(DRAFT) - Taxonomy
Species GAMBUSIA, AMISTAD
Species Id ESIS252010
Date 14 MAR 96
TAXONOMY
NAME - GAMBUSIA, AMISTAD
OTHER COMMON NAMES - GAMBUSIA, AMISTAD; GAMBUSIA, GOODENOUGH; GAMBUSIA and GOODENOUGH SPRINGS
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 - AMISTADENSIS,
SCIENTIFIC NAME - GAMBUSIA AMISTADENSIS
AUTHORITY -
TAXONOMY REFERENCES -
COMMENTS ON TAXONOMY -
Amistad Gambusia
Gambusia amistadensis Peden, 1973
KINGDOM: Animal GROUP: Fish
PHYLUM: Chordata CLASS: Osteichthyes
ORDER: Atheriniformes FAMILY: Poeciliidae
The Amistad gambusia (Gambusia amistadensis) is a member of the
Gambusia nobilis species group and appears closely related to G.
senilis and especially to the G. gaigei species group (including G.
gaigei, G. hurtadoi and G. alvarezi) (01,02,03,04,05). The species is
characterized by its relatively slender body, terminal mouth with
numerous teeth on each jaw and with males having longer serrae on ray
4p of the gonopodium. Preserved specimens have strong crosshatching
and numerous darkly pigmented crescent-shaped spots on the scale
margins. The mid-dorsal stripe is narrow and the lateral stripe is
broad. A short, dusky subocular bar is present. Adult females have a
permanent median dark anal spot (01).
The holotype of this extinct species is in the University of
Michigan Museum of Zoology (UMMZ 190407), the U.S. National Museum
(USNM 205858), the University of Texas' Natural History Collections
(TNHC 7247) and the National Museum of Canada (NMC 70-373) (01). A
Taxonomy - 1 (DRAFT) - Taxonomy
Species GAMBUSIA, AMISTAD
Species Id ESIS252010
Date 14 MAR 96
photograph of a male and female of this species and a comparative
diagnostic analysis appears in Peden's original description of the
Amistad gambusia (01). Common name synonyms for the Amistad gambusia
include the Goodenough gambusia and Goodenough Springs gambusia.
Taxonomy - 2 (DRAFT) - Status
Species GAMBUSIA, AMISTAD
Species Id ESIS252010
Date 14 MAR 96
STATUS
Coded Status
Delisted
Status - 1 (DRAFT) - Status
Species GAMBUSIA, AMISTAD
Species Id ESIS252010
Date 14 MAR 96
COMMENTS ON STATUS -
U.S. STATUSES AND LAWS:
The Amistad gambusia (Gambusia amistadensis) was 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 been delisted due to extinction.
RESPONSIBLE FEDERAL AGENCIES:
USFWS -Responsible for the management/recovery, listing, and
law enforcement/protection of this species. In
addition the USFWS is responsible for delisting this
particular 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: 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 Amistad gambusia was listed as endangered in the IUCN Red
Data Book, Vol. 4, 1977, but its status was changed to extinct
in the 1986 IUCN Red List of Threatened Animals.
ECONOMIC STATUSES:
None.
78/08/15:43 FR 36117/36120 - Proposed listing as Endangered
80/04/30:45 FR 28721/28722 - Listing as Endangered
85/07/22:50 FR 29901/29909 - Five year review
87/03/11:52 FR 07462/07463 - Proposed rule - Delist (Extinct)
87/07/07:52 FR 25522/ - Notice of 5-year review completion
87/12/04:52 FR 46083/46085 - Final rule - Delisted (Extinct)
Status - 2 HABITAT ASSOCIATIONS
HABITAT - AQUATIC
INLAND AQUATIC
COMMENTS ON HABITAT ASSOCIATIONS -
Gambusia amistadensis was restricted to the rapidly flowing warm
spring waters of Goodenough Springs and to the approximately 1.3 km
outflow creek which emptied into the Rio Grande (01). Goodenough
Springs, formerly the third largest springs of Texas (06), flowed over
limestone gravel and sand substrates along this 1.3 km course to the
Rio Grande. Waters originated in the relatively large Edwards-Trinity
aquifer (08) and maintained flow rates of approximately 2000 to 4000
cubic liters per second (06). The type locality and habitat for the
Amistad gambusia is now under approximately 30 meters of water behind
Amistad Reservoir and spring flows are greatly reduced (01,06). This
species is now considered extinct (07).
