Freshwater predator · Freshwater
Burbot
Lota lota
Holarctic coldwater cod relative; native across northern North America in deep lakes and connected rivers.
Also called cusk, freshwater cusk, eelpout, ling, lawyer, mariah.
- Flowing water
- Stillwater
- Ordinary target
- 4 of 4 overlays reviewed
- Reviewed 2026-08-27
Take this somewhere
This page is the record. The reading is what happens when you add water, a season and a temperature to it — that is where the families below get ranked against each other instead of just listed.
Those three links carry the fish and nothing else. No conditions were declared on this page, so none travel, and the link says so rather than sending an empty reading.
The half nobody publishes
What this record does not know
Everything else on this page comes from a named agency or peer-reviewed source. This is the other side of that: the questions a reviewer went looking for an answer to and came back without, and the fields the record leaves empty because filling them would mean guessing.
It is here rather than at the bottom because a page that only shows what it knows is easy to read as a page that knows everything. For Burbot there are 21 of them.
Named by a reviewer
18Somebody looked for this and wrote down that they did not find it.
- Behaviour
Nobody has sourced:
- the laboratory thermal preferendum (11.4–14.2°C) sits above the catalog's 42–52°F band and above the 10–12°C field summer preference; a human should reconcile lab preferendum against field-occupied temperatures
- no primary source found for cold-front / barometric response
- no primary source found for turbidity or clarity response
- no primary source found for water-level or flow-change response
- no primary source found for angling-pressure response
- territoriality, aggression, and predator avoidance are not described in the sources reached; fields omitted
- the winter shallow-water shift is described qualitatively by a state account rather than with sourced depth figures
- Identification
Nobody has sourced:
- no sourced description of juvenile appearance or regional colour variation was found; those fields are omitted
- no sourced sexual dimorphism outside maturation timing; field omitted
- the American eel lookalike entry is written from burbot-side characters only, because no eel-side agency key was retrieved
- longevity varies widely by latitude and the sources disagree on a maximum
- Forage
Nobody has sourced:
- no sourced spring or fall diet composition; only winter and summer entries are written
- no quantitative diet-by-region study was reached beyond the >80% fish figure for adults
- mollusk use (clams) is reported by one state account but is not in the catalog forage list and has not been carried into primaryForage
- Season
Nobody has sourced:
- the winter depth band is described qualitatively; no sourced winter depth figures were located to sit alongside the summer >20 m figure
- spring and fall entries rest on the thermal and migration record rather than on direct seasonal habitat studies
- no sourced forage emphasis by season beyond winter fish predation
- no light-sensitivity material specific to seasons other than winter, though the nocturnal habit is documented year-round
Absent from the record
3No reviewer wrote a gap here. The field is simply empty, which is its own answer.
- Water temperature
No agency or peer-reviewed temperature band for Burbot was found that a review would accept. The reading runs without one rather than borrowing a number from a related fish.
- Identification
No reviewed image. A photograph is only in this catalog when an agency or a named creator labelled the subject, and nobody has cleared one for this species yet.
- Population context
No regional population profile is registered. The species-level reading stands on its own; it does not silently become a local one.
Where the record puts it
Water and range
Flowing water
4 reviewed holding classes- Deep pool
- Current break
- Pool tail
- Submerged wood
Stillwater
5 reviewed holding classes- Basin
- Rocky shoreline
- Drop-off
- Submerged hump
- Thermocline edge
DepthDeep and benthic through much of the warm season; cold-season movement can bring fish shallower.
Moving waterBottom-oriented and generally favors deeper or slower current margins rather than sustained high-velocity lanes.
LightStrongly associated with night and low-light activity; daylight often reinforces cover, depth, and bottom contact.
Thermal band
Temperature
No reviewed temperature band
Nobody publishes a preferred or active temperature range for Burbot that a review would accept. Borrowing one from a related fish would look like knowledge and behave like a guess, so the reading runs without it and says which parts of the answer that weakens.
