Sheepnose and Spectaclecase Mussels
Final Rule to List as Endangered - Federal Register
Below is the first page of the Federal Register Final Rule to List the Sheepnose and Spectaclecase as Endangered. Download the complete 36-page PDF 
DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R3-ES-2010-0050]
[4500030113]
RIN 1018-AV93
Endangered and Threatened Wildlife and Plants; Determination of Endangered
Status for the Sheepnose and Spectaclecase Mussels Throughout Their Range
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Final rule.
SUMMARY: We, the U.S. Fish and Wildlife Service (Service), determine endangered
status under the Endangered Species Act of 1973 (Act), as amended, for the spectaclecase
(Cumberlandia monodonta) and sheepnose (Plethobasus cyphyus), two freshwater
mussels. This final rule implements the Federal protections provided by the Act for these species throughout their ranges, including sheepnose in Alabama, Illinois, Indiana,
Iowa, Kentucky, Minnesota, Mississippi, Missouri, Ohio, Pennsylvania, Tennessee,
Virginia, West Virginia, and Wisconsin, and spectaclecase in Alabama, Arkansas,
Illinois, Indiana, Iowa, Kansas, Kentucky, Minnesota, Missouri, Ohio, Tennessee,
Virginia, West Virginia, and Wisconsin. We determined that critical habitat for the
spectaclecase and sheepnose is prudent, but not determinable at this time.
DATES: This rule becomes effective on April 12, 2012.
ADDRESSES: This final rule is available on the Internet at http://www.regulations.gov at Docket No. FWS–R3–ES–2010–0050. Comments and materials received, as well as
supporting documentation used in preparing this final rule will be available for public
inspection, by appointment, during normal business hours, at the U.S. Fish and Wildlife
Service, Rock Island, Illinois Ecological Services Field Office, 1511 47th Avenue,
Moline, IL 61265; telephone 309–757–5800.
FOR FURTHER INFORMATION CONTACT: Richard Nelson, Field Supervisor, at
the U.S. Fish and Wildlife Service, Rock Island, Illinois Ecological Services Field Office,
(see ADDRESSES section). If you use a telecommunications device for the deaf (TDD),
call the Federal Information Relay Service (FIRS) at 800–877–8339.
SUPPLEMENTARY INFORMATION:
Background
Previous Federal Action
Federal actions for these species prior to January 19, 2011, are outlined in our
proposed rule - - 30-page PDF - - for these actions (76 FR 3392–3420). Publication of the proposed rule
opened a 60-day comment period, which closed on March 21, 2011.
Species Descriptions
The spectaclecase (Cumberlandia
monodonta) is a member of the mussel
family Margaritiferidae and was
originally described as Unio monodonta
Say, 1829. The type locality is the Falls
of the Ohio (on the Ohio River in the
vicinity of Louisville, Kentucky, and
adjacent Indiana), and the Wabash River
(probably the lower portion in Illinois
and Indiana) (Parmalee and Bogan 1998,
p. 49). Parmalee and Bogan (1998, p. 49)
summarized the synonymy of the
spectaclecase. The species has been
placed in the genera Unio, Margaritana,
Alasmidonta, Margarita, Margaron, and
Margaritifera at various times in history.
Ortmann (1912, p. 13) placed it in the
monotypic (a taxonomic group with
only one biological type) genus
Cumberlandia in the family
Margaritiferidae. Currently recognized
synonymy includes Unio soleniformis
(Lea). Smith (2001, p. 43) reassigned the
spectaclecase to the Holarctic genus
Margaritinopsis based on shell and gill
characters. The Service, however, will
defer to the Committee on Scientific and
Vernacular Names of Mollusks of the
Council of Systematic Malacologists,
American Malacological Union
(Turgeon et al. 1998), on whether the
genus Margaritinopsis is accepted as
valid for the spectaclecase. Until an
official decision is made, the Service
will use the commonly accepted
Cumberlandia for the genus of this
species. Spectaclecase is the accepted
common name for Cumberlandia
monodonta (Turgeon et al. 1998, p. 32).
