Fish Features

Question 1

• Jaws absent
• 7 gill slits
• Circular mouth
• Single nostril
• No paired fins
• Mouth is a circular oral disk lined with horny teeth

Answer 1

Petromyzontidae (Lamprey)

Question 2

• Mouth inferior & protrusible
• 2 pairs of mouth barbels
• Shovel-like snout
• 5 rows of bony scutes
• Tail heterocercal

Answer 2

Acipenseridae (Sturgeon)

Question 3

• Jaws long and beak-like
• Numerous needle-like teeth
• Thick rhombic ganoid scales
• Dosal fin short, located posteriorly
• Body elongate
• Abbreviated heterocercal tail

Answer 3

Lepisostidae (Gar)

Question 4

• Jaws normal, not beak-like
• Dorsal fin elongate, almost to caudal fin
• Abbreviated heterocercal tail
• Large median gular plates
• Body with cycloid scales
• Males with ocellus at base of caudal fin

Answer 4

Amiidae (Bowfin)

Question 5

• Midline of belly without strong, spiny scutes
• Lateral line present
• Dorsal fin at least partially overlapping with anal fin
• Always more than 25 anal fin rays

Answer 5

Hiodontidae (Mooneye)

Question 6

• Body extremely elongate, with tiny scales present
• Dorsal and anal fins continuous with caudal fin
• Pelvic fins absent

Answer 6

Anguillidae (Eels)

Question 7

• Sharp-edged row of spiny scutes along entire belly
• Lateral line absent, or only a few scales behind head
• Head scaleless
• Dorsal fin anterior to anal fin, not overlapping
• Never more than 23 anal fin rays

Answer 7

Clupeidae (Herring)

Question 8

• Distance from anal fin origin to caudal fin base is more than 1/3 distance from anal fin origin to snout
• single small dorsal fin w/ 9 or less soft rays (carp and goldfish have anterior, serrate spine-like ray)
• less than 10 teeth on each pharyngeal arch, confined to 2 or 3 rows
• Lips not sucker-like (seldom inferior)
• No adipose fin
• Small size (except carp)

Answer 8

Cyprinidae (Minnow)

Question 9

• Pelvic axillary process present
• Adipose fin present
• Fins soft-rayed
• Body with cycloid scales

Answer 9

-Salmonidae (Salmon)

Question 10

• Dorsal fin w/ 2 weak spines
• Pelvic and anal fins w/ 1 weak spine
• Adipose fin present
• Body with weakly ctenoid scales

Answer 10

Percopsidae (Trout-perch)

Question 11

• Chin with small distinct median barbel
• Small imbedded scales (appears scaleless)
• Dorsal and anal fins elongate
• Small pelvic fins located under the throat
• Body not compressed laterally

Answer 11

Lotidae (Freshwater Codfish)

Question 12

• Third anal ray branched
• Superior mouth w/ upper jaw protractile
• Flattened head
• Pelvic fins inserted on anterior half of body
• Anal fin of males not slender and rod-like
• Dorsal fin base almost completely overlapping with anal fin

Answer 12

Fundulidae (Killifish)

Question 13

• Third anal ray not branched
• Superior mouth
• Male has gonopodium (modified elongated anterior anal fin rays)
• Pelvic fins are inserted on anterior half of the body
• Dorsal fin base entirely (males) or almost entirely (females) behind anal fin base

Answer 13

Poecillidae (Livebearer)

Question 14

• Anal fin origin to caudal fin base is less than 1/3 the distance from anal fin origin to snout
• Pharyngeal arch w/ 10 or more teeth, 1 row only
• Lips thick and fleshy w/ plicae or papillae
• Dorsal fin w/ 10 or more rays, none spiny
• No adipose fin

Answer 14

Catostomidae (Sucker)

Question 15

• Adipose fin present, may be continuous with caudal fin
• Dorsal and pectoral fins w/ large spines
• 4 pairs of prominent barbels around mouth
• Body scaleless

Answer 15

Ictaluridae (Bullhead Catfish)

Question 16

• Pronounced, flattened snout, duckbill-shaped
• Jaws well-developed w/ strong, sharp teeth
• Dorsal and anal fins located posteriorly
• Scales developed on side of head
• No adipose fin
• Caudal fin forked
• Complete lateral line

Answer 16

Esocidae (Pike)

Question 17

• Upper jaw bound to snout by wide bridge of tissue (frenum)
• Lower jaw not protruding, snout not pronounced
• Dorsal and anal fins located posteriorly
• Caudal fin rounded
• No adipose fin
• Lateral line faint or absent

Answer 17

Umbridae (Mudminnow)

Question 18

• Pelvic axillary process absent
• Adipose fin present
• Large, toothy mouth
• Fins soft-rayed
• Body w/ cycloid scales

Answer 18

Osmeridae (Smelt)

Question 19

• 2 separate dorsal fins; small spiny-rayed in front of larger soft-rayed
• Lower jaw extends before upper jaw; snout flattened
• Broad silver band and slender body shape
• Pelvic fins abdominal
• No lateral line

Answer 19

Atherinidae (Silverside)

Question 20

• Well-developed, isolated dorsal spines
• First dorsal spine well before anal fin origin
• Pelvic fin formed of 1 spine
• Single anal spine
• Body scaleless

Answer 20

Gasterostidae (Stickleback)

Question 21

• Body scaleless or with prickles
• Broad, flat head w/ eyes located close together on upper surface
• Dorsal spines not free, untied by fin membrane
• Very large, broad pectoral fins
• Pelvic fin w/ 3-4 soft rays
• Anal spines absent

Answer 21

Cottidae (Sculpin)

Question 22

• Opercles w/ well-developed spine
• 2 distinct or narrowly-joined dorsal fins
• 3 anal spines
• Pseudobranchae present on under surface of opercles

Answer 22

Moronidae (Temperate Bass)

Question 23

• 1st & 2nd dorsal fins moderately or broadly conjoined
• Pseudobranchae poorly developed or absent
• Opercles w/o a well-developed spine
• Deep-bodied and spiny-rayed
• 3 or more anal spines

Answer 23

Centrarchidae (Sunfish)

Question 24

• 2 distinct or narrowly-joined dorsal fins
• Lateral line not extending onto caudal fin
• Anal fin w/ 1-2 spines
• 2nd anal spine, if present, about as thin and long as 1st anal spine

Answer 24

Percidae (Perch)

Question 25

• Dorsal fin almost completely divided
• Lateral line extending onto caudal fin
• Anal fin w/ 2 spines
• 2nd anal spine broader and longer than 1st anal spine

Answer 25

Sciaenidae (Drum)

Question 26

• Dorsal fin w/ 6-8 filamentous spines
• Pelvic fins close together, sometimes united
• Lateral line absent

Answer 26

Gobiidae (Goby)