Systema Naturæ
Systema Naturae
The book was one of the major works of the Swedish botanist, zoologist and physician Carolus Linnaeus. The first edition was published in 1735...
, is derived from Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
and means "angled eye", referring to the tilted pupil of whitefishes. It is closely related to the cisco or lake herring, Coregonus artedi, and the shortjaw cisco
Shortjaw cisco
The shortjaw cisco is a deepwater cisco or chub . It has large, smooth scales and is iridescent silver, with a greenish back and white belly. The mouth is small and toothless, and the lower jaw is shorter than or equal in length to the upper jaw...
, both of which it is known to hybridise with. The common name
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...
of the bloater comes from the swollen appearance it has after being brought up from the deep waters it inhabits. The same name is given to certain type of smoked herring
Herring
Herring is an oily fish of the genus Clupea, found in the shallow, temperate waters of the North Pacific and the North Atlantic oceans, including the Baltic Sea. Three species of Clupea are recognized. The main taxa, the Atlantic herring and the Pacific herring may each be divided into subspecies...
in Britain, which is swelled in its preparation.
Ecology and behaviour
The bloater is found at depths of 30 to 198 m (98.4 to 649.6 ft). There it inhabits underwater slopes, and is tolerant of temperatures between 34.7 to 52.4 degrees Fahrenheit (1.5 to 11.4 Celsius). When it is brought to the surface its gas bladderGas bladder
The swim bladder, gas bladder, fish maw or air bladder is an internal gas-filled organ that contributes to the ability of a fish to control its buoyancy, and thus to stay at the current water depth without having to waste energy in swimming...
expands, giving it a swollen appearance.
The bloater feeds mostly on animals living at the lake bottom (zoobenthos), but will sometimes eat small drifting animals, or zooplankton
Zooplankton
Zooplankton are heterotrophic plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word "zooplankton" is derived from the Greek zoon , meaning "animal", and , meaning "wanderer" or "drifter"...
. The shrimp Mysis diluviana
Mysis diluviana
Mysis diluviana is a mysid crustacean that inhabits freshwater lakes of northern North America.-Appearance:Mysis is a small, transparent shrimp-like crustacean, of less than length...
, and the amphipod Diporeia hoyi, also named after P. R. Hoy, are recorded as food items. The lake trout
Lake trout
Lake trout is a freshwater char living mainly in lakes in northern North America. Other names for it include mackinaw, lake char , touladi, togue, and grey trout. In Lake Superior, they can also be variously known as siscowet, paperbellies and leans...
, various species of introduced salmon
Salmon
Salmon is the common name for several species of fish in the family Salmonidae. Several other fish in the same family are called trout; the difference is often said to be that salmon migrate and trout are resident, but this distinction does not strictly hold true...
, and the burbot
Burbot
The burbot is the only gadiform fish inhabiting freshwaters. It is also known as mariah, the lawyer, and eelpout. It is closely related to the marine common ling and the cusk...
all are known to prey on the bloater. In the nineteenth century it was abundant, and was often caught by fishermen, among whom it was known as the "moon-eye". It was considered a good panfish
Panfish
A panfish, also spelled pan-fish or pan fish, is an edible game fish that usually doesn't outgrow the size of a frying pan. The term is also commonly used by anglers to refer to any small catch that will fit in a pan, but is large enough to be legal. However its definition and usage varies with...
, but too small to be marketable. Since most of the other "chubs" of the Great Lakes have become extinct, the average size of the bloater has increased, and it is caught and smoked in the United States. The bloater is ignored by sport fishermen, since it is small and found at great depths, and it has too small of a mouth to be used as bait.
Spawning occurs all year round, but is usually in the winter or autumn. Spawning occurs at depths of 37 to 92 m (121.4 to 301.8 ft). The amount of eggs produced by the female varies depending upon her size, and ranges between 3,230 and 18,768. Eggs incubate for 4 months, and bloaters are 1.01 centimetre (0.397637795275591 in) in length at hatching. Larval bloaters head to the cool bottom of lakes before becoming pelagic, and by their first summers they become bottom-dwellers. Larval bloaters have a high mortality until they become large enough to avoid predation by other bloaters and alewives. It is slow-growing, because of the scarcity of food in its habitat. The bloater's average length at maturity is 18.3 centimetres (7.2 in), and maximum age reported from otoliths is 10 years.
Literature cited
- Becker, George C. (1983). Fishes of Wisconsin Madison, Wisconsin: University of Wisconsin Press. ISBN 0299087905
- Crowder, Larry B., and Fred P. Binkowski (1983). "Foraging behaviors and the interaction of alewife, Alosa pseudoharengus, and bloater, Coregonus hoyi." Environmental Biology of Fishes. 8(2):105–113
- Dickson, Tom (2008). The Great Minnesota Fish Book Minneapolis: University of Minnesota Press. ISBN 978-0-8166-5135-1
- Hesselberg, Robert J.; James P. Hickey, David A. Nortrup, and Wayne A. Willford (1990) "Contaminant residues in the bloater (Coregonus hoyi) of Lake Michigan, 1969-1986." Journal of Great Lakes Research. 16(1):121–129.
- Hubbs, Carl C.; Lagler, Karl F.; and Smith, Gerald R. (2004). Fishes of the Great Lakes Region revised ed. Ann Arbor: University of Michigan Press. ISBN 0-472-11371-2
- Page, Lawrence M., and Burr, Brooks M. (1991). A Field Guide to Freshwater Fishes Boston: Houghton Mifflin. ISBN 0-395-910910
- Partridge, Eric (1983). Origins: a short etymological dictionary of modern English 1983 ed. New York: Greenwich House. ISBN 0-517-414252
- Rice, James A.; Larry B. Crowder, and Fred P. Binkowski (1987). "Evaluating Potential Sources of Mortality for Larval Bloater (Coregonus hoyi): Starvation and Vulnerability to Predation." Canadian Journal of Fisheries and Aquatic Sciences. 44(2): 467–472.
- Smith, Hugh M. (1895). "Notes on Two Hitherto Unrecognised Species of American Whitefishes" in McDonald, Marshall, ed. Bulletin of the United States Fish Commission, Volume XIV. pp. 1–14