1. Aphredoderidae (pirateperch)
Large head, mouth
Mouth epiterminal
Dorsal, anal fins with spines
Vertical stripe below eye
Anus anterior to usual position (often jugular)
Noel Burkhead
pirateperch (Aphredoderus sayanus))

2. Aphredoderidae Family consists of 1 species Inhabits slow waters
Preys on invertebrates
Possibly occurs near or in IA section of Mississippi River
Noel Burkhead
pirateperch (Aphredoderus sayanus))

3. Gadidae (cods) Long body Single barbel under lower jaw
Long dorsal fin; soft rays
Small pelvic fins located near pectoral fins
Cycloid scales
Manitoba Conservation Department
burbot (Lota lota))

4. Gadidae
1 species in IA
Inhabits deep waters of Mississippi, Missouri rivers
Edible, but “threatened” in IA; too rare to be commercially important
Manitoba Conservation Department
burbot (Lota lota))

5. Fundulidae (topminnows, killifishes)
Small body
Epiterminal mouth
Fins consist of soft rays
Dorsal fin near
posterior end of body
Caudal fin homocercal, unforked
3rd anal ray branched, umcompletely so in immatures
blackstripe topminnow (Fundulus notatus))

6. Fundulidae Uncommon in IA Adapted for surface feeding on invertebrates
Eddy and Underhill (1978)
Uncommon in IA
Adapted for surface feeding on invertebrates

7. Poeciliidae (livebearers)
Small body
Epiterminal mouth
Fins consist of only soft rays
Dorsal fin near posterior end of body
Caudal fin homocercal, unforked
3rd anal ray unbranched
Male anal fin modified into gonadopodium
mosquitofish (Gambusia affinis))

8. Poeciliidae Surface feed on invertebrates Live young
1 species in extreme southeast IA?
Eddy and Underhill (1978)

9. Atherinidae (silversides)
Small, slender body
Translucent
Epiterminal mouth; long, flat snout
Divided dorsal fin; spines (anterior), soft rays (posterior)
Homocercal, forked caudal fin
brook silverside (Labidesthes sicculus))

10. Atherinidae Surface feeders; swim near water surface
Brook silverside found in variety of rivers, streams
Atherinidae
New York State Department of Environmental Conservation
brook silverside (Labidesthes sicculus))