Couesius plumbeus - (Agassiz, 1850)
Lake Chub
Synonym(s): Hybopsis plumbea
Taxonomic Status: Accepted
Related ITIS Name(s): Couesius plumbeus (Agassiz, 1850) (TSN 163535)
French Common Names: méné de lac
Unique Identifier: ELEMENT_GLOBAL.2.104768
Element Code: AFCJB06010
Informal Taxonomy: Animals, Vertebrates - Fishes - Bony Fishes - Minnows and Carps
 
Kingdom Phylum Class Order Family Genus
Animalia Craniata Actinopterygii Cypriniformes Cyprinidae Couesius
Genus Size: A - Monotypic genus
Check this box to expand all report sections:
Concept Reference
Help
Concept Reference: Robins, C.R., R.M. Bailey, C.E. Bond, J.R. Brooker, E.A. Lachner, R.N. Lea, and W.B. Scott. 1991. Common and scientific names of fishes from the United States and Canada. American Fisheries Society, Special Publication 20. 183 pp.
Concept Reference Code: B91ROB01NAUS
Name Used in Concept Reference: Couesius plumbeus
Taxonomic Comments: Monotypic genus. Formerly included in the genera Hybopsis and Semotilus (Lee et al. 1980). Three subspecies have been recognized: plumbeus, greeni, and dissimilis.
Conservation Status
Help

NatureServe Status

Global Status: G5
Global Status Last Reviewed: 17Aug2015
Global Status Last Changed: 13Sep1996
Ranking Methodology Used: Ranked by inspection
Rounded Global Status: G5 - Secure
Nation: United States
National Status: N5 (05Dec1996)
Nation: Canada
National Status: N5 (17Aug2015)

U.S. & Canada State/Province Status
United States Alaska (S4S5), Colorado (S1), Idaho (SNR), Illinois (SU), Indiana (S1), Iowa (SX), Maine (S4), Massachusetts (S1), Michigan (S4), Minnesota (SNR), Montana (S5), Nebraska (S1), New Hampshire (S4), New York (S3), North Dakota (S3), South Dakota (S1), Vermont (S4), Washington (S2S3), Wisconsin (S4), Wyoming (S5)
Canada Alberta (S5), British Columbia (S5), Labrador (S3S4), Manitoba (S5), New Brunswick (S5), Northwest Territories (S5), Nova Scotia (S5), Nunavut (SU), Ontario (S5), Quebec (S5), Saskatchewan (S5), Yukon Territory (S5)

Other Statuses

Implied Status under the Committee on the Status of Endangered Wildlife in Canada (COSEWIC):PS
Comments on COSEWIC: The northern British Columbia hotsprings populations are considered Data Deficient
IUCN Red List Category: LC - Least concern

NatureServe Global Conservation Status Factors

Range Extent: >2,500,000 square km (greater than 1,000,000 square miles)
Range Extent Comments: The most northern minnow in North America; the only minnow in Alaska (Page and Burr 2011). Range includes much of Canada and the extreme northern United States, south to Delaware River of New York, Lake Michigan (Illinois), and Platte River system in Wyoming, with relict populations in the upper Missouri River drainage, South Dakota, Nebraska, Colorado, and Wyoming, and Twin Springs Creek (Mississippi River tributary), Iowa (Stasiak 1986, Bestgen et al. 1991, Page and Burr 2011).

Number of Occurrences: > 300
Number of Occurrences Comments: This species is represented by a very large number of occurrences (subpopulations).

Population Size: >1,000,000 individuals
Population Size Comments: Total adult population size is unknown but very large.

Overall Threat Impact Comments: No major threats are known.

Short-term Trend: Relatively Stable (<=10% change)
Short-term Trend Comments: Trend over the past 10 years or three generations is uncertain but likely relatively stable.

