1
SPECIES FACT SHEET
Common Name: Columbia pebblesnail; Ashy pebblesnail; Columbia River
spire snail
Scientific Name: Fluminicola fuscus (Haldeman, 1847).
Phylum: Mollusca
Class: Gastropoda
Order: Neotaenioglossa
Super-family: Rissooidea
Family: Lithoglyphidae
Taxonomic Notes:
1. Many taxonomic analyses (e.g., Kabat & Hershler 1993) treat the
lithoglyphid group as a subfamily (“Lithoglyphinae”) within the family
Hydrobiidae. However, a more recent classification system derived largely from
molecular phylogenetic research treats this group as a family (Lithoglyphidae)
nested within the Rissooidea superfamily rather than the Hydrobiidae family
(Bouchet et al. 2005).
2. Hershler & Frest (1996) provide a long list of synonyms for Fluminicola
fuscus, including Lithoglyphus fuscus, Amnicola hindsi, F. columbiana, F. hindsi
(in part), and F. nuttaliana.
Conservation Status:
Global Status (2005): G2 - Imperiled
National Status (United States): N2
State & Province Statuses: Idaho (SNR), Oregon (S1), Washington (S2),
Wyoming (SNR), British Columbia (SH)
(NatureServe 2013).
Technical Description:
Fluminicola is a diverse assemblage of northwestern North American freshwater
snails in the Lithoglyphidae family (Hershler & Frest 1996, Hershler et al.
2007). Morpholologically, this genus is not readily distinguishable from several
eastern North American lithoglyphine genera (Hershler & Frest 1996), and
recent genetic analysis has confirmed suspicions that the genus is paraphyletic
(Hershler & Liu 2012). As such, the Fluminicola genus is in need of revision
(Hershler & Frest 1996, Hershler & Liu 2012). However, nomenclatural
changes cannot be made until the phylogenetic relationships between the type
species, F. nuttallianus, and others in the genus are resolved. The type species
is known only from specimens that were collected in the lower Willamette River
during the 1800’s (Hershler & Frest, 1996). Although this watershed has been
severely degraded by urbanization, pebblesnails of uncertain taxonomic status
have been recently collected in many of its streams and are currently being
examined to determine whether F. nuttallianus is extant (Hershler & Liu 2012,
Hershler 2012, pers. comm.). At present, a diagnosis of the genus has not been
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presented, but see Hershler & Frest (1996) for a detailed description of the
genus as it is currently constituted. In short, the genus is composed of globose
to trochoid (rarely ovate- or narrow-conic) shells that vary widely in size (height
2.5-12.0 mm; whorls 3.5-5.0) (Hershler & Frest 1996, Hershler et al. 2007).
Fluminicola fuscus is distinguished from other species in the genus by the body
whorl shape (large with subglobular to trochoid shell having strong subsutural
angulation or keel on body whorl), and penis (sickle-shaped, of medium size)
(Hershler & Frest 1996). In addition, the frequently incomplete parietal lip,
pigmented salivary glands, and position of seminal receptacle entirely lateral to
albumen gland are unique to F. fuscus within the genus (Hershler & Frest
1996). This species is further distinguished by the relatively large size,
channeled suture, and reddish-black color, not only of the periostracum but
also of portions of the shell, excluding the aperture (Frest 1999).
A full description of this species is as follows (Hershler & Frest 1996):
Shell subglobular to trochoid, apex often eroded; height 7.0-11.2 mm;
whorls 4.0-4.5. Protoconch of 1.5 whorls; diameter about 1.0 mm;
microsculpture of numerous strong spiral striae. Teleoconch whorls
slightly convex, shouldered. Body whorl with subsutural angulation to
well-developed, thick ledge; periphery well below middle of whorl,
usually angulate, sometimes strongly so. Microsculpture of strong
collabral growth lines (conforming to the shape of the outer lip).
Periostracum tan, brown, or red. Shell opaque, usually pink. Aperture
large, ovate, narrowly angled to pyriform above. Outer lip sometimes
weakly sinuate (adapically advanced), usually thin. Parietal lip thin, often
glaze-like, sometimes incomplete across body whorl, rarely thick and
slightly detached. Columellar lip thick, columellar swelling broad, often
covering umbilical region, sometimes slightly flared basally. Shell usually
anomphalous, rarely with small umbilicus. Operculum of medium
thickness; outer margin with obvious rim. Outer edge of attachment-scar
margin slightly thickened, inner edge slightly to moderately thickened.
