(DRAFT) - Taxonomy
Species GAMBUSIA, PECOS
Species Id ESIS252006
Date 14 MAR 96
TAXONOMY
NAME - GAMBUSIA, PECOS
OTHER COMMON NAMES - GAMBUSIA and PECOS
ELEMENT CODE -
CATEGORY - Fish
PHYLUM AND SUBPHYLUM - CHORDATA,
CLASS AND SUBCLASS - OSTEICHTHYES,
ORDER AND SUBORDER - ATHERINIFORMES,
FAMILY AND SUBFAMILY - POECILIIDAE,
GENUS AND SUBGENUS - GAMBUSIA,
SPECIES AND SSP - NOBILIS,
SCIENTIFIC NAME - GAMBUSIA NOBILIS
AUTHORITY -
TAXONOMY REFERENCES -
COMMENTS ON TAXONOMY -
Pecos Gambusia
Gambusia nobilis (Baird and Girard, 1853)
KINGDOM: Animal GROUP: Fish
PHYLUM: Chordata CLASS: Osteichthyes
ORDER: Atheriniformes FAMILY: Poeciliidae
Gambusia nobilis (Pecos gambusia) is a small, livebearing
member of the Poeciliidae. Poeciliids are characterized by strong
sexual dimorphism. The anal fin of males is modified into a
gonopodium, an intromittent organ used in copulation. Gonopodial
structures distinguish G. nobilis from the other poeciliids (i.e.,
Gambusia affinis and Gambusia geiseri) known to occur within its
native range. Spines of ray 3 elongated; hooks on rays 4p and 5a
small and rounded; located near terminal end of gonopodium; elbow on
ray 4a located opposite the serrae of 4p, composed of 3 or 4 fused
segments.
Color patterns are useful in making preliminary field
identifications and morphometric characters, although environmentally
plastic, aid in identification. In profile the back is arched;
robust; caudal peduncle, depth approximately two thrids the head
length. Margins of scale pockets are outlined in black. The dorsal
Taxonomy - 1 (DRAFT) - Taxonomy
Species GAMBUSIA, PECOS
Species Id ESIS252006
Date 14 MAR 96
fin has a subbasal row of spots. Females have a black area on the
abdomen that surrounds the anus and anal fin (01). The caudal fin
normally lacks spots but a faint median row may occur (01).
The Pecos gambusia is metallic colored; best distinguished by
the lack of extensive carotenoid (yellowish) pigmentation. There is
substantial differentiation among the isolated populations (02) with
the most genetic divergence in the Balmorhea population (03). That
difference is sufficient enough that the Balmorhea population could be
considered as a distinct subspecies (03).
The Pecos gambusia was originally described as Heterandria
nobilis (04) but placed in Gambusia in 1859 (05). All subsequent
authors have considered Gambusia nobilis to be a valid taxon with the
exception of Garman (06), who called it a junior synonym of G.
gracilis (Heckel, 1848). A number of authors have confused or
synonomized the Pecos gambusia with the Conchos gambusia (G. senilis
Girard, 1859) (07,08,25) but, since 1926 (10), the two species have
generally been considered as distinct (02,03,10,11,12,13,14). A
drawing of a female may be found in the "Atlas of North American
Fishes" (15).
The lectoholotype is deposited in the Museum of Comparative
Zoology (MCZ 1455) as are the lectoparatypes (MCZ 1298). Other
specimens are deposited in the U.S. Museum of Natural History,
University of Michigan Museum of Zoology, Texas Natural History
Collection, University of New Mexico, Tulane University, and the
Oklahoma State University.
A summary of the taxonomic synonomy and scientific names used in
reference to the Pecos gambusia in the literature is as follows:
Gambusia nobilis (Baird and Girard)
Gambusia gracilis (Heckel)
Gambusia senilis (Girard)
Gambusia nobilis subsp.
Heterandria nobilis (Baird and Girard)
Taxonomy - 2 (DRAFT) - Status
Species GAMBUSIA, PECOS
Species Id ESIS252006
Date 14 MAR 96
STATUS
Coded Status
E: Federal Endangered
COMMENTS ON STATUS -
U.S. STATUSES AND LAWS:
The Pecos gambusia (Gambusia nobilis) 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 New Mexico and Texas.
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.
