(DRAFT) - Taxonomy
Species CHUB, BONYTAIL
Species Id ESIS256002
Date 13 MAR 96
TAXONOMY
NAME - CHUB, BONYTAIL
OTHER COMMON NAMES - CHUB, BONYTAIL; BONYTAIL and COLORADO; BONYTAIL
ELEMENT CODE -
CATEGORY - Fish
PHYLUM AND SUBPHYLUM - CHORDATA,
CLASS AND SUBCLASS - OSTEICHTHYES,
ORDER AND SUBORDER - CYPRINIFORMES,
FAMILY AND SUBFAMILY - CYPRINIDAE,
GENUS AND SUBGENUS - GILA,
SPECIES AND SSP - ELEGANS,
SCIENTIFIC NAME - GILA ELEGANS
AUTHORITY -
TAXONOMY REFERENCES -
COMMENTS ON TAXONOMY -
Bonytail Chub
Gila elegans Baird and Girard, 1853
KINGDOM: Animal GROUP: Fish
PHYLUM: Chordata CLASS: Osteichthyes
ORDER: Cypriniformes FAMILY: Cyprinidae
The bonytail chub has a streamlined body which is elongated (01)
and somewhat laterally compressed. Its "elegant" (elegans) form is
due to this elongated shape, which is also expressed in its long,
thin caudle peduncle. The head of the fish is smaller and more
laterally compressed than the roundtail chub (G. robusta) and the
skull is dorsally concave. This concavity of the head is not as
pronounced as in the humpback chub (G. cypha), and the general body
outline is blended more smoothly into a predorsal hump (02). The
mouth is terminal and somewhat oblique (02). Fins are long and
falcate (01) with dorsal and anal rays numbering 10 or more (02).
Pharyngeal teeth are 2;5 to 4;2 (01). The species has 47 to 50
vertebrae and reaches a length of 30 centimeters or more (02). The
squamation may be incomplete with embedded scales on predorsum,
venter, or peduncle (02).
The adult bonytail chub is gray or olivaceous on the back and
Taxonomy - 1 (DRAFT) - Taxonomy
Species CHUB, BONYTAIL
Species Id ESIS256002
Date 13 MAR 96
has white sides and belly. When breeding, the males have reddish-
orange blotches between the paired fins (03), and breeding tubercles
on the rostrum. Females are not as brightly colored as the males and
the tubercles are less evident (03), however, a light orange
coloration may exist in both sexes near fin bases at any time (04).
Common names for this species include; bonytail chub (Federal
Register), bonytail (local Colorado), and the Colorado bonytail (local
Nevada).
There have been some difficulties associated with the
identification of bonytail chub, since the genus Gila is represented
by three endemic species (G. cypha, G. elegans, and G. robusta) in the
Colorado River, and all are similar. Although adults may be separated
from other species by gross morphology, there are no easy means to
distinguish between the young of the three species (05). The
existence of hybrids or "morphological integrades" has been suggested
by some experts (02,06,07), but the extent or significance of
potential hybridization between the three endemic species is unknown
(07).
A summary of the taxonomic record is provided as follows
according to Minckley (02):
As with some of the trouts, the synomicon of the "robusta
series" of the minnow genus Gila is complicated. Gila
elegans has been considered as a full species, a subspecies,
and an "ecotype", in the last two cases as a form of G.
robusta. Many records of the last, therefore, include G.
elegans and G. intermedia at least in part. These are
not included in the listing of previous records unless
especially pertinent.
Gila emoryi, Baird and Girard, 1853b: 338 Jordan and
Gilbert, 1883: 229.
Gila emorii, Girard, 1856: 205/ 1859a: Cope and Yarrow,
1875: 667. Jordan and Gilbert, 1883: 241 Kirsch, 1889:
558.
Gila elegans, Girard, 1856: 205/ 1858: 286/ 1859a: 61.
Jordan and Gilbert, 1883: 227. Jordan, 1885: 818/ 1891b:
22. Evermann and Rutter, 1895: 482. Jordan and Evermann,
1896: 226. Gilbert and Scofield, 1898: 492. Meek, 1904:
xxxix, 53. Snyder, 1915: 580. Jordan et.al., 1930: 114.
