(DRAFT) - Taxonomy
Species MUSSEL, PENITENT
Species Id ESIS404024
Date 13 MAR 96
TAXONOMY
NAME - MUSSEL, PENITENT
OTHER COMMON NAMES - MUSSEL, PENITENT; SHELL, COMB and SOUTHERN
ELEMENT CODE -
CATEGORY - Aquatic Molluscs
PHYLUM AND SUBPHYLUM - MOLLUSCA,
CLASS AND SUBCLASS - BIVALVIA,
ORDER AND SUBORDER - UNIONOIDA,
FAMILY AND SUBFAMILY - UNIONIDAE,
GENUS AND SUBGENUS - EPIOBLASMA,
SPECIES AND SSP - PENITA,
SCIENTIFIC NAME - EPIOBLASMA PENITA
AUTHORITY -
TAXONOMY REFERENCES -
COMMENTS ON TAXONOMY -
Penitent Mussel
Epioblasma penita (Conrad, 1834)
KINGDOM: Animal GROUP: Clam
PHYLUM: Mollusca CLASS: Bivalvia
ORDER: Unionoida FAMILY: Unionidae
The penitent mussel, Epioblasma penita, is a bivalve mollusk
about 55 mm long, 40 mm high and 34 mm wide. The shell is yellowish,
greenish-yellow, or tawny, sometimes with darker dots. It is rhomboid
with irregular growth lines and a radially sculptured posterior,
posterior margin a diagonal straight line. The nacre is white or
straw-colored. Females have a large radially grooved swelling
projecting behind the shell (01).
Epioblasma penita (Conrad, 1824) was first described as Unio
penitus. In 1836, Lea renamed it Margarita (Unio) penitus and then
renamed it Margaron (Unio) penitus in 1852. In 1900, Simpson renamed
it Truncilla penita with Frierson putting it in the genus Dysonomia in
1927. Stansbery, in 1976, placed it in the genus Epioblasma based on
Rafinesque's work in 1831. Johnson placed it in the genus Plagiola,
subgenus Plagiola, in 1978. The name Dysnomia was first used in 1852
and is superceded by Epioblasma. E. penita is similar to E.
Taxonomy - 1 (DRAFT) - Taxonomy
Species MUSSEL, PENITENT
Species Id ESIS404024
Date 13 MAR 96
metastriata in the Mobile basin. The two species differ in the
posterior outline (01).
The figured holotype is at the Academy of Natural Science of
Philadelphia, ANSP 59860 (01). A drawing can be found in Stansbery
(01).
The penitent mussel is also known as the southern comb shell
(01).
Taxonomy - 2 (DRAFT) - Status
Species MUSSEL, PENITENT
Species Id ESIS404024
Date 13 MAR 96
STATUS
Coded Status
Alabama; Federal Endangered
Alabama; Unofficially Listed
Mississippi; Federal Endangered
Mississippi; State Recognized
E: Federal Endangered
COMMENTS ON STATUS -
U.S. STATUSES AND LAWS:
The penitent mussel (Epioblasma penita) has been designated an
Endangered species pursuant to the Endangered Species Act of 1973
(50 CFR 17.11; P.L. 93-205, 87 Stat. 884; 16 U.S.C. 1531-1540), as
amended. The species has this status wherever found including the
States of AL and MS. Critical Habitat has not been designated.
This species is protected by the Lacey Act (P.L. 97-79, as
amended; 16 U.S.C. 3371 et seq.) which makes it unlawful to import,
export, transport, sell, receive, acquire, or purchase any wild animal
(alive or dead including parts, products, eggs, or offspring):
(1) in interstate or foreign commerce if taken, possessed,
transported or sold in violation of any State law or
regulation, or foreign law; or
(2) if taken or possessed in violation of any U.S. law,
treaty, or regulation or in violation of Indian tribal law.
It is also unlawful to possess any wild animal (alive or dead
including parts, products, eggs, and offspring) within the U.S.
territorial or special maritime jurisdiction (as defined in
18 U.S.C. 7) that is taken, possessed, transported, or sold in
violation of any State law or regulation, foreign law, or Indian
tribal law.
RESPONSIBLE FEDERAL AGENCIES:
USFWS -Responsible for the management/recovery, listing, and
law enforcement/protection of this species.
All Federal agencies have responsibility to ensure that any
action authorized, funded, or carried out by that agency is not likely
to jeopardize the continued existence of the species or result in the
destruction or adverse modification of Critical Habitat (50 CFR 402),
and to utilize their authorities to carry out programs for the
conservation of the species.
