(DRAFT) - Taxonomy
Species SNAIL, THREE-TOOTHED, FLAT-SPIRED
Species Id ESIS355001
Date 13 MAR 96
TAXONOMY
NAME - SNAIL, THREE-TOOTHED, FLAT-SPIRED
OTHER COMMON NAMES - SNAIL, THREE-TOOTHED, FLAT-SPIRED; SNAIL, LAND, TOOTHED, THREE- and FLAT-SPIRED
ELEMENT CODE -
CATEGORY - Aquatic Molluscs
PHYLUM AND SUBPHYLUM - MOLLUSCA,
CLASS AND SUBCLASS - GASTROPODA,
ORDER AND SUBORDER - STYLOMMATOPHORA,
FAMILY AND SUBFAMILY - POLYGYRIDAE,
GENUS AND SUBGENUS - TRIODOPSIS,
SPECIES AND SSP - PLATYSAYOIDES,
SCIENTIFIC NAME - TRIODOPSIS PLATYSAYOIDES
AUTHORITY -
TAXONOMY REFERENCES -
COMMENTS ON TAXONOMY -
Flat-spired Three-toothed Snail
Triodopsis platysayoides (Brooks, 1933)
KINGDOM: Animal GROUP: Snail
PHYLUM: Mollusca CLASS: Gastropoda
ORDER: Stylommatophora FAMILY: Polygyridae
The following is taken from USFWS, 1983 (10):
The shell of T. platysayoides is thin, flattened and
shiny, ranging in color from light brown to light red-brown.
It is obliquely striated and 18-27 mm in diameter and 7-11
mm in height. The umbilicus is wide, nearly cylindrical,
and exhibits all of the 5 whorls. The shell's aperture is
oblique with a narrow, white, reflected lip. The lip teeth
are absent, but the lip swelling is somewhat thicker in those
places where the lip teeth would occur in other members of
the genus. A thick, short, white conical tooth is present
on the parietal wall.
Originally named Polygyra platysayoides by S.T. Brooks (01), the
species was later assigned to the genus Triodopsis. Vagvolgyi (14)
Taxonomy - 1 (DRAFT) - Taxonomy
Species SNAIL, THREE-TOOTHED, FLAT-SPIRED
Species Id ESIS355001
Date 13 MAR 96
Taxonomy - 2 (DRAFT) - Taxonomy
Species SNAIL, THREE-TOOTHED, FLAT-SPIRED
Species Id ESIS355001
Date 13 MAR 96
classified T. platysayoides as a subspecies of T. complanata but this
was not widely accepted. Solem (12) maintained that the available
evidence suggests specific, rather than subspecific rank. Emberton
(02) through electrophoretic and morphological analysis concluded that
T. platysayoides was indeed a distinct species, most closely related
to T. fraudulenta. Another common name used for this species is the
flat-spired three-toothed land snail.
The holotype specimen, collected by M.G. Netting on 18 May 1932,
is housed in the Section of Malacology in the carnegie Museum of
Natural History (No. 62.23750). Other specimens in museums and
private collections include the following:
Carnegie Museum of Natural History, Pittsburgh, Pa.
6 entire specimens, Cat. No. 62,26829, collected June 1933, M.G.
Netting.
2 entire specimens, Cat. No. 62.34084, collected 27 June 1936, N.D.
Richmond.
2 entire specimens, Cat. No. 62.34085, collected May 1938, N.D.
Richmond.
National Museum of Natural Sciences, Ottawa, Canada.
7 dry shells, 9 entire specimens, and 5 bodies only, Cat. No.
62911, collected 22 June & 3 July 1969, F.W. Grimm.
Field Museum of Natural History, Chicago, IL.
2 entire specimens, not catalogued, collected 14 April 1984, K.
Emberton.
Leslie Hubricht (private collection), Meridian, MS.
10 entire specimens, Cat. No. 11860, collected 30 May 1952, L.
Hubricht.
Steven Chambers, U.S. Fish and Wildlife Service, Wash., D.C.
Several shells, no entire specimens, not catalogued, collected 24
May 1983, S. Chambers.
West Virginia Dept. Nat. Resour., Elkins, WV.
1 dry shell, not catalogued, collected 18 May 1983, B. McDonald.
1 dry shell, not catalogued, collected 15 May 1984, C. Stihler.
1 dry shell, not catalogued, collected 16 August 1984, K. Knight.
Photographs and drawings of the species, known to exist include:
- Color slides of live snails, K. Knight, WV Dept. Nat. Resour.,
Elkins, WV.
- Color slides of live snails, S. Chambers, U.S. Fish and Wildlife
Service, Wash., D.C.
- Black & White photographs (2 views) in MacMillan (07).
