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Rainbow Darter (male). The beauty
of this native North American species
rivals that of better known tropical
fishes.
AMAZONAS
total of five new Etheostoma darter species were introduced
in 2012, and all were named after United States
presidents (and one former vice-president) in recognition
of their leadership in the fields of conservation and
environmental protection.
The life of an American jewel
The Rainbow Darter’s native range is predominantly
across the Ohio and Mississippi River drainages, from
northwestern New York, across southern Ontario,
Canada, and as far west as Minnesota, where Lake
Phalen, the only lake in which Rainbow Darters have
been found, is located. To the south, their range extends
into Arkansas and northern Alabama, with an isolated
population in southwestern Mississippi. Introduced
populations have become established in the Genesee and
Fox River drainages in New York State. While Etheostoma
caeruleum from different river drainages can be variable
in color, at this time no subspecies are recognized. This
would most likely change if the different Rainbow Darter
populations were studied, so it is best to not mix darters
from different locales.
Rainbow Darters inhabit areas of high water flow in
second-order and larger streams and rivers. A secondorder
stream is one formed by two tributaries coming
together into one stream, a third-order stream consists
of three tributaries that have come together into a single
stream, and so on. These darters are typically found
over riffles or relatively shallow areas with larger rock
substrates. They use these rocks as cover to hide from
predators and as a shield from the current. They prefer
waters that are slightly alkaline and moderately hard and
stay relatively cool. Water temperatures in their preferred
habitats in the north can vary from close to freezing to
over 70°F (21°C). They share this habitat with various
other Etheostoma and Percina darter species, chubs, and a
number of dace and minnow species.
Etheostoma caeruleum is a micro-predator, feeding on
aquatic insect larvae including those of midges, caddis
flies, mayflies, and black flies as
well as consuming fish eggs and
other small organisms. Their
diet varies during the course
of the year, depending on the
availability of food resources and
competition from other species.
Rainbow Darters are
relatively small, only reaching a
length of 2.5–3 inches (6.4–7.6
cm) when fully grown, and
their life expectancy in the wild
is between two and three years. Females exhibit a small
amount of color on the dorsal fin and on the flanks,
which intensifies during the breeding season. Males in
full breeding color are very gaudy when observed from
the side, with blue cheeks, brilliantly colored fins, and
banding on their flanks. However, observing these fish
in their habitat can be quite challenging. Due to their
bright coloring, one would think they would be easy to
spot in nature, but when viewed from above their dorsal
patterning blends into the substrate, and the activity
for which they were named becomes evident as they
dart from rock to rock in order to avoid capture. Rainbow
Darters are opportunistically preyed upon by larger
predatory fishes such as sculpins, trout, Smallmouth
Bass, Stonecats, and Burbots.
Gem hunting
Rainbow Darters can be obtained through specialized
breeders found online, or they can be collected from their
native habitat for individual use as regulations allow. Before
venturing out to capture your own Rainbow Darters,
be sure to know and follow the fishing rules and regulations
of the state in which you are collecting. A fishing
license is required, and a permit to collect and maintain
native fishes may also be necessary. In some locations,
collecting native fishes is prohibited altogether. Please
respect the natural habitat, don’t over-collect and risk
depleting the natural breeding population, respect private
property, and never transport fishes between drainages or
release any captive animals back into the wild. Also, be
sure to thoroughly clean and dry your collecting equipment
in order to prevent the exchange of invasive plants
and other harmful organisms between watersheds. In
captivity the Rainbow Darter can live for three years or
more, so be prepared to care for your captive fish for an
extended length of time.
Collecting Rainbow Darters can be accomplished
using a number of different techniques, any of which can
be quite entertaining to watch. Two of the most popular
BOTTOM: SHAELYN MCGEE; OTHERS: KEN ZEEDYK
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