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: New Mexico
DESIGNATED STATUS: Endangered Group II
ADMINISTRATIVE AGENCY: New Mexico Department of Game and Fish
Status - 1 (DRAFT) - Status
Species GAMBUSIA, PECOS
Species Id ESIS252006
Date 14 MAR 96
STATE STATUTE: Regulation No. 624 July 22, 1983
STATE: Texas
DESIGNATED STATUS: Endangered
ADMINISTRATIVE AGENCY: Texas Parks and Wildlife Department
STATE STATUTE: 31 Texas Administrative Code Sec. 57.133 (127.30.
003) July 1977
INTERNATIONAL STATUSES, TREATIES, AND AGREEMENTS:
The Pecos gambusia is listed as Vulnerable 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.
ECONOMIC STATUSES:
This species has value to naturalists and has a value as a
component of New Mexico and Texas' natural heritage of biotic
diversity.
70/10/13:35 FR 16047/16048 - Listing as Endangered
79/05/21:44 FR 29565/29577 - Five year review
85/07/22:50 FR 29901/29909 - Five year review
Status - 2 HABITAT ASSOCIATIONS
HABITAT - AQUATIC
INLAND AQUATIC
LAND USE -
Shrub and Brush Rangeland
Mixed Rangeland
Streams and Canals
Lakes
Reservoirs
NATIONAL WETLAND INVENTORY CODES
NWI NWICLS NWIMOD NWISPEC
Riverine, upper perennial AB1
Lacustrine, littoral OW0
Lacustrine, littoral AB1
Lacustrine, limnetic OW0
Palustrine EM1
Palustrine AB1
COMMENTS ON HABITAT ASSOCIATIONS -
Gambusia nobilis occurs abundantly in springheads and spring
runs. Moderately abundant populations are also known from areas with
little spring influence, but with abundant overhead cover, sedge
covered marshes, and gypsum sinkholes. G. nobilis has been observed
to occur from the surface to depths of three meters (01).
Occassionally individuals are taken in irrigation ditches especially
in the Balmorhea, TX area (02).
Gambusia is primarily a subtropical genus. The closest relatives
of G. nobilis occur in Mexico and south Texas. For this reason, G.
nobilis is known principally from the lower elevations and more
thermally stable localities (i.e., springs) within its geographic
range. Ink Pot, located on the Salt Creek Wilderness Area northeast
of Roswell, represents the highest elevation (approx. 1080 m) and
northernmost area presently known to be occupied by this species.
All populations, including those at historic, present, and
introduction sites, occur between 822 m and 1187 m elevation, a range
in elevation of 365 m (01).
The narrow elevation range suggests a narrow range of temperature
tolerance. Reported average critical thermal maxima is 38.1-39.3
degrees C for G. nobilis, with thermal preferenda of 21-25 degrees C
in the morning and 26-30 degrees C in the afternoon. In contrast, the
potential competitor G. affinis is more toleratnt of higher
temperatures. No data are available on cold tolerances of G.
nobilis (01).
Gambusia nobilis occurs abundantly in waters with conductivities
ranging form near 1200 umhos/cm at Blue Spring to 32,500 umhos/cm at
Sinkhole 27 on Bitter Lake National Wildlife Refuge. These
conductivity values roughly correspond to total dissolved solids
concentrations of 1 and 30 ppt, respectively. Within this range,
salinity apparently is not a major limiting factor, although 30 ppt
may be near the upper tolerance level of the species.
The Pecos gambusias essentially restricted to stenothermal,
clear water, lotic habitats (01). It lives in a variety of habitats
in Bitter Lake National Wildlife Refuge (21) in the absense of
congenors. When sympatric with Gambusia affinis, the Pecos gambusia
is restricted to flowing stenothermal waters (01). When sympatric
Habitat Associations - 1 with G. geiseri, the Pecos gambusia dominates most stenothermal
habitats with salinities of 15,000 umhos/cm, but in salinities of 3500
to 5000 umhos/cm the two species have relatively similar abundances
(03).
Lands surrounding the habitats are classified as Texas savanna
and shrub/brush rangelands of mixed rangelands.
