Chir: detailed description, lifestyle, habitat, reproduction and fishing

Whitefish: a detailed description, lifestyle, habitat, reproduction, and fishing. Whitefish (Coregonus nasus) is one of the largest and most valuable representatives of the whitefish family (Salmonidae ). This exclusively freshwater species never migrates to the sea and spends its entire life in the cold lakes and rivers of the North. Whitefish are also known as lake whitefish, northern whitefish, and Arctic whitefish. Its meat is white, very fatty (up to 20-30% in large specimens), tender, with a subtle sweet flavor and an almost complete absence of small bones. Whitefish is a key traditional fishery for the indigenous peoples of the North (Nenets, Khanty, Evenki, Yakuts, and Dolgans) and one of the most expensive delicacies on the Russian market. It is prized for its exceptional fat content and flavor, especially when lightly salted, smoked, and dried.

Chir is a salmon family of fish.

The broad whitefish is one of the most prominent representatives of the whitefish family (subfamily Coregoninae) of the salmon family. Unlike anadromous salmon ( chum, pink, and sockeye salmon ), broad whitefish live entirely in freshwater and never migrate to the sea. They prefer cold, clean, oxygen-rich water and do not tolerate even minor pollution or siltation. Broad whitefish is one of the fattest whitefishes; its meat and caviar are highly prized in Russian cuisine, and in recent decades, it has become one of the most sought-after fish species on the Russian market.

Origin of the species and description

The broad whitefish (Coregonus) is a typical representative of the whitefish genus, which evolved in the cold freshwater bodies of the Northern Hemisphere during the Pleistocene glaciations. Its ancestors adapted to life in glacial lakes and rivers, where water temperatures remain very low year-round. Today, the broad whitefish is endemic to the northern regions of Russia, where it remains a key species in the ecosystem.

The broad whitefish's body is elongated, spindle-shaped, and laterally compressed, with a small head and a large mouth. The mouth is inferior or semi-mobile, which helps it collect food from the bottom. The scales are very small, tightly set, and silvery. The back is dark gray, brown, or greenish, the sides are silvery with a metallic sheen, and the belly is white. Small dark spots are sometimes scattered over the body. The fins are powerful, the dorsal fin is set back, and the caudal fin is notched. An adipose fin is present—a characteristic feature of all salmonids.

Ulcer size

The chir is one of the largest whitefish:

• Average length in the fishery: 40–60 cm
• Average weight: 1.5–4 kg
• Maximum dimensions: length up to 80–90 cm, weight up to 12–16 kg (in rare cases up to 20 kg)
• Life expectancy: 10–15 years, sometimes up to 20–25 years

Whitefish grow relatively quickly for whitefish. In the first years of life, they gain 300–600 grams per year, but after 6–7 years, growth slows. The largest whitefish are caught in the lower reaches of the Ob and Yenisei rivers and in large Siberian lakes.

Whitefish spawning

Whitefish spawn in the fall, from late September to November (depending on the region and latitude). The peak period is October to early November.

Key conditions for the start of spawning:

• Water temperature: from 0.5 to +4 °C (optimally 1–3 °C)
• The water should be as clean, transparent and oxygenated as possible.
• The water level is stable or slightly rising (after autumn rains)
• Lack of strong ice cover (whitefish spawn until complete freezing, sometimes under the ice)

Spawning begins earlier in more southern populations (middle Ob, Irtysh) and later in northern ones (lower Ob, Yenisei, Yana, Lena).

Where does the whitefish spawn?

For spawning, broad whitefish prefer areas with clean pebble, gravel, or coarse sand bottoms and moderate to strong currents. Depths range from 1 to 5–7 meters (sometimes up to 10 meters in large lakes).

Typical places:

• Lower and middle reaches of large rivers (Ob, Yenisei, Lena, Pur, Taz, Nadym)
• Mouths of tributaries and channels
• Areas with pebble spits, riffles and dumps
• Shallow reaches and bays of large lakes

Whitefish avoid silted areas, quiet backwaters, and areas heavily overgrown with algae. They prefer clear water and currents that constantly wash the eggs and ensure a high survival rate.

