(DRAFT) - Taxonomy
Species CHUB, CHIHUAHUA
Species Id ESIS252017
Date 14 MAR 96
TAXONOMY
NAME - CHUB, CHIHUAHUA
OTHER COMMON NAMES - CHUB, CHIHUAHUA;TROUT and GILA;TROUT; SUCKER
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 - NIGRESCENS,
SCIENTIFIC NAME - GILA NIGRESCENS
AUTHORITY -
TAXONOMY REFERENCES -
COMMENTS ON TAXONOMY -
Chihuahua Chub
Gila nigrescens (Girard, 1857)
KINGDOM: Animal GROUP: Fish
PHYLUM: Chordata CLASS: Osteichthyes
ORDER: Cypriniformes FAMILY: Cyprinidae
The Chihuahua chub averages 5-6 inches in length at maturity but
may reach 12 inches. Typical of the genus Gila, the origin of the
dorsal fin is behind that of the pelvic fins. The number of scales
along the lateral line ranges from 67 to 78. This species is dusky
brown above and whitish below. An orange-red color develops around
the mouth and around the pectoral and pelvic fins and on the belly
during the reproductive season. The lateral line is deflexed on the
middle of the body. Scales are sub-elliptical with radii developed
in the posterior field. The dorsal, anal, and pelvic fin rays
usually number 9,8, and 9 respectively. The greater body depth is
contained about five times in the total length. The diameter of the
eye is contained about five and one half times in the length of the
head. The mouth is small with the posterior extremity of the
maxillary bone not extending to the anterior rim of the orbit. The
pharyngeal teeth are 2, 5-4, 2 (10,11,12). Post-larval Gila
Taxonomy - 1 (DRAFT) - Taxonomy
Species CHUB, CHIHUAHUA
Species Id ESIS252017
Date 14 MAR 96
nigrescens are characterized by a spot above the lateral line,
immediately preceding the caudal fin (01,02).
This species was first described as Gila pulchella by Baird and
Girard (03). A secondary homonym, Gila pulchellus, was proposed by
Gunther (05). Subsequent names applied to the species include:
Tigoma nigrescens (04); and Leuciscus nigrescens (06). Due to
taxonomic revision of the Genus Gila, a conflict with homonyms
developed, and the present name Gila nigrescens was adopted, with the
Rio Janos at Boca Grande, Chihuahua, Mexico, recognized as the type
locality. While the name Gila nigrescens has also been applied by
various authors (07) to the chub that resides in the Rio Grande and
Pecos drainages, that species (the Rio Grande chub, Gila pandora) is
quite distinct and should not be confused with the true G. nigrescens
of the Guzman drainage. Througout the southwest chubs are often
referred to as "trout". The Chihuahua chub has been referred to as
the "Gila trout" and "sucker" (09).
Various preserved specimens of Gila nigrescens are maintained as
follows:
Site: Museum Location: Specimen #:
Rio Casas Grandes Arizona State ASU 816
about 21 km southwest University UANL 588
of Ascension
Rio Padres Verdes near University of Michigan UMMZ 182401
Colonia Juarez Museum of Vertebrate
Zoology
Rio Santa Maria at Arizona State Univ. UANL 1850
Ana de Bavicora
Rio del Carmen near Arizona State Univ. UANL 2223
Ahumada
Arroyo Miguel Chiquito Arizona State Univ. UANL 2493
Arroyo San Antonio Arizona State Univ. UANL 552
Taxonomy - 2 (DRAFT) - Status
Species CHUB, CHIHUAHUA
Species Id ESIS252017
Date 14 MAR 96
STATUS
Coded Status
T: Federal Threatened
Commercial/consumption
Game (Consumptive Recreational)
Ceremonial/Cultural
COMMENTS ON STATUS -
U.S. STATUSES AND LAWS:
The Chihuahua chub (Gila nigrescens) has been designated an
Threatened 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 State of New Mexico and Chihuahua, Mexico.
Special rules concerning "take" for this species can be found
in 50 CFR 17.44(g).
