Lepidurus packardi - Simon, 1886
Vernal Pool Tadpole Shrimp
Other English Common Names: vernal pool tadpole shrimp
Taxonomic Status: Accepted
Related ITIS Name(s): Lepidurus packardi Simon, 1886 (TSN 684669)
Unique Identifier: ELEMENT_GLOBAL.2.108639
Element Code: ICBRA10010
Informal Taxonomy: Animals, Invertebrates - Crustaceans - Fairy, Clam, and Tadpole Shrimps
 
Kingdom Phylum Class Order Family Genus
Animalia Crustacea Branchiopoda Notostraca Triopsidae Lepidurus
Genus Size: A - Monotypic genus
Check this box to expand all report sections:
Concept Reference
Help
Concept Reference: McLaughlin, P.A., D.K. Camp, M.V. Angel, E.L. Bousfield, P. Brunel, R.C. Brusca, D. Cadien, A.C. Cohen, K. Conlan, L.G. Eldredge, D.L. Felder, J.W. Goy, T. Haney, B. Hann, R.W. Heard, E.A. Hendrycks, H.H. Hobbs III, J.R. Holsinger, B. Kensley, D.R. Laubitz, S.E. LeCroy, R. Lemaitre, R.F. Maddocks, J.W. Martin, P. Mikkelsen, E. Nelson, W.A. Newman, R.M. Overstreet, W.J. Poly, W.W. Price, J.W. Reid, A. Robertson, D.C. Rogers, A. Ross, M. Schotte, F. Schram, C. Shih, L. Watling, G.D.F. Wilson, and D.D. Turgeon. 2005. Common and scientific names of aquatic invertebrates from the United States and Canada: Crustaceans. American Fisheries Society Special Publication 31: 545 pp.
Concept Reference Code: B05MCL01EHUS
Name Used in Concept Reference: Lepidurus packardi
Taxonomic Comments: Lepidurus cryptus was recently separated as a distinct species from Lepidurus packardi but is inseparable morphologically; but is genetically distinct (see Rogers, 2001).
Conservation Status
Help

NatureServe Status

Global Status: G4
Global Status Last Reviewed: 08Oct2008
Global Status Last Changed: 12May2005
Rounded Global Status: G4 - Apparently Secure
Reasons: One of the more widely distributed California tadpole shrimp occurring in a wide range of vernal pool habitats in the southern and Central Valley areas of California, and in two vernal pool habitats within the Agate Desert area of Jackson County, Oregon. Although endemic to the northern Central Valley of California it is locally abundant and widespread in spite of losses to its' natural vernal pool habitat. It is federally listed as an endangered species. Endemic to the northern Central Valley of California it has suffered great losses of its natural vernal pool habitat.
Nation: United States
National Status: N4 (12May2005)

U.S. & Canada State/Province Status
Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
United States California (S3S4)

Other Statuses

U.S. Endangered Species Act (USESA): LE: Listed endangered (19Sep1994)
U.S. Fish & Wildlife Service Lead Region: R8 - California-Nevada
IUCN Red List Category: EN - Endangered

NatureServe Global Conservation Status Factors

Range Extent: 250-20,000 square km (about 100-8000 square miles)
Range Extent Comments: This species is endemic to the northern portion of the Central Valley, and Sacramento River Delta to the east side of San Fancisco Bay, California (Rogers, 2001). This species occurs from the Millville Plains and Stillwater Plains in Shasta County south throughout the Central Valley to Merced County (USFWS, 2004), but not north or east of the Great Central Valley (where Lepidurus cryptus occurs). It also occurs in Jackson County of southern Oregon.

Number of Occurrences: 81 to >300
Number of Occurrences Comments: Found in 33% of all seasonal wetlands in the Central Valley of California. In over 569 pools in California (USFWS, 2004) in 28 counties across the Central Valley and coast ranges of California, and in Jackson County of southern Oregon.. Rogers (2001) lists occurrences in Colusa, Glenn, Merced, Sacramento, San Joaquin, Shasta, Solano, Stanislaus, Tehama, Yolo, Yuba Cos.

