456
JAMES E. DEACON AND W. L MINCKLEY
and Minckley, 1969), may well be an attunement to avoid high turbidities
and shifting stream beds by taking advantage of low, clear, summer flow.
In smaller habitats low waters appear to inhibit reproduction, despite
the stimuli of increasing day length and temperatures in spring. This may,
of course, result from nutritional deficiencies, or other factors related to
crowding in intermittent habitats. John (1963) found that speckled dace
in the Chiricahua Mountains, Arizona, spawned after spring runoff and
again after late summer rains had produced freshets. He related day length,
temperature, and flooding to spawning activity, but without the last, no
summer spawning occurred.
Similar habits are implied by Koster (1957) for longfin dace and Rio
Grande mountain-sucker (Pantosteus plebeius) in New Mexico. However,
in Aravaipa Creek, Arizona, no correlation of spawning activity with
flooding by any of the seven native species of fishes has been detected.
Longfin dace and the Gila mountain-sucker produced young continuously
from December through June 1967 (and perhaps through July), despite
fluctuations in water levels, and no late summer spawn was detected that
related to flooding (in part, Barber et ai, 1970). Rinne (1970) also has
noted protracted spawning in a mountain-sucker of the Virgin River
system in Utah.
A pattern largely emerging from unpublished studies of stream minnows of the Sonoran and Mohave Deserts indicates a predominance of
reproduction in spring, first by older females and later by younger ones.
Old females may then develop additional complements of eggs, in some
instances throughout the summer. Males follow similar patterns, with a
surge of spawning in spring and with a few reripening at later times of
the summer period. In some instances, small fish of both sexes, spawned
late in the preceding summer, may achieve mature sizes in midsummer
and develop gametes then (Minckley and Carufel, 1967; Barber et al.,
1970; Rinne, 1970; Minckley and Barber, 1971). This produces a complex
pattern of recruitment in some species, which resembles a temperate cycle
in spring and for younger fish, and a tropical cycle (periodic, protracted
spawning) through the summer by older fish in the population.
Such a system certainly seems adaptive since at least a few reproductive
adults are available to capitalize on suitable conditions, almost throughout
the year. Catostomid fishes seem more fixed in habit, spawning principally
in late winter and early spring. The reason for the long season of reproduction by Gila mountain-suckers in Aravaipa Creek is unknown. Another
native catostomid of that stream, the Sonora sucker {Catostomus insignis),
totally failed to produce young in 1967. This also is unexplained.
Despite the volume of information on pupfishes (reviewed by Liu,
1969), only a general pattern of reproduction may yet be described. Vari-
JAMES E. DEACON AND W. L MINCKLEY
and Minckley, 1969), may well be an attunement to avoid high turbidities
and shifting stream beds by taking advantage of low, clear, summer flow.
In smaller habitats low waters appear to inhibit reproduction, despite
the stimuli of increasing day length and temperatures in spring. This may,
of course, result from nutritional deficiencies, or other factors related to
crowding in intermittent habitats. John (1963) found that speckled dace
in the Chiricahua Mountains, Arizona, spawned after spring runoff and
again after late summer rains had produced freshets. He related day length,
temperature, and flooding to spawning activity, but without the last, no
summer spawning occurred.
Similar habits are implied by Koster (1957) for longfin dace and Rio
Grande mountain-sucker (Pantosteus plebeius) in New Mexico. However,
in Aravaipa Creek, Arizona, no correlation of spawning activity with
flooding by any of the seven native species of fishes has been detected.
Longfin dace and the Gila mountain-sucker produced young continuously
from December through June 1967 (and perhaps through July), despite
fluctuations in water levels, and no late summer spawn was detected that
related to flooding (in part, Barber et ai, 1970). Rinne (1970) also has
noted protracted spawning in a mountain-sucker of the Virgin River
system in Utah.
A pattern largely emerging from unpublished studies of stream minnows of the Sonoran and Mohave Deserts indicates a predominance of
reproduction in spring, first by older females and later by younger ones.
Old females may then develop additional complements of eggs, in some
instances throughout the summer. Males follow similar patterns, with a
surge of spawning in spring and with a few reripening at later times of
the summer period. In some instances, small fish of both sexes, spawned
late in the preceding summer, may achieve mature sizes in midsummer
and develop gametes then (Minckley and Carufel, 1967; Barber et al.,
1970; Rinne, 1970; Minckley and Barber, 1971). This produces a complex
pattern of recruitment in some species, which resembles a temperate cycle
in spring and for younger fish, and a tropical cycle (periodic, protracted
spawning) through the summer by older fish in the population.
Such a system certainly seems adaptive since at least a few reproductive
adults are available to capitalize on suitable conditions, almost throughout
the year. Catostomid fishes seem more fixed in habit, spawning principally
in late winter and early spring. The reason for the long season of reproduction by Gila mountain-suckers in Aravaipa Creek is unknown. Another
native catostomid of that stream, the Sonora sucker {Catostomus insignis),
totally failed to produce young in 1967. This also is unexplained.
Despite the volume of information on pupfishes (reviewed by Liu,
1969), only a general pattern of reproduction may yet be described. Vari-