Callus well developed, crescent-like. Radula with about 85 rows of teeth;
ribbon length 3.2 mm, ribbon width 0.3 mm; central tooth width 81 µm.
Central tooth with slight dorsal indentation; lateral cusps 2-4; median
cusp broadly U-shaped, slightly broader and longer than laterals; basal
cusps 1-2, narrow, originating near dorsal edge of lateral angles; basal
tongue narrow, basal sockets weakly to moderately excavated; lateral
angles broad, thickened.
Lateral tooth with convex dorsal edge; dorsal edge about 50% of tooth
width; lateral shaft slightly shorter than height of tooth face; tooth face
taller than wide; central cusp U-shaped, lateral cusps 3 (sometimes 2 on
inner side). Inner marginal teeth with 10-13 cusps; outer marginal teeth
with 10-11 cusps. Snout, including distal lips, dark purple brown;
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tentacles similarly pigmented except for pale circle around eyes. Head
moderately pigmented; foot moderately to darkly pigmented. Pallial roof
and visceral coil almost uniformly black; pallial edge black. Ctenidium
overlapping pericardium; filaments about 36, tall, strongly pleated.
Osphradium about 45% of ctenidium length. Hypobranchial gland
swollen on proximal genital ducts. Fecal pellets oblique. Renal organ
rarely swollen; renal opening white. Salivary glands pigmented,
overlapping cerebral ganglia. Stomach about as long as style sac. Ganglia
pigmented. Testis 2.0 whorls, overlapping posterior stomach chamber,
filling 50%-67% of visceral coil behind stomach. Prostate gland with 33%
of length in pallial roof. Vas deferens nearly straight in pallial roof and in
neck. Penis of medium size, sickle-shaped, coiled, with strong folds along
proximal 50%-67% of length; base slightly narrowed; medial section
gently tapering; distal section narrowing slightly to medium-long, pointed
tip. Penial duct near center, medium wide, strongly undulating in basal
and medial sections. Penis usually with very dark epithelial pigment on
proximal 50% of dorsal surface; black subepithelial pigment scattered
along length of penial duct. Ovary 0.75 whorl, abutting posterior edge of
stomach, filling about 50% of visceral coil behind stomach. Coiled
oviduct narrow; proximal portion with 1-2 small, horizontal to oblique
twists or coils; distal portion of primary coil sometimes containing sperm.
Coiled oviduct and bursal duct join just behind pallial wall. Bursa
copulatrix 53%-63% of albumen gland length, pyriform, longer than
wide, positioned largely posterior to gland. Bursal duct short (15%-25%
of bursa length), originating slightly lateral to tip of organ. Seminal
receptacle about 25% of length of bursa copulatrix, positioned just
anterior to bursa copulatrix near posterior edge of albumen gland. Pallial
gonoduct with deep rectal furrow. About 33% of albumen gland lying in
front of posterior pallial wall. Capsule gland about as long and as wide as
albumen gland. Ventral channel with anterior vestibule. Genital opening
a very short, subterminal slit.
See Appendix (Attachment 4) for photographs of the shell of this species. The
male and female genitalia, opercula, and radula of this species are illustrated
in Hershler & Frest (1996).
Life History:
Similar to most of its aquatic relatives, the Fluminicola genus exhibits separate
sexes with both male and female individuals. According to Duncan (2008), this
species is presumed to be semelparous (reproducing only once in a lifetime).
Reproduction is by copulation and cross-fertilization. Eggs of this species are
laid from spring to autumn in gelatinous capsules attached to plants, stones,
or other objects (Duncan 2008). The individual life span of this species is
thought to be approximately 1-2 years, and population turn-over is probably
greater than 90% (Duncan 2008). Fluminicola feed by scraping bacteria,
diatoms and other perilithic organisms from rock surfaces, and may
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occasionally feed on aquatic plant surfaces (Duncan 2008). This species is
present all year, but not active in winter. Having no lungs or gills, snails in this
genus respire through the mantle cavity, and have low tolerance for hypoxia
and anoxia (Duncan 2008).