Population Size Comments: Several to several hundred individuals within any given waterbody.

Overall Threat Impact: High
Overall Threat Impact Comments: The elimination and degradation of vernal pool habitat from agricultural (grapes) and urban development seem to be the greatest threat, however, grazing, off-road vehicle use and hydrologic modification may also contribute (USFWS, 1992). The primary threats are elimination and degradation of vernal pool habitat by urban development and conversion of grasslands to agricultural fields (U.S. Fish and Wildlife Service, 1992).

From USFWS (2005):
Some 17 occurrences are threatened by development while an additional 16 occurrences are reported as threatened by various agricultural conversions. The species is threatened by the encroachment of nonnative annual grasses on the San Francisco Bay National Wildlife Refuge in the Central Coast region, and by urban development where it is known to occur on private land in Alameda County. In the Northeastern Sacramento Valley region, most of the known occurrences are on Caltrans rights of way where they continue to be threatened by road improvement projects related to general urban growth. In addition, itis known to have been parasitized by flukes (Trematoda) of an undetermined species at the Vina Plains, Tehama County (Ahl, 1991) (gonads of both sexes greatly reduced in size and body cavities filled with many young flukes). Ahl (1991) thus concluded that parasitic castration was the major limiting factor affecting reproduction of the vernal pool tadpole shrimp at the Vina Plains. In the Northwestern Sacramento Valley Vernal Pool Region, it is threatened by development on the few sites on private land where it is known to occur. In the Southeastern Sacramento Vernal Pool Region, extant populations are threatened by continued extensive urban development. In the San Joaquin Vernal Pool Region, the species is threatened by development on private land. In the Solano-Colusa region, the species is threatened by urbanization on private lands. In the Southern Sierra Foothills Vernal Pool Region, the species is threatened by development of the proposed University of California, Merced campus, which will likely contribute to significant growth in the region, resulting in additional loss of vernal pool crustacean habitat. Populations on the Stone Corral Ecological Reserve may be threatened by pesticide drift from adjacent farmlands.

Short-term Trend: Unknown

Long-term Trend: Unknown

Intrinsic Vulnerability: Moderately vulnerable
Intrinsic Vulnerability Comments: Vulnerable to injury and predation from other aquatic organisms during molt when their protective carapace is soft. Molted individuals are light brown in color. In addition, predation by water birds (i.e., waterfowl, shore birds and wading birds) is increased when foraging near the surface or shallow areas such as the pool's edge. Exposure to air also increases the chance of air pockets occurring under the carapace, which increases buoyancy and reduces their ability to submerge, thus increasing the period of exposure to surface predation. Fairy shrimp are ecologically dependent on the presence or absence and duration of water during specific times of the year, as well as water chemistry (U.S. Fish and Wildlife Service, 1992).

Other NatureServe Conservation Status Information

Distribution
Help
Global Range: (250-20,000 square km (about 100-8000 square miles)) This species is endemic to the northern portion of the Central Valley, and Sacramento River Delta to the east side of San Fancisco Bay, California (Rogers, 2001). This species occurs from the Millville Plains and Stillwater Plains in Shasta County south throughout the Central Valley to Merced County (USFWS, 2004), but not north or east of the Great Central Valley (where Lepidurus cryptus occurs). It also occurs in Jackson County of southern Oregon.

U.S. States and Canadian Provinces

Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
Color legend for Distribution Map
Endemism: endemic to a single state or province

U.S. & Canada State/Province Distribution
United States CA

Range Map
No map available.


