a field guide to fish invaders of the great lakes region
TRANSCRIPT
A Component of the Aquatic Invasive Species-HazardAnalysis and Critical Control Point (AIS-HACCP) Program
Non-Native Fish andNative Look-a-Likes
This guide highlights harmfulaquatic invasive fish that posethreats to the recreational,environmental, and economicvalue of the Great Lakes region.Similar-looking native speciesare included for comparison.
The non-native species identi-fied in this guide could spreadduring harvest, stocking, orfishery and law enforcementoperations.These fishes havethe potential to displace nativespecies, harm habitats, anddegrade lakes, rivers, streams,and wetlands.
The purpose of this guide is toassist private and public fisheriespersonnel in identifying andreporting potentially invasivefish species. It is also designedto accompany Aquatic InvasiveSpecies-Hazard Analysis andCritical Control Point (AIS-
HACCP) training workshops,curriculum, video (From Net toSale), and other programmaterials. For details, visitwww.seagrant.umn.edu/ais/haccp.
Specimens of non-native fishare needed to confirm sightingsand infestations, but manyGreat Lakes jurisdictions havediffering rules regardingpossession and transport. Somenon-natives represented inthis field guide are regulatedunder state or provincial laws.Other non-native or nativespecies can be harvested, trans-ported, or sold commercially.
Contact your local naturalresource management agencyfor instructions. Never dumplive fish from one body of waterinto another without a permit.
Fish Invaders
This Field Guide Contains:
• Full-color illustrations for 38 invasive and commonlook-a-like fishes
• Key characteristics to aid accurate identification*
*Size estimates taken from Page, L. M. and B. M. Burr. 1991. FreshwaterFishes, Peterson Field Guides. Houghton Mifflin Company, New York.
Group 1 . . . . . . . . . . . . . . . . . . . . 4Fourspine SticklebackThreespine SticklebackNinespine SticklebackBrook Stickleback
Group 2 . . . . . . . . . . . . . . . . . . . . 6Round GobyTubenose GobySpoonhead SculpinSlimy SculpinMottled SculpinDeepwater Sculpin
Group 3 . . . . . . . . . . . . . . . . . . . . 8RuddGolden ShinerRedfin ShinerGoldfish
Group 4 . . . . . . . . . . . . . . . . . . . . 9Bigmouth BuffaloBighead CarpSilver CarpBlack CarpGrass CarpCommon Carp
Group 5 . . . . . . . . . . . . . . . . . . 12RuffeWalleyeSaugerTrout-perchYellow PerchLogperch
Group 6 . . . . . . . . . . . . . . . . . . 14White PerchWhite BassYellow BassYellow PerchFreshwater Drum
Group 7 . . . . . . . . . . . . . . . . . . 16Inland SilversideBrook Silverside
Group 8 . . . . . . . . . . . . . . . . . . .17Rainbow SmeltEmerald ShinerCisco (Lake Herring)
Group 9 . . . . . . . . . . . . . . . . . . 18Northern SnakeheadBowfinBurbot
A Field Guide to
Fish Invadersof the Great Lakes Region
Guide to Key Features
dorsal fin
pectoral finpelvic fin
anal fin
caudal (tail) finadipose fin
To count lateral line scales: count the number ofscales along the line formed by a series of pore-likeopenings from behind the gill cover to the tail.
cheek
gill cover keel: a sharpcompressed edgealong the belly
countingfin rays(e.g., totalrays = 11)
Each page includes one or more invasive fish and its nativelook-a-likes with key characteristics such as length and color.