Range, Distribution, and Abundance:
Fluminicola fuscus was historically widespread, with populations scattered
throughout Washington (Asotin, Benton, Cowlitz, Chelan, Clark, Franklin,
Klickitat, Okanogan, Skamania, Spokane, and Walla Walla Counties), Oregon
(Clatsop, Hood River, Jefferson, Multnomah, Sherman, Wallowa, and Wasco
Counties), Idaho (Boise, Blaine, Custer, Idaho, Nez Perce, Valley, Washington,
and Twin Falls Counties), British Columbia, and possibly Montana (Frest &
Johannes 1995, NatureServe 2013, Hershler & Frest 1996, Lysne & Pierce
2009, DeixisMolluskDB 2012, USNM 2013, ANSM 2013, MCZ 2013, Hershler
2012, pers. comm.). In Oregon and Washington, this species has been
documented in the lower Snake River, lower to middle Columbia River, and
large tributaries of these rivers including the Methow, Willamette, Wenatchee,
Deschutes, Okanogan, Grande Ronde, lower Salmon, and Spokane Rivers
(Hershler & Frest 1996, USNM 2013).
Neitzel & Frest (1992) conducted targeted surveys for F. fuscus at over 500
sites in more than 30 streams in the Columbia River Basin (Oregon,
Washington, Idaho); this species was absent from nearly all sites (including
some historic sites), and detected at just five streams. According to Frest &
Johannes (1995), this species has been extirpated from much of its historic
range, including most of the middle and upper Columbia River, Washington &
Oregon; the Spokane River, Washington; the Wigwam and Kootenai Rivers,
British Columbia; and the Payette River, Idaho. It may also be extirpated from
the lower Columbia River, Washington and Oregon (Frest & Johannes 1995). In
recent years, this species has been reported as abundant in the Snake River,
Hagerman Valley of Idaho (Stockton et al. 2011) and in Crystal Creek-Spring
Creek, Blaine Co., Idaho (Lysne and Pierce 2009). In Washington, it has been
detected relatively recently (1990 or later) in the Okanogan, Grande Ronde and
Methow rivers; Hanford Reach of the Columbia River; and a limited portion of
the Snake River. In Oregon, recent detections are from the Imnaha and Grande
Ronde Rivers and a few sites on the Columbia River (Frest & Johannes 1995,
Neitzel & Frest 1989, 1992, Deixis MolluskDB 2012, USNM 2013, Hershler
2012, pers. comm.).
Forest Service/BLM Lands: In Washington, this species has been documented
in the Columbia River within the Columbia River Gorge National Scenic Area
(Duncan 2008). It is Suspected on BLM land in the Spokane District and on
Okanogan-Wenatchee National Forest, based on close proximity of these lands
to known records (see Maps in Attachment 4 of Appendix).
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In Oregon, this species has been found in the Columbia River Gorge National
Scenic Area (Oregon), Wallowa-Whitman National Forest, and on Prineville BLM
land (Duncan 2008). Some of these detections may no longer be extant.
Abundance: Abundance estimates of this species have not been conducted.
NatureServe (2013) notes that very few (1-3) occurrences (subpopulations) have
good viability. The entire population size is listed as 1000 - 2500 individuals
(NatureServe 2013). Neitzel & Frest (1992) report that there are just two
remaining “sizable populations” of this species (in the Okanogan and Methow
Rivers, Washington) and “smaller populations” in the Hanford Reach of the
Columbia River, Washington and lower Salmon River, Idaho. Lysne and Pierce
(2009) report this species as “abundant” in Crystal Creek-Spring Creek, Blaine
County, Idaho.
Habitat Associations:
The habitat for Fluminicola fuscus is described as small to large rivers, in swift
current on stable gravel to boulder substrate in cold, unpolluted, highly
oxygenated water, generally in areas with few aquatic macrophytes or epiphytic
algae (Frest & Johannes 1995). Neitzel & Frest (1992) note that while this
species is typically characterized as occurring in large rivers and rapids, it can
also thrive in small streams such as the Methow River. Neitzel & Frest (1989)
describe this species as occurring under rocks and vegetation in the slow to
rapid currents of streams. It is common at the edges of rapids or immediately
downstream from whitewater areas, and becomes much less common or absent
in major rapids (Neitzel & Frest 1992). In the absence of rapids or whitewater
areas, this species is restricted to habitat with sufficient flow, oxygenation, and
stable substrate (Neitzel & Frest 1992).