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 foreign law; 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.
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:
Status - 1 (DRAFT) - Status
Species CHUB, CHIHUAHUA
Species Id ESIS252017
Date 14 MAR 96
STATE: New Mexico
DESIGNATED STATUS: Endangered
ADMINISTRATIVE AGENCY: New Mexico Department of Fish and Game
STATE STATUTE: Regulation 624, Section 17-2-41 NMSA (1978);
Updated March 28, 1985.
INTERNATIONAL STATUSES, TREATIES, AND AGREEMENTS:
Listed as Endangered (for the U.S., and undetermined for Mexico)
in the IUCN Red Book (1979 edition).
ECONOMIC STATUSES:
Oldtimers in the Mimbres Valley angled for the Chihuahua chub,
which was locally known as the "Gila trout". It is also likely
that the ancient Mimbres Indians took Chihuahua chubs as food, as
their pottery depicts fish that resemble the species. In fact,
judging from pottery motifs, it would appear that the Mimbres River
once supported a notably greater diversity of species. The Mimbres
Indians inhabited the Mimbres Valley from AD 200 until around AD 1150.
Why designs of fish were so often used on Mimbres Indian burial bowls
is not known. Of those bowls depicting animals, approximately
one-third display fish.
80/12/15:45 FR 82474/82477 - Proposed Rule
83/10/11:48 FR 46053/46057 - Final Rule - Listed as Threatened.
Status - 2 HABITAT ASSOCIATIONS
HABITAT - AQUATIC
INLAND AQUATIC
LAND USE -
Residential
Cropland and Pasture
Orchards, Groves, Vineyards, Nurseries,
Herbaceous Rangeland
Shrub and Brush Rangeland
Mixed Rangeland
Deciduous Forest Land
Mixed Forest Land
Streams and Canals
NATIONAL WETLAND INVENTORY CODES
NWI NWICLS NWIMOD NWISPEC
Riverine, intermittent UB4
Riverine, intermittent UB3
Riverine, intermittent UB2
Riverine, intermittent UB1
4BB
Riverine, intermittent BB1
Riverine, lower perennial UB4
Riverine, lower perennial UB3
Riverine, lower perennial UB2
Riverine, lower perennial UB1
Riverine, lower perennial SB4
Riverine, lower perennial SB3
Riverine, lower perennial SB2
Riverine, lower perennial SB1
Riverine, lower perennial BB1
Palustrine AB1
COMMENTS ON HABITAT ASSOCIATIONS -
Miller (07) has provided the most comprehensive descriptions
of habitat associations for Gila nigrescens. Some combination of
habitat factors including pools at least one meter deep, shade, and
undercut banks or other cover features, including downed logs,
submerged shrubs, etc., were necessary adult habitat requirements.
These fish are usually found in streams over a substrate of sand,
gravel, and cobble with some occasional fine mud or silt (07, 12).
Habitat of this type apparently provides both escape cover and
suitable foraging (09). In addition, Miller (07) states that although
a constant flow of water may be optimum, it may not be necessary in
that Gila nigrescens appears to be able to survive and spawn in
isolated pools of water. Juveniles tend to occupy shallower habitats
with or without cover (07). There is no substantive information
about predation or competition from introduced exotic fish species;
however, the presence of these species cannot be considered
beneficial to Gila nigrescens (07).
Bednarz (12) reports some physical and chemical data on the
water quality from the Mimbres River. This data was taken in the
vicinity of the Mimbres Ranger Station about two miles north of the
northern-most present occurrence of Gila nigrescens at an elevation
of about 6000 feet: annual precipitation = 15.74 in.; annual mean air
temperature = 51 degrees F; water temperature = 38.3-75.2 degrees F;
Habitat Associations - 1 pH = 7.8-8.6; specific conductance (micro-ohms) = 164-303; turbidity
(JTU) = 1-10; hardness = 75-140 mg/l; dissolved oxygen (on 6/5/75) =
8.0 mg/l. Monthly mean discharges (in c.f.s.) at the town of Mimbres in
1978 were as follows:
Month Discharge (c.f.s.)