- Shell drawings (3 views) in Brooks (01).
- Shell drawings (3 views) in Pilsbry (11).
- Genitalia drawings (3 views) in Solem (13).
- Electron microscope photographs of jaw and radular teeth in Solem
(13).
- Shell and genitalia drawings in Emberton (02).
Taxonomy - 3 (DRAFT) - Taxonomy
Species SNAIL, THREE-TOOTHED, FLAT-SPIRED
Species Id ESIS355001
Date 13 MAR 96
Taxonomy - 4 (DRAFT) - Status
Species SNAIL, THREE-TOOTHED, FLAT-SPIRED
Species Id ESIS355001
Date 13 MAR 96
STATUS
Coded Status
West Virginia; State Recognized
West Virginia; Unofficially Listed
T: Federal Threatened
COMMENTS ON STATUS -
U.S. STATUSES AND LAWS:
The flat-spired three-toothed snail (Triodopsis platysayoides)
has been designated a Threatened 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 West 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: West Virginia
DESIGNATED STATUS: Recognized Threatened
ADMINISTRATIVE AGENCY: Department of Natural Resources
STATE STATUTES: Reorganization Plan Numbered 4 of 1970 as cited
in App. A of the limited Authorities Cooperative
Agreement with the U.S. Fish and Wildl. Service.
Status - 1 (DRAFT) - Status
Species SNAIL, THREE-TOOTHED, FLAT-SPIRED
Species Id ESIS355001
Date 13 MAR 96
UNOFFICIAL LIST: Threatened; Special Animal List; West Virginia
Heritage Program.
INTERNATIONAL STATUSES, TREATIES, AND AGREEMENTS:
None.
ECONOMIC STATUSES:
None.
76/04/28:41 FR 17742/17747 - Proposed listing
78/07/03:43 FR 28932/28935 - Final rule, listed as Threatened
83/12/08:48 FR 55100/55101 - Five year review
Status - 2 HABITAT ASSOCIATIONS
HABITAT - TERRESTRIAL
TERRESTRIAL
LAND USE -
Deciduous Forest Land
COMMENTS ON HABITAT ASSOCIATIONS -
T. platysayoides is a strictly terrestrial snail found among
Upper Conoquenessing sandstone outcrops and boulders along the rim of
the Cheat River gorge. Forest associations within its range are
oak-hickory and maple-beech-birch types. Primary tree species are
sweet birch (Betula lenta), chestnut oak (Quercus prinus), red oak
(Q. rubra), and sugar maple (Acer saccharum). Rhododendron
(Rhododendron maximum) is also frequently found within its habitat
(05).
All known populations are found between 580 and 625 m (1900-2040
ft.) elevation. Aspect of these sites is variable, ranging from
northeast to southwest to southeast.
Habitat Associations - 1 (DRAFT) - Food Habits
Species SNAIL, THREE-TOOTHED, FLAT-SPIRED
Species Id ESIS355001
Date 13 MAR 96
FOOD HABITS
TROPHIC LEVEL -
HERBIVORE
LIFESTAGE FOOD FOOD PART
General Myxomycophyta
General Detritus
Food Habits - 1 (DRAFT) - Environment Associations
Species SNAIL, THREE-TOOTHED, FLAT-SPIRED
Species Id ESIS355001
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: Cliffs/ledges
G Terrestrial Features: Rock outcrops
Environment Associations - 1 (DRAFT) - Life History
Species SNAIL, THREE-TOOTHED, FLAT-SPIRED
Species Id ESIS355001
Date 13 MAR 96
LIFE HISTORY
FOOD HABITS:
Little is known about the food habits of T. platysayoides.
Grimm (03) indicated that the species feeds on lichens while Solem
(12) stated that their feeding niche is ". . . apparently among
seasonal leaf litter alongside rocks".
HOME RANGE/TERRITORY:
No data have been collected regarding home range or territory of
this species. A mark-recapture study initiated in 1984 may provide
such information (05).
PERIODICITY:
T. platysayoides has been observed active both day and night.
Grimm, Hubricht, and Emberton collected specimens at night while
several other researchers collected or observed during the daytime
(02,04,05,08,09). Adults of the species have been observed or
collected between 14 April and 27 June, which probably roughly
corresponds with its breeding season (02).
MIGRATION PATTERNS:
This snail is thought to be non-migratory except for possible
seasonal movements in and out of deep recesses in sandstone boulders.
A mark-recapture study initiated in 1984 may provide additional
informatin (05).
COVER/SHELTER REQUIREMENTS:
Little is known about specific habitat requirements. The
sandstone outcrops, and certainly the deep recesses in the outcrops,
seem to be an essential feature of the snail's habitat.