This species is not found in springs, lakes, areas of slow flow, areas with mud
or silt substrate, areas with bare bedrock substrate, stream reaches with
unstable substrate such as rivers with high gradients (e.g., the Selway and
Lochsa rivers, Idaho, and the Klickitat River, Washington), streams with glacial
flour (e.g., the Hood River, Oregon), and the central deep areas in strongly
channelized streams (Neitzel & Frest 1992).
Members of this genus, as a whole, are usually found in clear, cold waters with
high dissolved oxygen content (Hershler & Frest 1996). Large species, such as
F. fuscus, are typically found in streams, whereas smaller species are
commonly found in either spring or stream environments (Hershler & Frest
1996). Frest & Johannes (1995) discuss the ecology of the larger Fluminicola
species as a group, stating that most of these taxa are classified as cold-water
stenotherms (functioning only within a narrow temperature range) and as
spring-influenced amniphiles (existing primarily in larger streams). Generally,
these species prefer cold, clear, streams with near-saturation amounts of
dissolved oxygen, no or minor nutrient enhancement (oligotrophic waters);
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continual current; and coarse but stable substrate (Frest & Johannes 1995).
Preferred habitats generally have few rooted aquatic macrophytes and relatively
minor amounts of coverage by epiphytic algae and such tolerant macrophytes
as Ceratophylum and Potamogeton crispus; such may occur in finer-substrate
areas nearby (Frest & Johannes 1995). Members of the Fluminicola genus are
generally lithophiles- found on hard rocky surfaces where they graze on
periphyton (Frest & Johannes 1995, Hershler & Frest 1996). Often, species in
this genus appear to be community dominants, comprising most of the
invertebrate biomass (Hershler & Frest 1996).
Fluminicola fuscus is known to co-occur with numerous other aquatic mollusks
including Fisherola nuttalli, Vorticifex effusus, Pisidium casertanum; Gyraulus
parvus, Corbicula fluminea, Menetus callioglyptus, Potamopyrgus antipodarium,
Juga plicifera; Anodonta oregonensis, Gonidea angulata, and Physella gyrina.
(Deixis MolluskDB 2012, Frest & Johannes 1995).
Threats:
Impaired water quality, habitat degradation and loss, and increasing
fragmentation and isolation of the few remaining populations are the main
threats to the continued survival of Fluminicola fuscus. This species has narrow
habitat tolerances and requires cold, unpolluted, fast-flowing, well oxygenated
water in moderately large perennial streams with stable gravel to boulder
substrate.
In most streams, the original condition prior to human modification was likely
as a single continuous population occupying suitable habitat bands parallel to
shore on both sides of the stream (Neitzel & Frest 1992). Many historic
populations of this species have been extirpated, and most currently living
populations have been fragmented by human modification of streams. Such
modifications include dams, impoundments, water diversions, increased
siltation from grazing and agriculture (e.g., orchards), and increased industrial
pollution (e.g., mining and pulp mill effluents) (Neitzel & Frest 1992, Frest &
Johannes 1995).
Many of these factors continue to threaten remaining habitat for this species. A
survey of the interior Columbia River basin conducted by the US Forest Service
(1996) found that most streams in the region are fully or over-appropriated for
water diversion, with irrigation as the primary usage. Changes in riparian
vegetation were noted basin-wide, including a significant decline in riparianassociated species such as cottonwood and willow due to forest conversion,
streamside disturbance, roads, and dams (USFS 1996). Decreased riparian
vegetation can destabilize stream banks and increase sedimentation and
siltation, filling in the cobble substrate inhabited by F. fuscus.
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Additional potential threats such as disease and predation have not been
assessed. However, small isolated populations such as the remnant F. fuscus
are extremely vulnerable to stochastic events, and are generally at greater risk
of extirpation from normal population fluctuations due to predation, disease,
and changing food supply, as well as from natural disasters such as floods or
droughts. They may also experience a loss of genetic variability and reduced
fitness due to the unavoidable inbreeding that occurs in such small
populations.
Conservation Considerations:
Inventory: Survey for this species at known sites and at additional habitat in
the vicinity of known populations. Neitzel & Frest (1989, 1992) suggest that
despite their extensive surveys for this species in the region, there is a
relatively good chance that additional undetected populations of F. fuscus exist,
e.g., at undersurveyed sites with the habitat required by this species. In
particular, it is noted that appropriate habitat and possible new populations
may be found in the Hells Canyon of the Snake River, Washington, Idaho, and
Oregon; Grande Ronde River, Washington and Oregon; and the middle Snake
River, Idaho (Neitzel & Frest 1992).