U.S. Distribution by County Help
State County Name (FIPS Code)
CA Alameda (06001), Butte (06007), Colusa (06011), Contra Costa (06013), Fresno (06019), Glenn (06021), Kings (06031), Madera (06039), Merced (06047), Placer (06061), Sacramento (06067), San Benito (06069), San Joaquin (06077), Shasta (06089), Solano (06095), Stanislaus (06099), Sutter (06101), Tehama (06103), Tulare (06107), Tuolumne (06109), Yolo (06113), Yuba (06115)
* Extirpated/possibly extirpated
U.S. Distribution by Watershed Help
Watershed Region Help Watershed Name (Watershed Code)
18 Sacramento-Stone Corral (18020104)+, Lower American (18020111)+, Upper Stony (18020115)+, Upper Bear (18020126)+, Cow Creek (18020151)+, Battle Creek (18020153)+, Clear Creek-Sacramento River (18020154)+, Paynes Creek-Sacramento River (18020155)+, Thomes Creek-Sacramento River (18020156)+, Big Chico Creek-Sacramento River (18020157)+, Butte Creek (18020158)+, Honcut Headwaters-Lower Feather (18020159)+, Upper Coon-Upper Auburn (18020161)+, Upper Putah (18020162)+*, Lower Sacramento (18020163)+, Upper Kaweah (18030007)+, Middle San Joaquin-Lower (18040001)+, Middle San Joaquin-Lower (18040002)+, San Joaquin Delta (18040003)+, Upper San Joaquin (18040006)+, Upper Chowchilla-Upper Fresno (18040007)+, Upper Tuolumne (18040009)+, Upper Stanislaus (18040010)+, Upper Mokelumne (18040012)+, Upper Cosumnes (18040013)+, Rock Creek-French Camp Slough (18040051)+, Suisun Bay (18050001)+, San Francisco Bay (18050004)+
+ Natural heritage record(s) exist for this watershed
* Extirpated/possibly extirpated
Ecology & Life History
Help
Basic Description: A large tadpole shrimp.
General Description: Dorsal compound eyes; a large (up to 3.5 cm long) dorsal shield-like carapace, which is attached to the head region, covering most of the 35 to 48 pairs of swimming appendages (phyllopods); and two long cercopods at the end of the last body segment (telson) (Pennak, 1978, and Longhurst, 1955).
Diagnostic Characteristics: Mostly resembles LEPIDURUS COUSEI; but, their ranges are apparently disjunct. Identifications of the species entails the examination of the arrangement of spines and length of the supra-anal plate, eyes, and nucral organ. Individuals similar in external morphology to both species have been collected in the Modoc Plateau area of northeastern California between each of their respective ranges. Although preliminary, genetic work on LEPIDURUS, conducted by King (pers comm., 1996), has revealed that specimens obtained from the Modoc Plateau area are genetically distinct. Yet, the genetic relationships between them and L. PACKARDI and L. COUSEI have not been determined.

The only useful external morphological characteristic to distinguish the sexes are the ovisacs (AKA foot capsules) attached to the eleventh pair of appendages (i.e., phyllopods) of females (Linder, 1952).

Reproduction Comments: Bisexual. Cysts occurring in the dry pool bottom hatch within three weeks of inundation (Ahl, 1991). Laboratory studies conducted by Ahl (1991) revealed cysts hatching within 17 days when incubated at 10 oC, however, the majority (64%) of the cysts hatched within four days. Lanway (1974) observed the appearance of hatchlings within two to three days after ponding in natural systems and 10 to 13 days after incubated at 10 oC in the laboratory. The author's dissertation work in the laboratory and field studies reveals similar hatching results as those obtained by Ahl (1991) and Lanway (1974). The hatched neonate is a metanauplius which undergoes several molts (ecdysis) each gaining additional phyllopod appendages until reaching allude. This process takes approximately six to seven weeks depending on temperature and food availability (Ahl, 1991, and Helm, in prep). Reproduction occurs throughout the ponding season, when females average between 10 and 12 mm in carapace length (Ahl, 1991). Ahl (1991) reported that fecundity increases with size and clutch size ranges from eight to 61 eggs. Ahl (1991) laboratory studies also revealed that eggs lain during the same ponding event can hatch without dehydration. Other life history characteristics include mean days to mature (38.1), mean days to reproduce (54.1), mean population longevity in days (143.6) (Helm, 1998).