STATE STATUSES AND LAWS:
STATE: Alabama
UNOFFICIAL LIST: Endangered, Bulletin No. 2, "Endangered and
Threatened Plants and Animals of Alabama",
Alabama Museum of Natural History.
Status - 1 (DRAFT) - Status
Species MUSSEL, PENITENT
Species Id ESIS404024
Date 13 MAR 96
STATE: Mississippi
DESIGNATED STATUS: Recognized Endangered
ADMINISTRATIVE AGENCY: Department of Wildlife Conservation
STATE STATUTES: Public Notice No. 2156, Eff. Sept. 1, 1981.
INTERNATIONAL STATUSES, TREATIES, AND AGREEMENTS:
Epioblasma penita, penitent mussel, is listed as endangered in
the 1986 IUCN Red List of Threatened Animals.
ECONOMIC STATUSES:
The species is valued by collectors for scientific purposes.
79/05/01:44 FR 25589/ - Notice of review
80/04/11:45 FR 24904/24905 - Notice of review
84/05/22:49 FR 21664/21675 - Notice of review
86/04/07:51 FR 11761/11768 - Proposed rule
86/06/18:51 FR 22092/ - Notice of public hearing
87/04/07:52 FR 11162/11169 - Final rule, listed as Endangered
Status - 2 HABITAT ASSOCIATIONS
HABITAT - AQUATIC
INLAND AQUATIC
LAND USE -
Streams and Canals
NATIONAL WETLAND INVENTORY CODES
NWI NWICLS NWIMOD NWISPEC
Riverine, upper perennial SB2
Riverine, upper perennial SB1
COMMENTS ON HABITAT ASSOCIATIONS -
The penitent mussel, Epioblasma penita, is found associated with
a riffle-run habitat. Williams (03) found it in the main channel in
gravel or sandy-gravel in moderate to swift current. It does better
in stable substrates in strong current (01). The Buttahatchie River
(in which this mussel occurs) is known to have frequent log jams, down
trees, sand and gravel bars and other obstructions to flow. These
features tend to create stable areas where unionids are protected and
where they can grow to maturity and reproduce over a period of years.
Streams cleared of such obstacles to flow typically have their unionid
fauna greatly reduced if not eliminated (01). Specific environmental
parameters required by adults are unknown.
Habitat of the glochidia is initially within the gills of the
female, then in the water column, and finally attached to a suitable
fish host. The host species is unknown. Any alteration of these life
stage-specific habitats during its life cycle would likely affect the
long-term success of a population. Habitat requirements or
associations for the juvenile stage are unknown.
Habitat Associations - 1 (DRAFT) - Food Habits
Species MUSSEL, PENITENT
Species Id ESIS404024
Date 13 MAR 96
FOOD HABITS
TROPHIC LEVEL -
OMNIVORE
LIFESTAGE FOOD FOOD PART
General Detritus
General Bacteria
General Phytoplankton
General Diatoms
General Zooplankton
General Fish
Food Habits - 1 (DRAFT) - Environment Associations
Species MUSSEL, PENITENT
Species Id ESIS404024
Date 13 MAR 96
ENVIRONMENTAL ASSOCIATIONS
G = General A = Adult
LIM = Limiting RA = Resting Adult
J = Juvenile FA = Feeding Adult
RJ = Resting Juvenile BA = Breeding Adult
FJ = Feeding Juvenile P = Pupae
L = Larvae E = Egg
RL = Resting Larvae
FL = Feeding Larvae
LIFESTAGE ENVIRONMENTAL ASSOCIATIONS
G Inland wetlands: swamp
G Aquatic Features: Pool areas
Environment Associations - 1 (DRAFT) - Life History
Species MUSSEL, PENITENT
Species Id ESIS404024
Date 13 MAR 96
LIFE HISTORY
FOOD HABITS:
Glochidia are probably obligate parasites on the tissues of the
gills or fins of fish. Adult Epioblasma penita are filter-feeders and
consume particulate matter suspended in the water column.
Identifiable stomach contents almost invariably include mud, desmids,
diatoms, other unicellular algae, protozoa, and zooplankters (02). No
study of the food habits of adult penitent mussels has been conducted;
specific required/preferred foods are therefore unknown.
HOME RANGE/TERRITORY:
Non-territorial. The species is sedentary during its adult life
and generally occurs in rivers with others of its kind.
