Salmon go through several distinct stages in their early development before reaching adulthood. Biologists use different names for each stage of a young salmon’s life. It is important to know the names of baby salmon in order to understand how they grow and stay alive. Here, we’ll talk about the different names for young salmon and their different stages of life.
Alevin – the Newly Hatched Fry Still Attached to the Yolk Sac
The first stage of a young salmon’s life begins when it hatches from the egg as an alevin The alevin is characterized by the large yolk sac still attached to its belly that provides it nutrients.
At this stage the alevin does not actively feed but continues to grow while absorbing the yolk sac. The yolk sac gives the alevin the energy it needs to develop.
Alevin stay hidden in the gravel beds of their natal streams, living off the nutrients from the yolk sac. They are extremely vulnerable to predators at this stage. Their camouflage in the gravel and lack of movement helps protect them.
Once the yolk sac reserves are fully absorbed, the alevin emerges from the gravel and begins the next stage of its life cycle.
Fry – the Free-Swimming Young Salmon After Losing the Yolk Sac
The next stage in a salmon’s life after it takes in its yolk sac is called the fry stage. This is when the baby salmon comes out of the gravel and starts swimming and eating on its own.
At this point, the salmon fry must catch food drifting by in the water column and avoid predators. Their small size, around 1 inch long, makes them vulnerable. Hiding and schooling behaviors help avoid predation.
During the fry stage, young salmon feed heavily to fuel rapid growth. They mostly eat zooplankton and tiny aquatic invertebrates. Growth at this stage is extremely important for survival.
The fry stage lasts around 3-9 months depending on the species. At the end of this stage, the juvenile salmon transitions from being called a fry to a parr.
Parr – the Young Salmon with Camouflage Markings
The parr stage follows the fry stage once the baby salmon is big enough to be distinguished by parr marks on its sides. These are the dark vertical bars that run along the flanks of young salmonids, helping camouflage them.
Parr range from around 1.5 – 3 inches long depending on the species. They continue feeding heavily and growing rapidly in their natal streams and tributaries.
Their parr marks provide camouflage from predators when swimming in shallow waters. Parr marks likely mimic dappling light effects in streams that break up the fish’s outline.
Young salmon will remain in the parr stage for 1-3 years before undergoing the smolt transformation to prepare for migration to the ocean.
Smolt – the Salmon Preparing to Migrate to the Ocean
The final stage of a young salmon’s freshwater life cycle is called the smolt stage. This is when parr undergo changes to transition from living in freshwater to saltwater.
Smolt develop a silvery color and lose their parr marks as camouflage is no longer needed. Other internal changes prepare them for life at sea.
Once the smolt transformation is complete, the young salmon migrate downstream to estuaries and the ocean to continue maturing. Years are spent feeding in the productive ocean waters before finally returning to freshwater streams as adults to spawn.
Atlantic salmon life history (summarisedbelow)
There are different names for the different stages of development in salmonid fish. The most important ones are alevins, parr, and smolts. Adult fish that have been to sea are called Grilse (one sea winter) or Salmon (multi-sea winter).
Atlantic salmon spawn in the UK in October and November. They bury their eggs in gravelly or cobblestone areas along streams. The depressions that the female fish make are called redds. The females lay between 7,000 and 8,000 eggs in two or more redds. It’s important to note that this number of eggs is about average for all salmonid species. A steady supply of clean, well oxygenated water is critical to sustain these eggs whilst they are buried. The eggs remain in the gravel throughout the winter before hatching in the spring. Salmon eggs that have just hatched are called sac fry or alevins. They get food from the yolk sac that is attached to their bodies and may stay buried for a while. The young salmon that can swim on their own, called fry, eventually come out of the redd. This usually happens between April and June, when the yolk sac has been fully absorbed. Feeding activities by the fry begin at this time.
When salmon fry first come out, they are about one and a quarter inches long. They quickly set up feeding areas that they defend against other fish. Salmon that are still growing like streams that have clean, cool water (15° C or less) and small rocks that don’t stick to the bottom. Fish live in riffles and along the edges of fast-moving water. They also hide under overhanging plants and near the bottom of the water column.
