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ANS—Fish

Asian Carp

Montana ANS Priority Class 1 (petitioned for listing as an injurious wildlife species)

Bighead Carp

Description

  • Hypophthalmichthys nobilis
  • Imported from China to control aquatic weeds
  • Spreads via pond escapement or by deliberate release and by release of bait
  • Feeds voraciously on plankton; can consume 40% of their body weight each day
  • Competes with larval fish and paddle fish for food resources
  • Quickly dominates fisheries and are widespread throughout the Mississippi River drainage

General Characteristics

  • grow to 50+ lbs
  • large scaleless head and opercle
  • deep bodied, somewhat laterally flattened
  • body dark gray upper to silver-white laterally
  • eyes forward, below midline and project downward
  • dorsal fin spine moderately stiff but not serrated
  • gill rakers long, comb-like, not net-like

Links

US Geological Survey (USGS)—Bighead Carp


Black Carp

Description

  • Mylopharyngodon piceus
  • Imported from Asia in early 1980s by fish farmers to control yellow grub and snails in catfish ponds, and as food fish
  • Spread via pond escapement or by deliberate release
  • Grows very quickly and feeds voraciously on snails, clams, mussels, and aquatic insects; can eat 3 to 4 lbs of mussels per day
  • Would impact native mussel and snail communities

General Characteristics

  • grows to more than 3 feet long, averages 33 lbs up to 150 lbs
  • broad, blunt head with slight down-turned mouth and no barbels
  • body blackish brown and fins blackish gray
  • ventral surface of head and abdomen whitish
  • dorsal fin short and pointed with 7-9 soft rays
  • anal fin set closer to base of caudal fin

Grass Carp

Description

  • Ctenoparyngodon idella
  • Imported from Eastern Asia in 1963 for aquatic vegetation control in aquaculture ponds
  • Spread accidentally from aquaculture facilities and intentionally introduced in canals for vegetation control
  • Can eliminate vegetation, eradicate habitat for native fishes, forage for waterfowl, and increase nutrients

General Characteristics

  • usually 1-20 lbs, occasionally up to 100 lbs and 48 inches long
  • broad, blunt head with slight down-turned mouth and no barbels
  • elongate body, somewhat laterally flattened, dark olive shading to brownish yellow laterally and white belly
  • scales gray with dark-edges
  • dorsal fin short and pointed with 8-10 soft rays
  • anal fin set closer to base of caudal fin

Links

US Geological Survey (USGS)—Grass Carp


Silver Carp

Description

  • Hypophthalmichthys molitrix
  • Imported from Asia in 1973 by fish farmers to control algae blooms and as a food fish
  • Spreads via pond escapement or by deliberate release
  • Tolerate a wide range of environmental conditions
  • Grows quickly and to a large size and feeds voraciously on plankton
  • Competes with larval fish and paddle fish for food resources
  • Can reproduce only in rivers
  • Known for great jumping ability

General Characteristics

  • usually 1-20 lbs, occasionally up to 100 lbs and 40 inches long
  • head and opercle scaleless with relatively large upturned mouth without teeth
  • body deep, laterally compressed, usually olive-green dorsally to silver laterally, but sometimes bronze to red
  • eyes far forward along midline and project somewhat downward
  • dorsal and anal fin first ray spine-like

Links

US Geological Survey (USGS)—Silver Carp


Round Goby

Montana ANS Priority Class 1 (petitioned for listing as an injurious wildlife species)

Description

Round Goby. Round Goby
  • Neogobius melanostomus
  • Introduced first into the Great Lakes via ballast water
  • Bottom-dwelling fish, native to Europe
  • Prefers cobble, rock, riprap habitats
  • Quickly dominates fisheries, can spawn several times a year
  • Are aggressive and compete with native bottom-dwellers, have reduced numbers of native fish in places where it has become established

General Characteristics

  • no other native fish in the Grate Lakes has the single pelvic fin
  • young are solid slate gray
  • usually 3-6 inches (7.6-15.2 cm) long, may be up to 10 inches (25.4 cm) long

Links

US Geological Survey (USGS)—Round Goby


Eurasian Ruffe

Montana ANS Priority Class 1

Description

  • Gymnocephalus cernuus
  • Small perch-like European fish
  • First introduced into Great Lakes via ballast water
  • Spiny dorsal fins discourage predation
  • Considered a nuisance by anglers
  • Out competes perch for food; caused 75% declines in perch populations in Lake Superior

Links

US Geological Survey (USGS)—Ruffe

 

Tench

Montana ANS Priority Class 1

Description

  • Tinca tinca
  • Member of the family cyprinidae
  • Introduced into Idaho in 1880’s, found throughout the Pend O’reille and the Coeur d’Alene river drainages, including downstream of Cabinet Gorge Dam
  • High reproductive potential; grow to 15 inches in Idaho and much larger in their native Europe
  • Would compete with native cyprinids and game fish

General Characteristics

  • resembles carp
  • flattened and stocky
  • very numerous small scales, smaller than the pupil of the eye and deeply embedded
  • one pair of barbels situated at the corner of the mouth
  • dark colored rounded fins
  • thick skin covered by abundant mucus

Zander

Montana ANS Priority Class 1

Description

  • Sander lucioperca
  • Also known as European pike-perch, closely related to walleye and native sauger
  • Introduced into North Dakota from Finland in 1989, which resulted in a reproducing population
  • Zander are thought to be in the Missouri River
  • Potential impacts include displacement, predation, and hybridization with walleye and sauger

General Characteristics

  • similar to walleye and sauger
  • elongate head and body with prominent and pointed snout with large jaws
  • 80-90 scales in lateral line, which continues on to the tail (sauger 75-88)
  • dorsal fin is divided, 13-17 spines in the first (sauger 12-13), one or two spines and 19-24 rays in the second (sauger 17-19 rays)
  • anal fin has 2-3 slender spines and 11-12 rays
  • typically 16-20 in, although can reach 51 inches and 44 pounds
  • dorsal fins have lines of dark spots on membranes and scattered dark spots on the tail (walleye have no spots on dorsal fin but have a dark blotch)

Northern Snakehead

Federal Injurious Wildlife Species

Description

  • Channa argus
  • At all life stages will compete for food and habitat with native and sport fish
  • Adults are voracious predators, feed on other fish, crustaceans, frogs, reptiles, birds and small mammals
  • Can survive underneath ice, northern snakeheads are present in siberia and would be able to survive in Montana
  • Can tolerate hypoxic conditions; they are air breathers from late juvenile stage
  • The use of pesticides to control or eradicate populations would likely be ineffective because of their ability to air breath and move across land

General Characteristics

  • maximum size exceeds 33 inches
  • similar to the native burbot
  • most easily identified by the long dorsal and anal fins, dark, irregular blotches along sides, pelvic fins located beneath the pectorals, and truncate (not rounded) tail
  • dorsal fin of burbot is split with a short dorsal fin in front of larger one
  • burbot can also be distinguished by a single barbel beneath the lower jaw
  • dorsal fins have lines of dark spots on membranes and scattered dark spots on the tail (walleye have no spots on dorsal fin but have a dark blotch)