Its natural geographic range extends from Newfoundland to South Carolina, and west to Minnesota, including the Great Lakes drainages.

[5] The banded killifish has a narrow, elongate bluish-gray or olive-colored body with a darker dorsal surface and white or yellowish underparts extending to the anal fin.

[11] The banded killifish, while euryhaline, is more commonly found in freshwater, whereas the mummichog primarily inhabits brackish and coastal waters.

[15] The banded killifish is widely distributed throughout eastern North America, ranging from the Pee Dee River, South Carolina to Newfoundland; also found in southern Pennsylvania, northeastern Nebraska, and northern Illinois, and north to St. Lawrence-Great Lakes and Mississippi River basins from Manitoba to Quebec.

Intergrades occur in the Saint Lawrence and Lake Erie drainages where the ranges of the two subspecies naturally come in contact.

[16] The banded killifish has been introduced outside of its native range in the states of Idaho, Ohio, Oregon, Pennsylvania, South Dakota, Washington, and West Virginia.

The fish are most often found in the shallow and quiet areas of clear lakes, ponds, rivers, and estuaries with sandy gravel or muddy bottoms and with abundant aquatic vegetation.

The sand and gravel provides hatchlings and juveniles with places to hide when threatened by predatory fish such as the largemouth bass Micropterus salmoides, northern pike Esox lucius, bluegill Lepomis macrochirus, and trout.

Because the banded killifish is small, it generally does not venture into deeper waters, where it would be vulnerable to predation as well as unable to swim in the fast currents.

However, adult banded killifish have been observed to travel into deep bodies of water to feed.

[citation needed] Banded killifish are euryhaline, but they usually inhabit freshwater streams and lakes.

Most people do not favor them as pets because they require a high level of maintenance and therefore do not survive well in an aquarium setting.

They are important to aquatic ecosystems because they are a food source for larger fish such as largemouth bass, northern pike, and trout.

[18] This species is facing habitat degradation due to industrial development, motorized watercraft activities, and removal of aquatic vegetation.

The adults feed on a variety of items such as insects, nymphs, mollusks, turbellarians, and other small crustaceans.

[19] Banded killifish are commonly observed to spawn in dense aquatic vegetation because they practice external fertilization where the female lays her eggs that are equipped with adhesive threads that adhere to plants.

Once together, the female emits 10 eggs that falls onto the bottom or gets attached to aquatic plants in the chosen spawn area.

[21] In the presence of a food stimulus, group size decreases, so that each individual does not have to compete with others for access to these resources.

[23] In the presence of a predatory stimulus, banded killifish decrease the amount of food attempts and duration of feeding posture.

In both the presence and absence of predatory stimuli, banded killifish feeding rate for individuals is independent of shoal size.

When deciding whether to join a shoal or not, banded killifish value predatory protection over foraging opportunities.

[24] In the presence of a predatory stimulus, shoal size increases to allow for greater protection via the dilution effect.

Banded killifish are likely to enter shoals with those of similar body color in order to maximize predator avoidance.

Banded killifishes' level of preference for similarly colored shoalmates differs in the presence and absence of a predatory stimulus.

If body size is similar, then banded killifish prefer conspecific shoals as opposed to heterospecific ones.