Loach – belongs to the salmon family and forms many different forms, which confuses ichthyologists, since it is often almost impossible to understand which species the presented sample corresponds to. Char is the northernmost salmon fish. Many members of this genus are popular sport fish and some have become commercial fish.
Origin and description
The char was originally assigned to the genus Salmo by Carl Linnaeus as Salmo Alpinus in 1758. At the same time time, he described Salmo salvelinus and Salmo umbla, which were later considered as synonyms. John Richardson (1836) identified the subgenus Salmo (Salvelinus), which is now considered a full genus.
Interesting fact: The name of the genus Salvelinus comes from the German word “Saibling” – a small salmon. The English name is believed to be derived from the Old Irish ceara/cera meaning “blood red”, referring to the pink-red underside of the fish. It is also related to its Welsh name torgoch, “red belly”. The body of the fish is not covered with scales, probably this was the reason for the Russian name for the fish – char.
Arctic char is distinguished by numerous morphological variants or “morphs” throughout the species' range. Therefore, the Arctic charr is called “the most variable vertebrate animal on Earth.” Morphs vary in size, shape, and color, and show differences in migratory behavior, residence or anadromous properties, and feeding behavior. Morphs often interbreed, but they can also be reproductively isolated and exhibit genetically distinct populations, which have been cited as examples of incipient speciation.
In Iceland, Lake Thingvallavatn is known for the development of four morphs: small benthic, large benthic, small limnetic, and large limnetic. In Svalbard, Norway, there are dwarf, “normal” and anadromous fish of normal size on Lake Linne-Vatn, and on Bear Island — dwarf, small intertidal and large pelagic morph.
Appearance and features
Char is a genus of salmon fish, some species of which are called “trout”. It is a member of the subfamily Salmoninae in the family Salmonidae. The genus has a northern circumpolar distribution and most of its members tend to be cold-water fish that mostly inhabit fresh waters. Many species also migrate to the sea.
Arctic char is closely related to salmon and lake trout, and shares many characteristics of both species. The fish is very variable in color, depending on the time of year and the environmental conditions where it lives. An individual fish can weigh 9.1 kg or more. Generally, all market size fish are between 0.91 and 2.27 kg. The color of the flesh can vary from bright red to pale pink. A giant char up to 60.6 cm long and a dwarf char up to 9.2 cm have been recorded. The back of the fish is dark in color, while the ventral part varies from red, yellow and white depending on the location.
Main Characteristics of the charr fish:
- torpedo-shaped body;
- typical adipose fin;
- large mouth;
- different colors depending on habitat;
- partly reddish belly (especially during spawning season);
- blue-gray or brownish-greenish sides and back;
- size generally: 35 to 90 cm (in nature);
- weight from 500 to 15 kg.
During the spawning period, the red color becomes more intense, the males show a brighter color. The breeding char has red pectoral and anal fins and yellow or gold borders on the caudal fin. The color of the fin of a young charr is paler than that of adults.
Where does char live?
Charr living in mountain lakes and coastal arctic and subarctic waters has a circular distribution. It can be migratory, resident, or landlocked depending on location. The char fish is native to arctic and subarctic coasts and mountain lakes. It has been observed in the Arctic regions of Canada and Russia and in the Far East.
The fish is present in the basins of the rivers of the Barents Sea from the Volonga to the Kara, Jan Mayen, Svalbard, Kolguev, Bear Islands and Novaya Zemlya, Northern Siberia, Alaska, Canada and Greenland. In the north of Russia, charr is absent from the rivers flowing into the Baltic and White Seas. It usually breeds and winters in fresh water. Migration to the sea occurs in early summer from mid-June to July. There they spend about 50 days and then return to the river.
No other freshwater fish has been found this far north. It is the only fish species found in Lake Heizen in the Canadian Arctic and the rarest species in Britain and Ireland, found mostly in deep, glacial lakes. In other parts of its range, such as the Nordic countries, it is much more common and widely harvested. In Siberia, the fish was released into the lakes, where it began to pose a danger to less hardy endemic species.
Now you know where the char fish is found. Let's see what it eats.
What does a char eat?
The char changes its feeding habits depending on the location. Scientists have found more than 30 types of products in her stomach. Charr is a predatory fish that can hunt both day and night. Fish from the salmon family are considered visual predators. Although a species of char has been observed whose predatory instincts were based on taste and tactile stimuli rather than sight.
The char is known to feed on:
- amphibians and other aquatic crustaceans.
Some giant char have even been recorded as cannibals, eating both young of their own species and pygmy arctic char. The diet changes depending on the season. At the end of spring and throughout the summer, they eat insects found on the surface of the water, salmon caviar, snails and other smaller crustaceans found at the bottom of the lake, and small fish. During the autumn and winter months, the char feeds on zooplankton and freshwater shrimp, as well as small fish.
The marine diet of char consists of: copepods and krill (Thysanoessa). Lake char feeds mainly on insects and zoobenthos (mollusks and larvae). As well as fish: capelin (Mallotus villosus) and spotted goby (Triglops murrayi). In the wild, the life expectancy of a char is 20 years. The maximum recorded age of the fish was 40 years.