How to Use This Guide
dorsal finorigin
Denotes Invasive Fish Denotes Native Fish
Pungitius pungitius
Length: Up to 3.5 in. (9 cm)Coloring: Body is olive green to pale green
Culaea inconstans
Length: Up to 3.5 in. (9 cm)Coloring: Body is olive green to dark green with
light spots
• Nine short dorsal spines
• Scaleless body sometimeswith bony plates
Ninespine Stickleback
• Five to six shortdorsal spines
• Scaleless body with nobony plates
Brook Stickleback
• Four dorsal spines;first two spines arelonger than secondtwo spines
• Scaleless body withno bony plates
Apeltes quadracus
Length: Up to 2.5 in. (6.4 cm)Coloring: Body is olive green with dark mottling
Fourspine Stickleback
Gasterosteus aculeatus
Length: Up to 4 in. (10 cm)Coloring: Body is silvery with dark mottling
• Three dorsal spines;first two spines arelonger than third
• Scaleless body withbony plates
• Native to Lake Ontario
Threespine Stickleback
Group 1 Page 5Group 1 Page 4
• Two separate pelvic fins
• Large head with largespine on each sidedirected upward andinward; two lower spinescovered by skin
• No spot on first dorsal fin
• Scaleless bodyCottus cognatus
Length: Up to 4.5 in. (12 cm)Coloring:Mottled brown to olive-green body
Slimy Sculpin
• Two separate pelvic fins
• Large head with largespine on each sidedirected upward andinward; two lower spinescovered by skin
• Large dark spots all overfirst dorsal fin
• Scaleless body
Cottus bairdii
Length: Up to 6 in. (15 cm)Coloring: Body is light to dark brown with mottled
back and sides
Mottled Sculpin
• Two separate pelvic fins
• Head is wide and flatwith four conspicuousspines on each side; topspine directed upward,others downward
• No spot on first dorsal fin
• Scaleless body
Myoxocephalus thompsonii
Length: Up to 9 in. (23 cm)Coloring: Body is gray brown with light mottling
on back and sides
Deepwater Sculpin
• Pelvic fins are fused toform a single scallop-shaped fin
• Large head with frog-likeraised eyes
• Black spot on rear offirst dorsal fin
• Fine scales on bodyApollonia melanostomus
Length: Up to 10 in. (25.4 cm)Coloring:Mottled olive and brown body
Round Goby
• Pelvic fins are fused toform a single scallop-shaped fin
• First nostrils extendbeyond lower lip
• Black lines on first dorsalfin; no black spot
• Fine scales on body
Proterorhinus semilunaris
Length: Up to 4 in. (10 cm)Coloring:Mottled brown body, usually with five
dark bars on sides
Tubenose Goby
• Two separate pelvic fins
• Large head with well-developed spine on eachside, curving upward andbackward
• All fins are lightly speckledexcept pelvic fins, whichare clear
• Scaleless body
Cottus ricei
Length: Up to 5 in. (13 cm)Coloring: Head and body are light brown and tan,mottled with small dark speckles
Spoonhead Sculpin
Group 2 Page 6 Group 2 Page 7
Ictiobus cyprinellus
Length: Up to 35 in. (90 cm)
Coloring: Olive-brown to bronze body; sides andbelly lighter
Carassius auratus
Length: Up to 16 in. (41 cm)Coloring: Body is gold to olive green with white or
black patches
• Buffalos, Quillback,Carpsuckers (Ictiobusand Carpoides species)
For all members ofthese groups:
• No barbels
• Single, long sickle-shaped dorsal finwithout serratedspine; 22-32 soft rays
• Large scales, 33-40 inlateral line
Bigmouth Buffalo (Carp Look-a-Likes)
• No barbels
• No keel along belly
• Single serrated spineon long dorsal finwith more than 15soft rays
• Large scales, 27–30 inlateral line
Goldfish• Scaled keel along belly,
from pelvic to anal fins
• Bright red-orange fins
• 38–42 lateral line scales
• Iris of eye has red spotdorsally
Scardinius erythrophthalmus
Length: Up to 19 in. (48 cm)Coloring: Golden bronze body; white belly
Rudd
• No keel along belly
• Fins typically clearexcept in breedingmales, which have pinkor orange tinted fins
• Small dark or duskyspot at anterior base ofdorsal fin
• 41–48 lateral line scales
Lythrurus umbratilis
Length: Up to 3.5 in. (9 cm)Coloring: Body is bluish with silvery tints
Redfin Shiner
• No scales on keelalong belly from pelvicto anal fins
• Breeding males haveorange on pelvic andanal fins, otherwisetheir fins are yellowish
• 44–54 lateral line scales
• No red spot on iris of eye
Notemigonus crysoleucas
Length: Up to 12 in. (30 cm)Coloring: Silvery to golden body with green to brown
back; yellowish to yellow-silvery belly
Golden Shiner
Group 4 Page 9Group 3 Page 8
Non-native carps to compare with the Bigmouth Buffalo are featuredon the next two pages.