How it uses water
Behaviour
An adult burbot is a solitary bottom animal that hides by day and hunts alone at night. The one documented departure from that is the winter spawning aggregation, which is conservation context and excluded from target guidance.
Hunts on and just above the bottom. Despite a sluggish look, adults are described as voracious predators equipped with a large mouth, strong jaw, and many inward-slanting teeth. Fish make up more than 80% of the adult diet, but crayfish, insects, and eggs are taken where available.
Genuinely nocturnal, and it starts early in life: age-0 fish become negatively phototactic at about 40 mm and shift to a nocturnal, solitary, benthic existence. Adults feed mostly at night, and one state account specifically ties peak activity to low-light winter conditions. Daytime is spent under cover.
Seasonal activityInverted relative to most freshwater predators. Burbot are inactive through the warm months and come alive in winter, when they are described as most active. Spawning migrations occur in late fall / early winter and again in late winter / early spring, at documented travel rates of 1.5–2.0 km per day and up to 8–11 km per day in some river populations.
Temperature-driven behaviourA cold-water specialist. Summer preference is reported around 10–12°C (50–54°F), and burbot are rarely found where water exceeds 70°F. Laboratory final thermal preferendum was measured at 11.4°C for 10–20 cm fish and 14.2°C for 20–30 cm fish, with the same work concluding that spring warming is what triggers juveniles to leave the littoral and avoid a summer thermal trap. Spawning occurs at 0.6–1.7°C and embryos fail above about 6°C.
Depth movementIn lakes, adults are associated with water deeper than about 20 m and are restricted below the thermocline through summer; juveniles use shallow cobble and boulder at 0.5–1.5 m. In rivers, recorded use spans about 1–30 m with a preference for depths beyond about 6 m in some systems. The seasonal direction is deep-and-cold in summer, shallower and more active in winter.
CoverStrongly substrate-associated. Shelters under stones, woody debris, and cut banks; interstitial spaces within coarse substrate are important cover for young fish. This is a fish that occupies the gaps in the bottom rather than the water column.
Open waterIn deep lakes, adults hold below the thermocline in summer rather than roaming open water. Lake fish also grow substantially larger than river fish.
Spawning (conservation context)Winter spawner, and in much of the range the only fish that spawns under ice. Timing runs November through May depending on region, compressed into a highly synchronised two-to-three-week window at 0.6–1.7°C. Fish gather and spawn in a writhing mass, broadcasting eggs into the water column well above the substrate with no nest and no substrate preparation; the eggs settle into interstices. Fecundity is very high — a large female can carry over a million eggs. Spawning water, spawning aggregations, and pre-spawn movement are all excluded from target guidance.
Where the general rule stops
- Night activity does not justify a surface presentation; this is a bottom-oriented species record.
- Winter spawning concentrations are a conservation-sensitive warning sign, not a hotspot map.
What it can eat
Forage
- Small forage fish
- Larger prey fish
- Crustaceans
- Aquatic insects
Adults are close to specialists — fish make up more than 80% of the adult diet, and one agency account describes adults as foraging almost exclusively on fish, including whitefish, sculpins, lampreys, and other burbot. Juveniles are broad invertebrate feeders. The whole diet is taken on or near the bottom at night. Crayfish are named as an important food where available, and fish eggs, clams, and mayfly larvae also appear. Capacity is not a current prey event.
- Feeding style
- Mixed
- Feeding zone
- Benthic
Through the year
- Winter
- The active feeding season. Fish prey dominates; eggs of other species are also taken. Activity peaks under low-light winter conditions.
- Summer
- Warm months are the inactive period. Adults are confined below the thermocline or to deep cold water, and feeding is correspondingly constrained. No season-specific prey composition was sourced.
By life stage
- Young of year
- Larvae take rotifers, then copepods and cladocerans, selecting the largest items they can engulf; age-0 fish move on to amphipods, insects, and young fish.
- Juvenile
- Amphipods, insects, and mysid shrimp where present; the proportion of fish rises steadily with size.
- Adult
- Fish make up more than 80% of the diet — whitefish, sculpins, lampreys, and other burbot are named — with crayfish and macroinvertebrates still taken.