Habitat Associations - 2 (DRAFT) - Food Habits
Species GAMBUSIA, PECOS
Species Id ESIS252006
Date 14 MAR 96
FOOD HABITS
TROPHIC LEVEL -
CARNIVORE
LIFESTAGE FOOD FOOD PART
General Algae
General Zooplankton
General Arthropods
General Fish
General Crustaceans
Food Habits - 1 (DRAFT) - Environment Associations
Species GAMBUSIA, PECOS
Species Id ESIS252006
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 Aquatic Features: Springs [flowing]
G Terrestrial Features: Depressions
G
Environment Associations - 1 (DRAFT) - Life History
Species GAMBUSIA, PECOS
Species Id ESIS252006
Date 14 MAR 96
LIFE HISTORY
FOOD HABITS:
The Pecos gambusia like other Gambusia, is considered to be a
carnivorous surface feeder (22). It consumes larger fractions of
amphpiods than do coexisting fishes (20). Stomachs contain a variety
of small invertebrates and will on occassion contain filamentous algae
(22). The species seems to be an opportunistic feeder (01).
HOME RANGE/TERRITORY:
Presumed to be quasi-territorial as is its relative G. heterochir
(23).
PERIODICITY:
The Pecos gambusia is diurnal as are other Gambusia (24).
MIGRATION PATTERNS:
No information is available on this subject, but, the species is
expected to have warm water preference (23).
COVER/SHELTER REQUIREMENTS:
The Pecos gambusia inhabits stenothermal environments with little
cover as well as stenothermal environments with abundant vegetation
(01). Moderately abundant populations are also known from areas with
little spring influence, but with abundant overhead cover, sedge
covered marshes, and gypsum sinkholes. G. nobilis has been observed
to occur from the surface to depths of three meters (01).
REPRODUCTIVE SITE REQUIREMENTS:
Viviparous, parturition primarily in shallow areas (01,,23).
REPRODUCTIVE CHARACTERISTICS:
Little is known on this subject for this species. At Blue Spring
the Pecos gambusia has a mean number of 38 offspring (22); however,
congenors have numerous broods each year with substantial seasonal
variations in the number of offspring (14).
PARENTAL CARE:
No parental care is known.
POPULATION BIOLOGY:
Predation on G. nobilis could be a major limiting factor in areas
where no submerged vegetation or sufficiently shallow areas provide
cover from predators. Predation by the centrarchids Lepomis cyanellus
and/or Micropterus salmoides may have eliminated the introduced
population of G. nobilis from Lake St. Francis on the Bitter Lake
National Wildlife Refuge and also may have contributed to the failure
of a population introduced into Geyser Spring, NM. Also, virtual
absence of G. nobilis from the head pool of Diamond-Y Spring may be
attributable partly to the presence of L. cyanellus and M. salmoides.
Gambusia nobilis is extremely abundant in shallow marshy areas of
Leon Creek and Blue Spring, even though predators (centrarchids) are
present in the deeper and more open waters (01).
Life History - 1 (DRAFT) - Life History
Species GAMBUSIA, PECOS
Species Id ESIS252006
Date 14 MAR 96
SPECIES INTERRELATIONSHIPS:
The Pecos gambusia has a wide range of tolerance to physical/
chemical factors in the water, however in the presence of congenors,
the Pecos gambusia is abundant only in special areas. Gambusia
affinis is widespread in the range of Gambusia nobilis. G. affinis is
tolerant of environmental extremes and where sympatric, G. nobilis is
restricted to stenothermal waters (01). At Blue Spring, G. nobilis is
very abundant near the head springs but, downstream almost all
gambusines are G. affinis. In intermediate reaches, G. nobilis
abounds in the spring flow and G. affinis is exceedingly abundant in
marginal areas that have substantial thermal oscillation. Gambusia
geiseri has been introduced into localities inhabited by G. nobilis
(18). At Balmorhea where the spring flows are of low salinity, G.
geiseri is the abundant form, but in Leon Creek where the spring flows
are of high salinity (ca 1/2 that of sea water) G. nobilis is the more
abundant of the two species (03). In Leon Creek, G. affinis
predominates downstream and there is a hybrid swarm between G. affinis
and G. nobilis at intermediate locations (20).
OTHER LIFE HISTORY DESCRIPTORS:
None.
