(DRAFT) - Taxonomy
Species SQUAWFISH, COLORADO
Species Id ESIS256003
Date 13 MAR 96
TAXONOMY
NAME - SQUAWFISH, COLORADO
OTHER COMMON NAMES - SQUAWFISH, COLORADO;SQUAWFISH, COLORADO RIVER; SQUAWFISH; FISH, WHITE;SALMON, COLORADO; SALMON and WHITE; SALMON
ELEMENT CODE -
CATEGORY - Fish
PHYLUM AND SUBPHYLUM - CHORDATA,
CLASS AND SUBCLASS - OSTEICHTHYES,
ORDER AND SUBORDER - CYPRINIFORMES,
FAMILY AND SUBFAMILY - CYPRINIDAE,
GENUS AND SUBGENUS - PTYCHOCHEILUS,
SPECIES AND SSP - LUCIUS,
SCIENTIFIC NAME - PTYCHOCHEILUS LUCIUS
AUTHORITY -
TAXONOMY REFERENCES -
COMMENTS ON TAXONOMY -
Colorado Squawfish
Ptychocheilus lucius Girard, 1856
KINGDOM: Animal GROUP: Fish
PHYLUM: Chordata CLASS: Osteichthyes
ORDER: Cypriniformes FAMILY: Cyprinidae
The Colorado squawfish, (Ptychocheilus lucius, Girard), is the
largest of four species of this genus living today. The genus dates
back to the Pliocene. The fish is elongate, dorsoventerally
compressed, with a pike-like ("lucius") body and long flattened head.
The body is countershaded with a dark olivaceous back, lighter on the
sides with a white belly (01). This is the largest North American
cyprinid with maximum weights exceeding 36 kilograms and maximum
lengths of nearly 1.8 meters recorded, however, specimens over 7
kilograms are now rare. The fish is a voracious predator and a top
carnivore of the Colorado River system, having a large mouth and long,
fragile gill arches well designed for grasping prey (01).
Common names found in the literature concerning this species
include: Colorado squawfish, Colorado River squawfish, squawfish,
white fish, Colorado salmon, white salmon and salmon.
Scientific names for the Colorado squawfish include Gila lucius
Taxonomy - 1 (DRAFT) - Taxonomy
Species SQUAWFISH, COLORADO
Species Id ESIS256003
Date 13 MAR 96
(Jordon and Copeland) and the following is a taxonomic summary
provided by Minckley, 1973 (01).
Ptychocheilus lucius, Girard, 1856: 209/ 1859a: 65.
Jordan and Gilbert, 1883: 227. Jordan, 1886: 127.
Kirsch, 1889: 558. Evermann and Rutter, 1895: 482.
Jordan and Evermann, 1896: 225. Gilbert and Scofield,
1898: 492. Meek, 1904: xxxix, 52. Grinnell, 1914: 54.
Jordan et al., 1930: 114. Evermann and Clark, 1931: 53.
Tanner, 1936: 168. Moffett, 1942: 82/ 1943: 182. Dill,
1944: 154. Miller, 1946a: 410/ 1952 b: 29/ 1955: 129/
1961a: 544/ 1961b: 373/ 1963a: 1/ 1964a: 7. Taft and
Murphy, 1950: 147. Winn and Miller, 1954: 274. Koster,
1957: 59. Kimsey and Fisk, 1960: 469. Lowe, 1960: 172.
Follett, 1961: 216. Beckman, 1963: 43. Sigler and Miller,
1963: 79. Miller and Lowe, 1964: 133/ 1967: 133. Minckley,
1965a: 48/ 1971: 184. Barber and Minckley, 1966: 322.
Branson, et al., 1966: 300. Bradley and Deacon, 1967: 230.
Minckley and Alger, 1968: 94. Minckley and Deacon, 1968:
1427. Eddy, 1969: 86. Vanicek and Kramer, 1969: 193.
Taxonomy - 2 (DRAFT) - Status
Species SQUAWFISH, COLORADO
Species Id ESIS256003
Date 13 MAR 96
STATUS
Coded Status
E: Federal Endangered
Commercial
Commercial/consumption
Game (Consumptive Recreational)
Non-consumptive recreational
COMMENTS ON STATUS -
U.S. STATUSES AND LAWS:
The Colorado squawfish (Ptychocheilus lucius) has been
designated an Endangered species pursuant to the Endangered Species
Act of 1973 (50 CFR 17.11; P.L. 93-205, 87 Stat. 884; 16 U.S.C.