March 71.00
April 22.10
May 11.60
June 8.96
July 4.97
August 3.61
September 2.64
Gila nigrescens has been found in association with aquatic
vegetation including Potamogeton sp., Hydrocotyle sp., Rorippa sp.,
Nasturtium sp., Lemna sp., Marsallia sp., Chara sp., Spirogyra sp.,
and Cladophora sp..
The habitat around this three miles of stream is highly diverse
in cover types. About 20-30% is apple orchards; 20-30% pasture (this
includes areas of hay production); 5-10% residential housing; 5-10
pct. "Spanish" gardens - a mixture of crop types such as - corn,
vegetables, fruit, and grapes (this area is heavily irrigated); and
about 5% is natural riparian vegetation (20). Riparian vegetation
includes broadleaf cottonwood, narrowleaf cottonwood, lanceleaf
cottonwood (a cross between the other two species) (Populus sp.);
coyote willow (Salix exigua), arroyo willow (Salix lasiolepis), and
others (Salix sp.); Arizona sycamore (Plantanua wrighitii), Arizona
alder (Alnus oblongifolia); Arizona walnut (Juglans californica);
elder (Sambucus sp.); live oak (Quercus sp.), juniper (Juniperus sp.);
Arizona grape; and a broad range of grasses, forbes, and sage brush
(i.e. these grass areas serve as secondary rangeland for cattle) (20).
Habitat Associations - 2 (DRAFT) - Food Habits
Species CHUB, CHIHUAHUA
Species Id ESIS252017
Date 14 MAR 96
FOOD HABITS
TROPHIC LEVEL -
OMNIVORE
LIFESTAGE FOOD FOOD PART
General Detritus
General Phytoplankton
General Diatoms
General Algae
General Floating aquat. plant
General Vascular Plants-Emergent Nonwoody
General Vascular Plants-Submerged Nonwoody
General Zooplankton
General Arthropods
General Worms
Food Habits - 1 (DRAFT) - Environment Associations
Species CHUB, CHIHUAHUA
Species Id ESIS252017
Date 14 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 Aquatic Features: Pool areas
G Terrestrial Features: Downed logs
Environment Associations - 1 (DRAFT) - Life History
Species CHUB, CHIHUAHUA
Species Id ESIS252017
Date 14 MAR 96
LIFE HISTORY
FOOD HABITS:
With exception of the statement by Hatch (09) that Gila
nigrescens probably feeds on surface insects, aquatic invertebrates,
and some vegetation, little else is known about the food habits of
this species (12). For purposes of comparison, Hardy (13) noted that
Gila robusta jordani in Ash Springs, Nevada rejected offered
invertebrates but readily consumed the algae Spirogyra. Cross (14)
found that filamentous algae comprised 90 % of the volume of the gut
contents of Gila robusta seminuda in the Virgin River with
invertebrates occupying the other 10 %. Gila robusta in the Colorado
River drainage are generally omnivorous (14, 15). The young of Gila
robusta in the Colorado River are primarily insectivorous shifting
more to plant material as they mature (15). This same pattern is
exhibited by Gila robusta seminuda in the Virgin River (16) and Gila
robusta ssp. in the Moapa River (20). Stomach contents of adult
Gila cypha primarily contained Chironomids and Simuliids (17). Gila
elegans is generally considered to be an insectivore (18). Assuming
a degree of omnivory, it is most likely that this chub also consumes
detritus, phytoplankton, diatoms, zooplankton, worms, and also
vascular plants.
HOME RANGE/TERRITORY:
No information is available concerning territoriality of this
species. In addition, no significant information exists concerning
territoriality for any other species of endangered western chub.
PERIODICITY:
No information is available concerning periodicity of this
species. For purposes of comparison, adult Gila robusta jordani
occupied a single, preferred habitat from January 1979 to
September 1981. They left this site only in February and March.
Such movement suggests seasonal spawning (13).
