Congo Killies - PageSuite

In addition to their amazing colors and
intriguing natural behaviors, these living
jewels also have plenty of character and
personality.
mature and the Iowa Darters spawn
later in the year and deposit their
eggs in floating vegetation and
spawning mops. This native fish
aquarium was quite entertaining to
watch—the darters and dace could
be frequently observed hopping and
zipping throughout the aquarium
looking for food and interacting.
Reflections of an American
jewel hunter
Experiencing these amazing and beautiful
fish in my own “backyard” was,
and still is, extremely rewarding. It
has given me an even greater respect
for the aquatic environments in my
area, and also has raised concerns over the troubles facing
our native fishes. Siltation, habitat destruction, and pollution,
as well as the introduction of non-native fishes and
invertebrates, are constant threats to the darters’ natural
habitats. One oil or chemical spill into a small tributary or
waterway can have long-lasting effects on the fish population.
Not only are the fish directly harmed, but their food
source of aquatic insects is lost.
In my home state of Michigan the Round Goby
(Neogobius melanostomus) has spread through many of
the waterways and can be easily caught by hook and line
or net. This non-native invader competes with darters for
habitat and food resources, and in areas of the river near
my home I can catch 10 gobies to every 1 Blackside Darter.
Fortunately, I have yet to find one of these gobies in the
same locations where I have found and observed Rainbow
Darters, so I hope that our beautiful little native fish occupies
a niche not suited to these unwelcome intruders.
Rainbow Darters are amazing fish with wonderful
colors and fascinating behaviors, and they well deserve
a place in the hobbyist’s fish room. They are very interesting
to observe in the aquarium, and often appear to
tilt their heads while observing their keepers, implying a
level of intelligence and awareness similar to that which
I’ve seen in some cichlids I have kept. I feel fortunate to
live in a region inhabited by such a fish, and believe it
deserves to be considered a North American jewel.
AMAZONAS
gravel while the male fertilizes them from above. After
spawning the female wriggles out of the gravel to rest.
Spawning occurs repeatedly over a number of days
until the female has exhausted her egg supply, which
usually averages around 300 eggs, depending on the
size of the female. The eggs stick together in the gravel,
which is a great preventative against being swept away in
the current, and are thus easily collected, either using a
gravel vacuum to siphon them out of the gravel or gently
swirling the gravel and removing the adhesive eggs.
Rainbow Darter eggs can be hatched in a small container
with an airstone and methylene blue as a fungicide.
An alternative is to remove the spawning adults and
let the eggs hatch out in the spawning aquarium. The
eggs hatch in 10 to 14 days, depending on temperature,
and the development of the young fish may be witnessed
through the clear eggs, with the eyes of the developing
fry being readily visible. Newly hatched darter fry can be
raised on brine shrimp nauplii and other small live foods,
such as microworms. I found the eggs to have a very good
hatch rate, and fry survival was also good. Clean water
and frequent feedings were very important to long-term
fry survival.
Native tankmates
Other residents that I have kept in aquariums with
Rainbow Darters include Iowa Darters (Etheostoma exile),
Northern Redbelly Dace (Phoxinus eos), Brook Sticklebacks
(Culaea inconstans), Western Blacknose Dace
(Rhinichthys obtusus), and small immature Blackside
Darters (Percina maculata). The Brook Sticklebacks and
Iowa Darters also spawned while in the same aquarium
with the Rainbow Darters. I was not concerned about
cross-breeding, since the Blackside Darters were im-
Ken Zeedyk has been keeping fish off and on for more than
30 years. He is a fellow of the Grand Valley Aquarium Club
(GVAC) in Grand Rapids, Michigan, and has bred more than
120 species of freshwater fishes and invertebrates and cultured a
number of aquatic plant species. Zeedyk and his family reside in
Zeeland, Michigan.
KEN ZEEDYK
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