Aurora trout
Encyclopedia
The aurora trout, Salvelinus fontinalis timagamiensis, is a variant or subspecies
of the brook trout
native to two lakes in the Temagami District of Ontario
, Canada. The existence of the fish was brought to the attention of the angling world by four American anglers who were taken by Archie King of Latchford, Ontario
Canada
into Ontario
's Lady Evelyn River
System in 1923. Recognising the fish as different or unique, the anglers took a specimen back to the Carnegie Museum in Pittsburgh
in the United States
, where Dr. Arthur W. Henn was asked to identify the fish. He wrote about the fish in 1925 wherein he and Rinckenbach identified it as a distinct species, Salvelinus timagamiensis but, since a seminal re-examination of the material by Sale in 1967, taxonomists
now agree that the fish is, in a fact, at most a subspecies of the brook trout, named Salvelinus fontinalis timagamiensis. Genetic data have not so far supported its taxonomic distinction.
The aurora trout is distinguished from the brook trout by its unique coloration. Aurora trout are generally without spots, the colouration grading from a magenta hue on the back to a bright, nearly fluorescent orange along the belly, especially in mature
males. The life history of the fish is essentially identical to that of the brook trout. Adults average about 0.5 to 1.5 kg although individuals up to 3.5 or 4 kg are known.
The aurora trout occupied a very restricted range, probably occurring in only two lakes, Whitepine and Whirligig, and their inflowing streams. The subspecies was extirpated
from the original lakes by the ravages of acid rain
in the late 1950s but was saved from extinction
by Paul Graf, a hatchery
manager at the Ontario Ministry of Natural Resources
. He had brought a brood stock of the fish into the hatchery at Hill's Lake near Charlton, Ontario. He sometimes feared that the fish might have been taking up valuable space in the hatchery and, on several occasions, thought about getting rid of them, until it was discovered that they were extirpated
from the wild.
Naturalised populations of aurora trout have been introduced into approximately a dozen lakes in Northeastern Ontario
as refugia. In the late 1980s, the original lakes were treated with lime
in order to raise the pH
to circumneutral conditions, and aurora trout were re-introduced. Natural reproduction of aurora trout has been documented in the original lakes since the re-introduction but the pH in the lakes has since begun to decline again, presumably because of reservoirs of acidic particulate depositions in the watershed.
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
of the brook trout
Brook trout
The brook trout, Salvelinus fontinalis, is a species of fish in the salmon family of order Salmoniformes. In many parts of its range, it is known as the speckled trout or squaretail. A potamodromous population in Lake Superior are known as coaster trout or, simply, as coasters...
native to two lakes in the Temagami District of Ontario
Ontario
Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....
, Canada. The existence of the fish was brought to the attention of the angling world by four American anglers who were taken by Archie King of Latchford, Ontario
Latchford, Ontario
Latchford is a Single-tier municipality town in Timiskaming District in Northeastern Ontario, Canada. It is located on Bay Lake on the Montreal River near the town of Cobalt and the municipality of Temagami, and is 20 kilometres from the city of Temiskaming Shores. The population of the town in...
Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
into Ontario
Ontario
Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....
's Lady Evelyn River
Lady Evelyn River
The Lady Evelyn River is a river in Temagami region in Nipissing, Sudbury and Timiskaming Districts, Ontario, Canada. The river begins at the confluence of the North and South Lady Evelyn Rivers and flows to its mouth at the Montreal River...
System in 1923. Recognising the fish as different or unique, the anglers took a specimen back to the Carnegie Museum in Pittsburgh
Pittsburgh, Pennsylvania
Pittsburgh is the second-largest city in the US Commonwealth of Pennsylvania and the county seat of Allegheny County. Regionally, it anchors the largest urban area of Appalachia and the Ohio River Valley, and nationally, it is the 22nd-largest urban area in the United States...
in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, where Dr. Arthur W. Henn was asked to identify the fish. He wrote about the fish in 1925 wherein he and Rinckenbach identified it as a distinct species, Salvelinus timagamiensis but, since a seminal re-examination of the material by Sale in 1967, taxonomists
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...
now agree that the fish is, in a fact, at most a subspecies of the brook trout, named Salvelinus fontinalis timagamiensis. Genetic data have not so far supported its taxonomic distinction.
The aurora trout is distinguished from the brook trout by its unique coloration. Aurora trout are generally without spots, the colouration grading from a magenta hue on the back to a bright, nearly fluorescent orange along the belly, especially in mature
Sexual maturity
Sexual maturity is the age or stage when an organism can reproduce. It is sometimes considered synonymous with adulthood, though the two are distinct...
males. The life history of the fish is essentially identical to that of the brook trout. Adults average about 0.5 to 1.5 kg although individuals up to 3.5 or 4 kg are known.
The aurora trout occupied a very restricted range, probably occurring in only two lakes, Whitepine and Whirligig, and their inflowing streams. The subspecies was extirpated
Local extinction
Local extinction, also known as extirpation, is the condition of a species which ceases to exist in the chosen geographic area of study, though it still exists elsewhere...
from the original lakes by the ravages of acid rain
Acid rain
Acid rain is a rain or any other form of precipitation that is unusually acidic, meaning that it possesses elevated levels of hydrogen ions . It can have harmful effects on plants, aquatic animals, and infrastructure. Acid rain is caused by emissions of carbon dioxide, sulfur dioxide and nitrogen...
in the late 1950s but was saved from 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 Paul Graf, a hatchery
Hatchery
A hatchery is a facility where eggs are hatched under artificial conditions, especially those of fish or poultry. It may be used for ex-situ conservation purposes, i.e. to breed rare or endangered species under controlled conditions; alternatively, it may be for economic reasons A hatchery is a...
manager at the Ontario Ministry of Natural Resources
Ministry of Natural Resources (Ontario)
The Ministry of Natural Resources is a government ministry of the Canadian province of Ontario that responsible for Ontario’s provincial parks, forests, fisheries, wildlife, mineral aggregates and the Crown lands and waters that make up 87 per cent of the province...
. He had brought a brood stock of the fish into the hatchery at Hill's Lake near Charlton, Ontario. He sometimes feared that the fish might have been taking up valuable space in the hatchery and, on several occasions, thought about getting rid of them, until it was discovered that they were extirpated
Local extinction
Local extinction, also known as extirpation, is the condition of a species which ceases to exist in the chosen geographic area of study, though it still exists elsewhere...
from the wild.
Naturalised populations of aurora trout have been introduced into approximately a dozen lakes in Northeastern Ontario
Northeastern Ontario
Northeastern Ontario is the region within the Canadian province of Ontario which lies north and east of Lakes Superior and Huron.Northeastern Ontario consists of the districts of Algoma, Sudbury, Cochrane, Timiskaming, Nipissing and Manitoulin; and the single-tier municipality of Greater...
as refugia. In the late 1980s, the original lakes were treated with lime
Lime (mineral)
Lime is a general term for calcium-containing inorganic materials, in which carbonates, oxides and hydroxides predominate. Strictly speaking, lime is calcium oxide or calcium hydroxide. It is also the name for a single mineral of the CaO composition, occurring very rarely...
in order to raise the pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
to circumneutral conditions, and aurora trout were re-introduced. Natural reproduction of aurora trout has been documented in the original lakes since the re-introduction but the pH in the lakes has since begun to decline again, presumably because of reservoirs of acidic particulate depositions in the watershed.
External links
- The Aurora Trout ... a Species at Risk in Ontario Fisheries and Oceans Canada (2010-09-27)