Prey sizeA large mouth, strong jaw, and bands of inward-slanting teeth let adults take prey that juveniles cannot, which is what carries the catalog's larger_prey_fish class. That class belongs to adults, not to juveniles.
Ontogenetic shiftA clear and progressive shift: rotifers and microcrustaceans as larvae, then amphipods and insects, then mysids and small fish, then a predominantly piscivorous adult diet. The shift tracks growth continuously rather than switching at one threshold.
SubstitutionsWhere mysid shrimp are present they carry the juvenile stage; where crayfish are available they become an important adult food. Elsewhere the adult diet reverts to whatever benthic and near-benthic fish are abundant. Substitution is system-specific.
Diet capacity is not proof that a baitfish, crayfish, or egg event is occurring. Observed current forage still comes from a user observation or Hatch Match.
Through the year
Season
Winter
- Where they sit
- The season of greatest activity. Bottom-associated water across the system: basins, rocky shoreline, drop-offs, and submerged humps in lakes; deep pools, current breaks, pool tails, and submerged wood in rivers.
- Depth
- Less confined by the summer thermal squeeze; fish are no longer restricted below a thermocline and use a wider depth band including shallower bottom.
- Feeding
- Active predation on fish, with eggs and invertebrates also taken.
- Temperature
- The coldest water of the year is not a constraint for this species — 0.6–1.7°C is spawning temperature, and 10–12°C is a summer preference, not a floor.
- Cover
- Stones, woody debris, undercut banks, and interstitial substrate by day.
- Light
- Activity peaks under low-light winter conditions; feeding is at night.
What that changesVertical jig, bottom contact, and drop presentation match a fish hunting on the substrate in still water; live/natural bait suspension held near bottom fits the same posture. In flowing water, bottom-contact drift, stationary bait, and pulse jig.
What would count against it
- carrying a mid-column or suspended search over from a warm-water predator
- assuming a daylight feeding posture
Winter is also the spawning season across much of the range, compressed into a synchronised two-to-three-week window. Spawning water and spawning aggregations are excluded from target guidance.
Early spring
- Where they sit
- Bottom-associated water while temperatures remain cold; late-winter / early-spring spawning movement occurs in some populations.
- Movement
- Documented spawning migrations occur in the late winter / early spring window at 1.5–2.0 km per day, and faster in some river populations.
- Temperature
- Still within the cold band the species tolerates well; spring warming is what eventually triggers juveniles to leave the littoral.
What that changesBottom contact and vertical jig in still water; bottom-contact drift and stationary bait in flow.
Spawning overlap continues in some populations. Spawning water and any associated movement are excluded from target guidance.
Spring
- Where they sit
- Transitional. Juveniles begin leaving shallow littoral cobble and boulder as water warms; adults move toward the deep cold water they will hold through summer.
- Movement
- Downward and offshore as warming proceeds.
- Temperature
- Rising temperature — not absolute summer heat — is identified as the trigger for the juvenile shift out of the littoral.
What would count against it
- expecting the shallow littoral juvenile pattern to persist as water warms
Summer
- Where they sit
- Deep cold water only: basin, thermocline edge and below, deep pools. In lakes, adults are restricted below the thermocline.
- Depth
- Deepest of the year — associated with water beyond about 20 m in lakes, and beyond about 6 m in some rivers.
- Feeding
- Reduced. This is the inactive season for the species.
- Temperature
- Summer preference around 10–12°C (50–54°F); rarely found where water exceeds 70°F.
What would count against it
- treating summer occupancy as equivalent to summer activity
- searching water above about 70°F
Fall
- Where they sit
- Bottom-associated water expanding upward and shoreward as the water column cools and the thermocline breaks down.
- Movement
- Activity increases as temperature falls; late-fall / early-winter spawning migrations begin in some populations.
- Temperature
- Cooling releases the summer thermal restriction that confined adults below the thermocline.
What that changesBottom contact and slow drag in still water; bottom-contact drift and stationary bait in flow.