Evermann and Clark, 1931: 62. Moffett, 1942: 82/ 1943: 182.
Dill, 1944: 153. Rostland 1952: 270. Minckley and Alger,
1968: 94. Minckley and Deacon, 1968: 1427. Vanicek and
Kramer, 1969: 193. Rinne and Minckley, 1970: 18. Holden
and Stalnaker, 1970: 409. Minckley, 1971: 185.
Gila robusta elegans, Miller, 1945c: 104/ 1946c: 410/
1955: 131/ 1961a: 544/ 1961b: 373/ 1963a: 1. Wallis,
1951: 90. LaRivers, 1952: 101. 1962: 391. LaRivers and
Trelease, 1952: 116. Shapovalov, et al., 1959: 172.
Miller and Hubbs, 1960: 31. Follett, 1961: 216. Miller
and Lowe, 1964: 140/ 1967: 104. Uyeno and Miller, 1965: 39.
Cole, 1968: 471.
In the literature, (La Rivers, 1962) this species is addressed as
Taxonomy - 2 (DRAFT) - Taxonomy
Species CHUB, BONYTAIL
Species Id ESIS256002
Date 13 MAR 96
Leuciscus elegans, Gunther, 1968.
At this point in time there have been no any further taxonomic
changes in reference to this species.
Taxonomy - 3 (DRAFT) - Status
Species CHUB, BONYTAIL
Species Id ESIS256002
Date 13 MAR 96
STATUS
Coded Status
E: Federal Endangered
Game (Consumptive Recreational)
COMMENTS ON STATUS -
U.S. STATUSES AND LAWS:
The bonytail chub (Gila elegans) 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, Nevada, Wyoming, and Utah.
This species is protected by the Lacey Act (P.L. 97-79, as
amended; 16 U.S.C. 3371 et seq.) which makes it unlawful to import,
export, transport, sell, receive, acquire, or purchase any wild animal
(alive or dead including parts, products, eggs, or offspring):
(1) in interstate or foreign commerce if taken, possessed,
transported or sold in violation of any State law or
regulation; or
(2) if taken or possessed in violation of any U.S. law,
treaty, or regulation or in violation of Indian tribal law.
It is also unlawful to possess any wild animal (alive or dead
including parts, products, eggs, and offspring) within the U.S.
territorial or special maritime jurisdiction (as defined in
18 U.S.C. 7) that is taken, possessed, transported, or sold in
violation of any State law or regulation, foreign law, or Indian
tribal law.
RESPONSIBLE FEDERAL AGENCIES:
USFWS -Responsible for the management/recovery, listing, and
law enforcement/protection of this species.
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.
Status - 1 (DRAFT) - Status
Species CHUB, BONYTAIL
Species Id ESIS256002
Date 13 MAR 96
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).
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
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: 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
Status - 2 (DRAFT) - Status
Species CHUB, BONYTAIL
Species Id ESIS256002
Date 13 MAR 96
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:
The bonytail chub is listed as Endangered in the IUCN Red Data
Book, Vol. 4, 1977.
ECONOMIC STATUSES:
The bonytail chub has no known negative economic value and had
some historical importance concerning recreational fishing.
78/04/24:43 FR 17375/17377 - Proposed Endangered
79/03/06:44 FR 12382/12384 - Supplemental proposal
80/04/23:45 FR 27710/27713 - Listing as Endangered
83/05/02:48 FR 19789/19790 - Permit applic.; San Diego Zoo et al.
85/07/22:50 FR 29901/29909 - Five year review
Status - 3 HABITAT ASSOCIATIONS
HABITAT - AQUATIC
INLAND AQUATIC
LAND USE -
Transportation, communications, and Util
Cropland and Pasture
Orchards, Groves, Vineyards, Nurseries,
Shrub and Brush Rangeland
Mixed Rangeland
Streams and Canals
Reservoirs
NATIONAL WETLAND INVENTORY CODES
NWI NWICLS NWIMOD NWISPEC
Riverine, upper perennial SB2
Riverine, upper perennial SB1
Riverine, lower perennial SB2
Riverine, lower perennial SB1
Lacustrine, littoral UB2
Lacustrine, littoral UB1
COMMENTS ON HABITAT ASSOCIATIONS -
The bonytail chub presently exists in very low numbers in its
natural riverine and manmade reservoir habitat. In riverine areas
the species is considered a "big-river" or mainstream fish since few
have ever been captured in small tributaries (03). In the Green
River, Vanicek (04) noted that the species used pools and eddies
instead of faster current.