• Broad, blunt head withslight downturnedmouth, no barbels
• No keel
• Pointed dorsal fin with7–8 soft rays
• Dark-edged scales, givea cross-hatched effect,39-46 in lateral line
Mylopharyngodon piceus
Length: Up to 48 in. (122 cm)Coloring: Blackish-brown to dark olive body;
blackish-gray fins; white belly
Black Carp
• Two barbels on eachside of the upper jaw
• No keel
• Single serrated spineon long dorsal finwith more than 16soft rays
• Large scales, 32–41 inlateral line
Cyprinus carpio
Length: Up to 48 in. (122 cm)Coloring: Bronze to golden-yellow body;
yellowish-white belly
Common Carp
• Broad, blunt head withslight downturnedmouth, no barbels
• No keel
• Pointed dorsal fin with8–10 soft rays
• Scales are silver to graywith a prominent darkedge, giving a cross-hatched effect, 34–45 inlateral line
Ctenopharyngodon idella
Length: Up to 49 in. (125 cm)Coloring: Body has dark olive shading with
brownish-yellow sides; white belly
Grass Carp
• Large scaleless headwith upturned mouth,no barbels
• Eyes forward, belowmidline and projectdownward
• Scaleless keel extendsonly from anal fin topelvic fin
• Single dorsal spine ismoderately stiff but notserrated, followed by 8soft rays
• Very tiny scales (trout-like), 91–120 in lateral line
• Long and comb-like gillrakers
Aristichthys nobilis
Length: Up to 44 in. (112 cm)Coloring: Body is dark gray dorsally to silver white
on sides.Many dark irregularly shapedblotches are scattered over body
Bighead Carp
Hypophthalmichthys molitrix
Length: Up to 41 in. (104 cm)Coloring: Body is olive green dorsally; silver but
sometimes bronze to red sides
• Scaleless head with largeupturned mouth, nobarbels
• Eyes forward, belowmidline and projectdownward
• Scaleless keel extends allthe way from anal fin tobase of gills
• Dorsal spine moderatelystiff but not serrated,followed by 8 soft rays
• Very tiny scales (trout-like), 91–124 in lateral line
• Gill rakers appearspongy
Silver Carp
Group 4 Page 10 Group 4 Page 11
• Single dorsal fin withtwo spines (usuallyquite soft) and anadipose fin
• Rows of black spots onback and sides
• Jaw ends below nostril,well in front of eye
Percopsis omniscomaycus
Length: Up to 7.75 in. (20 cm)Coloring: Body is pale olive or silvery to almost
translucent
Trout-perch
• Spiny and soft dorsalfins are separated
• Dusky coloration onthe front and back ofthe spiny dorsal fin, butno distinct spots
• Upper jaw reaches tothe pupil of the eye
Perca flavescens
Length: Up to 16 in. (40 cm)Coloring: Body is green above, 6-9 green-brown
saddles extend down yellow sides
Yellow Perch
• Spiny and soft dorsalfins are separated
• Lightly barreddorsal fin
• Dark vertical bandson sides
• Pig-like snout; upperjaw does not reachto the eye
Percina caprodes
Length: Up to 7.25 in. (18 cm)Coloring: Body is yellowish green with dark olive-
black markings
Logperch
• Spiny and soft dorsalfins are connected
• Rows of dark spotsbetween dorsal spines
• Many sharp spines ongill cover
• Small downturnedmouth
• Very slimy when handled
Gymnocephalus cernuus
Length: Up to 10 in. (25 cm)Coloring: Body is olive to golden brown on back,paler
on side with yellowish-white underside
Ruffe
• Spiny and soft dorsalfins are separated
• Single dark spot on rearbase of spiny dorsal fin
• Bottom of caudal finwhite-tipped
• Large mouth; jawextends beyond middleof eye
Sander vitreus
Length: Up to 36 in. (91 cm)Coloring: Body is olive brown to golden brown
to yellow
Walleye
• Spiny and soft dorsalfins are separated
• Rows of dark spots onboth dorsal fins
• Large mouth; upperjaw extends beyondmiddle of eye
• Caudal fin not white-tipped as in walleye
Sander canadense
Length: Up to 25 in. (63 cm)Coloring: Body is sandy to dull brown with 3-4
dark saddles along back and sides
Sauger
Group 5 Page 12 Group 5 Page 13
• Anal fin has three spines;second and third spinesare the same length
• Sides have 6-7 darkhorizontal stripes; loweststripes lines offset aboutmidbody
• Two dorsal fins are notjoined
• Native to MississippiRiver Basin
Morone mississippiensis
Length: Up to 18 in. (46 cm)Coloring: Golden-yellow body
Yellow Bass
• Anal fin has two spines
• Several dark verticalbands extend overback and down sides
• Two dorsal fins arenot joined
Perca flavescens
Length: Up to 16 in. (40 cm)Coloring: Body is green above, 6-9 green-brown
saddles extend down yellow sides
Yellow Perch
• Anal fin has twospines, the second isgreatly enlarged
• Two dorsal fins areconnected; longsecond dorsal fin,with 24–32 rays
• Rounded tail Aplodinotus grunniens
Length: Up to 35 in. (89 cm)Coloring: Body is silvery to bronze with no stripes
Freshwater Drum
• Anal fin has threespines; second andthird spines are thesame length
• Back or sides generallyhave no lines or stripes
