Pink salmon have been popular in the fishing industry for many years and remain one of the most sought after salmon species among consumers. It is well known for its taste, nutritional value and reasonable price, making it a valuable product in the global food market. Let's consider a detailed description of pink salmon, its lifestyle and where it is found.
Description of the species
Pink salmon is a common fish of the salmon family, known for its small size and habitat in cold sea and ocean waters. It is considered anadromous, meaning it spawns in freshwater rivers but lives in the salt waters of the oceans.Male pink salmon develop a characteristic hump on their back when they are ready to breed, hence the species name.
The oldest relative of the pink salmon was a small fish similar to the grayling that lived in the cold waters of the North American continent more than fifty million years ago. Over the next 30 million years there is no evidence of evolution of this species of salmonid fish. However, between 20 million years ago, all species of salmon fish existing today, including pink salmon, were already found in ancient seas.
This is interesting! All humpback salmon fry are initially female, and just before migrating to the ocean, half of them change sex. This is one of the methods that nature uses to help this species survive. Since females have a hardy body, this “transformation” increases the chances that more larvae will survive until migration time.
Appearance
Pink salmon is distinguished by an elongated body that is slightly flattened on the sides; this is a feature characteristic of all salmon fish. The head is conical in shape with tiny eyes, with males having a more elongated head than females. Tiny teeth are scattered throughout the jaws, lingual and palatal bones of pink salmon. The scales on the body come off easily, and they are very small.
The upper part of the body of the oceanic pink salmon has a blue-green tint, the sides appear silver, and the bottom appears white. When they return to spawn in river waters, they turn light gray, while their bellies appear yellow or green with dark spots. As they approach the spawning period, their color darkens and their heads become almost black.
Females retain their physique from birth and throughout life, but males undergo a radical transformation:
- the head increases in size and becomes longer;
- a set of large teeth appears on the expanded jaw;
- An impressive hump develops along the back.
Pink salmon, a salmon species, have an adipose fin located between the dorsal and caudal fins. As a rule, the weight of an adult pink salmon is about two and a half kilograms and its length is 50 cm. The largest recorded specimens weigh seven kilograms and measure seventy-five centimeters in length.
Pink salmon has certain characteristics that set it apart from other salmon species. These include:
- lack of teeth on the tongue;
- white mouth;
- dark oval markings along the back;
- V-shaped caudal fin.
Habitat
Pink salmon are found in abundance in northern Pacific waters. This unusual looking species of salmon is found off the coast of Alaska in the Arctic Ocean. The most significant populations occur in the North Pacific, where American and Asian groups mix during spawning. Pink salmon have even been known to make occasional appearances in parts of the Great Lakes of North America.
Pink salmon live in the ocean for one summer and winter, then migrate to rivers in the middle of the second summer to breed. The largest fish leave first, followed by the smaller ones. Females reach spawning grounds later than males, and by the end of summer, after the end of spawning, only babies return to the sea.
Interesting fact. The most notable member of the ancient salmon family is the now extinct “saber-tooth salmon.” This fish weighed more than two kilograms and measured approximately three meters in length. Her “decoration” was five-centimeter fangs. Despite its terrifying appearance and size, it was not a predator; her fangs were just part of her mating outfit.
Pink salmon feels great in cold waters with temperatures from five to fifteen degrees Celsius, the ideal being ten degrees. If the temperature rises above twenty-five degrees Celsius, it will be fatal to pink salmon.
Lifestyle
Pink salmon do not have a specific habitat and are capable of moving hundreds of miles from their place of birth. Their lives are devoted to reproduction, with a lifespan of only two years, starting as tiny fry and ending at the time of the next spawning. When these fish reproduce en masse, hundreds of dead adults are found along river banks.
The migrations of pink salmon are shorter than those of chum salmon and occur from June to the end of summer. The fish stays in the riverbed, gravitating towards places with large pebbles and strong currents. As soon as the spawning process is completed, the spawners die.
As a rule, salmonids have an extraordinary sense of direction and are able to return to their original habitat with amazing accuracy. However, pink salmon are not so lucky in this area, since their inherent “navigation” system sometimes fails, and therefore they sometimes end up in places unsuitable for spawning or habitat. From time to time, a large group of these fish floods one river, completely filling it with their bodies, which, unfortunately, does not allow them to reproduce normally.
