Fish
Johnny Darter
Etheostoma nigrum · also called johnny darters
Beneath a submerged log in a slow, clear stream, a male johnny darter stands guard over a clutch of eggs glued upside down to the wood above him, one of the most ordinary-looking yet genuinely widespread small fish across an entire continent.
Overview
The johnny darter, Etheostoma nigrum, is a small, hardy darter with one of the broadest ranges of any species in its family, found across streams, rivers, and lakes throughout the central and eastern United States and southern Canada. Its notable tolerance for varied water conditions sets it apart from many more habitat-sensitive darter relatives.
Unremarkable in looks, remarkable in reach
Lacking the vivid breeding colours of relatives like the orangethroat or rainbow darter, the johnny darter instead wins on sheer adaptability, thriving across a genuinely wider range of freshwater habitat than almost any other member of its family.
Status
Least Concern — widespread and abundant across a broad range of freshwater habitat throughout the central and eastern United States and southern Canada.
Johnny Darter: common questions
Why is the johnny darter found in so many different places?
The johnny darter is notably tolerant of a wide range of water conditions compared with many other darter species, allowing it to persist across streams, rivers, and even lakes, a hardiness that has given it one of the broadest geographic ranges of any darter found across the central and eastern United States and southern Canada.
How does the johnny darter lay its eggs?
A female johnny darter attaches her eggs to the underside of a flat rock, log, or other submerged object, positioning the clutch upside down within the chosen nest cavity, after which a male guards the site until the eggs hatch, defending them from potential egg predators.
Is the johnny darter sensitive to pollution like other darters?
Less so than many of its relatives — while some darter species such as the greenside darter or rainbow darter are quite sensitive to water quality degradation, the johnny darter tolerates a broader range of conditions, which is part of why it remains so widespread across varied freshwater habitat.
Where does the johnny darter live?
The johnny darter is native to a wide range of freshwater habitat, including streams, rivers, and lakes, across much of the central and eastern United States and southern Canada, making it one of the more broadly distributed small fish in its family.