Life History - 2 (DRAFT) - Management Practices
Species GAMBUSIA, PECOS
Species Id ESIS252006
Date 14 MAR 96
MANAGEMENT PRACTICES
RESULT MANAGEMENT PRACTICE
Beneficial Maintaining/Controlling Water Flow
Beneficial Controlling water levels
Beneficial Land Acquisition
Beneficial Water Right Acquisition
Beneficial Controlling pollution [thermal, chemical, physical]
Beneficial Controlling/Restricting Pesticide Use
Beneficial Controlling/Restricting Herbicide Use
Beneficial Reforestation
Beneficial Stocking captive-reared wild-strain animals
Beneficial Controlling/Removing Exotic Vertebrates
Adverse Hybridization
Existing Hybridization
Adverse Salinity alteration
Existing Salinity alteration
Adverse Water Level Fluctuation
Existing Water Level Fluctuation
Adverse Groundwater drawdown
Existing Groundwater drawdown
Adverse Irrigating
Existing Irrigating
Adverse Reservoirs
Existing Reservoirs
Adverse Competition
Existing Competition
Adverse Exotic/Feral/Introducted Species
Existing Exotic/Feral/Introducted Species
Adverse
Existing
COMMENTS ON MANAGEMENT PRACTICES -
The Pecos gambusia faces two major threats: 1) Loss of habitat
and 2) the inability to interact successfully with nonnative
(exogenous) fish species, especially Gambusia. The known occurrences
of G. nobilis indicate that the species once was more widespread (01).
The Pecos River mainstream has been influenced by man for more
than 100 years, first through water withdrawals for irrigation and
more recently through the construction of mainstream dams for
irrigation and flood control. These water uses have severely depleted
natural flows in the river along major sections and caused drastic
increases in salinities in the remaining reaches.
Although the mainstream Pecos River probably was never important
as permanent habitat, the mainstream served as a dispersal route
between tributary springs and streams. The more important lateral
habitats initially were impacted by extensive ground water pumping of
the aquifers surrounding the Pecos River in the mid-1900's. This
caused cessation of flow and extirpation of G. nobilis from Comanche
Springs (02) and undoubtedly from the vicinity of Ft. Sumner, NM, as
well as its tributary North Spring River; and caused reduced flow with
Management Practices - 1 (DRAFT) - Management Practices
Species GAMBUSIA, PECOS
Species Id ESIS252006
Date 14 MAR 96
loss of habitat in other areas. As a result of these habitat losses,
the fish became isolated in permanent springs and is totally dependent
upon spring flow for their survival (01).
Concurrent with stream flow reduction, average water salinity has
increased substantially (10). Disappearance of Pecos gambusia from
Leon Springs preceeded drying of the spring and is associated with
inundation by a small reservoir and the presence of introduced species
(16). Declining spring flow and/or periodic drying of irrigation
ditches may have played a substantial role in the decline of
Endangered fishes in the Balmorhea area (17) as well as the release of
introduced species (18).
The native fishes, which have evolved in communities with low
species diversity, are often unable to compete with introduced
species. The effects of competition on G. nobilis are well known and
indicate that they were disappearing in the Balmorhea area because of
the expansion of G. geiseri, a nonnative poeciliid introduced into
the springs in the early 1930's.
Predation on G. nobilis could be a major limiting factor in areas
where no submerged vegetation or sufficiently shallow areas provide
cover from predators. Predation by the centrarchids Lepomis cyanellus
and/or Micropterus salmoides may have eliminated the introduced
population of G. nobilis from Lake St. Francis on the Bitter Lake
National Wildlife Refuge and also may have contributed to the failure
of a population introduced into Geyser Spring, NM. Also, virtual
absence of G. nobilis from the head pool of Diamond-Y Spring may be
attributable partly to the presence of L. cyanellus and M. salmoides.
Pecos gambusia hybridizes with congenors at Balmorhea (03), Leon
Creek (18), and at Bitter Lake (01). Abundance of Pecos gambusia is
inverse to abundance of congenors such as G. affinis. As stream flows
decline, environmental conditions become more favorable for G. affinis
and less favorable fo G. nobilis. It seems as if G. nobilis cannot
coexist with G. affinis in eurythermal or ponded environments (01).
APPROVED PLAN:
U.S. Fish and Wildlife Service. 1983. Pecos Gambusia Recovery Plan.
U.S. Fish and Wildlife Service, Albuquerque, New Mexico. 41 pp.
The prime objective of the Recovery Plan is to improve the status
of the Pecos gambusia to the point that survival of populations from
the four major areas of occurrence is secured. Maintenance and
enhancement of existing populations and their habitats should include:
1) Monitoring populations (numbers, condition, and age
structure).
