The burbot, scientifically known as Lota lota, is a freshwater fish adapted to cold, often icy, aquatic environments. It is notable for its distinctive appearance and habits, allowing it to thrive in northern regions. Its unique characteristics and role in freshwater ecosystems interest anglers, scientists, and nature enthusiasts.
Distinctive Features
The burbot is the only freshwater species within the cod family (Gadidae), setting it apart from marine relatives like Atlantic cod. A prominent physical identifier is the single, whisker-like barbel located centrally under its chin. This sensory organ assists the fish in navigating and locating prey in dark, often murky, bottom waters.
Physical Characteristics
The burbot has an elongated, eel-like body tapering towards a rounded tail fin. Its skin, though appearing smooth, is covered with very small scales. Coloration ranges from mottled brown, olive, or grey, often with darker spots or blotches, providing effective camouflage against rocky or muddy lake and river bottoms.
It has two dorsal fins; the first is short, while the second is much longer, extending nearly the length of its body. A single, elongated anal fin runs along the underside, almost reaching the tail. Its head is relatively flattened, with a wide mouth equipped with numerous small, inwardly slanting teeth that help secure prey.
Habitat and Behavior
Burbot prefer cold, deep, well-oxygenated waters in large lakes, rivers, and reservoirs across northern latitudes. Their native range extends across North America, Europe, and Asia, particularly in boreal and subarctic regions. They are benthic bottom-dwellers, spending most of their time near the lake or riverbed.
These fish are primarily nocturnal. During daylight hours, burbot often remain hidden in shelters such as rock slabs, submerged logs, or other debris. This behavior helps them conserve energy and avoid predators.
Reproduction and Feeding Habits
Burbot spawn during winter months, often under the ice, from November through March. They typically use shallow areas over sand or gravel bottoms. Multiple males and females gather, forming a writhing mass, sometimes called a “spawning ball,” to release eggs and sperm directly into the water. Females can produce 60,000 to over 3 million eggs, depending on their size.
As opportunistic predators, burbot feed on a varied diet. Younger burbot primarily consume aquatic insects and invertebrates, including zooplankton and crayfish. As they mature, their diet shifts to include smaller fish species, such as minnows, sculpins, perch, and even other burbot. Their bottom-dwelling lifestyle and sensory barbel give them an advantage in locating prey in low-light conditions.