In reservoirs, bonytails are found more in lacustrine rather than
riverine habitat (02), but very little is known about their habitat
requirements. Apparently reproduction does not occur in reservoirs
since no young have ever been recovered and fish aged from reservoirs
are quite old (03), possibly living there since the reservoirs were
filled.
Specific environmental parameters required in nature are unknown
for this species. There is some hatchery information suggesting that
water temperature colder than 17 degrees Celsius results in heavy egg
mortality (10).
Terrestrial habitats/areas within the range of the bonytail chub
that may impact the riverine habitat include; transportation/utility/
communication corridors and facilities, shrub/brush 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 CHUB, BONYTAIL
Species Id ESIS256002
Date 13 MAR 96
FOOD HABITS
TROPHIC LEVEL -
OMNIVORE
LIFESTAGE FOOD FOOD PART
General Phytoplankton
General Algae
General Zooplankton
General Crustaceans
General Arthropods
Food Habits - 1 (DRAFT) - Environment Associations
Species CHUB, BONYTAIL
Species Id ESIS256002
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 Aquatic Features: Pool areas
Environment Associations - 1 (DRAFT) - Life History
Species CHUB, BONYTAIL
Species Id ESIS256002
Date 13 MAR 96
LIFE HISTORY
FOOD HABITS:
The bonytail chub is generally considered to be an insectivore
(05), however, little information is available on specific food
habits. Young chubs (G. robusta and G. elegans) presumably eat
chironomid larvae and mayfly nymphs in the Green River where juveniles
consumed terrestrial and aquatic insects and the adults consumed
terrestrial insects, plant debris, and filamentous algae (04). No
other information is known on river feeding preferences, but the
species is reported to eat plankton and algae in reservoir habitat
(02).
HOME RANGE/TERRITORY:
No information is available on this subject.
PERIODICITY:
No information is available on this subject.
MIGRATION PATTERNS:
No information is available on this subject.
COVER/SHELTER REQUIREMENTS:
No information is available on this subject.
REPRODUCTIVE SITE REQUIREMENTS:
Spawning has never been observed in riverine habitats, however,
collection of "ripe" fish indicate that the species prefers canyon
habitat (04). Fertile fish were collected in the upper Green River
in late June and early July at a water temperature of 18 degrees
Celsius (04). Spawning behavior observed in Lake Mohave (11)
indicated that the fish attempted to spawn on gravel bars in water
depths up to 9 meters, however, no young have ever been recovered from
Lake Mojave. Spawning at water temperatures of about 20 degrees
Celsius in a hatchery resulted in the best survivorship rate of the
eggs (10).
REPRODUCTIVE CHARACTERISTICS:
The species breeding behavior has only been observed in Lake
Mojave (11). Approximately 500 fish congregated over a gravel bar
in 9 meters of water. The male to female ratio was documented at
2:1 (10). Females were escorted by 3-5 males and eggs were deposited
randomly with no indication of parental care. Eggs fertilized in a
hatchery and incubated at 20 degrees Celsius hatched (90 percent
hatch rate) in 170 to 269 hours (10).
PARENTAL CARE:
No information is available on this subject.
POPULATION BIOLOGY:
No information is available on this subject.
SPECIES INTERRELATIONSHIPS:
Life History - 1 (DRAFT) - Life History
Species CHUB, BONYTAIL
Species Id ESIS256002
Date 13 MAR 96
Although bonytail and roundtail chubs (G. robusta) were found in
association (12), their relationships are unknown.
No information is available on this subject.
OTHER LIFE HISTORY DESCRIPTORS:
No information is available on this subject.