On the Putorana Plateau, broad whitefish are found in limited numbers in large lakes (Lama, Keta, Khantayskoye, Sobachye, and Ayan) and their lower tributaries. Here, they don't form mass spawning grounds, as in Siberian rivers, but the spawning conditions (icy, clear water, a pebble bottom, and high oxygen levels) are ideal, and the survival rate of eggs and juveniles here is among the highest in the world.

How does whitefish spawn?

Whitefish spawning is a gregarious and fairly lengthy process. The fish gather in schools of 50–300 or more individuals. Males usually predominate.

Main stages:

1. Approaching the spawning grounds: Chir begin entering their spawning grounds 3-6 weeks before spawning. The fish migrate upstream, often covering tens and hundreds of kilometers.
2. Preparing the nest The female selects a suitable site and digs a small depression (nest) with her tail, 10–30 cm deep and 40–80 cm in diameter. The soil is scattered downstream.
3. Egg-laying: The female lies on the nest, trembles, and spawns a batch of eggs (1,000–4,000 at a time). The eggs are large (2–3 mm), light yellow, heavy, and sink immediately to the bottom.
4. Fertilization: A male (or several males) settles down nearby and releases milt simultaneously with the spawning of eggs. Fertilization is external and occurs instantly.
5. Nest filling: After fertilization, the female covers the eggs with sediment by slapping her tail on the bottom. She then moves to a new nest upstream and repeats the cycle.

During a season, a female makes 4-10 approaches and lays an average of 20,000-100,000 eggs (the largest females lay up to 120,000-150,000). Males actively protect the nests from competitors and predators.

After spawning, whitefish do not die. Most individuals survive and return to their feeding grounds to recuperate. This allows whitefish to spawn multiple times—up to 6–10 times in their lifetime.

Habitat of the whitefish

The chir is endemic to northern lakes and rivers of Russia. Its main habitat is:

• Ob basin with tributaries
• The Yenisei and its tributaries
• Lena, Kolyma, Indigirka, Yana
• Baikal (rarely, in the northern part)
• Large lakes of Siberia and the Far East

The broad whitefish prefers clean, cold water with a temperature of 4–15°C, high oxygen content, and a pebble or sandy-pebble bottom. It does not tolerate even slight pollution or siltation.

The lifestyle of the chir

The broad whitefish (Coregonus nasus) is one of the largest and most resilient representatives of the northern whitefish family. It is a purely freshwater species, never migrating to the sea and spending its entire life in cold lakes and rivers. The broad whitefish leads a calm, measured life, avoiding strong currents and preferring deep waters with clean, oxygenated water. It is not an aggressive predator like the taimen or lenok, but rather an omnivorous benthophage with pronounced predatory tendencies. It feeds slowly and carefully, often remaining in one place for long periods, biding its time.

Whitefish nutrition

The broad whitefish is a bottom-feeding predatory and benthic fish. Its diet varies greatly depending on its age and size.

• Juveniles and small individuals (up to 3–4 years): zooplankton, small crustaceans (amphipods, gammarus, mysids), mosquito and chironomid larvae, small mollusks, eggs of other fish.
• Adults (5–6 years and older): – bottom invertebrates (insect larvae, mollusks, worms, crustaceans) – small fish (young whitefish, grayling, char, smelt, ruff) – eggs of other fish species (especially whitefish, grayling, broad whitefish) – insects and their larvae falling into the water – sometimes plant remains and detritus

The whitefish feeds neither voraciously nor quickly. It often stands in one place, slowly exploring the bottom with its mouth and fins, collecting everything edible. Large specimens can lie in deep holes for long periods, waiting for the current to bring food.

On the Putorana Plateau, broad whitefish are found in limited numbers in large lakes (Lama, Keta, Khantayskoye, Sobachye, and Ayan) and their tributaries. Here, they feed primarily on juvenile whitefish, grayling, char, and insect larvae. The abundance of natural food and the lack of competition from other predators allows them to maintain good nutrition even at low population densities.

Daily and seasonal activity

The chir is active all year round, but its rhythm of life changes greatly with the seasons.