PERIODICITY:
No known periodicity.
MIGRATION PATTERNS:
Non-migratory.
COVER/SHELTER REQUIREMENTS:
The penitent mussel requires flowing water, frequently a riffle,
over stable sand and gravel. Water velocity can vary greatly. The
sand and gravel substrate must remain free of any heavy sediment (01).
REPRODUCTIVE SITE REQUIREMENTS:
Water velocity can vary greatly. The sand and gravel substrate
must remain free of any heavy sediment (01) (See also Cover/Shelter
Requirements, above).
REPRODUCTIVE CHARACTERISTICS:
Sperm are discharged into the surrounding water and dispersed by
water currents. Females downstream from the males obtain sperm during
the normal process of siphoning water while feeding and during
respiration. Fertilization occurs within the gills of females, which
serve as marsupia for embryos developing to the parasitic stage
(glochidia) and are then released (02). The specifics of reproductive
characteristics for this species are unknown.
PARENTAL CARE:
No parental care is known to occur.
POPULATION BIOLOGY:
The population biology of this species is unknown.
SPECIES INTERRELATIONSHIPS:
The required fish hosts for the parasitic glochidia of this
species are unknown.
OTHER LIFE HISTORY DESCRIPTORS:
None.
Life History - 1 (DRAFT) - Management Practices
Species MUSSEL, PENITENT
Species Id ESIS404024
Date 13 MAR 96
MANAGEMENT PRACTICES
RESULT MANAGEMENT PRACTICE
Beneficial Maintaining/Controlling Water Flow
Beneficial Land Acquisition
Beneficial Creating Artificial Habitat/Nesting Structure
Adverse Siltation
Existing Siltation
Adverse Water Level Fluctuation
Existing Water Level Fluctuation
Adverse Reservoirs
Existing Reservoirs
Adverse Dredging
Existing Dredging
COMMENTS ON MANAGEMENT PRACTICES -
The decline of the penitent mussel (Epioblasma penita) is
directly related to habitat destruction or alteration. Habitat in the
Alabama and Coosa Rivers has been modified by impoundment and
channelization for navigation, flood control and hydro-power
production. The only specimen taken from the Cahaba River was
collected in the 1800's and more recent collections have failed to
find this species. With the exception of a bendway below Gainesville
Dam in Alabama, the habitat in the mainstem Tombigbee River was
destroyed by construction of the Tennessee-Tombigbee Waterway. The
species continues to exist in the East Fork Tombigbee and Buttahatchie
Rivers where it is threatened by channel modification for flood
control (01).
UNAPPROVED PLAN:
No recovery plan is yet developed for the penitent mussel. Recovery
planning should be initiated in FY 1988.
Recovery actions that are anticipated for the penitent mussel
include: Maintaining water flow; creating artificial habitat (e.g.,
gravel bars); prohibiting sand and gravel dredging; and land easement
protection for remaining habitat.
At present, dredging is being prohibited and water flow is being
maintained.
Management Practices - 1 (DRAFT) - References
Species MUSSEL, PENITENT
Species Id ESIS404024
Date 13 MAR 96
References
***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCURRENCE *****
01 Stansbery, D.H. 1983. The status of Epioblasma penita (Conrad
1834) (Mollusca:Bivalvia:Unionoida). Unpublished rep. on file at:
USFWS, Jackson Field Office, Jackson, MS. 10 pp + 6 pp museum
records.
02 U.S. Fish and Wildlife Service. 1984. Recovery Plan for the Rough
Pigtoe Pearly Mussel [Pleurobema plenum (Lea, 1840)]. U.S. Fish
and Wildlife Service, Atlanta, GA. 51 pp.
03 Williams, J.D. 1982. Distribution and habitat observations of
selected Mobile basin unionid mollusks. Pages 61-85. IN: Report
of freshwater mollusks workshop, 19-20 May 1981. A.C. Miller, ed.
U.S. Army Engin. Water. Exp. Sta., Environ. Lab., Vicksburg, MS.
184 pp.
***** REFERENCES FOR N-OCCURRENCE NARRATIVE ONLY *****
01 Stansbery, D.H. 1983. The status of Epioblasma penita (Conrad,
1834) (Mollusca:Bivalvia:Unionoida). Unpublished rep. on file at:
USFWS, Jackson Field Office, Jackson, MS. 15 pp + 6 pp museum
records.
References - 1