In Washington, targeted surveys are recommended on BLM land in the
Spokane District and on Okanogan-Wenatchee National Forest (see maps in
Attachment 4 of Appendix). Surveys examining the current status and
abundance of this species at the 51-mile long Hanford Reach may also be
valuable; the population at this site is considered “small” (Neitzel & Frest
1992), and the species was last detected in 2005. Standardized abundance
estimates for this species at Hanford Reach as well as other known and new
sites would assist future conservation efforts, since population size is
important in evaluating the stability of a species at a given locality.
Management: Protect the remaining habitat and populations of this species. In
Washington, habitat alteration or stream modification at Hanford Reach (the
only remaining undammed, non-tidal stretch of the Columbia River) could be
severely detrimental to the survival of this species. Manage extant sites and
their associated watersheds to reduce the impacts of any practices that may
adversely affect water quality. Limit waste water outflow and agricultural runoff
into rivers which may add nutrients and other pollutants to water (Duncan
2008). Avoid new construction of dams or other structures which slow water
flow and cause reduced oxygenation (Duncan 2008). Research effective habitat
management strategies in the areas where the species still exists.
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Prepared by: Sarah Foltz Jordan, Xerces Society
Date: 14 June 2013
Edited by: Sarina Jepsen, Xerces Society
Date: 19 June 2013
Final Edits by: Rob Huff, FS/BLM, Portland OR
Date: 8 July 2013
ATTACHMENTS:
(1)
References
(2)
List of pertinent or knowledgeable contacts
(3)
Map of Species Distribution
(4)
Illustration and Scanning Electron Micrographs of Species
(5)
Aquatic Gastropod Survey Protocol, including specifics for this
species
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ATTACHMENT 1:
References:
The Academy of Natural Sciences (ANSP): Malacology Collection. Online
database. Available at:
http://clade.ansp.org/malacology/collections/index.html. (Last accessed June
2013).
Bouchet, P., Rocroi, J.-P., Frýda, J., Hausdorf, B., Ponder, W., Valdés, Á. and
A. Warén. 2005. Classification and nomenclator of gastropod families.
Malacologia: International Journal of Malacology (Hackenheim, Germany:
ConchBooks) 47 (1-2): 1–397.
Deixis MolluscDB database. 2012. An unpublished collection of mollusk
records maintained by Ed Johannes.
Duncan, N. 2008. Fluminicola fuscus Species Fact Sheet. Interagency Special
Status / Sensitive Species Program (ISSSSP). 3 pp.
Frest, T.J. and E.J. Johannes. 1995. Interior Columbia Basin mollusk species
of special concern. Final report: Interior Columbia Basin Ecosystem
Management Project, Walla Walla, WA. Contract #43-0E00-4-9112. 274 pp.
plus appendices.
Frest, T.J. 1999. A review of the land and freshwater mollusks of Idaho. Final
report to the Idaho Conservation Data Center, Idaho Department of Fish and
Game, 600 South Walnut, P.O. Box 25, Boise, Idaho. 281 pp plus appendices.
Harvard University Museum of Comparative Zoology (MCZ). 2013. Malacology
Collection, Online database. Available at:
http://collections.mcz.harvard.edu/Mollusks/MolluskSearch.htm. (Accessed
June 2013).
Hershler, R. and T.J. Frest. 1996. A review of the North American freshwater
snail genus Fluminicola (Hydrobiidae). Smithsonian Contributions to Zoology
583: 1-41.
Hershler R., Liu, H.-P., Frest, T.J. and E.J. Johannes. 2007. Extensive
diversification of pebblesnails (Lithoglyphidae: Fluminicola) in the upper
Sacramento River basin. Zoological Journal of the Linnean Society 149(3): 371422.
Hershler R. and H.-P. Liu. 2012. Molecular phylogeny of the western North
American pebblesnails, genus Fluminicola (Rissooidea: Lithoglyphidae),
with description of a new species. Journal of Molluscan Studies 78: 321–329.
10
Hershler, Robert. Research Zoologist. Smithsonian National Museum of Natural
History, Washington DC. 2012. Personal communication with Sarah Foltz
Jordan, Xerces Society.