Other NatureServe Conservation Status Information

Distribution
Help
Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) The most northern minnow in North America; the only minnow in Alaska (Page and Burr 2011). Range includes much of Canada and the extreme northern United States, south to Delaware River of New York, Lake Michigan (Illinois), and Platte River system in Wyoming, with relict populations in the upper Missouri River drainage, South Dakota, Nebraska, Colorado, and Wyoming, and Twin Springs Creek (Mississippi River tributary), Iowa (Stasiak 1986, Bestgen et al. 1991, Page and Burr 2011).

U.S. States and Canadian Provinces
Color legend for Distribution Map
Endemism: occurs (regularly, as a native taxon) in multiple nations

U.S. & Canada State/Province Distribution
United States AK, CO, IAextirpated, ID, IL, IN, MA, ME, MI, MN, MT, ND, NE, NH, NY, SD, VT, WA, WI, WY
Canada AB, BC, LB, MB, NB, NS, NT, NU, ON, QC, SK, YT

Range Map
No map available.


U.S. Distribution by County Help
State County Name (FIPS Code)
CO Boulder (08013)
IA Dubuque (19061)*
MA Berkshire (25003), Hampden (25013)*, Hampshire (25015)
ND Dunn (38025), Golden Valley (38033), McKenzie (38053), Stark (38089)
NE Brown (31017), Cherry (31031)*
SD Custer (46033)*, Harding (46063), Pennington (46103)
WA Okanogan (53047)+, Stevens (53065)+
* Extirpated/possibly extirpated
U.S. Distribution by Watershed Help
Watershed Region Help Watershed Name (Watershed Code)
01 Upper St. John (01010001), Allagash (01010002), Fish (01010003), Aroostook (01010004), West Branch Penobscot (01020001), East Branch Penobscot (01020002), Mattawamkeag (01020003), Upper Kennebec (01030001), Dead (01030002), Upper Androscoggin (01040001), St. Croix (01050001), Maine Coastal (01050002), Presumpscot (01060001), Piscataqua-Salmon Falls (01060003), Pemigewasset (01070001), Contoocook (01070003), Upper Connecticut (01080101), Passumpsic (01080102), Waits (01080103), White (01080105), Black-Ottauquechee (01080106), West (01080107), Middle Connecticut (01080201), Westfield (01080206)+, St. Francois (01110000)
02 Lake George (02010001), Winooski (02010003), Ausable (02010004), Lamoille (02010005), Great Chazy-Saranac (02010006), Missisquoi (02010007), Hudson-Hoosic (02020003), Mohawk (02020004)*, Middle Hudson (02020006)*, East Branch Delaware (02040102)
04 Baptism-Brule (04010101), Beaver-Lester (04010102), St. Louis (04010201), Beartrap-Nemadji (04010301), Bad-Montreal (04010302), Black-Presque Isle (04020101), Keweenaw Peninsula (04020103), Dead-Kelsey (04020105), Betsy-Chocolay (04020201), Waiska (04020203), Lake Superior (04020300), Manitowoc-Sheboygan (04030101), Door-Kewaunee (04030102)*, Brule (04030106), Cedar-Ford (04030109), Tacoosh-Whitefish (04030111), Fishdam-Sturgeon (04030112), Pike-Root (04040002), Black-Macatawa (04050002), Betsie-Platte (04060104), Boardman-Charlevoix (04060105), Brevoort-Millecoquins (04060107), Lake Michigan (04060200), St. Marys (04070001), Lone Lake-Ocqueoc (04070003), Au Gres-Rifle (04080101), Birch-Willow (04080104), St. Clair (04090001), Oak Orchard-Twelvemile (04130001), Irondequoit-Ninemile (04140101), Seneca (04140201)*, Black (04150101), Oswegatchie (04150302), Raquette (04150305), St. Regis (04150306)
07 Grant-Little Maquoketa (07060003)+*, Apple-Plum (07060005)+*
09 Rainy Headwaters (09030001), Rainy Lake (09030003), Lake of the Woods (09030009)