MIGRATION PATTERNS:
No information is available concerning migration of this
species. Gila robusta jordani (13), Gila cypha (17), and Gila
elegans are also considered non-migratory.
COVER/SHELTER REQUIREMENTS:
Miller (07) has noted that Gila nigrescens is most abundant in
habitats which include pools to about one meter deep, with riparian
and submerged cover, shade, undercut banks and submerged shrubs.
Juveniles apparently are more often found in shallow water with or
without cover. This species is usually found in streams over a
substrate of sand, gravel, and cobble with some occasional fine mud
or silt (12). For purposes of comparison, Gila robusta jordani
adults prefer deep pools with a slow current (13) while Gila cypha is
found in canyon habitats associated with deep (15 m), fast water over
boulder substrates. Baugh et al. (19) have summarized the
information on the site requirements of Gila robusta jordani from Ash
Springs, Nevada, Gila robusta seminuda from the Virgin River, Nevada,
Life History - 1 (DRAFT) - Life History
Species CHUB, CHIHUAHUA
Species Id ESIS252017
Date 14 MAR 96
and Gila robusta ssp. from the Moapa River, Nevada as follows:
"Deacon and Bradley (1972) found Gila robusta ssp. from the Moapa
River to be most often associated with a firm bottom of clay with
rock riffles. Cross (1978) found Gila robusta seminuda in the
Virgin River to be most often associated with bottoms of sand and
silt (70%) and, less commonly (30%), associated with gravel and
rubble. Cross (1978) also found G. r. seminuda more often in runs
and less commonly (35%) in pools and riffles. In terms of riparian
cover, most of the G. r. seminuda captured by Cross (1978) were taken
from areas of cover including boulders, deadfalls, overhanging trees
and/or undercut banks."
REPRODUCTIVE SITE REQUIREMENTS:
Hatch (09) suggests that spawning takes place in water about
1-2.5 meters deep, in quiet pools, over matted beds of aquatic
vegetation. On March 17, 1979, ten Gila nigrescens from the Mimbres
River were placed in ponds at the Dexter National Fish Hatchery where
they have increased to over 1,000 fish. These fish spawned naturally
in 1/10 acre ponds about 1 m deep on a gravel, rock substrate.
REPRODUCTIVE CHARACTERISTICS:
Very little is known about the reproductive biology of Gila
nigrescens. Apparently, this fish spawns over an extended period
from spring through summer (12) with spawning in the Mimbres River
taking place in late April and May (12). Miller and Chernoff (07)
have suggested a possible bimodal spawning periodicity.
PARENTAL CARE:
No information exists on parental care by this species. Such
care is unlikely and is not exhibited by other species of Gila.
POPULATION BIOLOGY:
Very little information exists about the population biology of
this species. Limiting factors appear to be related to habitat
degradation with the possibility of predation and/or competition from
introduced exotic fishes.
SPECIES INTERRELATIONSHIPS:
Gila nigrescens exists sympatrically with the following native
species: Catostomus plebius, Pimephales promelas, Notropis formosus,
Campostoma ornatum, and a Cyprinodon sp.. Introduced exotic species
include Cyprinus carpio, Ictalurus melas, Salmo gairdneri, Agosia
chrysogaster (01), and Gambusia affinis (07). No information exists
which would indicate the positive or negative nature of the
relationship of any of these species with Gila nigrescens. The
introduction of exotic fishes has been related to competition,
predation, hybridization, and disease by a number of authors for
numerous other species.
OTHER LIFE HISTORY DESCRIPTORS:
No additional information is available for this species.