• Winter: Remains in deep holes and pools (depths of 5–15 m or more), feeding almost entirely. Metabolism slows, conserving energy. Occasionally makes short movements in search of warmer water.
• Spring (April–May): After the ice melts, whitefish begin feeding actively. They move into shallow water and approach the mouths of tributaries. This is the time of pre-spawning and post-spawning feeding frenzy.
• Summer (June–August): Peak activity. Whitefish disperse throughout the river and lakes, staying at depths of 3–10 meters. They feed most actively in the evening and at night, sometimes moving into shallow water.
• Autumn (September–October): Pre-spawning run. Fish gather in schools and migrate upstream to their spawning grounds. Feeding becomes less intense, but still active.

Behavior and character

The broad whitefish is a cautious, secretive, and very timid fish. It dislikes bright light, noise, and sudden movements. In rivers, it stays close to the bottom, often lying motionless in the deep, waiting for the current to bring food. When threatened, it immediately retreats to cover—under rocks, snags, or a hole.

Large specimens (3–5 kg) become true territorial predators. They occupy the best holes and areas with a constant water flow, driving away competitors. Small and medium-sized whitefish stay in schools of 10–50 individuals.

Whitefish are very sensitive to changes in pressure, temperature, and water level. Before sudden weather changes (especially before frosts or warmer weather), the bite may completely stop for several days.

The life cycle of a chir

The broad whitefish (Coregonus nasus) is one of the largest and longest-lived representatives of the northern whitefish family. Its life cycle is spent entirely in freshwater and does not include marine feeding, which distinguishes it from most anadromous salmon. It grows very slowly, matures late, and can live for 15–20 years, and under ideal conditions, up to 25 years or more. This long life cycle and late sexual maturity allow it to reach gigantic sizes and high nutritional levels, especially in pristine northern waters.

1. Caviar and embryonic period (autumn–spring)

The whitefish's life begins with the laying of eggs. Spawning occurs in the fall (late September – November) at water temperatures of 0.5–4°C. The female lays 20,000–100,000 eggs (2–3 mm in diameter) in pebble or sandy-pebble soil at a depth of 1–5 m.

The eggs are heavy and sink immediately to the bottom, burrowing into the spaces between rocks or remaining in the sediment. Embryo development takes 5–6 months (sometimes up to 7 months) due to the very low water temperature. This is one of the longest periods among whitefish. The fry hatch in the spring (April–May), initially feeding on the remains of the yolk sac while remaining on the nest bottom or in shelters.

2. Juveniles and early growth (0–5 years)

After the yolk sac is absorbed, the fry switch to external feeding:

• zooplankton (daphnia, cyclops, bosmins)
• small crustaceans
• mosquito and chironomid larvae

Juveniles stay in the coastal zone, in quiet backwaters, channels, and the mouths of tributaries. They are extremely vulnerable: survival rates in the first 1–3 years rarely exceed 5–15%, even under favorable conditions.

Growth in the first years is very slow:

• end of 1st year - 8–12 cm
• end of the 2nd year - 15–22 cm
• end of the 3rd year - 25–35 cm
• end of the 5th year - 40–55 cm, weight 0.5–1.5 kg

During this period, young whitefish are very shy, hiding among rocks and vegetation, and avoiding open areas.

On the Putorana Plateau, whitefish juveniles survive better than in most other regions. The conditions here are ideal: icy-clear water, extremely high oxygen levels, a pebble bottom with plenty of shelter, and an abundance of zooplankton and insect larvae. Thanks to this, the survival rate of the fry can reach 20–40%, one of the highest rates for whitefish.

3. Juvenile period and transition to adult diet (5–8 years)

From 5-6 years of age, the broad white begins to exhibit more predatory tendencies. It switches to larger food:

• larvae of caddisflies, mayflies, freckles
• small fish (young whitefish, grayling, char)
• crustaceans and mollusks

Growth is gradually accelerating, but remains slow:

• 7–8 years old – 55–70 cm, weight 2–4 kg

At this age, the whitefish already occupies deep holes, pools and dumps, becomes more territorial and begins to displace competitors from the best places.