10 St. Mary (10010002), Upper Missouri (10030101), Upper Missouri-Dearborn (10030102), Smith (10030103), Sun (10030104), Belt (10030105), Two Medicine (10030201), Cut Bank (10030202), Marias (10030203), Willow (10030204), Teton (10030205), Bullwhacker-Dog (10040101), Arrow (10040102), Judith (10040103), Fort Peck Reservoir (10040104), Big Dry (10040105), Little Dry (10040106), Upper Musselshell (10040201), Middle Musselshell (10040202), Flatwillow (10040203), Box Elder (10040204), Lower Musselshell (10040205), Milk Headwaters (10050001), Upper Milk (10050002), Wild Horse Lake (10050003), Middle Milk (10050004), Big Sandy (10050005), Sage (10050006), Lodge (10050007), Battle (10050008), Peoples (10050009), Cottonwood (10050010), Whitewater (10050011), Lower Milk (10050012), Frenchman (10050013), Beaver (10050014), Rock (10050015), Porcupine (10050016), Prarie Elk-Wolf (10060001), Redwater (10060002), Poplar (10060003), West Fork Poplar (10060004), Charlie-Little Muddy (10060005), Big Muddy (10060006), Brush Lake closed basin (10060007), Yellowstone Headwaters (10070001), Upper Yellowstone (10070002), Shields (10070003), Upper Yellowstone-Lake Basin (10070004), Stillwater (10070005), Clarks Fork Yellowstone (10070006), Upper Yellowstone-Pompeys Pillar (10070007), Pryor (10070008), Upper Wind (10080001), Little Wind (10080002), Popo Agie (10080003), Lower Wind (10080005), Badwater (10080006), Upper Bighorn (10080007), Nowood (10080008), Greybull (10080009), Big Horn Lake (10080010), Shoshone (10080014), Lower Bighorn (10080015), Little Bighorn (10080016), Upper Tongue (10090101), Lower Tongue (10090102), Middle Powder (10090207), Little Powder (10090208), Lower Powder (10090209), Mizpah (10090210), Lower Yellowstone-Sunday (10100001), Big Porcupine (10100002), Rosebud (10100003), Lower Yellowstone (10100004)+, O'fallon (10100005), Lake Sakakawea (10110101), Upper Little Missouri (10110201)+, Boxelder (10110202), Middle Little Missouri (10110203), Beaver (10110204)+, Lower Little Missouri (10110205)+, Middle Cheyenne-Spring (10120109)+, Rapid (10120110)+, Middle Cheyenne-Elk (10120111)+*, Upper Belle Fourche (10120201), Knife (10130201)+, Upper Heart (10130202)+, Fort Randall Reservoir (10140101), Crow (10140105), Upper Niobrara (10150003), Middle Niobrara (10150004)+, Sweetwater (10180006)*, Middle North Platte-Casper (10180007), Clear (10190004), St. Vrain (10190005)+, Cache La Poudre (10190007)
17 Lower Kootenai (17010104), Pend Oreille (17010216), Franklin D. Roosevelt Lake (17020001), Kettle (17020002), Okanogan (17020006)
+ Natural heritage record(s) exist for this watershed
* Extirpated/possibly extirpated
U.S. Distribution by Watershed (based on multiple information sources) Help
Ecology & Life History
Help
Reproduction Comments: Spawns in spring and summer. Eggs hatch in about 10 days. Sexually mature in 3rd or 4th year (Becker 1983).
Ecology Comments: Sometimes occurs in large schools (Becker 1983).
Habitat Type: Freshwater
Non-Migrant: Y
Locally Migrant: Y
Long Distance Migrant: N
Mobility and Migration Comments: May migrate up to 1.6 km between separate spawning and nonspawning habitats (Scott and Crossman 1973).
Riverine Habitat(s): BIG RIVER, CREEK, MEDIUM RIVER, Moderate gradient, Pool, Riffle
Lacustrine Habitat(s): Deep water, Shallow water
Habitat Comments: This chub occurs in varied habitats, including standing or flowing water, and large or small bodies of water; it is most common in gravel-bottomed pools and runs of streams and along rocky lake margins (Page and Burr 2011). It is more common in lakes in the southern part of the range, mostly in rivers in the north (but in lakes if available). Often it occurs in shallows but may move into deeper parts of lakes in summer. Spawning occurs in river shallows, along rocky shores, in shoals of lakes.
Adult Food Habits: Herbivore, Invertivore
Immature Food Habits: Herbivore, Invertivore
Food Comments: Eats insect larvae, zooplankton, and algae; sometimes fishes (Scott and Crossman 1973).
Length: 23 centimeters
Economic Attributes Not yet assessed
Help
Management Summary Not yet assessed
Help
Population/Occurrence Delineation
Help
Group Name: Medium Cyprinids