1531-1540), as amended. The species has this status wherever found
including the States of Arizona, California, Colorado, New Mexico,
Nevada, Utah and Wyoming.
Special rules specifically address the "nonessential experimental
populations" which are being reintroduced into the Gila River drainage
(i.e., the Salt and Verde Rivers) from 1985 for a period of ten years
(50 CFR 17.84(b)). These populations of this Endangered species
are designated to be treated as if they were Threatened. Non-
essential experimental populations not occurring on National Park or
National Wildlife Refuge lands are treated as "proposed" species for
purposes of Section 7, interagency cooperation (50 CFR, Sec 17.83).
This species is protected by the Lacey Act (P.L. 97-79, as
amended; 16 U.S.C. 3371 et seq.) which makes it unlawful to import,
export, transport, sell, receive, acquire, or purchase any wild
animal (alive or dead including parts, products, eggs, or offspring):
(1) in interstate or foreign commerce if taken, possessed,
transported or sold in violation of any State law or
regulation; or
(2) if taken or possessed in violation of any U.S. law,
treaty, or regulation or in violation of Indian tribal law.
It is also unlawful to possess any wild animal (alive or dead
Status - 1 (DRAFT) - Status
Species SQUAWFISH, COLORADO
Species Id ESIS256003
Date 13 MAR 96
including parts, products, eggs, and offspring) within the U.S.
territorial or special maritime jurisdiction (as defined in
18 U.S.C. 7) that is taken, possessed, transported, or sold in
violation of any State law or regulation, foreign law, or Indian
tribal law.
RESPONSIBLE FEDERAL AGENCIES:
USFWS -Responsible for the management/recovery, listing, and
law enforcement/protection of this species.
BIA -Responsible for the law enforcement/protection of this
species with applicable State and Federal laws on
public lands under their control. Also responsible
for management/recovery on Bureau of Indian Affairs
lands.
BLM -Responsible for the law enforcement/protection of this
species with applicable State and Federal laws on
public land under their control (43 CFR 4140). Also
responsible for management/recovery on Bureau of Land
Management lands.
NPS -Responsible for the law enforcement/protection of this
species with applicable State and Federal laws on
public lands under their control. Also responsible
for conservation (Nat. Park System Organic Act - 16
U.S.C. 1, 2-3)/management/recovery on National Park
Service lands. Taking, possessing, or disturbing of
Federally listed species is prohibited on NPS lands
(36 CFR 2.1, 2.2, and 2.3).
USFS -Responsible for the law enforcement/protection of this
species with applicable State and Federal laws on
public lands under their control. Also responsible
for management/recovery on Forest Service lands. The
Forest Service is responsible for integrating
management, protection, and conservation of Federally
listed species into the Forest Planning process
(36 CFR 219.19 and 219.20).
Management practices that would cause detrimental
changes in water temperature or composition, water
course blockage, or sediment deposits within 100 feet
of the edges of perennial streams, lakes or other
bodies of water are prohibited (36 CFR 219.27(e)).
All Federal agencies have responsibility to ensure that any
action authorized, funded, or carried out by that agency is not likely
to jeopardize the continued existence of the species or result in the
destruction or adverse modification of Critical Habitat (50 CFR 402),
and to utilize their authorities to carry out programs for the
conservation of the species.