4. Puberty and adulthood (8–20+ years)

Sexual maturity occurs late—at 6–8 years for males and 7–10 years for females (later in northern populations). This is one of the latest stages among large whitefish.

Once mature, whitefish begin spawning. Females lay eggs annually or every other year. Males spawn more frequently.

The adult broad whitefish is a bottom-dwelling predator. It feeds primarily on benthic invertebrates and small fish. Its primary diet includes:

• benthic invertebrates (insect larvae, mollusks, worms, crustaceans)
• small fish (young whitefish, grayling, char)
• caviar of other fish species
• insects and their larvae

Growth continues throughout life, but after 12–15 years it becomes very slow.

5. Longevity and aging

Whitefish can live up to 15–20 years, and in exceptional conditions, up to 22–25 years. The oldest specimens caught in the lower Ob and Yenisei rivers were 20–23 years old and weighed 10–16 kg.

Longevity is ensured by: life in hard-to-reach, clean waters, a very slow metabolism in cold water, late sexual maturity, multiple spawning without death after spawning, and the absence of serious natural enemies in adult fish.

Methods of catching whitefish

The whitefish is one of the largest and most sought-after whitefish in the North. It is a cautious, strong, and highly selective benthic predator that requires light, sensitive tackle and precise bait presentation. Whitefish rarely bite roughly; they often bite softly, testing the bait and letting go at the slightest mistake. The best bite occurs in summer and early fall, when the fish actively feed on zooplankton, larvae, and small fish. Whitefish are caught in Siberian rivers and lakes year-round, but the best results are seen in July–September.

The most effective methods for catching whitefish are bottom fishing, float fishing, light spinning rods, and ice jigs. Fly fishing and jigging are less effective, as whitefish rarely rise to the surface.

1. Bottom fishing is the most reliable and effective method

Donka is the main method of catching large whitefish in deep water.

• Tackle: Rod 3.6–4.5 m, test weight 30–80 g. Reel 4000–6000. Braided line 0.14–0.20 mm + fluorocarbon leader 0.18–0.25 mm.
• Baits: Bloodworms (a bunch of 10-15 maggots) are the most effective bait. Maggots, worms (dung worms, earthworms). Caddis flies, amphipods, and bloodworms. Fresh fish cuts (grayling, whitefish). Live bait – small char, grayling.
• Technique: Cast to a depth of 4–15 m. Set the rod at an angle of 45–60°. The bite is a gentle tug or a series of small twitches. The hookset is firm, but not abrupt (whitefish have delicate lips).

2. Float rod - for shallow water and lakes

Float fishing tackle works in lakes and calm sections of rivers.

• Tackle: 5–7 m rod (pole or Bolognese). 0.14–0.20 mm line, 0.12–0.16 mm leader. 1–3 g float (sensitive, with a long antenna). 0.5–2 g pellet sinker.
• Baits: Bloodworm, maggot, worm. Caddisfly, amphipod. Artificial caviar, paste.
• Technique: Fishing along the bottom or mid-water in a slow current. Fishing with a current or standing still in lakes. A bite is indicated by a slight twitch or a slow movement of the float to the side. The hookset is gentle.

3. Light spinning rod - for active searching

Spinning rods are used in rivers and lakes to search for schools of whitefish.

• Tackle: Rod 2.4–3.0 m, test 5–21 g or 7–28 g. Reel 2500–4000. Braided line 0.10–0.14 mm + fluorocarbon 0.16–0.22 mm.
• Lures: Spoons 10–30 g (Kuusamo Rasanen, Smith Pure, Forest Pal). Spinners #3–5 (Mepps Black Fury, Blue Fox Vibrax). Micro wobblers 5–8 cm (Salmo Hornet, Yo-Zuri L-Minnow). Silicone jig head 5–15 g.
• Technique: Slow, steady retrieve along the bottom. Gradually, with pauses of 3–5 seconds. A bite is indicated by a light tap or tug.

4. Winter whitefish fishing

In winter, whitefish are caught with a jig and a spoon in lakes and non-freezing sections of rivers.

