Species learning profile
Haddock
Melanogrammus aeglefinus
Haddock (Melanogrammus aeglefinus) is a saltwater fish associated with demersal habitat in North Atlantic. A dark shoulder mark is traditionally called the Devil's thumbprint.
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At a glance
- Water
- Salt water
- Habitat
- Sea floor
- Maximum length
- 112 cm
- Range
- North Atlantic
- Family
- Gadidae
- Order
- Gadiformes
Observe
How to identify Haddock
- A dark shoulder mark is traditionally called the Devil's thumbprint.
- Guide context: demersal habitat in North Atlantic.
- Reported maximum length: 112 cm — capable of growing longer than many people are tall. Maximum is not the same as typical adult size.
Field note: color, size, and markings can change with age, sex, season, depth, and lighting. Use several traits together.
Place and pattern
Where it lives—and how it behaves
Habitat and range
This species is associated with demersal habitat across North Atlantic. It lives on or close to the bottom, where sediment, rock, depth, and bottom-dwelling prey matter most.
Behavior
Schools near the seafloor
Food-web connections
What it eats and why it matters
Diet
Bottom invertebrates and small fish.
Ecological role
A major consumer and prey species on northern shelves.
Remember
One fact worth keeping
A dark shoulder mark is traditionally called the Devil's thumbprint.
Think like a conservationist
A conservation lens
Bottom-associated fish can be affected by seafloor disturbance, bycatch, warming, and changes to benthic prey.
This habitat lens is not a current population-status assessment. Status can differ among regions and change as new assessments are published; follow the reference links and local fisheries or wildlife agencies for current decisions.
Recall
Quick knowledge check
Which habitat is most closely associated with Haddock in this guide?
Keep exploring
References and further reading
Fishdle summarizes stable identification and ecology concepts in plain language. Taxonomy and population knowledge continue to change, so use primary assessments and regional authorities for conservation or management decisions.
Make connections