Use Class: Not applicable
Minimum Criteria for an Occurrence: Occurrences are based on evidence of historical presence, or current and likely recurring presence, at a given location. Such evidence minimally includes collection or reliable observation and documentation of one or more individuals (including eggs and larvae) in appropriate habitat.
Separation Barriers: Dam lacking a suitable fishway; high waterfall; upland habitat.
Separation Distance for Unsuitable Habitat: 15 km
Separation Distance for Suitable Habitat: 15 km
Separation Justification: Data on dispersal and other movements generally are not available. In some species, individuals may migrate variable distances between spawning areas and nonspawning habitats.

Separation distances (in aquatic kilometers) for cyprinids are arbitrary but reflect the presumption that movements and appropriate separation distances generally should increase with fish size. Hence small, medium, and large cyprinids, respectively, have increasingly large separation distances. Separation distance reflects the likely low probability that two occupied locations separated by less than many kilometers of aquatic habitat would represent truly independent populations over the long term.

Because of the difficulty in defining suitable versus unsuitable habitat, especially with respect to dispersal, and to simplify the delineation of occurrences, a single separation distance is used regardless of habitat quality.

Occupied locations that are separated by a gap of 15 km or more of any aquatic habitat that is not known to be occupied represent different occurrences. However, it is important to evaluate seasonal changes in habitat to ensure that an occupied habitat occurrence for a particular population does not artificially separate spawning areas and nonspawning areas as different occurrences simply because there have been no collections/observations in an intervening area that may exceed the separation distance.

Date: 21Sep2004
Author: Hammerson, G.
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: 06Apr2012
NatureServe Conservation Status Factors Author: Hammerson, G.
Element Ecology & Life History Edition Date: 11Nov2011
Element Ecology & Life History Author(s): Hammerson, G.

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

References
Help
  • Aquin, P. 1999. Évaluation de la situation des groupes taxonomiques des poissons du Québec. Ministère de l'Environnement et de la Faune. 9 pages.

  • Atton, F.M. and J.J. Merkowsky. 1983. Atlas of Saskatchewan Fish. Saskatchewan Department of Parks and Renewable Resources, Fisheries Branch Technical Report 83-2. 281pp.

  • Bestgen, K. R., K. D. Fausch, and S. C. Riley. 1991. Rediscovery of a relict southern population of lake chub, COUESIUS PLUMBEUS, in Colorado. Southwest. Nat. 36:125-127.

  • Fisheries Branch. 1991. Fish Species Distributions in Saskatchewan. Report 91-7. Saskatchewan Parks and Renewable Resources, Fisheries Branch. Regina. 102pp.

  • Fulman, L.A. and J.J. Loos. 1981. Larval stages of the lake chub, COUESIUS PLUMBEUS. Canadian Journal of Zoology. 59(2):218-224.

  • Legendre, V. et J.F. Bergeron. 1977. Liste des poissons d' eau douce du Québec. MLCP, Service Aménage. Expl. Faune. Rap. dact. 6

  • Nelson, J. S., E. J. Crossman, H. Espinosa-Perez, L. T. Findley, C. R. Gilbert, R. N. Lea, and J. D. Williams. 2004. Common and scientific names of fishes from the United States, Canada, and Mexico. American Fisheries Society, Special Publication 29, Bethesda, Maryland. 386 pp.