Habitat Type: Freshwater
Non-Migrant: N
Locally Migrant: N
Long Distance Migrant: N
Palustrine Habitat(s): HERBACEOUS WETLAND, SCRUB-SHRUB WETLAND, TEMPORARY POOL
Habitat Comments: Found in a variety of natural, and artificial, seasonally ponded habitat types including: vernal pools, swales, ephemeral drainages, stock ponds, reservoirs, ditches, backhoe pits, and ruts caused by vehicular activities. Wetland habitats vary in size from very small (2 square meters) to very large (356,253 square meters) and exhibit extremes in depth (2-15 cm) and volume (23-9,262,573 cubic meters (Helm, 1998).
Food Comments: Diet remains relatively unstudied. Adults are omnivorous, foraging on detritus, vegetation and other aquatic invertebrates when available (Pennak, 1978). Food is collected by their phyllopods (gilled appendages) while scramming over vegetation or plowing through pool sediments. Early instar stages are most likely obligate filter feeders which later increase active prey consumption as larger size and complexity ensue.

The author has on numerous occasions observed foraging activity at the water's surface on leaf blades of grasses, especially GLYCERIA SSP. This behavior is especially apparent in the evening hours during the spring when water oxygen concentrations are low due to lack of photosynthesis.

Length: 5 centimeters
Economic Attributes Not yet assessed
Help
Management Summary
Help
Stewardship Overview: This Recovery Plan uses an ecosystem-level approach because many of the listed species and species of concern co-occur in the same natural ecosystem and share the same threats. Management objectives of the recovery plan (USFWS, 2005) include: (1) Habitat Protection: accomplish habitat protection that promotes vernal pool ecosystem function sufficient to contribute to population viability of the covered species (suitable vernal pool habitat within each prioritized core area for the species is protected; species localities distributed across the species geographic range and genetic range are protected and protection of extreme edges of populations protects the genetic differences that occur there; reintroduction and introductions must be carried out and meet success criteria; additional localities are permanently protected, if determined essential to recovery goals; habitat protection results in protection of hydrology essential to vernal pool ecosystem function, and monitoring indicates that hydrology that contributes to population viability has been maintained through at least one multi-year period that includes above average, average, and below average local rainfall as defined above, a multi-year drought, and a minimum of 5 years of post-drought monitoring), (2) Adaptive Habitat Management and Monitoring (habitat management and monitoring plans that facilitate maintenance of vernal pool ecosystem function and population viability have been developed and implemented for all habitat protected; mechanisms are in place to provide for management in perpetuity and long-term monitoring; monitoring indicates that ecosystem function has been maintained in the areas protected for at least one multi-year period that includes above average, average, and below average local rainfall, a multi-year drought, and a minimum of 5 years of post-drought monitoring), (3) Status Surveys (status surveys, 5-year status reviews, and population monitoring show populations within each vernal pool region where the species occur are viable and have been maintained (stable or increasing) for at least one multi-year period that includes above average, average, and below average local rainfall, a multi-year drought, and a minimum of 5 years of post-drought monitoring; status surveys, status reviews, and habitat monitoring show that threats identified during and since the listing process have been ameliorated or eliminated and site-specific threats identified through standardized site assessments and habitat management planning also must be ameliorated or eliminated); (4) Research (research actions necessary for recovery and conservation of the covered species have been identified and research actions on species biology and ecology, habitat management and restoration, and methods to eliminate or ameliorate threats have been completed and incorporated into habitat; research on genetic structure has been completed and results incorporated into habitat protection plans to ensure that within and among population genetic variation is fully representative by populations protected; research necessary to determine appropriate parameters to measure population viability for each species have been completed); (5) Participation and outreach (Recovery Implementation Team is established and functioning to oversee rangewide recovery efforts; vernal pool regional working groups are established and functioning to oversee regional recovery efforts; participation plans for each vernal pool region have been completed and implemented; vernal pool region working groups have developed and implemented outreach and incentive programs that develop partnerships contributing to achieving recovery criteria). The majority of the known Conservancy fairy shrimp localities are not currently managed under management plans. None of the known localities have sufficient funding for systematic monitoring to determine habitat quality or species status trends. In most cases, threats to this species, such as those described above, will not be detected and managed for.