In the fall, fry that spent their first summer in the stream where they hatched are called parr. They are 7 to 10 cm long. When the parr has been in fresh water for a year, it will be 10 to 15 cm long. Parr remain in freshwater for a period of one to three years. The freshwater residence period is largely dependent on growth rate. The fastest growing parr, usually from warmer, more productive tributaries, spend only one year in freshwater. Slower growing parr, often from colder, less fertile tributaries, spend three, or rarely, four years in freshwater. Most parr in the UK spend two years in freshwater. During their first autumn, parr may disperse widely from their first summer location to seek new habitat.
Parr that are going to leave freshwater environments in the spring of the following year start a process called smoltification during the winter before. When salmon reach a size (15 to 20 cms or more) that allows them to migrate to the sea in the spring, they go through clear physical changes. These changes allow juvenile salmon to adapt to life in marine waters. As a salmon smoltifies, it goes through a series of behavioral, physiological, and morphological changes that change it from a territorial, bottom-dwelling freshwater fish to a schooling saltwater fish. Juvenile salmon leaving for the ocean are called smolts. Smolts lose the dark vertical stripes, parr marks, on their sides and become bright silver in color. Smolts migrate to sea from April through June. Some smolts may commence pre-smolt movement in the fall to start their long migration.
For a long time, UK smolts have been moving west and north, first along the coast and then out to sea. In the end, the salmon make it to the water off the west coast of Greenland, where they feed with Atlantic salmon from North America and Europe. Most UK salmon now come back after only one winter at sea (1SW). These fish are called grilse. Other salmon return to spawn after residing in the ocean through two sea winters (2SW). and others wait until after their third sea winter to return (3SW). Grilse (1SW) are around 2 kgs in weight. The 2SW salmon grows to about 75 cms and 4. 5 kgs as a returning mature salmon. and 3SW salmon often weigh more than 7 kgs.
Adult salmon return to their home rivers at various times of year depending on various factors. When adult salmon are in fresh water, their color slowly changes from silver to a very dark color. Salmon attempt to reach their natal streams as conditions allow. If they are early, they spend the summer holding in deep, cold pools before spawning in the autumn. Salmon don’t eat from the time they enter fresh water until they spawn, which is usually six months later. They start eating again when they go back to salt water in the fall or spring, if they make it through. Unlike Pacific salmon, not all Atlantic salmon die after spawning. However, many do die because of the hard work of the upriver migration, spawning, and not being able to eat for up to a year while they are in freshwater. Adults that survive the rigors of migration and spawning are called kelts. When the kelts go back to the ocean in late fall or early spring, they turn silver again. A small percentage of salmon survive several spawning runs, alternating between freshwater and marine environments. Repeat spawners and grilse are important to the salmon population because they keep the genetic diversity high and protect the population from all the things that can kill it, whether it’s in salt or fresh water.
Young salmon are..
FAQ
What is another name for young salmon?
What is a young salmon or trout called?
What is a juvenile salmon called?
Is a young salmon called a smelt?
What is a young salmon called?
When salmon are born, they are called “alevins.” Alevins are the newly hatched salmon that still have the yolk sac attached to their bodies. Once the yolk sac is absorbed, they are then referred to as “fry.” Fry are young salmon that have fully developed into fish and are ready to head out into the open waters. What do young salmon eat?
What is a Salmo fish called?
These fish are also called bay salmon, black salmon, caplin-scull salmon, silver salmon, outside salmon, fiddler, sebago salmon, and winnish. Its scientific name is Salmo salar, with Salmo coming from the Latin word for salmon and salar likely meaning “saltwater resident.”
How long does it take a salmon to mature?
A salmon is called an alevin, a fry, a parr and a smolt before it is considered an adult. It takes about four years for a salmon to reach maturity since it must go through many stages of growth before it can swim in salt water. When a salmon egg hatches, the young is called an alevin and still depends on the yolk sac for nutrition.
What is a spring salmon called?
They are called fry, fingerling, parr, smolt, grilse, grilt, kelt, slink, or spring salmon depending on the stage of their life cycle. To prepare for spawning, the female locates a gravel bed in a stream, and then uses her tail to push water and create a “redd” or nest.