STATE STATUSES AND LAWS:
STATE: Arizona
DESIGNATED STATUS: Recognized Endangered
Status - 2 (DRAFT) - Status
Species SQUAWFISH, COLORADO
Species Id ESIS256003
Date 13 MAR 96
ADMINISTRATIVE AGENCY: Arizona Game and Fish Department
STATUTE: Arizona Revised Statutes 17-201, 211, 214 and 231,
Arizona Game and Fish Commission, Sec 17-23(B)7
STATE: California
DESIGNATED STATUS: Endangered
ADMINISTRATIVE AGENCY: California Department of Fish and Game
STATUTE: California Fish and Game Code 2000, 2002, 2013 and 2052
STATE: Colorado
DESIGNATED STATUS: Endangered
ADMINISTRATIVE AGENCY: Colorado Division of Wildlife
STATE STATUTES: Colorado Revised Statutes 33-6-101, 33-8-103(4)
Code of Colorado Regulations 406-8 No 1002a, Dec
1982
STATE: Nevada
DESIGNATED STATUS: Rare
ADMINISTRATIVE AGENCY: Nevada Department of Fish and Game
STATUTE: Nevada Administrative Code 503.584, 503.589
Nevada Revised Statutes 501.105, 501.181, 501.187,
STATE: New Mexico
DESIGNATED STATUS: Endangered, Group I
ADMINISTRATIVE AGENCY: New Mexico Department of Game and Fish
STATUTE: New Mexico Statutes Annotated 77-18-1, Reg No 624, July
1983
STATE: Utah
DESIGNATED STATUS: Recognized Endangered
ADMINISTRATIVE AGENCY: Utah Department of Natural Resources
STATUTE: Utah Code Annotated 23-13-2, 23-20-1, 23-13-5, 23-13-13
and 23-13-14
STATE: Wyoming
DESIGNATED STATUS: Recognized Endangered
ADMINISTRATIVE AGENCY: Wyoming Game and Fish Department
STATUTE: Wyoming Statutes Annotated 23-1-101 and 23-1-103
Wyoming Game and Fish Law, Sec 23.1-1
INTERNATIONAL STATUSES, TREATIES, AND AGREEMENTS:
Listed in CITIES II; February 22, 1977. The Colorado squawfish
is listed as Endangered in the IUCN Red Data Book, Vol. 4, 1977; and
is also listed by the Convention on Nature Protection and Wildlife
Preservation in the Western Hemisphere, 1970. This species has
recently been removed from CITES-II and is no longer protected by
the Convention (1988).
ECONOMIC STATUSES:
The Colorado squawfish once had commercial value as a food fish,
and was described as the largest and best food fish of the lower
Colorado River. It was also valued as fertilizer, and for sport
fishing.
Status - 3 (DRAFT) - Status
Species SQUAWFISH, COLORADO
Species Id ESIS256003
Date 13 MAR 96
70/08/25:35 FR 13519/13520 - Proposed Endangered
70/10/13:35 FR 16047/16048 - Listed as Endangered
75/05/16:40 FR 21499/21500 - Proposal to determine Critical Habitat
76/06/16:41 FR 24367/24377 - Proposed listing, CITES-II
77/02/22:42 FR 10462/10488 - Listed CITES-II
78/09/14:43 FR 41060/41062 - Reproposal to determine Critical Habitat
79/03/06:44 FR 12382/12384 - Withdraw/supplement prop. for Crit. Hab.
79/05/21:44 FR 29566/29567 - Five year review
84/04/10:49 FR 14149/14152 - Determ. of status of introduced pop.
85/07/22:50 FR 29901/29909 - Five year review
85/07/24:50 FR 30188/30195 - Reintroduced experimental pop. status
85/09/30:50 FR 39691/ - Correction, final rule
87/08/26:52 FR 32143/32145 - Proposed Exp. Pop. Status (CO. River)
87/09/23:52 FR 35743/35748 - Proposed change to CITES
87/12/28:52 FR 48820/48823 - Final Rule; delist from CITES
Status - 4 HABITAT ASSOCIATIONS
HABITAT - AQUATIC
INLAND AQUATIC
LAND USE -
Transportation, communications, and Util
Mixed Urban or Built-up Land
Cropland and Pasture
Orchards, Groves, Vineyards, Nurseries,
Shrub and Brush Rangeland
Streams and Canals
Reservoirs
NATIONAL WETLAND INVENTORY CODES
NWI NWICLS NWIMOD NWISPEC
Riverine, upper perennial UB2
Riverine, upper perennial UB1
Riverine, upper perennial RB2
Lacustrine, littoral UB
COMMENTS ON HABITAT ASSOCIATIONS -
The Colorado squawfish is a riverine fish requiring depths over 1
meter and a strong to moderate current. Young seek shelter and grow
in shallow, ephemeral embayments which often protect them from the
velocity of the water and predators (06).
The Colorado squawfish is adapted to variable flows with high
silt loads and high turbulence. This species uses a variety of
microhabitats during its life history (02). Recent advances in
knowledge about habitat preferences have been made by radiotelemetry
(06) indicating adult use of a variety of habitats ranging from rapids
to shorelines (06).
