http://www.biology.ualberta.ca/jackson.hp/IWR/Taxa/Cyprinodontiformes/Fundulidae/index.php
--Bruce Stallsmith
Huntsville, AL, US of A
(never quite made it to Quebec...)
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Lucania interioris
Cuatro Ciénegas killifish / sardinilla de Cuatro Ciénegas
FUNDULIDAE - killifishes
ABSTRACT
Size
20-30 mm SL as adults, rarely >35 mm
Conservation Status
Listed as Endangered by the American Fisheries Society in 1989, and as
------------- by the Mexican
Government in 1994.
Distribution
Restricted to margins of saline lakes and pools, marshes, springs, and their
outflows, throughout much of the central and southwestern Cuatro Ciénegas
basin, Coahuila, México.
Abundance
Generally rare in collections, sometimes frequent in restricted, local
areas.
Habitat & Ecology
Little is known of the ecology and behavior of this diminutive fish, which
is likely more common than
indicated by collections because of it's habitat and an evasive and
secretive behavior. Cuatro Ciénegas
killifish have been taken in habitats varying from seasonally hot,
hypersaline, shallow and otherwise
severe lake and pool margins through marshlands, to quiet,
constant-temperature springs. They tolerate
temperatures >44°C and total dissolved solids >95 gm/l. Occurrences are
solitary or in small groups in
water 5-30 mm deep along and within clumps of terrestrial and aquatic
plants, vegetative debris, or even
in livestock hoofprints. Individuals do not hesitate to force their way
through water < 5 mm deep to attain
such places or to flee when disturbed. Based on 10 stomachs analyzed they
feed on detritus and algae.
They are invariably associated with flocculent bottoms into which they
abruptly dive to disappear when
disturbed. Fish diving into the substrate remain there, invisible, for times
often exceeding the patience of
an observer. Such bottoms are often reducing in nature, yielding toxic
gasses (e.g., hydrogen sulfide)
when disturbed by collecting, which, along with presumably reduced dissolved
oxygen, may result in
death of fishes not otherwise captured.
Reproduction
Reproductive behavior of Cuatro Ciénegas killifish has yet to be reported.
Breeding males are
spectacularly colored, with pearl-like pigment spots on each lateral scale,
yellow to orange fins with
darkened margins, and iridescent blue eyes. The tiny young are locally
common along shorelines in spring,
summer and autumn in water a few millimeters deep.
Threats
Reduced volumes of flow during drought results in vast reductions of
shallow, marginal habitats, which
must be reflected in reduced populations of killifish. Some springs have
further been canalized, resulting in
reduced water levels and in some instances desiccation, both of springheads
and downflow marshes.
Groundwater extraction within and adjacent to springs clearly exacerbates
these conditions. Anticipated
detrimental impacts of non-indigenous crayfish, molluscs, and perhaps fishes
(none yet confirmed as
naturalized) may be far less severe on this species than others because of
it's special habitats and
behaviors.
Conservation Actions
A substantial proportion of the Cuatro Ciénegas basin, including many
springs their outflows, marshes,
and other habitats inhabited by this killifish, were set aside in 1994 as a
biological preserve. Specific
conservation actions are, however, yet to be proposed or implemented.
Conservation Recommendations
Devise and implement conservation actions preventing further loss and change
of habitat and prohibit
introductions of non-indigenous organisms. Especially needed are provisions
to maintain marshes, which
are quickly and permanently drained by canalization.
Important References
Hubbs, C. L. & R. R. Miller. 1965. Studies of cyprinodont fishes. XXII.
Variation in Lucania
parva, its establishment in western United States, and description of a
new species from an interior
basin in Coahuila, México. Misc. Publ. Mus. Zool. Univ. Mich. 127:
1-111.
Miller, R. R. 1978. Composition and derivation of the native fish fauna
of the Chihuahuan Desert
region. Pp. 365-382, in R. H. Wauer & D. Riskind (eds.). Transactions
of the Symposium of the
Biological Resources of the Chihuahuan Desert Region, United States and
México. US Natl. Park
Ser. Trans. Proc. Ser. 3(1977). US Gov. Print. Off., Wash., DC.
Minckley, W. L. 1969. Environments of the Bolsón of Cuatro Ciénegas,
Coahuila, México, with
special reference to the aquatic biota. Texas Western Press, Univ.
Texas El Paso Sci. Ser. 2: 1-65.
______. 1978. Endemic fishes of the Cuatro Ciénegas basin, Coahuila,
México. Pp. 383-404, in R.
H. Wauer & D. Riskind (eds.). Symposium on the Biological Resources of
the Chihuahuan Desert
Region, United States and México. US Natl. Park Ser. Trans. Proc. Ser.
3(1977). US Gov. Print.
Off., Wash., DC.
______. 1992. Three decades near Cuatro Ciénegas, México: Photographic
documentation and a
plea for area conservation. Pp. 81-110, in M. R. Sommerfeld & D. M.
Kubly (eds.). Limnology and
Aquatic Biology of the Southwest, Proceedings of a Special Symposium to
Honor Professor Gerald
Ainsworth Cole. 34th Annual Meeting of the Arizona-Nevada Academy of
Science, Tempe, AZ, 21
April 1990. J. AZ-NV Acad. Sci. 26(2).
______. 1994. A bibliography for natural history of the Cuatro Ciénegas
basin and environs,
Coahuila, México. Proc. Desert Fishes Council 25(1993): 47-64.
Secretaria de Desarrollo Social. 1994. Norma Oficial Mexicana
NOM-059-ECOL-1994, que
determina las especies y subspecies de flora y fauna silvestres y
acuáticas en peligro de extinción,
amenazadas, raras y sujetas a protección especial, y que establece
especificaciones para su
protección. Diario Oficial De La Federación, México, CDLXXVIII. 2-60.
Williams, J. E., Bowman, D. B., Brooks, J. E., Echelle, A. A., Edwards,
R. J., Hendrickson, D. A.
& Landye J. J. 1989. Fishes of North American endangered, threatened,
or of special concern:
1989. Fisheries (Bethesda, MD) 14(6): 12-20.
Preparator
W. L. Minckley, Department of Zoology, Arizona State University, Tempe,
Arizona 85287-1501
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