Life History - 2 (DRAFT) - Management Practices
Species CHUB, BONYTAIL
Species Id ESIS256002
Date 13 MAR 96
MANAGEMENT PRACTICES
RESULT MANAGEMENT PRACTICE
Beneficial Regulating Water Temperature
Beneficial Maintaining/Controlling Water Flow
Beneficial
Beneficial Controlling/Restricting Mining
Beneficial Maintaining undisturbed/undeveloped areas
Beneficial Stocking captive-reared wild-strain animals
Beneficial Controlling/Removing Exotic Vertebrates
Adverse Surface Mines
Existing Surface Mines
Adverse Siltation
Existing Siltation
Adverse Water Temperature Alteration
Existing Water Temperature Alteration
Adverse Incidental Capturing/Killing
Existing Incidental Capturing/Killing
Adverse Water Level Stabilization
Existing Water Level Stabilization
Adverse Water Level Fluctuation
Existing Water Level Fluctuation
Adverse Irrigating
Existing Irrigating
Adverse Reservoirs
Existing Reservoirs
Adverse Exotic/Feral/Introducted Species
Existing Exotic/Feral/Introducted Species
Adverse Low Gene Pool
Existing Low Gene Pool
COMMENTS ON MANAGEMENT PRACTICES -
The bonytail chub declined in numbers during the first half of
this century in the lower Colorado River Basin. The species became
very rare by 1942 (08) and was not found in: the Salt River, AZ by
1926; and both the Colorado and Gila Rivers near Yuma, AZ by 1950
(03). Reasons stated for the loss of this fish from the lower basin
of the Gila River were given by Miller (08), and included: flow
depletions, dams, mining impacts and the resulting siltation,
incidental capture, and the introduction of exotic fish. Loss of
riverine habitat is cited as the single main factor in the decline of
the bonytail chub in the lower Colorado River Basin in general (03).
The decline of this species in the upper Colorado River Basin
has been more recent and swift. One area where the chub was taken in
any number was below the present site of Flaming Gorge Dam on the
Green River. The impoundment of that dam in 1962, and a
preimpoundment fish eradication program effectively eliminated the
bonytail chub from that location (09). According to Vanicek, et al.
(09), the loss of the species below Flaming Gorge Dam was due to flow
and temperature alterations.
Presently, the fish is very rare and at low population numbers
Management Practices - 1 (DRAFT) - Management Practices
Species CHUB, BONYTAIL
Species Id ESIS256002
Date 13 MAR 96
impacting the ability of the species to effectively reproduce and,
therefore, there seems to exist a rather low gene pool. Changes in
the river flow regimes may be forcing G. robusta, and G. elegans to
reproduce in closer proximity (03).
APPROVED PLAN:
U.S. Fish and Wildlife Service. 1984. Bonytail Chub Recovery
Plan. U.S. Fish and Wildlife Service, Denver, CO. 52 pp.
The immediate goal of the Bonytail Chub Recovery Plan is to
prevent extinction of the species. The primary goal is to establish
and maintain at least four viable, self-sustaining populations.
Delisting will be considered when a total of six naturally self-
sustaining populations are secured and their natural habitats are
legally protected. Objectives to accomplish these goals include;
determination of status, life history information, identifying threats
to the species, protection of any riverine populations and their
habitat, captive propagation/reintroduction and monitoring programs,
habitat improvement, enforcement of laws protecting the species, and
the development of information and education programs through
publications and workshops (03).
The protection of riverine populations and their habitat
includes: Controlling or removing exotic vertebrates, restricting
development, and controlling mining activities. Habitat improvement
objectives include the regulation of the water regime concerning
original/optimum flow, temperature, and salinity (03).
Recovery activities currently ongoing include; research into life
history and habitat characteristics, hatchery propagation (Willow
Beach and Dexter Hatcheries; R-2); and reintroduction of the species
to suitable habitat (Lake Mojave; R-2).
Management Practices - 2 (DRAFT) - References
Species CHUB, BONYTAIL
Species Id ESIS256002
Date 13 MAR 96
References
***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCURRENCE *****
01 Jordon, D.S. and B.W. Evermann. 1896. The fishes of north and
middle America. Bull. U.S. Nat. Mus. 47(1):1-1240.