  • Page, L. M., H. Espinosa-Pérez, L. T. Findley, C. R. Gilbert, R. N. Lea, N. E. Mandrak, R. L. Mayden, and J. S. Nelson. 2013. Common and scientific names of fishes from the United States, Canada, and Mexico. Seventh edition. American Fisheries Society, Special Publication 34, Bethesda, Maryland.

  • Page, L. M., and B. M. Burr. 1991. A field guide to freshwater fishes: North America north of Mexico. Houghton Mifflin Company, Boston, Massachusetts. 432 pp.

  • Page, L. M., and B. M. Burr. 2011. Peterson field guide to freshwater fishes of North America north of Mexico. Second edition. Houghton Mifflin Harcourt, Boston. xix + 663 pp.

  • Robins, C.R., R.M. Bailey, C.E. Bond, J.R. Brooker, E.A. Lachner, R.N. Lea, and W.B. Scott. 1991. Common and scientific names of fishes from the United States and Canada. American Fisheries Society, Special Publication 20. 183 pp.

  • Saskatchewan Environment and Resource Management. 1996. The Fisheries Regulations being Chapter F-16.1 Reg 1 (effective 9 May 1995) as ammended by Saskatchewan Regulations 13/96.

  • Scott, W. B., and E. J. Crossman. 1973. Freshwater fishes of Canada. Fisheries Research Board of Canada, Bulletin 184. 966 pp.

  • Scott, W.B. and E.J. Crossman. 1979. Freshwater Fishes of Canada. Fisheries Research Board of Canada. Bull. 84. 966pp.

  • Stasiak, R. H. 1986. New record of the lake chub (Couesius plumbeus) from Nebraska. Proceedings of the Nebraska Academy of Sciences 1986:29-30.

References for Watershed Distribution Map
  • Baxter, G. T., and J. R. Simon. 1970. Wyoming fishes. Wyoming Game and Fish Department, Cheyenne, Wyoming, 168 pp.

  • Becker, G. C. 1983. Fishes of Wisconsin. University of Wisconsin Press, Madison. 1,052 pp.

  • Fago, D. 2000. Relative abundance and distribution of fishes in Wisconsin. Fish Distribution Database to year 2000. Wisconsin Department of Natural Resources.

  • Harlan, J. R., E. B. Speaker, and J. Mayhew. 1987. Iowa fish and fishing. Iowa Conservation Commission, Des Moines, Iowa. 323 pp.

  • Holton, G. D., and H. E. Johnson. 1996. A field guide to Montana fishes. 2nd edition. Montana Fish, Wildlife and Parks, Montana State Parks and wildlife Interpretive Association, Helena, Montana. 104 pp.

  • Lee, D. S., C. R. Gilbert, C. H. Hocutt, R. E. Jenkins, D. E. McAllister, and J. R. Stauffer, Jr. 1980. Atlas of North American freshwater fishes. North Carolina State Museum of Natural History, Raleigh, North Carolina. i-x + 854 pp.

  • McPhail, J. D., and R. Carveth. 1993. Field key to the fishes of British Columbia. Department of Zoology, University of British Columbia, Vancouver. 233 pp.

  • Simpson, J. and R. Wallace. 1982. Fishes of Idaho. The University Press of Idaho, Moscow, Idaho. 238 pp.

  • Smith, C. L. 1983. Fishes of New York (maps and printout of a draft section on scarce fishes of New York). Unpublished draft.

  • Smith, C. L. 1985. The inland fishes of New York State. New York State Department of Environmental Conservation. Albany, New York, xi + 522 pp.

  • Smith, P. W. 1979. The fishes of Illinois. University of Illinois Press, Urbana. 314 pp.

  • State Natural Heritage Data Centers. 1996a. Aggregated element occurrence data from all U.S. state natural heritage programs, including the Tennessee Valley Authority, Navajo Nation and the District of Columbia. Science Division, The Nature Conservancy.

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 November 2016.
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 © 2017 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. 2017. 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.