Adults spawn in whitewater rapids and riffles (06). Larvae fish
drift downstream (07) from spawning sites and use shallow, ephemeral
instream embayments for growth (02). The juvenile fish use deeper
habitats and are more similiar to adults in their use of habitat (08).
Terrestrial habitats within the range of the squawfish, which
might impact the riverine habitat, include: Mixed urban development,
urban transportation/utility corridors and facilities, shrub/brush
rangelands, and pinyon/juniper rangelands. Agricultural activities
basin wide include wheat, corn, beans (vegetables), pasture, and
fruit (peaches and apples, especially in the Grand Junction, CO area).
Habitat Associations - 1 (DRAFT) - Food Habits
Species SQUAWFISH, COLORADO
Species Id ESIS256003
Date 13 MAR 96
FOOD HABITS
TROPHIC LEVEL -
CARNIVORE
LIFESTAGE FOOD FOOD PART
General Arthropods
General Crustaceans
General Carrion
General Fish
Food Habits - 1 (DRAFT) - Environment Associations
Species SQUAWFISH, COLORADO
Species Id ESIS256003
Date 13 MAR 96
ENVIRONMENTAL ASSOCIATIONS
G = General A = Adult
LIM = Limiting RA = Resting Adult
J = Juvenile FA = Feeding Adult
RJ = Resting Juvenile BA = Breeding Adult
FJ = Feeding Juvenile P = Pupae
L = Larvae E = Egg
RL = Resting Larvae
FL = Feeding Larvae
LIFESTAGE ENVIRONMENTAL ASSOCIATIONS
G
G
G Aquatic Features: Pool areas
Environment Associations - 1 (DRAFT) - Life History
Species SQUAWFISH, COLORADO
Species Id ESIS256003
Date 13 MAR 96
LIFE HISTORY
FOOD HABITS:
The Colorado squawfish young consume crustaceans and insect
larvae (01) until about 40-50 millimeters in length when they begin
eating fish (red shiners and others) (01). At a length of 200
millimeters in length they become obligate piscivores, probably eating
any available fish small enough to catch (09). Native suckers have
been cited as a potential major food source (10). Larger food items
of terrestrial nature, including; carcasses of mice, birds and rabbits
are also taken (13). The food supply is condusive to the growth in
all age catagories of the species.
HOME RANGE/TERRITORY:
No information is available on this subject.
PERIODICITY:
This species is seasonally active. Activity is reduced during
the cold of winter. Spawning migrations prior to July-August. Diel
movements appear to be important only during the spawning season (06).
MIGRATION PATTERNS:
The Colorado squawfish is a migratory species (06). The fish
undertakes long distance spawning migrations of 400 kilometers round-
trip and homing behavior has also been noted (11). Migrations of
adults during the spawning season occurs both downstream and upstream.
Newly hatched larvae drift downstream immediately after hatching (06,
07). There is apparently a long term upstream movement of the
juveniles that repopulate and maintain the upstream populations of
adults.
COVER/SHELTER REQUIREMENTS:
The larvae or young of the year require shallow ephemeral
backwaters with zero velocity current (08,01). The adults require
large eddies and rapids with cobble or boulder substrate. Deep, well
defined riverine channels are also preferred by adults. The juveniles
require main channels of the river with a low gradient and shallow
water conditions.
REPRODUCTIVE SITE REQUIREMENTS:
The spawning sites for this fish consist of deep pools and/or
eddies adjacent to or near riffles and rapids (06). The fish rest or
stage in pools or in large shoreline eddies over 2 meters deep and
have been observed spawning in riffles or rapids less than 2 meters
in depth (06). Spawning adults use large boulders for cover and
appear to deposit eggs in the eddies behind them (06).
REPRODUCTIVE CHARACTERISTICS:
Spawning occurs in July and August (06). Males averaged about
550 millimeters in length and females averaged about 700 millimeters
in total length during the spawning years of 1981-83 (06). Colorado
squawfish are long-lived fish and spawning occurs in females at about
15 years of age (06).
Life History - 1 (DRAFT) - Life History
Species SQUAWFISH, COLORADO
Species Id ESIS256003
Date 13 MAR 96
PARENTAL CARE:
No information is available concerning the Colorado squawfish on
this subject.