Restoration Potential: High, considering the large number of occurrences in artificially created seasonal aquatic habitats (i.e., stock ponds, reservoirs).
Preserve Selection & Design Considerations: Preserves for this species should be designed around remaining vernal pool habitats, since the majority of occurrences are within this habitat type (Helm, in prep). Efforts should be made to protect large (>160 acres) areas of hydrological intact vernal pool and swale systems, which are found on a variety of soils and geomorphic surfaces that have permanent water bodies and other naturally occurring biotopes, such as oak woodlands. Large permanent waterbodies (i.e., natural ponds and lakes, and human-made stock ponds and reservoirs ) attract water birds (e.g., waterfowl, shore birds, wading birds) that are important for the dispersal of cysts either attached to feet or feathers with mud, or ingested.
Monitoring Requirements: Populations need to be verified periodically. The best sampling periods are in the late winter and early spring when large adults, usually gravid females, are present. Reliable identification requires collection, proper preservation of specimens, and consultation with an individual experienced with the genus.
Management Research Needs: Management research is needed in the following areas: 1.) Detailed information on the kind of management for maintaining optimum habitat conditions; 2). Identification of water quality parameters for survival, growth, and reproduction: 3). Relative contribution and success of potential dispersal mechanisms such as; migrating birds, livestock, water, and wind; 4). Determination of potential effects of management tools such as grazing, fire, disking, herbicides, and pesticides to adults and cysts within the soil.
Biological Research Needs: Research is needed in the following areas: 1.) Habitat requirements; 2). Food habits; 3.) Cues that break cyst dormancy; 4.) Genetic variance within, and among, pools and within, and between, pool complexes; 5). Information on cyst banks such as vertical and horizontal density and distribution in the soil profile, % or proportion of viable cysts, and the decreasing viability rate of cysts overtime.
Population/Occurrence Delineation
Help
Group Name: Phyllopodous Branchiopods

Use Class: Not applicable
Minimum Criteria for an Occurrence: Occurrences are based on some evidence of historical or current presence of single or multiple specimens of mature adult males at a given location with potentially recurring existence. Often both males and females are necessary for identification to the specific level. Evidence is derived from reliable published observation or collection data; unpublished, though documented (i.e. government or agency reports, web sites, etc.) observation or collection data; or museum specimen information. Photographs, diagnostic or not, are not acceptable for minimum occurrences.
Mapping Guidance: Due to the stochastic nature of local species distribution, map each pool, or series of pools within 100 m of one another, as separate occurrences.
Separation Barriers: Separation barriers are based on hydrological discontinuity. Any hydrological discontinuity, including presence of upland habitat, greater than 100 m constitutes a separation barrier. Note that dried ponds or pools that refill annually or cyclically are not considered separation barriers as phyllopodous branchiopod eggs are capable of dormancy in a resting stage typically lasting 6 to 10 months in temperate latitudes (Smith, 2001). In laboratory conditions, eggs have been reared from the resting stage years later.

Separation Distance for Unsuitable Habitat: 1 km
Separation Distance for Suitable Habitat: 1 km
Alternate Separation Procedure: Freshwater cave (troglobitic) species may occur from near entrances to very deep in cave systems. For cave species, each cave where an observation or collection was recorded (see Minimum EO Criteria, above) constitutes an element occurrence regardless of separation distance unless caves are part of a single hydrological system (see below). Occurrences are additionally separated by underground physical barriers to movement. Multiple caves within a single hydrological cave system are considered to be a single element occurrence when they are less than one km apart. Multiple caves within a single hydrological cave system are considered separate element occurrences when hydrological connections have not been determined or when separated by a distance of at least one km.
Separation Justification: Phyllopodous Branchiopoda (Crustacea: Anostraca, Notostraca, Laevicaudata, Spinicaudata) include the fairy, tadpole, and clam shrimps, respectively. They inhabit temporary ponds and pools and are absent from running water. Most species have few specific habitat preferences (Smith, 2001) occurring in most often in small (seldom exceeding one hectare) roadside ditches, vernal pools; as well as small to large permanent and (to a much lesser degree) temporary ponds. Rogers and Fugate (2001) report finding Branchinecta hiberna from railroad bed toe-drains and roadside ditches as small as 0.15 m2.