REPRODUCTIVE SITE REQUIREMENTS:
Little is known about reproductive site requirements for T.
platysayoides. Grimm (03) kept a colony which increased from 3 to 15
snails between 1967 and 1970. He stated that the species would breed
in captivity "if kept upon a lime-rich, insect-free substrate with
much cover." They thrive best between 5 and 15 degrees C and become
cannibalistic above 15 degrees C.
REPRODUCTIVE CHARACTERISTICS:
Little information is known about the reproductive
characteristics of this species. Hubricht (04) theorized that
individuals of this species live for 2 years. Adults found in the
spring hatched 2 years before and will breed before dying. Juveniles
found in the spring hatched the previous summer and will become adults
by the following spring. Egg laying probably occurs in May and June.
Egg clutches contain 3 to 5 eggs each (03).
PARENTAL CARE:
Nothing is known about parental care in this species.
POPULATION BIOLOGY:
Life History - 1 (DRAFT) - Life History
Species SNAIL, THREE-TOOTHED, FLAT-SPIRED
Species Id ESIS355001
Date 13 MAR 96
Little is known about the population biology of T. platysayoides.
The life span is believed to be 2 years (04).
SPECIES INTERRELATIONSHIPS:
Unknown.
OTHER LIFE HISTORY DESCRIPTORS:
None.
Life History - 2 (DRAFT) - Management Practices
Species SNAIL, THREE-TOOTHED, FLAT-SPIRED
Species Id ESIS355001
Date 13 MAR 96
MANAGEMENT PRACTICES
RESULT MANAGEMENT PRACTICE
Beneficial Restricting/regulating human disturbance of populations
Beneficial Maintaining undisturbed/undeveloped areas
Beneficial Land Acquisition
Adverse Rock Climbing
Existing Rock Climbing
Adverse Hiking/Camping
Existing Hiking/Camping
Adverse Inherent Reproductive Characteristics
Existing Inherent Reproductive Characteristics
Adverse Low Gene Pool
Existing Low Gene Pool
Adverse Predation
Existing Predation
Adverse Recreational development
Existing Recreational development
Adverse Competition
Existing Competition
Adverse Fire
Existing Fire
Adverse Harvesting
Existing Harvesting
COMMENTS ON MANAGEMENT PRACTICES -
Before 1981 only one very restricted population of T.
platysayoides was known. Grimm (03) observed 50 individuals on one
occasion and estimated a population of "several hundred". Solem (12)
estimated a population of 300-500. Field surveys in May and June 1984
located only 35 individuals in 70 man-hours of searching (06).
Although 6 additional sites supporting the species have been located
since Grimm and Solem made their estimates, this snail seems
to be extremely rare. It seems to be active only during its breeding
season in May and June. Otherwise it apparently retreats to the
fissures between and below the sandstone boulders. Due to its rarity
and secretive nature, more precise population estimates will require
intensive research. In 1984, 12 snails were marked but no recaptures
were obtained.
The area encompassing the known range of T. platysayoides was a
major iron ore extraction center in the first half of the 19th
Century. One of four large furnaces in the area, Henry Clay Furnace,
is about 1100 m from the Coopers Rock Overlook population. The forest
was cut and burned several times between about 1800 and 1936 (15).
The effects of cutting and burning on T. platysayoides are not
known. It is possible, though there is no evidence, that the species
was more widespread and was restricted by habitat alteration. The
large sandstone boulders and crevasses currently inhabited by the
snail would have been relatively protected due to the difficulty of
logging these sites. Grimm (03), Solem (12), and USFWS (10) expressed
concern that heavy trampling of the leaf litter by visitors below the
Management Practices - 1 (DRAFT) - Management Practices
Species SNAIL, THREE-TOOTHED, FLAT-SPIRED
Species Id ESIS355001
Date 13 MAR 96
Coopers Rock Overlook threatens the snail. However, more snails are
generally found at this site than at the other six , which are much
less disturbed. Fire, which could also destroy leaf litter or the
lichens, upon which the species may feed (03), is also cause for
concern.
The effects of intra- or interspecific competition are not known.
Grimm (03) maintained a breeding colony in captivity for 4 years and
found that a population density above 3-4 per square foot induced
cannibalism. Other species found within the habitat of T.
platysayoides include T. tridentata, T. albolabris, Mesodon zaletus,
Stenotrema sp., Haplotrema concavum, and an unidentified Zonitidae
(05). Predators may include shrews, carabid beetles, and lampyrid
beetles (03).
In summary, little was known until recently about the population
status and distributional range of T. platysayoides. Thus, it cannot
be stated with certainty whether the current restricted range of the
species is natural or related to human activities. Indeed, the rarity
and secretive nature of the snail makes assessment of its current
status and range difficult.