POPULATION BIOLOGY:
Recruitment is limited in the Green River of Utah by the
availability of desirable nursery habitat. Many years of abnormally
high fall discharge have resulted in high mortality of young fish
(14). Population biology attributes for adults and juveniles are
difficult to determine because of seasonal movements and spawning
migrations (06).
SPECIES INTERRELATIONSHIPS:
Colorado squawfish do feed on a variety of prey. Largemouth bass
in the upper mainstream Colorado River have been documented as preying
on young squawfish (14). Largemouth bass do not, however, occur in
all rivers where the squawfish is found, so the effect of this
predation on the species in general is not known.
OTHER LIFE HISTORY DESCRIPTORS:
None.
Life History - 2 (DRAFT) - Management Practices
Species SQUAWFISH, COLORADO
Species Id ESIS256003
Date 13 MAR 96
MANAGEMENT PRACTICES
RESULT MANAGEMENT PRACTICE
Beneficial Developing fishways
Beneficial Regulating Water Temperature
Beneficial Developing/maintaining stream structures
Beneficial Maintaining/Controlling Water Flow
Beneficial
Beneficial Maintaining undisturbed/undeveloped areas
Beneficial Controlling pollution [thermal, chemical, physical]
Beneficial Creating Artificial Habitat/Nesting Structure
Beneficial Stocking captive-reared wild-strain animals
Beneficial Transplanting wild animals
Adverse Water Temperature Alteration
Existing Water Temperature Alteration
Adverse Water Level Fluctuation
Existing Water Level Fluctuation
Adverse Irrigating
Existing Irrigating
Adverse Reservoirs
Existing Reservoirs
Adverse Migration barriers
Existing Migration barriers
Adverse Competition
Existing Competition
Adverse Exotic/Feral/Introducted Species
Existing Exotic/Feral/Introducted Species
COMMENTS ON MANAGEMENT PRACTICES -
The loss of the Colorado squawfish from the lower Colorado River
Basin and its decline in the upper Colorado River Basin has been
linked with direct loss of habitat, changes in flow regime, blockage
of spawning and seasonal migration routes, temperature changes, and
competition with introduced fish species (02).
The Colorado River has been changed by the construction of over
20 mainstream dams beginning with the Hoover Dam in 1935. The river
has been changed from muddy and turbulent, to the clear and cold.
This change, in many areas, has blocked spawning migrations (03).
Also, the proliferation of introduced species (04) and resultant
competition have contributed to the decline of this species (05).
Recent work by the USFWS has implicated abnormally high fall
discharges from reservoirs as a factor in loss of recruitment, since
preferred shallow embayments are flooded and young are forced into
the mainstream rivers (06).
APPROVED PLAN:
U.S. Fish and Wildlife Service. 1978. Colorado Squawfish
Recovery Plan. U.S. Fish and Wildlife Service, Denver, CO. First
revision; December 1984. 31 pp.
Management Practices - 1 (DRAFT) - Management Practices
Species SQUAWFISH, COLORADO
Species Id ESIS256003
Date 13 MAR 96
The primary goal of the Recovery Plan is to restore and maintain
self-sustaining populations of the Colorado squawfish in their native
ecosystems and ultimately delist the species. Recovery tasks include
the preservation, protection, and improvement of existing habitat
through studies, information and education programs, and law
enforcement, as well as the restoration of Colorado squawfish
populations to their former range. Restoration involves; captive
propagation, reintroduction, monitoring of populations, transplanting
wild individuals, creating artificial habitat, restricting pollutants,
restricting development, controlling water salinity, controlling water
flow, stream channel modification, regulating water temperature,
providing fish passage devices, and a final determination of when
non-endangered status is reached.
Recovery activities currently ongoing include: Research into
life history and habitat characteristics, hatchery propagation (Dexter
and Willow Beach Hatcheries), and some reintroduction projects into
the Colorado River. In 1985 the USFWS reintroduced the Colorado
squawfish into the Gila River drainage of Arizona (specific locations
can be found in the occurrence narrative). These populations are
determined as "nonessential experimental" populations of an Endangered
species to be treated as if they were Threatened. In the past this
species was more widespread in the State of Arizona where it occurred
in several river drainages. This action is being taken in an effort
to reestablish populations of squawfish within their historic range.
Present plans as of 1985 call for annual stocking for the next ten
years.