Species typically occur in the absence of fish. Presence of fish, though not considered a separation barrier for EO SPECS purpooses, is a very strong indicator of phyllopod absence and a barrier to dispersal. Rare exceptions occur when anostracans are found in large, deep freshwater lakes where fish predation is very low (Branchinecta in Canada- Anderson, 1974; Cyclestheria hislopi- Olesen et al., 1996). Species often have high tolerance to fluctuations in osmotic pressure, oxygen concentration, salinity, alkalinity, pH (though they prefer alkaline waters). Phyllopodous branchiopods typically have one (or two) generations each time potential habitat is made available often only hatching only some of the eggs at any given time while cyst banking the remainder (Belk and Cole, 1975; Loring et al., 1988; Ripley et al., 2004) so a major strategy is to produce as many small resistant eggs as possible in the shortest amount of time that aestivate and then hatch when the pool fills again.

Separating populations can be exceedingly difficult because a species may be abundant for several successive years, then be absent unaccountably for one or two years, then mysteriously return. Adults tend to be restricted to their area of occurrence only, and, although minimum separation distance has been set at only one km and some random dispersal by predators may occur (see below), phyllopods are usually present in scattered pools with nearby pools completely absent, for whatever reason. This may be attributed to stochastic distribution patterns resulting from dispersal of resting eggs by wind or transported by birds or insects that visit branchiopod habitat to drink or breed (Loring et al., 1988). Recently, resting eggs of the European fairy shrimp, Chirocephalus diaphanus, were shown to survive ingestion by trout and subsequent freezing and re-incubation in the laboratory without losing viability indicating fish may aid in dispersal of some species of fairy shrimp (Beladjal et al., 2007). Only subtle generic differences among populations of anostracans, even when close to each other (Boileau et al., 1992), suggests dispersal rate is either very low or completely random. Diversity in Arizona, for example, depends mainly on chemical heterogeneity among (mostly temporary) habitats; and thermal variation resulting both from ponds filling at different seasons and from altitudinal and latitudinal effects (Belk, 1977; Eng et al., 1990).

Date: 09Feb2007
Author: Cordeiro, J.
Population/Occurrence Viability
Help
U.S. Invasive Species Impact Rank (I-Rank) Not yet assessed
Help
Authors/Contributors
Help
NatureServe Conservation Status Factors Edition Date: 08Oct2008
NatureServe Conservation Status Factors Author: Cordeiro, J.
Management Information Edition Date: 13Mar1997
Management Information Edition Author: HELM, BRENT P.
Element Ecology & Life History Edition Date: 08Oct2008
Element Ecology & Life History Author(s): Cordeiro, J.

Zoological data developed by NatureServe and its network of natural heritage programs (see Local Programs) and other contributors and cooperators (see Sources).

References
Help
  • Ahl, J. S. B. 1991. Factors affecting contributions of the tadpole shrimp, Lepidurus packardi, to its oversummering egg reserves. Hydrobiologia 212:137-43.

  • Helm, B. P. 1998. Biogeography of eight large branchiopods endemic to California. Pages 124-139 in: C.W. Witham, E.T. Bauder, D. Belk, W.R. Ferren Jr., and R. Ornduff (editors). Ecology, Conservation, and Management of Vernal Pool Ecosystems ? Proceedings from a 1996 Conference. California Native Plant Society, Sacramento, CA.

  • Helm, B.P. 1998. Biogeography of eight large branchiopods endemic to California. Pages 124-139 in C.W. Witham, E.T. Bauder, D. Belk, W.R. Ferren, Jr. and R. Ornduff (eds.) Ecology, Conservation, and Management of Vernal Pool Ecosystems- Proceedings from a 1996 Conference. California Native Plant society, Sacramento, California.

  • Lanway, C. S. 1974. Environmental factors affecting crustacean hatching in five temporary ponds. Department of Biological Sciences, Chico State University, Chico.

