Acipenser fulvescens
Lake Sturgeon

Lake Sturgeon

Flora, fauna, earth, and sky...
The natural history of the northwoods

...

Name:

  • Acipenser, from the Latin, "sturgeon"
  • fulvescens, from the Latin, "yellowish red"
  • Common name from its preference for large bodies of water
  • Other common names include: Black Sturgeon, Bony Sturgeon, Freshwater Sturgeon, Rock Fish, Rock Sturgeon, Rubber-nose, Smoothback

Taxonomy:

  • Kingdom Animalia
    • Phylum Chordata, animals with a spinal chord
    • Subphylum Vertebrata, animals with a backbone
      • Superclass Osteichthyes, bony fishes
      • Class Actinopterygii, ray-finned and spiny rayed fishes
      • Subclass Chondrostei, paddlefishes, spoonfishes, and sturgeons
        • Order Acipenseriformes, paddlefishes, spoonfishes, and sturgeons
        • Suborder Acipenseroidei
          • Family Acipenseridae, sturgeons, comprising 23 species native the to Northern Hemisphere
            • Genus Acipenser, greater sturgeons

Description:

  • A leathery giant and living "dinosaur" of the fish world
  • Length
    • generally 3'-5'
    • can grow to 7' or more
  • Weight
    • 10-80 lbs
    • reaches several hundred pounds in some waters, with reports of Minnesota fish over 200 lbs from earlier in the century.
  • Color
    • slate-grey to black above
    • light beneath
    • young tan or buff colored, sometimes contrastingly blotched with dark becoming more uniformly dark as they grow older.
  • Body thick-set and torpedo-shaped
    • skin tough and leathery
    • armor-plated, with five longitudinal rows of heavy, bony plates
    • skeleton cartilaginous
    • tail upturned and shark-like; upper lobe longer than lower
  • Head roundly conical in shape and not flattened.
    • spiracles (openings from the throat cavity to the outside above and behind the eyes) are present.
    • snout long, pointed, with four barbels, or tissue filaments.
    • Mouth inferior and almost sucker-like, capable of being protracted for ease in sucking foods off the bottom. Feeds entirely by taste, having four fleshy barbels on the underside of the snout, which act as sense organs to gauge the distance from the mouth to the bottom.
  • Lifespan to 150 years or more.
  • Minnesota Record officially 94lbs. 4oz., from the Kettle River (Pine County). However, a 162lb. 8oz.fish was pulled from the Rainy River, just west of the BWCA, in1968, a 225 lb. sturgeon was found dead on the shores of Rush Lake (Chisago County) in 1947, and a whopper reported to weigh in at 236 lbs. was taken, probably by net, from the Lake of the Woods in 1911. Fish over 300 lbs. are reported from the Great Lakes.

Identification:

  • Unique among Northwoods fishes; unlikely to be mistaken for any other.
  • Field Marks:
    • heterocercal (shark like) tail
    • bony plates on leathery skin
    • flattened snout
    • mouth on underside of head

Distribution:

  • Hudson Bay drainage south as far as Louisiana.
  • Now sporadic and rare.

Habitat:

  • Generally the bottom in the shoal areas of large freshwater lakes and rivers.

Food:

  • Largely worms, insect larvae, snails, clams, some fish and fish eggs, bits of aquatic plants, and other litter from the floor of a lake or stream.
  • Young fish less than 8" in length will feed on minute crustaceans.
  • Primarily a bottom feeder.

History:

  • These "living fossils" of fish evolution once ranged widely throughout the Mississippi River, the Great Lakes and the Hudson River.
  • Regarded as a nuisance in the 19th century for becoming entangled in and ripping commercial fishing nets. Only later prized for its meat, eggs (caviar), and oil. A sturgeon fishery in the Lake of the Woods of immense economic potential was destroyed by early commercial fishermen in search of walleye. It has not yet recovered.
  • Gelatin from inner lining of its air bladder was used to make isinglass--a clarifying agent in jellies, glues, and the isinglass windows of carriages and early cars.
  • Historically, has been exceptionally vulnerable to overfishing, largely because of its slow reproductive cycle.
  • Sensitive to pollution.
  • Reproduction has suffered from dams blocking upriver spawning runs.

Uses:

  • Sturgeon fishing is limited, and generally prohibited during the spring spawning period (mid-May through the end of June).
  • Not considered a sport fish, it now supports minor commercial fisheries in New-Brunswick, Quebec, Ontario, Manitoba, and Saskatchewan.
  • Commercial fishing with gillnets, poundnets, and set lines (long horizontal lines having many baited hooks attached by shorter lines and set on the bottom).
  • Sells for more per pound than any of our other freshwater species. Flesh is firm, white, rich; popular smoked. Often considered a gourmet item, as are the processed eggs, known as caviar.

Reproduction:

  • Very slow. Female requires 15-20 years or more to mature, then spawns only every 4-6 years during its 50-100 year lifespan. Males mature at a smaller size and spawn every year or two.
  • Spawns in late spring, or early summer, usually in streams, but also in shallow areas of lakes where it is native to lentic waters.
  • Large females produce 500,000 eggs or more, hatching in 8 days at 55º F.
  • Males and females grow at the same rate, but females are longer lived, with 97% of the fish over 30 years of age being female.

Comments:

  • The largest and oldest living fish in Minnesota and the Great Lakes.

Links:

Boreal border

Last updated on 7 November 1999