Kabat, A.R. & R. Hershler. 1993. The prosobranch snail family Hydrobiidae
(Gastropoda: Rissooidea): review of classification and supraspecific taxa.
Smithsonian Contributions to Zoology 547: 1-94.
Lysne, S.J. and R. Pierce. 2009. Mollusk survey of Crystal Creek-Spring Creek
Ranches, Blaine County, Idaho, USA. Ellipsaria 11(1):20.
NatureServe. 2012. “Fluminicola fuscus.” NatureServe Explorer: An online
encyclopedia of life [web application]. Feb. 2009. Version 7.1. NatureServe,
Arlington, Virginia. Available at: http://www.natureserve.org/explorer/
(Accessed 25 Sep. 2012).
Neitzel, D.A. and Frest, T.J. 1989. Survey of Columbia River Basin streams for
giant Columbia River spire snail Flumincola columbiana and great Columbia
River limpet Fisherola nuttalli. Technical Report PNL-7103, Battelle Pacific
Northwest Laboratory, Richland, WA. 59 pp.
Neitzel, D.A. and Frest, T.J. 1992. Survey of Columbia River Basin streams for
Columbia pebblesnail Fluminicola columbiana and shortface lanx Fisherola
nuttalli. Technical Report PNL-8229, Battelle Pacific Northwest Laboratory,
Richland, WA. 83 pp.
Smithsonian National Museum of Natural History: Invertebrate Zoology
Collection. (USNM). Online database. Available at:
http://collections.nmnh.si.edu/search/iz/ (Accessed June 2013).
Stockton, K.A., C.M. Moffitt, D.L. Blew, and C.N. Farmer. 2012. Acute toxicity
of sodium fluorescein to ashy pebblesnails Fluminicola fuscus. Northwest
Science 86:190.
U.S. Fish & Wildlife Service (USFWS). 2013. Federal Register. Fluminicola
fuscus. Available at: http://ecos.fws.gov/docs/federal_register/fr2729.pdf
(Accessed 11 June 2013).
U.S. Department of Agriculture (USDA) Forest Service. 1996. Status of the
interior Columbia basin: summary of scientific findings. Gen. Tech. Rep. PNWGTR-385. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific
Northwest Research Station; U.S. Department of the Interior, Bureau of Land
Management. 144 p.
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ATTACHMENT 2:
List of pertinent, knowledgeable contacts:
Ed Johannes, Consultant, Deixis Consultants, Seattle-Tacoma, Washington.
Robert Hershler, Research Zoologist, Smithsonian National Museum of Natural
History, Washington DC.
Steven Lysne, Assistant Professor, College of Western Idaho, Nampa, Idaho.
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ATTACHMENT 3:
Map of Species Distribution
Records of Fluminicola fuscus in Washington and Oregon relative to Forest
Service and BLM lands.
13
Records of Fluminicola fuscus along the Methow River in Washington relative to
Okanogan-Wenatchee National Forest and Spokane District BLM lands.
14
Records of Fluminicola fuscus along the Okanogan River in Washington relative
to Okanogan-Wenatchee National Forest and Spokane District BLM lands.
15
ATTACHMENT 4:
Species
Photographs and Scanning Electron Micrograph of
Shells of Fluminicola fuscus. A, ANSP 62341 (shell height, 8.5 mm); B, USNM
883516 (7.3 mm); C, USNM 473390 (9.2 mm); D. USNM 854693 (9.3 mm); E,
USNM 883515 (7.8 mm); F. USNM 380804 (7.7 mm); G. USNM 883499 (8.7
mm); H. USNM 130527 (11.2 mm); I. USNM 883182 (10.0 mm); J. USNM
883640 (10.0 mm); K. USNM 511051 (8.8 mm); L. BMNH 1863.2.4.16 (8.3
mm). Figure extracted from Hershler & Frest (1996), used with permission.
16
Shell protoconch of Fluminicola fuscus, USNM 883495 (bar = 0.33 mm). Figure
extracted from Hershler & Frest (1996), used with permission.
17
ATTACHMENT 5: Aquatic Gastropod Survey Protocol, including specifics
for this species:
Survey Protocol
Taxonomic group:
Aquatic Gastropoda
How:
Please refer to the following documents for detailed mollusk survey
methodology:
1. General collection and monitoring methods for aquatic mollusks (pages 6471):
Frest, T.J. and E.J. Johannes. 1995. Interior Columbia Basin mollusk
species of special concern. Final report: Interior Columbia Basin
Ecosystem Management Project, Walla Walla, WA. Contract #43-0E00-49112. 274 pp. plus appendices.