Adults consume large amounts of plankton. In the deepest parts of the ocean, their diet consists of juvenile fish, small fish and squid.When approaching the plume, pink salmon are able to completely change their food source to fry of invertebrates and other fish species.
As they prepare to spawn, their appetite disappears and their digestive system begins to atrophy; but despite this, they retain a strong grasping reflex, which makes spinning fishing quite successful during this period.
Young animals primarily consume small inhabitants of the depths of reservoirs and plankton. Having migrated to the ocean, they feed on small zooplankton. As they mature, their diet shifts towards large species of zooplankton and small fish. Even though pink salmon are relatively small compared to other species, they grow at an accelerated rate. By their first summer season, young fish reach a length of approximately twenty to twenty-five centimeters.
In the mid-1900s, due to the high economic value of pink salmon, several attempts were made to introduce this species of salmon into rivers near Murmansk, but all these attempts were unsuccessful.
Spawning
Humpback salmon use their tail fin to dig a nesting hole at the bottom of a body of water and lay their eggs in it. After spawning and fertilization, the fish closes the hole back with its caudal fin.
One female is capable of laying from a thousand to two and a half thousand eggs. These eggs are then fertilized by the male. There are always more males swimming around the spawning holes than females. This is because each batch of eggs must be fertilized by another male so that the genetic code is passed on to subsequent generations.
Baby fish (or larvae) appear in November or December, but sometimes hatch in January.They use up their yolk sac while they are in the ground and then leave the spawning pits in May. Their path lies to the sea. Unfortunately, most of them do not survive this journey, as they become food for other fish and birds. At this stage of their life they are only three centimeters long. Their bodies are silver in color, without admixtures of other shades.
After leaving the river, pink salmon fry migrate to the North Pacific Ocean and remain in this area until August of the following year. This species has a two-year life cycle, which explains why there is a biennial periodicity in their population size. This red fish reaches sexual maturity only in the 2nd year of life.
Are there any enemies?
Pink salmon are highly endangered in their natural habitat as their eggs are eaten by a wide range of predators, including char, grayling, gulls, wild ducks and other fish.
In addition, adult pink salmon are often hunted by beluga whales, seals, and sharks, and on freshwater spawning grounds they become food for bears, otters, and birds of prey.
It is interesting to note that more than a third of the Pacific salmon caught worldwide are pink salmon. During the 1980s, an average of two hundred and forty thousand tons of this fish were caught annually. The Soviet Union's share of the total salmon fishery was about eighty percent.
In addition to danger from predators, pink salmon suffer from competition from other species that seek the same food as them. In some cases, pink salmon also cause declines in the numbers of other fish or bird species. Scientists have noticed a correlation between the increase in the number of pink salmon in northern Pacific waters and the decline in the population of petrels.The two species fight for food when the petrels spend their winter in the north. They do not have enough food given the abundance of pink salmon in the local waters, which leads to the death of the birds during their next trip to the south.
Species status
The pink salmon population changes dramatically in its natural habitat due to the cyclical nature of its life, while predators have virtually no effect on its numbers. Although pink salmon are a popular fishing target, there is no danger of extinction as the status of the species remains stable.
In the past two decades, the population of pink salmon living in the northern part of the Pacific waters has doubled compared to the 1970s of the last century. This surge occurred not only due to the natural growth of the species, but also as a result of the introduction of fry from incubators. Now there are no farms with a full cycle of pink salmon cultivation, which makes it even more desirable for buyers.
Canadian scientists have made a shocking discovery: the close proximity of wild pink salmon spawning grounds to fish hatcheries where other salmon species are raised causes significant harm to the natural population of the former. The cause of death for juvenile fish is believed to be a special type of lice that they pick up from farmed fish when they migrate to the ocean. If nothing is done, then in 4 years only 1% of the indigenous population will remain in these regions.
Historical reference
Scientists in Russia have observed a strange feature of pink salmon: it migrates to the rivers of Primorye to breed only in odd-numbered years, and to the rivers of Kamchatka and Amur in even-numbered years. There is no consensus yet on the reasons for this behavior.
An interesting aspect of this type of fish is that they do not have distinct subspecies. This is due to three factors:
- Individuals from different populations are able to mix with each other.
- Pink salmon have an amazing tolerance to many environmental elements throughout their life cycle.
- The homogeneity of the environment throughout its range prevents the formation of subspecies with unique characteristics and external features.