2) Monitoring the condition of their habitat, which should also
include evaluation of proposed activities such as pumping
ground water, surface water diversions, roads, oil and gas
field activities and phreatophyte management. This would
include the controlling of pollutants such as herbicides or
pesticides, oil and gas drilling and associated pollutants,
and maintaining the water flow and water table. Water
right acquisition or land easements may be necessary to
Management Practices - 2 (DRAFT) - Management Practices
Species GAMBUSIA, PECOS
Species Id ESIS252006
Date 14 MAR 96
achieve these restraints.
It is also important to:
1) Regulate the introduction of novel exotic fishes.
2) Preclude immigration of novel exotic fishes.
3) Remove exotic fishes where possible from Pecos gambusia
habitat.
4) Evaluate, protect, and enhance deficient habitats through
habitat rehabilitation.
5) Further study the ecology (i.e., fecunity, food habits,
competition, hybridization potential, etc.) of this species.
6) Determine systematic relationships between the four major
areas of occurrence.
Efforts should be made to reestablish Pecos gambusia within four
(of nine original) historic collection areas. Such a reintroduction
should follow in this order:
1) Thorough surveys of potential reintroduction sites.
2) Remedial improvement of habitats as needed.
3) Introduction of pure stock.
4) Monitoring reintroduced populations.
5) Reintroduction of sympatric native fish after this species is
reestablished.
Captive populations of Pecos gambusia from each of the four major
areas should be maintained at Dexter NFH for scientific research,
transplanting for mosquito control in areas of suitable habitat, and
as a reserve gene pool. Pecos gambusia should be provided the full
protection mandated by Federal, New Mexico, and Texas laws. Finally,
public awareness of the uniqueness of the Pecos gambusia should be
increased through the preparation of information pamphlets,
interpretive programs, and the use of broadcast and print media.
Management Practices - 3 (DRAFT) - References
Species GAMBUSIA, PECOS
Species Id ESIS252006
Date 14 MAR 96
References
***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCURRENCE *****
01 U.S. Fish and Wildlife Service. 1983. Pecos Gambusia Recovery
Plan. U.S. Fish and Wildlife Service, Albuquerque, NM. 41 pp.
02 Hubbs, C. and V.G. Springer. 1957. A revision of the Gambusia
nobilis species group, with descriptions of three new species, and
notes on their variation, ecology, and evolution. Tex. J. Sci.
9:297-327.
03 Echelle, A.A. and A.F. Echelle. 1980. Status of the Pecos
gambusia, Gambusia nobilis. U.S. Fish and Wildlife Service,
Albuquerque, NM. Endangered Species Rep. No. 10. 73 pp.
04 Baird, S.F. and C. Girard. 1853. Descriptions of new subspecies
of fishes collected by Mr. J.H. Clark on the U.S. and Mexican
Boundary Survey, under Lt. Col. Jas D. Graham. Proc. Acad. Nat.
Sci., Phila. 6:387-390.
05 Girard, C. 1959. Ichtyology of the boundary. U.S. and Mexican
Boundary Survey. 3:1-85.
06 Garman, S. 1895. The Cyprinodonts. Mem. Mus. Comp. Zool.
19:1-179.
07 Regan, C.T. 1913. A revision of the Cyprinodont fishes of the
subfamily Poeciliinae. Proc. Zool. Soc., London:977-1018.
08 Alvarez, J. 1950. Claves para la determinacion de species en los
peces de las aguas continentales Mexicanas. Secretaria de Marina,
Mexico. 144 pp.
09 Hubbs, C.L. 1926. Studies of the fishes of the order
Cyprinodontes. VI. Material for a revision of American genera and
species. Univ. Mich. Mus. Zool. Misc. Publ. 16. 87 pp.
10 Robins, C.R. and others. 1980. A list of common and scientific
names of fishes, 4th ed. Sp. Publ. Am. Fish. Soc. 12. 174 pp.
11 Rivas, L.R. 1963. Subgenera and species groups in the Poeciliid
fish genus Gambusia Poey. Copeia 1963:331-347.
12 Peden, A.E. 1973. Variation in anal spot expression of gambusine
females and its effect on male courtship. Copeia 1973:250-263.
13 Deacon, J.E., et al. 1979. Fishes of North America
Endangered, Threatened, or of special concern. Fisheries
4(2):29-44.
