(DRAFT) - Taxonomy
Species SNAIL, MOUNTAIN, FRINGED, VIRGINIA
Species Id ESIS355003
Date 13 MAR 96
TAXONOMY
NAME - SNAIL, MOUNTAIN, FRINGED, VIRGINIA
OTHER COMMON NAMES - SNAIL, MOUNTAIN, FRINGED, VIRGINIA; COIL, VIRGINIA; MOUNTAINSNAIL, FRINGED, VIRGINIA; SNAIL, MOUNTAINS, FRINGED and VIRGINIA
ELEMENT CODE -
CATEGORY - Aquatic Molluscs
PHYLUM AND SUBPHYLUM - MOLLUSCA,
CLASS AND SUBCLASS - GASTROPODA,
ORDER AND SUBORDER - STYLOMMATOPHORA,
FAMILY AND SUBFAMILY - HELICODISCIDAE,
GENUS AND SUBGENUS - POLYGYRISCUS,
SPECIES AND SSP - VIRGINIANUS,
SCIENTIFIC NAME - POLYGYRISCUS VIRGINIANUS
AUTHORITY -
TAXONOMY REFERENCES -
COMMENTS ON TAXONOMY -
Virginia Fringed Mountain Snail
Polygriscus virginianus P. R. Burch, 1947
KINGDOM: Animal GROUP: Snail
PHYLUM: Mollusca CLASS: Gastropoda
ORDER: Stylommatophora FAMILY: Helicodiscidae
Polygyriscus virginianus (Burch, 1947) has a flattened, disc
shaped shell (3.9-4.4 x 1.3 mm) with a wide shallow umbilicus which
shows all the whorls. Adults have about 4-4.5 well-rounded whorls
that increase regularly in size. The final 1/3 of whorl is swollen,
often detached from the preceding whorl, and reflected ventrally.
Around the surface of the shell there are 8-10 lirae with flattened
fringes (much as in Helicodiscus fimbriatus and H. hexdon). Four
of the lirae are quite prominent while the others are smaller.
There is a V-shaped palatal tooth and a recessed fold along the
outer edge. A transverse callus on the parietal wall fits into
the arch formed by this fold. The shell is wood brown but appears
greenish and pale when the snail is alive. The animal is entirely
white even lacking pigment in the eyestalks (01,02,03).
Burch (01) described this snail as Polygyra virginiana
(Polygyridae) and contrasted it with Polygyra cereolus carpenteriana.
Taxonomy - 1 (DRAFT) - Taxonomy
Species SNAIL, MOUNTAIN, FRINGED, VIRGINIA
Species Id ESIS355003
Date 13 MAR 96
Pilsbry (02) examined the snail and felt that it was not a Polygyra at
all and erected a new subgenus Polygyriscus for it (still family
Polygyridae). Burch (04) treats this as a full genus equal to
Polygyra and Mesodon, thereby making it a monotypic genus. Solem
(05) reviewed its status and placed it, on the basis of shell
morphology and anatomy, in the family Helicodiscidae. Another
name used in literature is Polygyriscus virginicus (06).
Other common name synonyms are the Virginia coil (06) and the
Virginia fringed mountainsnail.
The type specimen is in the U.S. National Museum and paratypes
were placed in the Academy of Natural Sciences, Philadelphia (183550)
(02). Burch (01), Pilsbry (02), Solem (05) and the Recovery Plan
(03) give adequate illustrations and descriptions to aid
identification.
Taxonomy - 2 (DRAFT) - Status
Species SNAIL, MOUNTAIN, FRINGED, VIRGINIA
Species Id ESIS355003
Date 13 MAR 96
STATUS
Coded Status
Virginia; Federal Endangered
Virginia; State Recognized
E: Federal Endangered
COMMENTS ON STATUS -
U.S. STATUSES AND LAWS:
The Virginia fringed mountain snail (Polygyriscus virginianus)
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 State of Virginia.