Life History - 2 (DRAFT) - Management Practices
Species CHUB, CHIHUAHUA
Species Id ESIS252017
Date 14 MAR 96
MANAGEMENT PRACTICES
RESULT MANAGEMENT PRACTICE
Beneficial Developing/maintaining stream structures
Beneficial Maintaining/Controlling Water Flow
Beneficial Controlling water levels
Beneficial Land Acquisition
Beneficial Water Right Acquisition
Beneficial Controlling pollution [thermal, chemical, physical]
Beneficial Creating Artificial Habitat/Nesting Structure
Beneficial Reforestation
Beneficial Restricting Timber Harvest
Beneficial Stocking captive-reared wild-strain animals
Beneficial Controlling/Restricting Noncommercial Harvest
Beneficial Controlling/Removing Exotic Vertebrates
Adverse Food Supply Reduction
Existing Food Supply Reduction
Adverse Predation
Existing Predation
Adverse Rural Residential/Industrial Areas
Existing Rural Residential/Industrial Areas
Adverse Siltation
Existing Siltation
Adverse Water Temperature Alteration
Existing Water Temperature Alteration
Adverse Dissolved Oxygen Reduction
Existing Dissolved Oxygen Reduction
Adverse Water Level Stabilization
Existing Water Level Stabilization
Adverse Water Level Fluctuation
Existing Water Level Fluctuation
Adverse Flooding
Existing Flooding
Adverse Irrigating
Existing Irrigating
Adverse Reservoirs
Existing Reservoirs
Adverse Dredging
Existing Dredging
Adverse Developing/maintaining stream bank vegetation
Existing Developing/maintaining stream bank vegetation
Adverse Applying fertilizers
Existing Applying fertilizers
Adverse Environmental Contamination/Pollution
Existing Environmental Contamination/Pollution
Adverse Exotic/Feral/Introducted Species
Existing Exotic/Feral/Introducted Species
Adverse Erosion
Existing Erosion
Adverse
Existing
Adverse Vegetation Composition Changes
Management Practices - 1 (DRAFT) - Management Practices
Species CHUB, CHIHUAHUA
Species Id ESIS252017
Date 14 MAR 96
RESULT MANAGEMENT PRACTICE
Existing Vegetation Composition Changes
Adverse Forest Alteration
Existing Forest Alteration
Adverse Harvesting
Existing Harvesting
COMMENTS ON MANAGEMENT PRACTICES -
Miller (07) and others (02) report that the reduction in
abundance and distribution of Gila nigrescens throughout its range is
due, primarily, to habitat alteration including groundwater mining,
channelization, water diversion, deforestation (causing erosion,
siltation and water temperature alteration), and pollution.
Severe flooding caused by degradation of the watershed and loss of
riparian vegetation has contributed to the decline of this species as
has the channelization of the Mimbres River by land owners in order
to protect from flooding (01). Antisell (08) reports that in 1850
the terminus of the Mimbres River was composed of a series of pools
or lagoons surrounded by willow (Salix sp.). In addition, from four
to six miles above the terminus, the river was up to 2.5 feet deep
and flowed at a rate of up to 2.5 miles per hour in the summer (08).
Presently, the terminus of the Mimbres River is usually dry (01).
In the State of Chihuahua, Mexico, the Rio Casas Grandes about
21 km southwest of Ascension is badly polluted, the pools stagnant
and choked with Spirogyra and other algae, flow is minimal and
riffles are absent (this leads to reduced dissolved oxygen) (07).
In the Rio Casas Grandes just east of Casas Grandes proper,
the river is sluggish, murky, strewn with trash, and choked
with Spirogyra and narrow-leafed Potamogeton (07). In the Rio
San Miguel at Ignacio Zaragoza the river channel has been dredged and
levees built. The water at this site is murky, less than 5 cm deep,
and without noticable current (07). The Rio Santa Maria at Bachiniva
is, in places, used as a garbage dump (07). Water in the Rio del
Carmen near Ahumada has been diverted for irrigation and no longer
flows in the river channel (07). The Rio del Carmen near Ricardo
Flores Magon is dry due to the presence, about ten km upstream, of an
earthen dam and hydroelectric power plant (07). In the Laguna
Bustillos Basin, Arroya Miguel Chiquito was dry and the waters in
Arroyo San Antonio were polluted (07).
