Anguillidae (eels)• Eel-like body (long,

slender)• Terminal mouth; jaws• Small opercle• Small scales; smooth

skin• Long dorsal fin

continuous with caudal, anal fins; no pelvic fin

• Homocercal caudal fin

American eel (Anguilla rostrata))

Pennsylvania Fish and Boat Commission

Anguillidae• Catadromous – Females migrate long

distances (15 years in fresh water); males remain near coast

• Nocturnal movements (can move over land)

• 3 larval forms (leptocephala, glass eels, elvers)

• Uncommon in Iowa; large rivers

American eel (Anguilla rostrata))

Clupeidae (herrings, shads)• Laterally compressed• Silvery scales• Saw-tooth margin

(pointed scales) on abdomen (belly)

• No lateral line• Fins lack spines• Caudal fin

homocercal, forked

gizzard shad (Dorosoma cepedianum))

Pennsylvania Fish and Boat Commission

Clupeidae• Diets primarily zoo-, phytoplankton; gizzard shad strain organisms form soft sediments

• Gizzard shad an important food web component in lakes and reservoirs with soft bottoms gizzard shad (Dorosoma cepedianum))

Ohio Department of Natural Resources

Hiodontidae (mooneyes)• Laterally compressed• Silvery color• Large eye• Part of belly

sharp/knifelike, but no saw-tooth margin

• Lateral line present• Fins lack spines• Caudal fin

homocercal, forked

mooneye (Hiodon tergisus))

GLERL/NOAA

Hiodontidae• Diet consists of small animals, including fishes

• Sportfishes where they are common (e.g., western Canada)

• Uncommon in Iowa; present in large border rivers goldeye (Hiodon alosoides))

University of Alberta Department of Biology

Salmonidae (trouts)

• Terminal mouth• Small scales• Fins lack spines• Adipose fin• Axillary process at

base of pelvic fin• Caudal fin

homocercal, squared or forked

brook trout (Salvelinus fontinalis))

Adipose fin

Axillary process Eddy and Underhill (1978)

Salmonidae• Cool/cold waters

• Prey on invertebrates, fishes

• Economically important sport/food fishes

• Brook trout native to northeast IA; 2 nonindigenous species propagated, stocked (some natural reproduction)

brook trout (Salvelinus fontinalis))

Virginia Tech virtual aquarium

Umbridae (mudminnows)

• Terminal mouth• Lateral line absent• Fins with soft rays• Dorsal, anal fins

toward posterior end of body

• Caudal fin homocercal, rounded

central mudminnow (Umbra limi))University of Michigan Museum of Zoology

New York State Department of Environmental Conservation

Umbridae

• Inhabit swamps, ponds

• Very tolerant of low oxygen concentrations, drought

• Bury themselves in mud

• Prey on invertebrates

central mudminnow (Umbra limi)University of Michigan Museum of Zoology