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The snail darter was
discovered by Dr. David A. Etnier in August 1973. Dr. Etnier discovered
the snail darter in the lower Little Tennessee River, Loudon
County,
Tennessee. After
further collections and study, Dr. Etnier published his findings in January
1976, indicating the snail darter to be a new species of percid
fish. The fish
probably inhabited rivers such as
the Holston, French Broad, Lower Clinch, and Hiwassee Rivers, and
downstream in the Tennessee drainage to northern Alabama before many of the man-made
dams were constructed.
The snail darter is a member
of the subgenus Imostoma with characteristics most similar to the
closely related stargazing darter. Body color can vary from brown
to olive, sometimes blanched,
with a dorsal saddle pattern often strongly evident.
Maximum size is
about 3 ½ inches.
The spawning
period is estimated to occur from mid-winter through mid-spring,
and take place in shallow shoal areas over larger, smooth gravel.
Hatching takes place
in about 18 to 20 days, with the
larvae then drifting with the current to nursery areas farther downstream. After a
nursery period of 5 to 7 months, the juvenile darters begin to migrate back to the
upstream spawning areas where they spend the remainder of their lives.
The maximum life-span for snail darters seems to be four years.
In 1979, critical
habitat for the snail darter in the Little Tennessee River wascompletely destroyed by the
completion of the Tellico Dam. There is someevidence, however that
immediately downstream in the Tennessee River a healthy population still exists in
the 5-to-10 mile stretch of river habitat below Fort Loudon Dam. In November 1980, Dr.
Etnier found another natural population inSouth Chickamauga Creek between
creek mile 5.6 in Tennessee (Hamilton County) and creek mile 19.3 in Georgia
(Catoosa County). Surveys in 1981 and 1982 in the Tennessee River
drainage have revealed snail darters in Sewee Creek (Meigs County), and a few darters
have also been taken from the Tennessee River mainstream just below
Chickamauga and Nickajack Dams, the Sequatchie River (Tennessee), and Paint Rock
River (Alabama). Since 1975, snail darters have been transplanted in the following
Tennessee Rivers: Hiwassee (Bradley and Polk Counties), Nolichucky (Cocke
and Greene Counties), Holston (Knox County), and Elk (Giles
County). In 1988, snail darters were found in the French Broad
River
upstream from its confluence with the Holston River.
Before the construction of
the Tellico Dam, the population of snail darters in the Little Tennessee River was
estimated at 5,000 to 20,000 specimens. Snail darterstransplanted to the Hiwassee
River in 1975 and 1976 had produced an estimated population of 2,500 by 1979.
From December 1978 through November 6, 1979, a total of 104 darter from the
Hiwassee and 427 from the Little Tennessee were transplanted to the Holston
River near Mascot. In July 1980, a total of 425 snail darters,
previously removed from the Tellico project area were stocked in the
Elk
River. The South Chickamauga Creek population is estimated at 200
to 400.
When the species was listed
as endangered in 1975, the Little Tennessee River was the snail darter’s only
known spawning habitat when the species was listed as endangered. The construction
of the Tellico Dam sparked reintroduction efforts and population surveys. Other
populations were discovered and started in the main stem Tennessee River and in
six of its tributaries. When Dr. Etnier’s discovered the population of the South
Chickamauga Creek in 1980, the Tennessee Valley Authority and the U.S.
Fish and Wildlife Service initiated new strudies in 1981 to better determine the
species’ range. With this research, the Sewee Creek population was discovered
along with specimens collected at the Sequatchie and Paint Rock Rivers. Once
several populations had been discovered, the Snail Darter Recovery met with the Fish
and Wildlife Service biologists to recommend the following actions:
(1) Downlist the
species from endangered to threatened.
(2) Keep the
species on the Federal list. (3) Retain requirements for a Federal
permit to collect snail
darters if downlisting occurs. All three recommendations were
adopted,
and the species was downlisted to
threatened in July 1984.
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