2. Standard survey methodology that can be used by field personnel to
determine presence/absence of aquatic mollusk species in a given waterbody,
and to document species locations and habitats in a consistent format:
Duncan, N. 2008. Survey Protocol for Aquatic Mollusk Species:
Preliminary Inventory and Presence/Absence Sampling. Version 3.1.
Portland, OR. Interagency Special Status/Sensitive Species Program.
U.S. Department of Interior, Bureau of Land Management,
Oregon/Washington and U.S. Department of Agriculture, Forest Service,
Region 6. 52 pp. [Available at:
http://www.fs.fed.us/r6/sfpnw/issssp/species-index/faunainvertebrates.shtml].
Species-specific Survey Details:
Fluminicola fuscus
Where: Once widespread in the western United States, this species has been
recently extirpated from much of its historic range (Frest & Johannes 1995). In
Washington, it has been detected relatively recently (1990 or later) in the
Okanogan, Grande Ronde and Methow rivers; Hanford Reach of the Columbia
River; and a limited portion of the Snake River. In Oregon, recent detections are
from the Imnaha and Grande Ronde Rivers and a few sites on the Columbia
River (Frest & Johannes 1995, Neitzel & Frest 1989, Deixis MolluskDB 2012,
USNM 2013, Hershler 2012, pers. comm.).
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Neitzel & Frest (1989, 1992) suggest that despite their extensive surveys for
this species in the region, there is a relatively good chance that additional
undetected populations of F. fuscus exist, e.g., in the Hells Canyon of the
Snake River, Washington, Idaho, and Oregon; Grande Ronde River, Washington
and Oregon; the middle Snake River, Idaho; and other undersurveyed sites
with the pristine habitat required by this species.
In Washington, surveys targeting this species are recommended on BLM land
in the Spokane District and on Okanogan-Wenatchee National Forest, in the
vicinity of known sites (see maps in Attachment 4 of Appendix). Surveys
examining the current status and abundance of this species at the 51-mile long
Hanford Reach, the only remaining undammed, non-tidal stretch of the
Columbia River in the United States, may also be warranted. The population at
this site is considered “small” (Neitzel & Frest 1992), and the species was last
detected in this area in 2005. Standardized abundance estimates for this
species at this site as well as other known and new sites would assist future
conservation efforts, since population size is important in evaluating the
stability of a species at a given locality.
Habitat: The habitat for Fluminicola fuscus is described as small to large rivers,
in swift current on stable gravel to boulder substrate in cold, unpolluted,
highly oxygenated water, generally in areas with few aquatic macrophytes or
epiphytic algae (Frest & Johannes 1995). Neitzel & Frest (1989) describe this
species as occurring under rocks and vegetation in the slow to rapid currents
of streams. See species fact sheet for addition habitat specifics.
When: Surveys for this species are possible year-round, although most known
records are from August to December (USNM 2013). Neitzel & Frest (1989)
recommend late summer to early fall surveys for this species at Columbia River
sites.
How: A variety of methods may be used to sample for this species, including
hand and dip-net collection, kick-net collection, and the use of surber
samplers, dredges, and wire-basket benthos samplers (Deixis MolluskDB 2012,
Neitzel & Frest 1989, 1992). Neitzel & Frest (1989) used wire-basket benthos
samplers to target this species in the Columbia River; their collection methods
are described as follows:
Wire-basket benthos samplers were placed in streams and allowed to
incubate for about 3 months. Before retrieving the baskets, they were
placed in cloth bags. The bagged baskets were then returned to the
surface and tagged to identify sample location and date. Benthic
organisms were removed from the rocks and baskets and washed into
600 µm mesh sieving buckets. The washed samples were preserved in
70% isopropyl alcohol. Additional surveys were accomplished by
removing rocks from the stream and hand collecting snails from the
rocks; these snails were also placed in jars and preserved in alcohol.
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Identification of this species is based on external shell morphology and other
characters outlined and illustrated in Hershler & Frest (1996) and in the fact
sheet. This is a large and difficult genus, and expert identification of this
species is especially important. Frest (1999) does not recommend identification
from shells, alone, in areas where multiple species in the genus are known or
likely to occur.