A number of exotic fishes have been introduced within the range
of Gila nigrescens including Agosia chrysogaster and Salmo gairdneri
in the Mimbres River (01), Cyprinus carpio and Ictalurus melas in Rio
Casas Grandes, Ictalurus melas and Ambloplites rupestris in Rio
Piedras, Gambusia affinis in Rio Santa Maria near Buenaventura, and
Cyprinus carpio in Rio Santa Maria at Santa Ana de Bavicora (07).
There is no substantive information about predation or competition
from introduced exotic fish species; however, the presence of these
species cannot be considered beneficial to Gila nigrescens (07).
APPROVED PLAN:
Management Practices - 2 (DRAFT) - Management Practices
Species CHUB, CHIHUAHUA
Species Id ESIS252017
Date 14 MAR 96
U.S. Fish and Wildlife Service. 1986. Chihuahua Chub Recovery Plan.
U.S. Fish and Wildlife Service, Albuqerque, NM. 47 pp.
The prime objective of the recovery plan is to improve the status
of the Chihuahua chub to the point that survival is secured through
viable populations established and maintained in the wild.
Maintenance and enhancement of existing Chihuahua chub populations and
their habitats should include annual monitoring of:
1. Chihuahua chub populations (numbers, conditions, and age
structure of fish), and
2. the condition of their habitat, which should also include
evaluation of proposed activities, such as reclamation,
activities, logging, grazing, new roads, cropland
irrigation, and the use of chemical agents.
It is also important to reclaim and perpetuate habitat essential to
the Chihuahua chub, since channelization has made the Mimbres River
unfavorable habitat for Chihuahua chubs. This should involve:
1. determination of preferred chub habitat,
2. providing flood protection to private property which is
consistent with the needs of the chub,
3. recreation of chub habitat (i.e., pool excavation), and
4. providing of protection for and enhancement of existing
suitable habitats (this might include land acquisition
or water right acquisition).
Human activities in the proximity of the Chihuahua chub habitat should
be regulated, including the following measures:
1. banning the introduction of non-native fishes;
2. prohibiting the taking of minnows for bait purposes, since
identification of Chihuahua chubs is difficult; and
3. providing or limiting permanent irrigation diversions which
are consistent with the needs of the chub.
The propagation stock at Dexter NFH should be maintained to
provide offspring for stocking purposes and to maintain a reserve gene
pool, should the natural population be extirpated. The stock should
be supplemented every two years with wild Mimbres River Chihuahua
chubs to maintain the genetic integrity of the species. The genetic
diversity between U.S. and Mexican populations of Chihuahua chub
should be determined. The Chihuahua chub should be reestablished
within its former range in New Mexico where suitable habitat presently
exists or can be created and maintained. These introductions should
be monitored to document reproductive success and population
parameters. Finally, public awareness of the uniqueness of the
Chihuahua chub should be increased through the preparation of
information pamplets, interpretive programs, and use of the broadcast
and print media.
Ongoing recovery efforts: None at present.
Management Practices - 3 (DRAFT) - References
Species CHUB, CHIHUAHUA
Species Id ESIS252017
Date 14 MAR 96
References
***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCURRENCE *****
01 U.S. Fish and Wildlife Service. 1986. Chihuahua Chub Recovery
Plan. USFWS, Albuquerque, New Mexico. 47 pp.
02 U.S. Government. 1983. Endangered and threatened wildlife and
plants; Threatened status for Gila nigrescens (Chihuahua chub).
Fed. Reg. 48(197):46053-46057.
03 Baird, S.F. and C. Girard. 1854. Description of new species of
fishes collected in Texas, New Mexico, and Sonora, by Mr. John H.
Clark, on the U.S. and Mexican Boundary Survey, and in Texas by
Capt. Stewart Van Vilet, U.S.A. Proc. Acad. Nat. Sci. Phila.
7:24-29.
04 Girard, C. 1856. Researches upon Cyprinoid fishes inhabiting the
freshwaters of the United States of America, west of the
Mississippi Valley, from specimens in the museum of the
Smithsonian Institution. Proc. Acad. Nat. Sci. Phila. 8:165-213.