Habitat Associations - 1 (DRAFT) - Food Habits
Species GAMBUSIA, AMISTAD
Species Id ESIS252010
Date 14 MAR 96
FOOD HABITS
TROPHIC LEVEL -
OMNIVORE
LIFESTAGE FOOD FOOD PART
General Detritus
General Algae
General Arthropods
Food Habits - 1 (DRAFT) - Environment Associations
Species GAMBUSIA, AMISTAD
Species Id ESIS252010
Date 14 MAR 96
ENVIRONMENTAL ASSOCIATIONS
Environment Associations - 1 (DRAFT) - Life History
Species GAMBUSIA, AMISTAD
Species Id ESIS252010
Date 14 MAR 96
LIFE HISTORY
FOOD HABITS:
Little is known concerning the food habits of the Amistad
gambusia, however, the gut contents of 10 paratypes examined by Peden
(01) contained mostly unidentified items, some insect fragments and
traces of filamentous algae.
HOME RANGE/TERRITORY:
Territoriality and home ranges for the Amistad gambusia are
unknown. Presumably when the species was extant, it behaved similarly
to other species of Gambusia where males maintain breeding territories
(09,10).
PERIODICITY:
No information is available on periodicity of the Amistad
gambusia, however, most members of the genus are diurnal (11).
MIGRATION PATTERNS:
No information exists concerning migration, but, migration is
unlikely.
COVER/SHELTER REQUIREMENTS:
Prior to its extinction, the Amistad gambusia inhabited shallow
water environments at Goodenough Springs and its outflow which
contained sparse stands of submerged aquatic vegetation (01).
REPRODUCTIVE SITE REQUIREMENTS:
Observations in aquaria of pregnant female Gambusia amistadensis
indicated that these individuals gave birth to their young in
vegetated areas and that presumably females sought similar areas in
the wild to give birth to their young (01,09).
REPRODUCTIVE CHARACTERISTICS:
The reproductive behavior of the Amistad gambusia has been
reported by Peden (09,10) who found that this species has similar
breeding characteristics to other members of the Gambusia nobilis
complex. Male courtship appears similar to other poeciliids (10).
Of 10 female paratypes examined by Peden (01), the mean size was
29.8 mm standard length (SL) (range =25.9 to 34.6 mm SL) and 7
contained 5 to 11 (mean 8.9) embryos in each ovary while the other 3
females contained 1 to 7 eggs.
PARENTAL CARE:
Gambusia amistadensis is a member of the family Poeciliidae and
all females bear their young alive. Following partuition, no further
parental care is provided by the female (09,10).
POPULATION BIOLOGY:
All known populations of Gambusia amistadensis are extinct due to
the inundation of their only known natural environment and the
extirpation of this species in the two artificial cultures by
mosquitofish (Gambusia affinis) (07). Captive populations were
Life History - 1 (DRAFT) - Life History
Species GAMBUSIA, AMISTAD
Species Id ESIS252010
Date 14 MAR 96
maintained until the late-1970's at the Brackenridge Field Laboratory
of the University of Texas at Austin and at the U.S. Fish and Wildlife
Service's hatchery facility at Dexter, NM (Dexter NFH). Sometime
during this period, both cultures became contaminated with
mosquitofish (G. affinis) and all Amistad gambusia were extirpated
(07).
SPECIES INTERRELATIONSHIPS:
Little informataion is known concerning other species'
relationships with Gambusia amistadensis. Other fishes co-occurring
with the Amistad gambusia prior to the inundation of its habitat
included: Astyanax mexicanus (Mexican tetra), Hybopsis aestivalis
(speckled dace), Notropis lutrensis (red shinner), N. braytoni
(Tamaulipan shiner), N. jemezanus (Rio Grande shiner), N. proserpinus
(proserpine shiner), N. venustus (blacktail shiner), Cycleptus
elongatus (blue sucker), Icatalurus punctatus (channel catfish), I.
melas (black bullhead), Pylodictus olivaris (flathead catfish),
Gambusia affinis (mosquitofish), Micropterus salmoides (largemouth
bass), Lepomis cyanellus (green sunfish), and Cichlasoma cyanoguttatum
(Rio Grande cichlid) (01).