The spectaclecase is a large mussel
that reaches at least 9.25 inches (23.5
centimeters (cm)) in length (Havlik
1994, p. 19). The shape of the shell is
greatly elongated, sometimes arcuate
(curved), and moderately inflated, with
the valves being solid and moderately
thick, especially in older individuals
(Parmalee and Bogan 1998, p. 49). Both
anterior and posterior ends of the shell
are rounded with a shallow depression
near the center of the shell (Baird 2000,
p. 6; Parmalee and Bogan 1998, p. 49). The anterior end is higher than the
posterior end (Baird 2000, p. 6). The
posterior ridge is low and broadly
rounded (Parmalee and Bogan 1998, p.
50). Year-one specimens have heavy
ridges running parallel with the growth
arrests, which are shell lines that
indicate slower periods of growth,
thought to be laid down annually (Baird
2000, p. 6). The periostracum (external
shell surface) is somewhat smooth,
rayless, and light yellow, greenish-tan,
or brown in young specimens, becoming
rough and dark brown to black in old
shells (Parmalee and Bogan 1998, p. 50).
The shell commonly will crack
posteriorly when dried (Oesch 1984,
p. 31).
Internally, the single pseudocardinal
tooth (a triangular tooth-like structure
along the hinge line of the internal
portion of the shell) is simple and peglike
in the right valve, fitting into a
depression in the left (Parmalee and
Bogan 1998, p. 50). The lateral teeth are
straight and single in the right valve,
and double in the left valve, but become
fused with age into an indistinct raised
hinge line (Parmalee and Bogan 1998, p.
50). The soft anatomy was described by
Williams et al. (2008, pp. 497–498). The
color of the nacre (interior covering of
the shell) is white, occasionally granular
and pitted, mostly iridescent in young
specimens, but becoming iridescent
posteriorly in older shells (Parmalee and
Bogan 1998, p. 50). There are no
differences between the sexes in the
shells of this species (Baird 2000, p. 19). Key characters for distinguishing the
spectaclecase from other mussels are its
large size, elongate shape, arcuate
ventral margin, dark coloration,
roughened periostracum, poorly
developed teeth, and white nacre
(Oesch 1984, pp. 31–32). No other North
American mussel species has this suite
of characters.
The sheepnose (Plethobasus cyphyus)
is a member of the mussel family
Unionidae and was originally described
as Obliquaria cyphya Rafinesque, 1820. The type locality is the Falls of the Ohio
(Parmalee and Bogan 1998, p. 175) on
the Ohio River in the vicinity of
Louisville, Kentucky, and adjacent
Indiana. Parmalee and Bogan (1998, p.
175) summarized the synonymy of the
species. Over the years, the name of this
species has been variably spelled
cyphya, scyphius, cyphius, cyphia,
cyphyum, and ultimately cyphyus. Over
the years the species has been placed in
the genera Obliquaria, Unio,
Pleurobema, Margarita, and Margaron.
It was ultimately placed in the genus
Plethobasus by Ortmann (1919, pp. 65–
66), where it remains today (Turgeon et
al. 1998, p. 35). The Service recognizes
Unio aesopus and U. compertus as
synonyms of Plethobasus cyphyus.
Sheepnose is the accepted common
name for Plethobasus cyphyus as
established by the Committee on
Scientific and Vernacular Names of Mollusks of the Council of Systematic Malacologists, American Malacological Union (Turgeon et al. 1998, p. 35). The Service also recognizes ‘‘bullhead’’ and ‘‘clear profit’’ as older common names for the sheepnose.
Above is the first page of the Federal Register Final Rule to List the Sheepnose and Spectaclecase as Endangered. Download the complete 36-page PDF
Sheepnose Home
Spectaclecase Home
Midwest Endangered Species Home