  • Linder, F. 1952. Contributions to the morphology and taxonomy of the Branchiopoda Notostraca, with special reference to the North American Species. Proc. U.S. Natl. Mus. 102:1-69.

  • Longhurst, A. R. 1955. A review of the Notostraca. Bull. Brit. Mus. Zool. 3:1-57.

  • McLaughlin, P.A., D.K. Camp, M.V. Angel, E.L. Bousfield, P. Brunel, R.C. Brusca, D. Cadien, A.C. Cohen, K. Conlan, L.G. Eldredge, D.L. Felder, J.W. Goy, T. Haney, B. Hann, R.W. Heard, E.A. Hendrycks, H.H. Hobbs III, J.R. Holsinger, B. Kensley, D.R. Laubitz, S.E. LeCroy, R. Lemaitre, R.F. Maddocks, J.W. Martin, P. Mikkelsen, E. Nelson, W.A. Newman, R.M. Overstreet, W.J. Poly, W.W. Price, J.W. Reid, A. Robertson, D.C. Rogers, A. Ross, M. Schotte, F. Schram, C. Shih, L. Watling, G.D.F. Wilson, and D.D. Turgeon. 2005. Common and scientific names of aquatic invertebrates from the United States and Canada: Crustaceans. American Fisheries Society Special Publication 31: 545 pp.

  • Pennak, R.W. 1978. Fresh-water Invertebrates of the United States. John Wiley & Sons, New York, New York. 803 pp.

  • Rogers, D.C. 2001. Revision of the Nearctic Lepidurus (Notostraca). Journal of Crustacean Biology, 21(4): 991-1006.

  • Rogers, D.C. and B.J. Hann. 2016. Class Branchiopoda (in Chapter 16, Phylum Arthropoda). Pages 437-477 in J.H. Thorp and and D.C. Rogers (Editors), Thorp and Covich?s Freshwater Invertebrates, 4th edition, Volume II: Keys to Nearctic Fauna. Academic Press.

  • U.S. Fish and Wildlife Service (USFWS). 1994. Endangered and Threatened Wildlife and Plants; Animal Candidate Review for Listing as Endangered or Threatened Species. Federal Register 59(219):58982-59028.

  • U.S. Fish and Wildlife Service (USFWS). 2004. Endangered and threatened wildlife and plants; 12-month finding for a petition to list the midvalley fairy shrimp as endangered. Federal Register, 69(16): 3592-3598.

  • U.S. Fish and Wildlife Service (USFWS). 2005. Recovery plan for vernal pools ecosystems of California and Southern Oregon. U.S. Fish and Wildlife Service, Portland, Oregon. xxvi + 606 pages.

Use Guidelines & Citation

Use Guidelines and Citation

The Small Print: Trademark, Copyright, Citation Guidelines, Restrictions on Use, and Information Disclaimer.

Note: All species and ecological community data presented in NatureServe Explorer at http://explorer.natureserve.org were updated to be current with NatureServe's central databases as of March 2018.
Note: This report was printed on

Trademark Notice: "NatureServe", NatureServe Explorer, The NatureServe logo, and all other names of NatureServe programs referenced herein are trademarks of NatureServe. Any other product or company names mentioned herein are the trademarks of their respective owners.

Copyright Notice: Copyright © 2018 NatureServe, 4600 N. Fairfax Dr., 7th Floor, Arlington Virginia 22203, U.S.A. All Rights Reserved. Each document delivered from this server or web site may contain other proprietary notices and copyright information relating to that document. The following citation should be used in any published materials which reference the web site.

Citation for data on website including State Distribution, Watershed, and Reptile Range maps:
NatureServe. 2018. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available http://explorer.natureserve.org. (Accessed:

Citation for Bird Range Maps of North America:
Ridgely, R.S., T.F. Allnutt, T. Brooks, D.K. McNicol, D.W. Mehlman, B.E. Young, and J.R. Zook. 2003. Digital Distribution Maps of the Birds of the Western Hemisphere, version 1.0. NatureServe, Arlington, Virginia, USA.