Management Practices - 2 (DRAFT) - References
Species SQUAWFISH, COLORADO
Species Id ESIS256003
Date 13 MAR 96
References
***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCURRENCE *****
01 Minckley, W.L. 1973. Fishes of Arizona. AZ Fish and Game.
Phoenix, AZ. 292 pp.
02 U.S. Fish and Wildlife Service. 1984. Colorado Squawfish Recovery
Plan. Colorado River Fishes Recovery Team and Region 6, U.S. Fish
and Wildlife Service; Denver, CO.
03 Tyus, H.M. 1984. Loss of stream passage as a factor in the
decline of the Endangered Colorado squawfish. P 138-144 In: Issues
and technology in the management of impacted western wildlife-
proceedings of a national symposium. Thorne Ecological Inst. Tech.
Publ. No. 14. Boulder, CO.
04 Tyus, H.M., B.D. Burdick, R.A. Valdez, C.M. Haynes, T.A. Lytle and
C.R. Berry. 1982. Fishes of the upper Colorado River Basin:
distribution, abundance, and status. P. 12-70 In: Miller et al.
(eds) Fishes of the upper Colorado River system, present and
future. Western Division of the American Fisheries Society;
Bethesda, MD.
05 Behnke, R.J. and D.E. Benson. 1983. Endangered and Threatened
fishes of the upper Colorado River Basin. Bull. 503A. Coop. Ext.
Serv. Colorado State Univ. Fort Collins, CO.
06 Tyus, H.M. and C.W. Mcada. 1984. Migration, movements and habitat
preferences of Colorado squawfish, Ptychocheilus lucius, in the
Green, White, and Yampa Rivers, Colorado and Utah. Southwestern
Naturalist 29:289-299.
07 Haynes, C.M., T.A. Lytle, J. Wick and R.T. Muth. 1984. Larval
Colorado squawfish (Ptychocheilus lucius, Girard) in the upper
Colorado River Basin, Colorado 1979-81. Southwestern Naturalist
29(1):21-34.
08 Tyus, H.M., C.W. McAda, and B.D. Burdick. 1982. Green River
fishery investigations, P. 1-99, In: U.S. Fish and Wildlife
Service and Bureau of Reclamation, Colorado River Fishery Project,
Part 2. Salt Lake City, UT.
09 Vanicek, C.D. and R.H. Kramer. 1969. Life history of the Colorado
squawfish, Ptychocheilus lucius, and the Colorado chub, Gila
robusta, in the Green River in Dinosaur National Monument, 1964-66.
Trans. Amer. Fish. Soc. 98(2).
10 Holden, P.B. and E.J. Wick. 1982. Life history and prospects for
recovery of the Colorado squawfish, P. 98-108. In: Miller, W.H.,
H.M. Tyus, and C.A. Carlson (eds.). Fishes of the upper Colorado
River system: Present and future. Western Div. Amer. Fish. Soc.
Bethesda, MD.
11 Tyus, H.M. 1985. Homing behavior noted for the Colorado
squawfish. Copeia 1985 No. 1. P. 213-215.
12 Archer, D.L. and H.M. Tyus. 1984. Colorado squawfish spawning
study, Yampa River. Final report. USFWS, Colorado River Fishery
Project; Salt Lake City, UT. 34 pp.
13 Beckman, W.C. 1952. Guide to the fishes of Colorado. Univ. CO.
Mus. Boulder, CO. 110 pp. (Reprinted 1974).
14 Archer, D.L., H.M. Tyus, L.R. Kaeding, C.W. McAda and B.D.
Burdick. 1984. Colorado River fishes monitoring project. Second
References - 1 (DRAFT) - References
Species SQUAWFISH, COLORADO
Species Id ESIS256003
Date 13 MAR 96
Annual Report. USFWS. Salt Lake City, UT. 31 pp.
***** REFERENCES FOR N-OCCURRENCE NARRATIVE ONLY *****
01 Tyus, H.M., B.D. Burdick, R.A. Valdez, C.M. Haynes, T.A. Lytle, and
C.R. Berry. 1982. Fishes of the upper Colorado River Basin:
distribution, abundance, and status. P 12-70 In: Miller et al.
(eds) Fishes of the upper Colorado River system, present and
future. Western Division of the American Fisheries Society;
Bethesda, MD.