• Two dorsal fins slightlyjoined by membraneat base, 11–12 rays onsecond dorsal fin
Morone americana
Length: Up to 22.8 in. (58 cm)Coloring: Silvery-green to brownish-black body
White Perch
Morone chrysops
Length: Up to 17.8 in. (45 cm)Coloring: Silvery to pale-green body
• Anal fin has threespines of differentlengths, stair-stepped
• Six or more dark hori-zontal stripes on sides
• Two dorsal fins arenot joined
White Bass
Group 6 Page 14 Group 6 Page 15
• Has single dorsal finand an adipose fin
• Large teeth on bothjaws and especially ontongue
• Large mouth, protrudinglower jaw, upper jawextends to middle ofeye or beyond
• 11-14 pectoral fin rays
Osmerus mordax
Length: Up to 12 in. (30 cm)Coloring: Silvery body with steel blue along back;
white belly
Rainbow Smelt
For all shiners:
• Single dorsal fin and noadipose fin
• No large teeth on jawsor tongue
• Small mouth, lower jawdoes not protrude,upper jaw does notextend past front of eye
Emerald Shiner(and other shiners,Notropis species)
• Single dorsal fin and anadipose fin
• No teeth on jaws
• Large mouth, upper jawdoes not extend beyondpupil of eye
• 15-16 pectoral fin rays(14-18 for all species inthis group)
Coregonus artedi
Length: Up to 20 in. (51 cm)Coloring: Silvery body with iridescence along
back; white belly
Cisco (formerly Lake Herring)(and other Coregonines)
Notropis atherinoides
Length: Up to 4 in. (10 cm)Coloring: Silvery body with slightly darker back
and silvery-white belly
• Anal fin has one spineand 18 or fewer rays
• 36–44 lateral scales
• Beak-like mouth,considerably upturned
• First dorsal fin origin infront of anal fin origin
Menidia beryllina
Length: Up to 6 in. (15 cm)Coloring: Silvery body with bands that extend
caudally
Inland Silverside
Labidesthes sicculus
Length: Up to 5 in. (13 cm)Coloring: Translucent to silvery body
• Anal fin has one spineand 22 or more rays
• 75–84 lateral scales
• Beak-like mouth, almosthorizontal near tip
• First dorsal fin origindirectly above analfin origin
Brook Silverside
Group 7 Page 16 Group 8 Page 17
• Single long dorsal fin
• Long anal fin
• Square tail
• Head has large scales
• Jaws with canine-liketeeth Channa argus
Length: Up to 33 in. (84 cm)Coloring: Dark brown body or tan with irregular
blotches
Northern Snakehead
• Single long dorsal fin
• Short anal fin
• Caudal eyespots foundon juveniles and adultmales
• No scales on head, largescales on body
• Jaws with canine-liketeeth
Amia calva
Length: Up to 43 in. (109 cm)Coloring: Dark olive to brown body
Bowfin
• Two dorsal fins
• Long anal fin
• Single median chinbarbel
• Scales so small theyare almost invisible
• Jaws with many tinyteeth in wide bands
Lota lota
Length: Up to 33 in. (84 cm)Coloring: Light yellow body that is mottled dark
brown or black dorsally
Burbot
Group 9 Page 18
Prevention guidelines for public and private aquacultureand baitfish managers and researchers can be found in SeaGrant’s “Aquatic Invasive Species-Hazard Analysis andCritical Control Point Training Curriculum,” Appendix 1.
When you leave a body of water:
• Inspect your boat, trailer, and equipment and remove visible
aquatic plants, fish or animals, and mud.
• Drain water from bait buckets, livewell, bilge, transom, and motor.
• Dispose of unwanted live bait and worms in the trash.
• Spray/wash your boat, trailer, and equipment with high pressure
or hot water before going to other waters, OR
• Dry everything for at least five days.
The University of Minnesota is an equal opportunity employer and educator.
A Field Guide to Fish Invaders of the Great Lakes Region
Citation:Jesse Anderson, Doug Jensen, Jeff Gunderson, and Marie Zhuikov. 2008.A Field Guide to Fish Invaders of the Great Lakes Region. University ofMinnesota Sea Grant Program, Duluth, MN. USA.
Product Number:X 105
Illustration Credits:Images used with permission. Some images are copyrighted and otheruses may require the artist’s consent. Credits: Joe Tomelleri (CimarronTrading Company), Ted Walke (Pennsylvania Fish and Boat Commision),Duane Raver (U.S. Fish and Wildlife Service), Susan Trammell(SusanTrammell.com, Inc.), and the New York Department ofEnvironmental Conservation.
Technical Assistants:Corey Boeck and Sean Dobie
Editor:Sharon Moen
Original Design:Evan Heisler 2007
Revision Design:Chris Benson 2008
For more information, contact:University of Minnesota Sea Grant Program2305 E 5 St.Duluth, MN 55812(218) 726–8106 or [email protected]
Produced by the University of Minnesota Sea Grant Program on behalf ofthe Great Lakes Sea Grant Network. Funding was provided by a grantfrom the National Oceanic and Atmospheric Administration to theNational Sea Grant College Program through an appropriation byCongress based on the National Invasive Species Act.