APPROVED PLAN:
U.S. Fish and Wildlife Service. 1983. Flat-spired Three-toothed
Snail Recovery Plan. U.S. Fish and Wildlife Service, Newton Corner,
MA. 20 pp.
Actions recommended for recovery of the flat-spired three-toothed
include:
(1) Determine total distributionand landownership for all
populations.
(2) Implement protection measures, including a management plan for
populations at Cooper's Rock State Forest, conservation easements
or acquisitions at sites on private land, controlling development, and
limiting human access.
(3) Conduct research on snail habitat requirements and activity
periods.
(4) Develop and implement a systematic monitoring program.
Recovery actions underway include determination of land ownership
at known sites and conducting surveys to determine total distribution.
As a result of joint surveys by the WV Dept. Nat. Resour. personnel
and U.S. Fish and Wildlife Service personnel, several small
populations have been discovered since the recovery plan was written,
but additional survey work remains to be completed. In addition, the
WV Dept. Nat. Resour. has done some studies to determine seasonal
activity patterns.
Management Practices - 2 (DRAFT) - References
Species SNAIL, THREE-TOOTHED, FLAT-SPIRED
Species Id ESIS355001
Date 13 MAR 96
References
***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCURRENCE *****
01 Brooks, S.T. 1933. Polygyra platysayoides, a new species from
West Virginia. Nautilus 46:54.
02 Emberton, K.C. 1984. Personal communication. Letter and
enclosures dated 22 September 1984.
03 Grimm, F.W. 1972. Information Form on file at: Office of
Endangered Species, Washington D.C.
04 Hubricht, L. 1984. Personal communication. Telephone
conversation, 5 October 1984.
05 Knight, K.B. 1984. Field trip reports, 23-25 May 1983,
31 May - 1 June 1983, 22 June 1983, 3 August 1983, 15 May 1984,
and 29-31 May 1984; WV Dept. Natural Resour., Elkins, WV.
06 Knight, K.B. and J.M. Crum. 1984. Endangered Species Performance
Report. Proj. No. E-1. WVa. Dept. Nat. Resour., Elkins, WV.
07 MacMillan, C.K. 1949. Land snails of West Virginia. Annals
Carnegia Mus. 31:9-239.
08 Moser, G.A. 1981. Field trip report, 13-15 May 1981. U.S. Fish
and Wildlife Service, Annapolis, MD.
09 Moser, G.A. 1982. Field trip report, 24-26 May 1982. U.S. Fish
and Wildlife Service, Annapolis, MD.
10 U.S. Fish and Wildlife Service. 1983. Flat-spired Three-toothed
Snail (Triodopsis platysayoides) Recovery Plan. U.S. Fish and
Wildlife Service, Boston, MA. 22 pp.
11 Pilsbry, H.A. 1940. Land mollusca of North America (North of
Mexico). Acad. Nat. Sci., Philadelphia, Monograph 3
1(2):iii-vi + 575-994.
12 Solem, A. 1974. Information form on file at: Office of Endangered
Species, Washington, D.C.
13 Solem, A. 1976. Comments on Eastern North American Polygridae.
Nautilus 90(1):25-36.
14 Vagvolgyi, J. 1968. Systematics and evolution of the genus
Triodopsis (Mollusca:Pulmonata:Polygyridae). Bull. Mus. Comp.
Zool. 136(7):145-254.
15 Anon. [n.d.] Wildlife management plan for Coopers Rock State
Forest. On file at: West Virginia Department of Natural Resources.
***** REFERENCES FOR N-OCCURRENCE NARRATIVE ONLY *****
01 Brooks, S.T. 1933. Polygyra platysayoides, a new species from
West Virginia. Nautilus 46:54.
02 Grimm, F.W. 1972. Information form on file at: Office of
Endangered Species, Washington, D.C.
03 Knight, K.B. 1984. Field trip reports, 23-25 May 1983,
31 May - 1 June 1983, 22 June 1983, 3 August 1983, 5 May 1984,
and 29-31 May 1984; WV Dept. Natural Resour., Elkins, WV.
04 Moser, G.A. 1981. Field trip report, 13-15 May 1981. U.S. Fish
and Wildlife Service, Annapolis, MD.
05 Moser, G.A. 1982. Field trip report, 24-26 May 1982. U.S. Fish
and Wildlife Service, Annapolis, MD.
References - 1 (DRAFT) - References
Species SNAIL, THREE-TOOTHED, FLAT-SPIRED
Species Id ESIS355001
Date 13 MAR 96
06 Solem, A. 1974. Information form on file at: Office of Endangered
Species, Washington, D.C.
References - 2