02 Holden, P.B. and C.B. Stalnaker. 1975. Distribution and
abundance of mainstream fishes of the middle and upper Colorado
River basins, 1967-1973. Transactions of the American Fisheries
Society, 104(2):217-231.
03 Tyus, H.M. and C.W. Mcada. 1984. Migration, movements and habitat
preferences of Colorado squawfish, Ptychocheilus lucius, in the
Green, White, and Yampa Rivers, Colorado and Utah. Southwestern
Naturalist 29:289-299.
04 Wick, E.J., D.L. Stoneburner, and J.A. Hawkins. 1983.
Observations on the ecology of Colorado squawfish (Ptychocheilus
lucius) in the Yampa River, Colorado, 1982. Water Resources Field
Support Lab Technical Rept. 83-7. National Park Service. Fort
Collins, CO.
05 Valdez, R.A., R.R. Smith, P Mangan, and B. Nilson. 1982. Colorado
River investigations. P. 100-279; In: USWFS and Bureau of
Reclamation: Colorado River Fishery Project. Part 2. Salt Lake
City, UT.
06 Archer, D.L. and H.M. Tyus. 1984. Colorado squawfish spawning
study, Yampa River. Final report. USFWS, Colorado River Fishery
Project; Salt Lake City, UT. 34 pp.
07 Lanigan, S.H. and C.R. Berry, Jr. 1981. Distribution of fishes in
the White River, Utah. Southwestern Naturalist 26:389-393.
08 Miller, W.H., H.M. Tyus and K.C. Harper. 1982. White River
fishes study. Final report. USFWS Colorado River Fishery Project.
Salt Lake City, UT. 58 pp.
09 Radant, R.D., J.S. Cranney, R.G. Ruesinie and K. Rose. 1983.
Colorado squawfish investigations, White River, Utah. Utah
National Resources, Wildlife Resources. Salt Lake City, UT.
39 pp.
10 Persons, W.R. and R. Buckley. 1982. Feeding activity and spawning
time of striped bass in the Colorado River inlet, Lake Powell,
Utah. North American J. of Fishery Management. 4:403-408.
11 U.S. Fish and Wildlife Service. 1984. Colorado Squawfish Recovery
Plan. Colorado River Fishes Recovery Team and Region 6, U.S. Fish
and Wildlife Service; Denver, CO.
12 Ellis, M.M. 1914. Fishes of Colorado. Univ. of CO Studies, 11:
1-136. Boulder, CO.
13 Lemons, D.B. 1954. A field survey of western Colorado streams
and lakes. CO Dept. of Fish and Game. Denver, CO. 29 pp.
14 Johnson, J.E. 1976. Status of Endangered and Threatened fish
species in Colorado. USDI, BLM Technical Note 280:1-28.
15 Holden, P.B. 1973. Distribution, abundance, and life histories of
References - 2 (DRAFT) - References
Species SQUAWFISH, COLORADO
Species Id ESIS256003
Date 13 MAR 96
the upper Colorado River Basin. Ph.D. Dissertation. UT State
Univ. Logan, UT. 58 pp.
16 Koster, W.J. 1957. Guide to the fishes of New Mexico. Univ. of
NM Press. Albuquerque. 116 pp.
17 Conway, M. 1975. New Mexicos Endangered fishes. NM Wildlife.
May/June: P. 18-24.
18 Minckley, W.L. 1973. Fishes of Arizona. AZ Fish and Game.
Phoenix, AZ. 292 pp.
19 LaRivers, I. 1962. Fishes and fisheries of Nevada. NV State
Game and Fish Comm. Reno, NV. 782 pp.
20 Follett, W.A. 1961. The freshwater fishes-their origins and
affinities. Syst. Zool. 9:212-232.
21 Baxter, G.T. and J.R. Simon. 1970. Wyoming fishes. Bull. No. 4.
WY Game and Fish Dept. Cheyenne, WY. 168 pp.
22 Miller, R.R. 1961. Man and the changing fish fauna of the
American southwest. Michigan Acad. of Sci., Arts, and Letters.
46:365-404.
23 USDI/USFWS. 1984. Proposed determination of experimental
population status for certain introduced populations of Colorado
squawfish and woundfin. Federal Register 49: 14149/14152; April
10, 1984.
24 Jenson, B.L. 1985. Dexter National Fish Hatchery annual report.
USFWS, Region 2. Albuquerque, NM. 11 pp.
References - 3