Environment: milieu / climate zone / depth range / distribution range
Ecology
Freshwater; brackish; demersal; potamodromous (Ref. 51243); depth range 5 - 9 m (Ref. 117245). Temperate; 60°N - 30°N, 100°W - 71°W
North America: St. Lawrence-Great Lakes, Hudson Bay, and Mississippi River basins.
Length at first maturity / Size / Weight / Age
Maturity: Lm 99.7, range 90 - 120 cm
Max length : 274 cm TL male/unsexed; (Ref. 5723); common length : 97.5 cm TL male/unsexed; (Ref. 12193); max. published weight: 125.0 kg (Ref. 3672); max. reported age: 152 years (Ref. 72475)
Single row of preanal shields. Soft area on the top of the head absent and black viscera. Large blotches present on anterior half of upper surface of snout and on back. Lower surface whitish (Ref. 37032). Anal fin origin behind dorsal fin origin; scutes on back and along side same color as skin (Ref. 86798).
Inhabits bottom of lakes and large rivers (Ref. 10294), usually in 5-9 m depth, over mud, sand, and gravel. Occasionally enters brackish water. A specimen caught in 1952 was reputed to have been 152 years old (Ref. 6866). Search for food, with the aid of the sensory ability of the barbels, by constantly moving close to the substrate. Omnivorous, virtually anything edible that enters the mouth is sucked up and consumed. The food is worked or pulled in the mouth, often partly ejected and sucked in again (Ref. 1998). Spawning sites are rocky and boulder filled areas along the outside bend of rivers (Ref. 41542). In the 1800s, it was extensively exploited for oil to fire boilers on steamboats, animal feed and fertilizer. Later is was high-valued as smoked, caviar and isinglass (Ref. 117245). In 1951, Canada, 2,000 lbs. of caviar were made from the eggs (Ref. 37032). It continous to be an important source of food for Indigenous people in North America (Ref. 117245). Threatened due to over harvesting, habitat loss and pollution (Ref. 58490).
Spawning sites are rocky and boulder filled areas along the outside bend of rivers (Ref. 41542).
Page, L.M. and B.M. Burr, 1991. A field guide to freshwater fishes of North America north of Mexico. Houghton Mifflin Company, Boston. 432 p. (Ref. 5723)
IUCN Red List Status (Ref. 130435: Version 2024-2)
Threat to humans
Harmless
Human uses
Fisheries: commercial; aquaculture: experimental; gamefish: yes; aquarium: public aquariums
Tools
Special reports
Download XML
Internet sources
Estimates based on models
Phylogenetic diversity index (Ref.
82804): PD
50 = 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00263 (0.00205 - 0.00337), b=3.19 (3.14 - 3.24), in cm total length, based on LWR estimates for this species (Ref.
93245).
Trophic level (Ref.
69278): 3.3 ±0.49 se; based on food items.
Resilience (Ref.
120179): Very Low, minimum population doubling time more than 14 years (tm=16-26; tmax=152; K=0.04; Fec=50,000).
Fishing Vulnerability (Ref.
59153): Very high vulnerability (86 of 100).