What would count against it
- assuming the summer deep-water pattern holds after turnover
Late fall
- Where they sit
- Bottom-associated water with increasing movement; the transition into the winter active season.
What that changesVertical jig, bottom contact, and drop presentation in still water; bottom-contact drift and pulse jig in flow.
Late-fall / early-winter spawning migration occurs in some populations. Pre-spawn movement and any concentration associated with it are excluded from target guidance.
Spawning · Winter
Mid-winter spawner, often under ice or in very cold nearshore/river habitat. Aggregation behavior must not become a location recommendation.
Recorded as conservation context. No spawning site, staging concentration or migration bottleneck is named anywhere in this catalog, because naming one is how a population gets fished out.
Telling it apart
Identification
What to look at
- A single conspicuous barbel hangs under the chin. Nothing else in the North American freshwater fauna combines that barbel with an eel-like body and a rounded tail.
- The only freshwater member of the cod family (Gadidae) in North America.
- Two distinct dorsal fins, the second very long, with a long anal fin beneath; both run to a rounded caudal.
- Pelvic fins are set forward of the pectoral fins — an unusual arrangement worth checking on any eel-like fish.
- Skin looks and feels scaleless and slimy; scales are present but microscopically small and embedded.
- Nostrils are tubular.
- Large mouth with bands of many small inward-slanting teeth.
- Average adult length
- Most adults run 300–600 mm (roughly 12–24 in). Reaching 18 in typically takes five to seven years. River-dwelling populations stay much smaller than lake populations — one state account reports fish in flowing systems rarely exceeding 12 in.
- Common angling size
- 3–5 lb is given as typical in Alaska, with over 8 lb treated as a trophy; one state account puts most fish under 8 lb and under 28 in.
- Typical weight
- 1–3 kg (roughly 2–7 lb) for adults at 300–600 mm.
- Maximum documented
- State records include 34.5 in / 12.22 lb and 19 lb 3 oz. Maxima are strongly fishery-specific and lake fish far exceed river fish.
- Longevity
- Reported to 15 years in one state account; fish older than 20 years are described as not uncommon in Alaska, and northern populations show maxima of 20–22 years. Southern populations are generally younger. Maturity at 2–8 years, with males maturing about a year before females; southern populations mature at 3–4, northern at 4–7.
What it gets confused with
- Bowfin
- Bowfin has a short anal fin — less than a quarter of the dorsal's length — pelvic fins set back under the dorsal, a rounded broad head with no chin barbel, and often an eye-spot near the tail. Burbot has a long anal fin, pelvic fins forward of the pectorals, a flattened head, and the chin barbel.
- Northern snakehead
- Snakehead has a long pointed flattened head with no chin barbel and pelvic fins directly beneath the pectorals. Burbot has the chin barbel, two distinct dorsal fins, and pelvic fins ahead of the pectorals.
- American eel
- Distinguish on the burbot characters that were sourced: burbot has a chin barbel, paired pelvic fins set forward under the throat, and a rounded caudal fin separate from the long dorsal and anal fins. A fish lacking a chin barbel and lacking pelvic fins is not a burbot.
What follows from all of that
Presentation families
Flowing water
Bottom-contact drift
Tick or crawl a food form along the substrate through a feeding lane without snagging constantly.
- feel the bottom
- short hops
- reset after hang
- weight just enough
What it asks of the tackle
- Depth control
- High
- Sensitivity
- High
- Casting distance
- Moderate
- Weight range
- 1/8–3/8 oz
- Cover resistance
- Moderate
- Line visibility
- Low
- Retie frequency
- Moderate
Pulse / jig
Lift and drop a compact bait so it occupies a pocket, seam, or head without leaving the water column.
- short lift
- controlled drop
- stay in the pocket
- repeat on the same piece
What it asks of the tackle
- Depth control
- High
- Sensitivity
- High
- Casting distance
- Short to moderate
- Weight range
- 1/8–3/8 oz
- Cover resistance
- Moderate
- Line visibility
- Low
- Retie frequency
- High
Stationary bait
Hold a scent or food form in one feeding station and wait for a fish to move to it.