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
(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: Virginia
DESIGNATED STATUS: Recognized Endangered
ADMINISTRATIVE AGENCY: (VA) Commission of Game and Inland
Fisheries
STATE STATUTE: (VA) Code 29-230 to 29-237 (Chapter 11 -
Endangered Species)
Status - 1 (DRAFT) - Status
Species SNAIL, MOUNTAIN, FRINGED, VIRGINIA
Species Id ESIS355003
Date 13 MAR 96
INTERNATIONAL STATUSES, TREATIES, AND AGREEMENTS:
This species is listed as Endangered in the 1986 IUCN Red List
of Threatened Animals.
ECONOMIC STATUSES:
None.
76/04/28:41 FR 17742/17747 - Proposed Listing
78/07/03:43 FR 28932/28935 - Final Listing
83/12/08:48 FR 55100/55102 - Notice of review
85/07/07:50 FR 29900/29901 - Notice of 5 year review completion
Status - 2 HABITAT ASSOCIATIONS
HABITAT - TERRESTRIAL
TERRESTRIAL
LAND USE -
Deciduous Forest Land
Strip Mines, Quarries, and Gravel Pits
Transitional Areas
COMMENTS ON HABITAT ASSOCIATIONS -
Polygyriscus virginianus is fossorial, living up to 2 m beneath
the surface of talus slope. It is found among the fragments of
weathered dolomite in loose clay-like soil broken by roots and worked
by worms. The soil at that level is entirely free of leaf litter.
The dolomite of the steep bluff and embankment is overlain by soil
which in turn is overgrown by a stand of small trees (Robinia,
Quercus, Acer, Juglans, Carya, Liriodendron, etc.) and a thick mat
of honeysuckle. (03) This talus slope lies to the west of the River
Road about 60 feet above the New River at an elevation of 1800 feet
(01). The known habitat also borders an abandoned limestone quarry
(03).
Though this snail's habitat requirements are not at all well
understood, it is thought that Polygyriscus needs a place with moist,
loosely compacted soil and moderate temperatures. The soil must have
a high calcium content (03). Grimm and Hubrict doubt that the species
ever approaches the soil surface though Solem believes the wet weather
might bring it out (05). The talus stone and its overburden of soil
as well as the vegetation seal off Polygyriscus from contact with the
outside. Perhaps only because the talus, especially in wet weather,
becomes a window into the under-world, collectors with diligent
searching can find the snail at this site.
Helicodiscus hexodon from Tennessee is known to produce mazes of
small burrows in the soil immediately beneath the litter and duff
layers (09).
Habitat Associations - 1 (DRAFT) - Food Habits
Species SNAIL, MOUNTAIN, FRINGED, VIRGINIA
Species Id ESIS355003
Date 13 MAR 96
FOOD HABITS
TROPHIC LEVEL -
HERBIVORE
LIFESTAGE FOOD FOOD PART
General Detritus
General Bacteria
General Diatoms
General Roots/Tubers/Rhizomes-Herbaceous
General Roots/Tubers/Rhizomes-Woody
General Myxomycophyta
General Deciduous Shrubs-Leaves/Twigs
Food Habits - 1 (DRAFT) - Environment Associations
Species SNAIL, MOUNTAIN, FRINGED, VIRGINIA
Species Id ESIS355003
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 Terrestrial Features: Burrows
G Terrestrial Features: Talus
G Terrestrial Features: Cliffs/ledges
Environment Associations - 1 (DRAFT) - Life History
Species SNAIL, MOUNTAIN, FRINGED, VIRGINIA
Species Id ESIS355003
Date 13 MAR 96
LIFE HISTORY
FOOD HABITS:
Nothing is directly known about the food habits of this animal
but other species in this Family possess radulas with numerous small
teeth specialized for scraping fungi, algae, and plant cells off
surfaces where they graze (02,07,08). Rootlets of herbaceous and
woody plants as well as microscopic plants would be available in the
soil layers where they live (03). High levels of calcium must be
available to this snail. Pilsbry believed Helicodiscus parallelus
lives on decaying wood and damp leaves.