02 Minckley, W.L. 1973. The fishes of Arizona. Arizona Game and
Fish Comm. Phoenix, AZ. 292 pp.
03 U.S. Fish and Wildlife Service. 1985. Bonytail Chub Recovery
Plan. Colorado River Fishes Recovery Team and Region 6, U.S. Fish
and Wildlife Service; Denver, CO.
04 Vanicek, C.D. 1967. Ecological studies of native Green River
fishes below the Flaming Gorge Dam; 1964-1966. Ph.D. dissertation
Utah State Univ; Logan, UT.
05 Valdez, R.A. and G.H. Clemmer. 1982. Life history and prospects
for recovery of the humpback and bonytail chub. P 109-119. In:
Miller et al. (eds) Fishes of the upper Colorado River system,
present and future. Western Division of the American Fisheries
Society; Bethesda, MD.
06 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.
07 Smith, G.R., R.R. Miller, and W.D. Sable. 1979. Species
relationships among fishes of the genus Gila in the upper Colorado
River drainage. P. 613-623. In: Linn, R.M. (ed). Proceedings of
the first conference on scientific research in the National Parks.
U.S. Department of the Interior, National Park Service, Washington,
D.C.
08 Miller, R.R. 1961. Man and the changing fish fauna of the
American southwest. Michigan Acad. of Sci., Arts, and Letters.
46:365-404.
09 Vanicek, C.D., R.H. Kramer, and D.R. Franklin. 1970. Distribution
of Green River fishes in Utah and Colorado following closure of
Flaming Gorge Dam. Southwestern Naturalist 14(3):297-315.
10 Hamman, R.L. 1982. Induced spawning and culture of bonytail chub.
P. 169-175. In: U.S. Fish and Wildlife Service and Bureau of
Reclamation. Colorado River Fish Project. Part 3. 324 pp.
11 Jonez, A. and R.C. Sumner. 1954. Lakes Mead and Mohave
investigations, a comparative study of an established reservoir as
related to a newly created impoundment. Fed. Aid Proj. F-1-R.
Nevada Fish and Game Dept.; Reno, NV.
12 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;
1964-1966. Transactions of the Am. Fish. Soc. 98(2):193-208.
***** REFERENCES FOR N-OCCURRENCE NARRATIVE ONLY *****
01 Jordon, D.S. 1891. Report of exploration in Colorado and Utah
during the summer of 1889, with an account of the fishes found in
each of the river basins examined. Bull. U.S. Fish Comm. 9:1-40.
References - 1 (DRAFT) - References
Species CHUB, BONYTAIL
Species Id ESIS256002
Date 13 MAR 96
02 Jordon, D.S. and B.W. Evermann. 1896. The fishes of north and
middle America. Bull. U.S. Nat. Mus. 47(1):1-1240.
03 Smith, G.R., R.R. Miller, and W.D. Sable. 1979. Species
relationships among fishes of the genus Gila in the upper Colorado
River drainage. P. 613-623 In: Linn, R.M. (ed). Proceedings of
the first conference on scientific research in the National Parks.
U.S. Department of the Interior, National Park Service, Washington,
D.C.
04 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.
05 U.S. Fish and Wildlife Service. 1985. Bonytail Chub Recovery
Plan. Colorado River Fishes Recovery Team and Region 6, U.S. Fish
and Wildlife Service; Denver, CO.
06 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.
07 Kaeding, L.R. 1984. Pers. comm. U.S. Fish and Wildlife Service;
Grand Junction, CO.
08 Valdez, R.A. and G.H. Clemmer. 1982. Life history and prospects
for recovery of the humpback and bonytail chub. P. 109-119. In:
Miller et al. (eds) Fishes of the upper Colorado River system,
present and future. Western Division of the American Fisheries
Society; Bethesda, MD.
09 U.S. Fish and Wildlife Service. 1986. Endangered species
technical bulletin. Vol. XI, No. 4, April 1986. USDI, USFWS,
Endangered Species Program. Washington DC. 12 pp.
References - 2