05 Gunter, A. 1868. Catalog of the fishes in the British Museum.
London 7:XX + 512 pp.
06 Jordan, D.S. and B.W. Everman. 1896. The fishes of North and
Middle America. Bull. U.S. Nat. Mus. 47(1):I-IX, 1-1240.
07 Miller, R.R. and B. Chernoff. 1979. Status of populations of the
endangered Chihuahua chub, Gila nigrescens, in New Mexico and
Mexico. IN: Proc. Desert Fish. Council XI:74-84.
08 Antisell, T. 1856. Geological report. IN: Pacific Railroad Expl.
Surv. 7(2):1-204.
09 Hatch, M.D. 1980. Management plan for the Chihuahua chub, Gila
nigrescens (Girard 1856) in New Mexico. Unpubl. Rep. on file with
the NM Dept. Game and Fish, Santa Fe. 16 pp.
10 Miller, R.R. and C. Hubbs. 1962. Gila pandora, a cyprinid new to
the Texas fish fauna. Texas J. Sci. 14:111-113.
11 Rinne, J. N. 1976. Cyprinid fishes of the genus Gila from the
lower Colorado River basin. Wasmann J. Biol. 34:65-107.
12 Bednarz, J. 1980. Status report on Gila nigrescens (Girard),
Chihuahua chub. Unpubl. Rep. on file with the NM. Dept. Game and
Fish, Albuquerque.
13 Hardy, T.B. 1982. Ecological interactions of the introduced and
native fishes in the outflow of Ash Spring, Lincoln Co., Nevada.
M.S. thesis, Univ. Nev., Las Vegas. 79 pp.
14 Cross, J. N. 1978. Status and ecology of the Virgin River
roundtail chub, Gila robusta seminuda (Osteichthy: Cyprinidae).
Southwest. Nat. 23(3):519-527.
15 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. Trans Am. Fish. Soc. 98:193-208.
16 Greger, P. 1982. Feeding relationships of the fishes of the
Virgin River. M.S. thesis, Univ. Nev., Las Vegas. 38pp.
17 Keading, L.R. and M.A. Zimmerman. 1983. Life history and ecology
of the humpback chub in the Little Colorado and Colorado Rivers of
the Grand Canyon. Trans. Am. Fish. Soc. 112:577-594.
18 Valdez, R.A. and G.H. Clemmer. 1982. Life history and prospects
References - 1 (DRAFT) - References
Species CHUB, CHIHUAHUA
Species Id ESIS252017
Date 14 MAR 96
for recovery of the humpback and bonytail chub. Pp 109-119. IN:
Miller et al. (eds), Fishes of the Upper Colorado River System,
present and future. West. Div. Am. Fish. Soc., Bethesda, MD.
19 Baugh, T.M., J.W. Pedretti, and J.E. Deacon. 1986.
Recommendation for the management of Gila robusta jordani in
Crystal Springs, Nevada. Unpubl. rept. on file with the Nev.
Dept. Wildl., Las Vegas.
20 Hubbard, John P. 1987. Pers. comm. NM. Dept. of Game and Fish,
Sante Fe, NM.
***** REFERENCES FOR N-OCCURRENCE NARRATIVE ONLY *****
01 U.S. Fish and Wildlife Service. 1986. Chihuahua Chub Recovery
Plan. Prepared by USFWS, Albuquerque, New Mexico. 47 pp.
02 Miller, R.R. and B. Chernoff. 1979. Status of populations of the
endangered Chihuahua chub, Gila nigrescens, in New Mexico and
Mexico. IN: Proc. Desert Fish. Council XI:74-84.
03 New Mexico Department of Game and Fish. [n.d.] Handbook of
species endangered in New Mexico. Albuquerque, New Mexico.
04 Hatch, M.D. 1980. Management for the Chihuahua chub, Gila
nigrescens (Girard 1856) in New Mexico. Unpubl. Rep. on file with
the New Mexico Dept. Game Fish, Santa Fe. 16 pp.
References - 2