HOME RANGE/TERRITORY:
Nothing is known about this snail's territoriality.
PERIODICITY:
Little is known about this snail's periodicity. It is not even
known for certain if periods of high humidity bring it to the surface
of the talus (03).
MIGRATION PATTERNS:
As far as is known Polygyriscus does not migrate.
COVER/SHELTER REQUIREMENTS:
Polygyriscus apparently needs a habitat that is shaded and
permanently damp (03). The stones, soil overburden, and vines would
effectively moderate the soil temperature and prevent moisture loss
(03). The loosely compacted clay under the rock fragments and
boulders must be friable enough for easy burrowing.
REPRODUCTIVE SITE REQUIREMENTS:
Reproduction has never been observed in this species (03).
REPRODUCTIVE CHARACTERISTICS:
Reproduction has never been observed in this species (03). Of
course Polygyriscus, as most land snails, are true hermaphrodites,
capable of producing both eggs and sperm. An individual, though,
usually exchanges these products with another snail to maximize
outcrossing (10). Most snails deposit their eggs in moist soil (10).
Certain helicodiscids have the ability to delay egg laying apparently
until favorable conditions for hatching are available (10).
PARENTAL CARE:
Parental care is unknown in land snails.
POPULATION BIOLOGY:
There is no reliable estimate of the total number of Polygyriscus
in existence and surveying for live snails is so destructive of the
known habitat that it should not be encouraged. Grimm (03) located
three living snails in a five square meter area excavated to a depth
of 10-40 cm.
SPECIES INTERRELATIONSHIPS:
Life History - 1 (DRAFT) - Life History
Species SNAIL, MOUNTAIN, FRINGED, VIRGINIA
Species Id ESIS355003
Date 13 MAR 96
The following land snails were found in the same habitat (same
soil level) as Polygyriscus:
Glyphyalinia lewisiana - pale glyph snail
G. cf. rhoadsi - sculpted glyph
Paravitrea reesei - round supercoil
Helicodiscus notius - tight coil
H. parallelus - compound coil
H. hardenoecus - cricket coil
OTHER LIFE HISTORY DESCRIPTORS:
None.
Life History - 2 (DRAFT) - Management Practices
Species SNAIL, MOUNTAIN, FRINGED, VIRGINIA
Species Id ESIS355003
Date 13 MAR 96
MANAGEMENT PRACTICES
RESULT MANAGEMENT PRACTICE
Beneficial Controlling/Restricting Mining
Beneficial Controlling/Restricting Road Maintainance Actions
Beneficial Maintaining undisturbed/undeveloped areas
Beneficial Land Acquisition
Beneficial Controlling/Restricting Pesticide Use
Beneficial Controlling/Restricting Herbicide Use
Adverse Inherent Reproductive Characteristics
Existing Inherent Reproductive Characteristics
Adverse Low Gene Pool
Existing Low Gene Pool
Adverse Surface Mines
Existing Surface Mines
Adverse Highway/Railroads
Existing Highway/Railroads
Adverse Forest Alteration
Existing Forest Alteration
COMMENTS ON MANAGEMENT PRACTICES -
Polygriscus is an extremely rare snail with a restricted habitat
and very narrow habitat requirements. Like many in its family, it is
known to be a burrowing creature and thought to be an obligate
calciphile. It probably has a low reproductive capacity, may be less
active than other types of snails in its size range, and lives only
well beneath the surface of permanently damp and shaded ground (03).
Living animals are occasionally found so its population, always
small, does not appear to be rapidly decreasing and its habitat
appears stable. Threats to its existence would then include problems
caused by man. Polygyriscus could be threatened by treatment of
roadside with herbicide, overcollecting (or destruction of habitat
by digging of overzealous collectors), widening the River Road
(Pulaski Co., Va.) especially on its western side (if not properly
controlled), or possible resumption of activity in the quarry (03).