OTHER LIFE HISTORY DESCRIPTORS:
The Amistad gambusia (Gambusia amistadensis) is now extinct (07).
In reporting the circumstances in the extinction of this species,
Hubbs and Jensen cite potential hazards of attempting to maintain only
culture populations of Endangered and Threatened species (07).
Life History - 2 (DRAFT) - Management Practices
Species GAMBUSIA, AMISTAD
Species Id ESIS252010
Date 14 MAR 96
MANAGEMENT PRACTICES
RESULT MANAGEMENT PRACTICE
Adverse Hybridization
Existing Hybridization
Adverse Low Gene Pool
Existing Low Gene Pool
Adverse Reservoirs
Existing Reservoirs
COMMENTS ON MANAGEMENT PRACTICES -
The Amistad gambusia's only known habitat at Goodenough Springs
and its outflow was inundated by waters from the filling of Amistad
Reservoir in 1968 (01,06). Captive populations were maintained until
the late-1970's at the Brackenridge Field Laboratory of the University
of Texas at Austin and at the U.S. Fish and Wildlife Service's
hatchery facility at Dexter, NM (Dexter NFH). Sometime during this
period, both cultures became contaminated with mosquitofish (G.
affinis) and all Amistad gambusia were extirpated (07). In reporting
the circumstances in the extinction of this species, Hubbs and Jensen
cite potential hazards of attempting to maintain only culture
populations of Endangered and Threatened species (07).
UNAPPROVED PLAN:
The U.S. Fish and Wildlife Service considers this species extinct.
This species is considered extinct by the U.S. Fish and
Wildlife Service and therefore no Recovery objectives have been
identified.
Management Practices - 1 (DRAFT) - References
Species GAMBUSIA, AMISTAD
Species Id ESIS252010
Date 14 MAR 96
References
***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCURRENCE *****
01 Peden, A.E. 1973. Virtual extinction of Gambusia amistadensis n.
sp., a poeciliid fish from Texas. Copeia 1973:210-221.
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. Texas J. Sci.
9:279-327.
03 Minckley, W.L. 1963. A new poeciliid fish (genus Gambusia) from
the Rio Grande drainage of Coahuila, Mexico. Southwest. Nat.
8:145-161.
04 Rosen, D.E. and R.M. Bailey. 1963. The poeciliid fishes
(Cyprinodontiformes), their structure, zoogeography, and
systematics. Bull. Amer. Mus. Nat. Hist. 126:1-176.
05 Peden, A.E. 1972. Differences in the external gentalia of female
gambussin fishes. Southwest. Nat. 17:265-272.
06 Brune, G. 1981. Springs of Texas. Vol. 1. Branch-Smith, Inc.,
Fort Worth, Texas.
07 Hubbs, C. and B.L. Jenson. 1984. Extinction of Gambusia
amistadensis, an endangered fish. Copeia 1984:529-530.
08 Peckham, R.C. 1963. Summary of the ground-water resources in the
Rio Grande Basin. Texas Water Comm. Circ. 63-05:1-16.
09 Peden, A.E. 1970. Courtship behavior of Gambusia (Poeciliidae)
with emphasis on isolating mechanisms. Unpubl. Ph.D. Diss., Univ.
of Texas, Austin, TX. 274 pp.
10 Peden, A.E. 1973. Variation in anal spot expression of gambussin
females and its effect on male courtship. Copeia 1973:250-263.
11 Hubbs, C. 1971. Competition and isolation mechanisms in the
Gambusia affinis x G. heterochir hybrid swarm. Bull. Tex. Mem.
Mus. 19. 46 pp.
***** REFERENCES FOR N-OCCURRENCE NARRATIVE ONLY *****
01 Peden, A.E. 1973. Virtual extinction of Gambusia amistadensis n.
sp., a poeciliid fish from Texas. Copeia 1973:210-221.
02 Brune, G. 1981. Springs of Texas. Vol. 1. Branch-Smith, Inc.,
Fort Worth, Texas.
03 Hubbs, C. and B.L. Jenson. 1984. Extinction of Gambusia
amistadensis, an Endangered fish. Copeia 1984:529-530.
04 U.S. Fish and Wildlife Service. 1987. Endangered and
threatened wildlife and plants; Removal of Gambusia amistadensis,
the Amistad gambusia from the list of endangered and threatened
wildlife. Federal Register 52:46083-46085
References - 1