• Winter fishing tackle: fishing rod with a nod. 5–10 mm jig (black, silver, copper). 0.10–0.14 mm line.
• Bloodworm, jig, and maggot bait. Jigless bait with bloodworm bait.
• Technique: Playing along the bottom with short twitches. A bite is indicated by a light tap or a lift of the nod.

Nutritional value of chir

Whitefish (Coregonus nasus) is one of the fattest and most nutritious whitefish in the North. Its meat is white, exceptionally tender, with a subtle sweet flavor and a virtually complete absence of small bones. Whitefish has one of the highest fat contents among freshwater salmonids: 18–25% on average, and can reach 28–32% in large lake and river specimens from pristine northern waters. This natural fat content, combined with complete protein and a rich array of micronutrients, makes whitefish one of the healthiest and most delicious foods in northern cuisine. It is easily digestible, leaves a light, and is ideal for any age and health condition.

Chemical composition of whitefish meat (per 100 g of raw product)

• Caloric content: 160–260 kcal (on average 190–230 kcal, depending on fat content and season)
• Proteins: 15.5–18.5 g (high-quality, easily digestible protein with a complete set of essential amino acids)
• Fats: 18–32 g (on average 22–26 g), of which: – polyunsaturated fatty acids Omega-3 — 3.0–7.0 g (one of the absolute leaders among freshwater fish) – Omega-6 — 0.5–1.2 g – saturated fats — 5–10 g
• Carbohydrates: 0 g
• Water: 50–65 g
• Ash (mineral substances): 1.3–1.8 g

Whitefish hold the record for highest omega-3 fatty acid content among freshwater whitefish. Its fat is light, quickly digestible, and virtually undetectable when eaten, even with extremely high fat content.

Vitamins (per 100 g)

• Vitamin D – 15–32 mcg (150–320% of the daily value)
• Vitamin B12 – 5–10 mcg (200–420% of the daily value)
• Vitamin B6 - 0.5–1.0 mg
• Niacin (PP, B3) - 7-14 mg
• Riboflavin (B2) - 0.2–0.45 mg
• Thiamine (B1) — 0.12–0.3 mg
• Vitamin A - 40-120 mcg
• Vitamin E — 2–5 mg

Chir is especially rich in vitamin D and B12, which are key nutrients for northern regions where deficiency is very common.

Minerals (per 100 g)

• Phosphorus — 280–420 mg
• Potassium - 380–550 mg
• Magnesium - 40-65 mg
• Calcium - 30-50 mg
• Sodium - 70-120 mg
• Iron - 0.9-1.9 mg
• Zinc — 1.2–2.5 mg
• Selenium — 40–90 mcg
• Iodine - 25–60 mcg
• Copper - 0.08–0.20 mg

Chir is one of the leaders among freshwater fish in terms of selenium and iodine content, which makes it especially useful for preventing thyroid disease and supporting the immune system.

Health benefits of chir meat

Regular moderate consumption of chir (100–200 g 2–3 times a week) has a powerful positive effect on the body:

• strengthens the cardiovascular system (Omega-3 reduces triglyceride levels, "bad" cholesterol, and blood pressure)
• supports brain health, nervous system health, and cognitive function (vitamin B12, Omega-3, selenium)
• improves the condition of bones and teeth (high content of vitamin D and phosphorus)
• increases immunity and resistance to infections
• helps with anemia and iron deficiency
• has a beneficial effect on skin, hair and nails (vitamins A, E, zinc, selenium)
• normalizes metabolism and blood sugar levels
• promotes recovery after physical exertion, surgery and long-term illnesses
• reduces inflammation in the body
• prevention of thyroid diseases (high content of iodine and selenium)

Chir is especially useful in northern regions where there is little sun and a deficiency of vitamin D, Omega-3 and iodine is often observed.

Features of preparation and use

It is best to cook chira with minimal heat treatment to preserve the maximum amount of nutrients:

• lightly salted (stroganina) is the healthiest and most popular northern method
• cold smoked
• dried
• baked in foil or steamed
• fried or boiled - less preferable (some fats and vitamins are destroyed at high temperatures)

Whitefish fat is light and easily digestible, so even with a very high fat content the fish does not leave a feeling of heaviness.