- anchor the presentation
- keep bait in the pocket
- detect takes without sweeping
- refresh often
What it asks of the tackle
- Depth control
- High
- Sensitivity
- Moderate
- Casting distance
- Short
- Weight range
- 1/4–1 oz
- Cover resistance
- High
- Line visibility
- Moderate
- Retie frequency
- High
Stillwater
Vertical jig
Work a compact bait up and down through a marked depth, basin, or timber pocket.
- stay over the target
- measured lift
- controlled drop
- watch slack
What it asks of the tackle
- Depth control
- High
- Sensitivity
- High
- Casting distance
- Vertical
- Weight range
- 1/8–3/4 oz
- Cover resistance
- Moderate
- Line visibility
- Low
- Retie frequency
- Moderate
Bottom contact
Keep a bait on or just above the substrate along a break, flat, or inside a weed edge.
- feel bottom
- drag or hop
- pause on the break
- stay in contact
What it asks of the tackle
- Depth control
- High
- Sensitivity
- High
- Casting distance
- Moderate
- Weight range
- 1/8–1/2 oz
- Cover resistance
- High
- Line visibility
- Low
- Retie frequency
- High
Slow drag
Move a bait along the bottom slowly enough that it stays in the feeding layer of inactive fish.
- continuous contact
- very slow travel
- pause at changes in bottom
- do not hop out of the zone
What it asks of the tackle
- Depth control
- High
- Sensitivity
- High
- Casting distance
- Moderate
- Weight range
- 1/8–3/8 oz
- Cover resistance
- Moderate
- Line visibility
- Low
- Retie frequency
- Moderate
Live / natural bait suspension
Present a natural food form with enough life or scent to hold in a station without looking mechanical.
- keep it alive or fresh
- match the holding depth
- minimize hardware bulk
- detect without pulling it away
What it asks of the tackle
- Depth control
- High
- Sensitivity
- High
- Casting distance
- Short to moderate
- Weight range
- As light as conditions allow
- Cover resistance
- Moderate
- Line visibility
- Low
- Retie frequency
- High
What moves them for this fish
Reviewed rules that push particular families up when the conditions match. Each one names the conditions it needs and why it exists, so you can disagree with it.
Burbot are cold-active, bottom-oriented predators; winter/deep structure should strongly reinforce vertical and substrate mechanics.
When
Winter or Late fall · Deep pool, Basin, Drop-off, Submerged hump, Rocky shoreline
Moves up
Vertical jig, Bottom contact, Slow drag, Stationary bait, Bottom-contact drift
Reviewed 2026-08-27
Where every sentence came from
Sources
Agency
Alaska Department of Fish and Game — Burbot (Lota lota) species profile
Used for identification; behaviour; forage; season. Read 2026-08-30, next check 2026-11-25.
Agency
Minnesota Department of Natural Resources — Species Profile: Burbot
Used for identification; behaviour; forage; season. Read 2026-08-30, next check 2026-11-25.
Agency
New Hampshire Fish and Game Department — Burbot / Freshwater Cusk species page
Used for identification; behaviour; forage; season. Read 2026-08-30, next check 2026-11-25.
Agency
Used for identification; behaviour; forage; season. Read 2026-08-30, next check 2026-11-25.
Agency
Used for identification; behaviour; forage. Read 2026-08-30, next check 2026-11-25.
Agency
USGS Lake Superior burbot life-history literature
Used for habitat, thermal band and presentation families. Read 2026-08-27, next check 2026-11-27.
Agency
Used for identification. Read 2026-08-30, next check 2026-11-25.
Peer reviewed
Used for behaviour; season. Read 2026-08-30, next check 2026-12-03.
Peer reviewed
USGS Great Lakes burbot thermal-distribution research
Used for habitat, thermal band and presentation families. Read 2026-08-27, next check 2026-11-27.
A source with no link predates the rule that one has to carry a URL. It is still a real citation and still checkable; it just takes a search rather than a click, and that is worth knowing before you rely on it.