14 Hubbs, C. and D.T. Mosier. In press. Fecundity of Gambusia
gaigei, an Endangered species. Copeia.
15 Guillory, V. 1980. Gambusia nobilis Baird and Girard, Pecos
gambusia. In: Atlas of North American freshwater fishes. D.S.
Lee, et. al. 544 pp.
16 Hubbs, C. 1980. The solution to the Cyprinodon bovinus problem:
Eradication of a pupfish genome. Proc. 10th Desert Fishes Council
Pp. 9-18.
17 Davis, J.R. 1979. Die-offs of an Endangered pupfish, Cyprinodon
elegans (Cyprinodontidae). The Southwest Nat. 24:534-536.
18 Hubbs, C. 1982. Occurrence of exotic fishes in Texas waters.
Pearce-Sollards Series. TX Mem. Mus. 36:19 pp.
19 Rosen, D.E. and R.M. Bailey. 1963. The Poeciliid fishes
(Cyprinodontiformes), their structure, zoogeography, and
systematics. Bull. Am. Mus. Nat. Hist. 126:1-176.
References - 1 (DRAFT) - References
Species GAMBUSIA, PECOS
Species Id ESIS252006
Date 14 MAR 96
20 Hubbs, C. 1978. Result of an eradication program on the
ecological relationships of fishes in Leon Creek, Texas. Southwest
Nat. 23:487-496.
21 Bouma, R. 1984. A contribution to the management of Gambusia
nobilis at Bitter Lake National Wildlife Refuge. Rep. to USFWS,
Albuquerque, NM. 88 pp.
22 Bednarz, J.C. 1979. Ecology and status of the Pecos gambusia,
Gambusia nobilis (Poeciliidae), New Mexico. Southwest Nat. 24:311-
322.
23 Hubbs, C. 1971. Competition and isolation mechanisms in the
Gambusia affinis x G. heterochir hybrid swarm. Bull. TX Mem. Mus.
19:47 pp.
24 Hubbs, C. 1984. Changes in fish abundance with time of day and
among years at a station in Lake Texoma. 1983 Trans. TX Chap. Am.
Fish. Soc:42-57.
25 Jordan, D.S. and B.W. Evermann. 1898. Fishes of North America.
Bull. U.S. Nat. Mus. 47(1):1-1240.
***** REFERENCES FOR N-OCCURRENCE NARRATIVE ONLY *****
01 U.S. Fish and Wildlife Service. 1983. Pecos Gambusia Recovery
Plan. U.S. Fish and Wildlife Service, Albuquerque, NM. 41 pp.
02 Bouma, R. 1984. A contribution to the management of Gambusia
nobilis at Bitter Lake National Wildlife Refuge. Rep. to USFWS,
Albuquerque, NM. 88 pp.
03 Echelle, A.A. and A.F. Echelle. 1980. Status of the Pecos
gambusia, Gambusia nobilis. U.S. Fish and Wildlife Service,
Albuquerque, NM. Endangered Species Rep. No. 10. 73 pp.
04 Bednarz, J.C. 1979. Ecology and status of the Pecos gambusia,
Gambusia nobilis (Poeciliidae), New Mexico. Southwest Nat.
24:311-322.
05 Hubbs, C. 1978. Result of an eradication program on the
ecological relationships of fishes in Leon Creek, Texas. Southwest
Nat. 23:487-496.
06 Hubbs, C. and V.G. Springer. 1957. A revision of the Gambusia
nobilis species group, with descriptions of three new species, and
notes on their variation, ecology, and evolution. Tex. J. Sci.
9:297-327.
07 Girard, C. 1959. Ichtyology of the boundary. U.S. and Mexican
Boundary Survey. 3:1-85.
08 Hubbs, C. 1980. The solution to the Cyprinodon bovinus problem:
Eradication of a pupfish genome. Proc. 10th Desert Fishes Council.
Pp. 9-18.
09 Hubbs, C.L. 1926. Studies of the fishes of the order
Cyprinodontes. VI. Material for a revision of American genera and
species. Univ. Mich. Mus. Zool. Misc. Publ. 16:87 pp.
10 Hubbs, C. and A.A. Echelle. 1973. Endangered non-game fishes of
the Upper Rio Grande Basin. In: Endangered vertebrates of the
southwest. W.C. Huey. NM Game and Fish:147-167.
References - 2