Character and lifestyle features
Loaches are migratory and highly social fish, found in groups during migration. They breed and winter in fresh water. Fish communicate with each other during spawning using the sense of smell. Males release a pheromone that attracts ovulated females. During the spawning period, males occupy their territory. Dominance is maintained by larger males. The char has a lateral line that helps them detect movements and vibrations in their environment.
Like most salmonids, there are huge differences in color and body shape between sexually mature individuals of different sexes. Males develop jaws with hooks that turn bright red. The females remain fairly silvery. Most males establish and guard territories and often appear with several females. Char does not die after spawning like Pacific salmon and often mate several times during their life (every second or third year).
The young fry emerge from the gravel in spring and live in the river for 5 to 7 months or until they are 15–20 cm long. The char fish do not provide parental care for the fry after spawning. All obligations are reduced to the construction of a nest by the female and the territorial protection of the area by males during the entire spawning period. Most species of char spend time at depths of up to 10 meters, and some rise to depths of up to 3 meters from the surface of the water. The maximum diving depth was recorded at 16 meters from the water surface.
Social Structure and Reproduction
Charr fish return from the ocean to their native freshwater rivers to spawn. Charr males are polygamous, while — monogamous. In preparation for spawning, males establish a territory that they defend. The females will choose a site within the male's territory and dig their spawning nest. Males begin to court females, circle around them, then move near the females and tremble. Together, males and females release eggs and milk into the pit area, so fertilization is external. Fertilized eggs are laid in gravel.
The onset of puberty for Arctic char varies from 4 to 10 years. This happens when they reach a length of 500-600 mm. Most populations spawn in autumn from September to December, although there are some landlocked populations that spawn in spring, summer, or winter. Arctic char usually spawns once a year, and some individuals do not spawn more than once every 3-4 years. Dominant males are territorial and protective of females.
Males usually breed with more than one female during the mating season. Females can lay from 2500 to 8500 eggs, which are then fertilized by males. Incubation time varies but usually occurs between 2-3 months. Hatching mass varies within populations. The weight of charr larvae at hatching was in the range from 0.04 to 0.07 g. The fry immediately become independent from their parents at hatching.
Egg development occurs in three stages:
- the splitting phase begins after fertilization and continues until the formation of an early embryo;
- epiboly phase. At this time, the cells formed during the cleavage phase begin to form specialized tissues;
- the organogenesis phase begins when internal organs begin to emerge.
Sex differentiation occurs shortly after hatching and is controlled by the chromosomal configuration of the nucleus in the fertilized egg. AY and an X chromosome result in a male, while two X chromosomes result in a female. Morphological sex characteristics are determined by hormones.
Natural enemies of char fish
The anti-predatory adaptation of the char is its ability to change color depending on the environment. They tend to be darker in lakes and lighter in the sea. A 2003 study found that some juvenile Arctic charrs have very sensitive scent recognition of predators. Observations have shown that the innate anti-predator behavior of juvenile fish is to respond specifically to chemical cues from various predatory fish as well as to the diet of predators.
Common predators of char are:
- sea otters;
- polar bears;
- arctic char;
- fish larger than char.
In addition, charr fish becomes a victim of such a parasite as sea lamprey. This vampire, sailing from the Atlantic Ocean, clings to the char with a sucker-like mouth, makes a hole in the skin and sucks out the blood. Other known parasites of char fish are protozoa, trematodes, tapeworms, nematodes, spiny worms, leeches and crustaceans.
People benefit from arctic char as a food source and for sport fishing. As a food, char fish is considered an expensive delicacy. The market price differs depending on the volume. Higher prices correlate with lower volume. Charr prices in 2019 average around $9.90 per kg of fish caught.
Population and species status
Arctic char is listed as Least Endangered by the IUCN Red List. The biggest threat to him — these are people. Another threat — salinization of water. In southern Scotland, several populations of char fish have become extinct due to the salinization of streams. Many populations of Arctic char in Ireland have become extinct due to lake salinization and declining water quality caused by domestic and agricultural pollution.
Fun Fact: The perceived threat faced by some populations of Arctic char, — lack of genetic variation. The char population in Lake Siamaa in southeast Finland depends on aquaculture for survival, which is explained by the fact that the lack of genetic variation in the native population causes egg death and predisposition to disease.
In some hard-to-reach lakes, the char population reaches a significant size. In the lakes located within the BAM zone, gold mining and exploration, the number of individuals has been significantly undermined, and in some water bodies the char has been completely exterminated. The main factors affecting the composition and number of charr populations are pollution of water bodies and unauthorized fishing.
Protection of char
Creating favorable conditions in the streams of southern Scotland is a possible conservation effort for char. Conservation methods have been proposed in Ireland as an attempt to protect populations of the remaining Arctic charr. Some of the methods proposed include ensuring sustainability, releasing fry, controlling nutrient intake, and preventing predatory fish from entering loach lakes. The restocking of these fish in lakes is another conservation effort being undertaken in some places such as Lake Siamaa in southeastern Finland.
In 2006, programs were established to raise char in arctic conditions as an environmentally sustainable best choice for consumers as these fish use only a moderate amount of marine resources for food. In addition, arctic char can be farmed in closed systems that minimize the chance of escaping into the wild.
The arctic char is currently listed as an endangered species under the federal Species at Risk Act and the Ontario Species at Risk Act. endangered species that provide legal protection to fish and their habitat. Additional protection is provided by the Federal Fisheries Act, which provides for habitat protection measures for all fish species.