A somewhat serious threat is posed by fire (or timber harvest)
removing vegetative cover, with resultant changes in soil moisture
and temperature in the snail's habitat.
APPROVED PLAN:
U.S. Fish and Wildlife Service. 1983. Recovery Plan for Virginia
Fringed Mountain Snail. U.S. Fish and Wildlife Service, Newton
Corner, MA. 16 pp.
Actions recommended for recovery include:
(1) Conduct research to determine essential elements of habitat.
(2) Determine ownership of known habitats and implement protection
where feasible. This may include acquisition or conservation
easements on private lands.
(3) After identifying adverse human activities at known habitats,
Management Practices - 1 (DRAFT) - Management Practices
Species SNAIL, MOUNTAIN, FRINGED, VIRGINIA
Species Id ESIS355003
Date 13 MAR 96
develop and implement a management plan. Management activities
may include controlling or restricting road maintenance or
modifications, herbicide use, development and reactivation of
quarry mining.
(4) Identify and survey other potential habitat sites to define total
distribution of this snail. Implement protection at any additional
sites identified.
(5) Monitor distribution and habitat quality to determine any long-
term trends.
Recovery actions implemented to date include determination of
land ownership at known habitats, and initial surveys to better define
distribution. The Virginia Division of Game and Inland Fisheries is
currently funding more intensive surveys for the species.
Management Practices - 2 (DRAFT) - References
Species SNAIL, MOUNTAIN, FRINGED, VIRGINIA
Species Id ESIS355003
Date 13 MAR 96
References
***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCURRENCE *****
01 Burch, Paul R. 1947. Polygyra virginiana, a new species from
Virginia. Nautilus, 61(2):40-41.
02 Pisbry, H.A. 1948. Land Mollusca of North America (North of
Mexico). Monograph No. 3, Volume 2(2): 622-635:1097-1098.
03 U.S. Fish and Wildlife Service. 1983. Virginia Fringed Mountain
Snail (Polygriscus virginianus) Recovery Plan. U.S. Fish and
Wildlife Service, Newton Corner, MA. 16 pp.
04 Burch, J.B. 1962. How to know the eastern land snails. Wm. C.
Brown Publishers. Dubuque, Iowa. 148 pp. + 363 fig.
05 Solem, Alan. 1975. Polygriscus virginianus (Burch,1947). A
helicodiscid land snail (Pulmonata: Helicodiscidae). Nautilus,
89(3): 80-86.
06 Committee on Scientific and Vernacular Names of Mollusks. In
Press. A list of common and scientific names of aquatic
invertebrates from the United States and Canada - Mollusca.
Special Publication. American Fisheries Society. Bethesda, MD.
07 Solem, Alan 1974. The shell makers. Introducing mollusks. John
Wiley & Sons. New York. 289 pp.
08 Hymen, Libbie. 1967. The Invertebrates (VI): Mollusca I. McGraw-
Hill Book Company. New York. 792 pp.
09 VanDevender, A.S. 1985. Status report on Helicodiscus hexodon.
U.S. Fish and Wildlife Service, Newton Corner, MA.
10 Tompa, Alex. 1984. Land snails (Stylommatophora). Chapter 2.
The Mollusca: Reproduction. Vol.7: Pp. 47-140.
***** REFERENCES FOR N-OCCURRENCE NARRATIVE ONLY *****
01 Burch, Paul R. 1947. Polygyra virginiana, a new species from
Virginia. Nautilus, 61(2):40-41.
02 U.S. Fish and Wildlife Service. 1983. Virginia Fringed Mountain
Snail (Polygriscus virginianus) Recovery Plan. U.S. Fish and
Wildlife Service, Newton Corner, MA. 16 pp.
03 Batie, Robert E. 1987. Pers. comm. Radford Univ. Biology Dept.,
Radford, VA.
References - 1