Acknowledgement Statement for Bird Range Maps of North America:
"Data provided by NatureServe in collaboration with Robert Ridgely, James Zook, The Nature Conservancy - Migratory Bird Program, Conservation International - CABS, World Wildlife Fund - US, and Environment Canada - WILDSPACE."

Citation for Mammal Range Maps of North America:
Patterson, B.D., G. Ceballos, W. Sechrest, M.F. Tognelli, T. Brooks, L. Luna, P. Ortega, I. Salazar, and B.E. Young. 2003. Digital Distribution Maps of the Mammals of the Western Hemisphere, version 1.0. NatureServe, Arlington, Virginia, USA.

Acknowledgement Statement for Mammal Range Maps of North America:
"Data provided by NatureServe in collaboration with Bruce Patterson, Wes Sechrest, Marcelo Tognelli, Gerardo Ceballos, The Nature Conservancy-Migratory Bird Program, Conservation International-CABS, World Wildlife Fund-US, and Environment Canada-WILDSPACE."

Citation for Amphibian Range Maps of the Western Hemisphere:
IUCN, Conservation International, and NatureServe. 2004. Global Amphibian Assessment. IUCN, Conservation International, and NatureServe, Washington, DC and Arlington, Virginia, USA.

Acknowledgement Statement for Amphibian Range Maps of the Western Hemisphere:
"Data developed as part of the Global Amphibian Assessment and provided by IUCN-World Conservation Union, Conservation International and NatureServe."

NOTE: Full metadata for the Bird Range Maps of North America is available at:
http://www.natureserve.org/library/birdDistributionmapsmetadatav1.pdf.

Full metadata for the Mammal Range Maps of North America is available at:
http://www.natureserve.org/library/mammalsDistributionmetadatav1.pdf.

Restrictions on Use: Permission to use, copy and distribute documents delivered from this server is hereby granted under the following conditions:
  1. The above copyright notice must appear in all copies;
  2. Any use of the documents available from this server must be for informational purposes only and in no instance for commercial purposes;
  3. Some data may be downloaded to files and altered in format for analytical purposes, however the data should still be referenced using the citation above;
  4. No graphics available from this server can be used, copied or distributed separate from the accompanying text. Any rights not expressly granted herein are reserved by NatureServe. Nothing contained herein shall be construed as conferring by implication, estoppel, or otherwise any license or right under any trademark of NatureServe. No trademark owned by NatureServe may be used in advertising or promotion pertaining to the distribution of documents delivered from this server without specific advance permission from NatureServe. Except as expressly provided above, nothing contained herein shall be construed as conferring any license or right under any NatureServe copyright.
Information Warranty Disclaimer: All documents and related graphics provided by this server and any other documents which are referenced by or linked to this server are provided "as is" without warranty as to the currentness, completeness, or accuracy of any specific data. NatureServe hereby disclaims all warranties and conditions with regard to any documents provided by this server or any other documents which are referenced by or linked to this server, including but not limited to all implied warranties and conditions of merchantibility, fitness for a particular purpose, and non-infringement. NatureServe makes no representations about the suitability of the information delivered from this server or any other documents that are referenced to or linked to this server. In no event shall NatureServe be liable for any special, indirect, incidental, consequential damages, or for damages of any kind arising out of or in connection with the use or performance of information contained in any documents provided by this server or in any other documents which are referenced by or linked to this server, under any theory of liability used. NatureServe may update or make changes to the documents provided by this server at any time without notice; however, NatureServe makes no commitment to update the information contained herein. Since the data in the central databases are continually being updated, it is advisable to refresh data retrieved at least once a year after its receipt. The data provided is for planning, assessment, and informational purposes. Site specific projects or activities should be reviewed for potential environmental impacts with appropriate regulatory agencies. If ground-disturbing activities are proposed on a site, the appropriate state natural heritage program(s) or conservation data center can be contacted for a site-specific review of the project area (see Visit Local Programs).

Feedback Request: NatureServe encourages users to let us know of any errors or significant omissions that you find in the data through (see Contact Us). Your comments will be very valuable in improving the overall quality of our databases for the benefit of all users.