12 Nebraskaland • October 2020
IN THE FIELD
The finescale dace (Chrosomus neogaeus) is
considered to be a "glacial relict" fish, because the
species expanded into Nebraska when glaciation
was shaping the landscape during the Pleistocene
era. The fish species was then left behind as the
glaciers retreated. Finescale dace live in small
coolwater streams of Nebraska's Sandhills. These
minnows prefer clear water, often in headwaters of
small creeks or in spring-fed marshes and beaver
ponds.
The finescale dace is small enough that it could
easily fit in the palm of your hand. The female of
the species typically grows a bit larger than the
male. The fish's tiny scales give it a slick, shiny
appearance, and it has a distinct stripe that runs
along each side of its body. Breeding males are the
most colorful with yellow fins and a red-orange
belly.
This pint-sized predatory minnow feeds in an
interesting way by using its pharyngeal teeth
to grind and crush food in its throat rather than
in its toothless mouth. Finescale dace consume
plankton, algae and small invertebrates such as
aquatic insects and fingernail clams that are in
fact smaller than a person's fingernail.
Finescale dace are listed as threatened in
Nebraska. Not only do they have a restricted
distribution in the state, but they are also
vulnerable to extended, severe drought conditions
combined with stream dewatering, reduced
water and habitat quality, and predation by and
competition with predatory fish species.
Finescale dace can continue to survive in
Nebraska's Sandhills as long as their current
populations are not severely impacted. The
conservation of the species depends on
maintenance of quality areas along the streams
where they occur, adequate beaver populations
to create pond habitat and restrictions on the
introduction of fish predators. It is most important
to conserve finescale dace where they are, because
they need exceptional coolwater habitats provided
by groundwater and are reliant on the special
conditions in the Sandhills that resulted from the
last ice age.
Melissa J. Panella is a wildlife biologist for the
Nebraska Game and Parks Commission.
By Melissa Panella
THREATENED AND ENDANGERED:
THE FINESCALE DACE
PHOTO
BY
ALEX
ENGEL
