(DRAFT) - Taxonomy
Species STICKLEBACK, THREESPINE, UNARMORED
Species Id ESIS251007
Date 14 MAR 96

TAXONOMY

NAME - STICKLEBACK, THREESPINE, UNARMORED

OTHER COMMON NAMES - STICKLEBACK, THREESPINE, UNARMORED;STICKLEBACK and UNARMORED

ELEMENT CODE -

CATEGORY - Fish

PHYLUM AND SUBPHYLUM - CHORDATA,

CLASS AND SUBCLASS - OSTEICHTHYES,

ORDER AND SUBORDER - GASTEROSTEIFORMES,

FAMILY AND SUBFAMILY - GASTEROSTEIDAE,

GENUS AND SUBGENUS - GASTEROSTEUS,

SPECIES AND SSP - ACULEATUS, WILLIAMSONI

SCIENTIFIC NAME - GASTEROSTEUS ACULEATUS WILLIAMSONI

AUTHORITY -

TAXONOMY REFERENCES -

COMMENTS ON TAXONOMY -
Unarmored Threespine Stickleback

Gasterosteus aculeatus williamsoni Girard, 1854

KINGDOM: Animal GROUP: Fish

PHYLUM: Chordata CLASS: Osteichthyes
ORDER: Gasterosteiformes FAMILY: Gasterosteidae

Gasterosteus aculeatus williamsoni is a member of the threespine
stickleback species complex (10). Threespine sticklebacks are small
(usually less than 70 mm standard length), laterally compressed
fusiform fish characterized by the presence of three dorsal spines, a
robust pelvic complex and lateral plates instead of scales (52). The
first two spines are large and followed by a triangular membrane and
the last spine is small, followed by a small membrane which is
separated from the dorsal fin by a notch. The pelvic complex consists
of the pelvic girdle, and on each side a strong spine and usually one
fin ray (43). The bilateral counterparts forming the pelvic girdle
are sutured medially, and each includes an anterior process, a
posterior process, and the ascending branch which projects dorsally
along the surface of the body. The lateral plates are modified scales
that occur as a single longitudinal row along each side of the body,
sometimes covering the entire side and forming a keel on the caudal
Taxonomy - 1 (DRAFT) - Taxonomy
Species STICKLEBACK, THREESPINE, UNARMORED
Species Id ESIS251007
Date 14 MAR 96

peduncle. Wootton (52,53) and Bell (10) provide useful summaries of
morphological variation within Gasterosteus aculeatus.
Although threespine sticklebacks are notoriously variable, G. a.
williamsoni diverges from the norm for the species complex in a number
of conspicuous respects. It reaches a maximum size of about 58 mm,
but most specimens are less than 50 mm standard length (04). The body
appears to have more rounded contours than most other threespine
sticklebacks, and the posterior margins of the pectoral and caudal
fins are distinctly rounded. However, the hallmark of the subspecies
is poorly developed armor structures. The dorsal and pelvic spines
are short with weakly developed denticulations, the pelvic girdle has
a narrow ascending branch, and the suture connecting the two sides
of the pelvic girdle is relatively short. Lateral plates are entirely
lacking in the vast majority of specimens, but the maximum plate count
in the type locality (Soledad Canyon, Los Angeles County, California
(36)) reaches 6 plates per fish (total both sides). The mean plate
count ranges between 0.06 and 0.53 plates per fish at various points
along the stream in Soledad Canyon, and the frequency of zero-plated
fish varies between 76.2 and 95.6 per cent. Downstream of Soledad
Canyon, plate counts increase gradually (clinally) and armor
structures tend to be more robust (05,06,04). Except as noted,
lateral plate counts and other information on the morphology of
G. a. williamsoni are presented by Miller (36), Miller and Hubbs (38),
Ross (46) and Bell (06).
Serious problems of identification arise because convergent or
parallel evolution is a very common phenomenon within G. aculeatus.
G. a. williamsoni has been characterized largely on the basis of a
single character, lateral plate number, and systematic comparisons of
other morphological characters, by which it is reputed to differ from
other populations, have been undertaken. Outside of southern
California, populations with very low plate counts have been reported
from southern Europe, Algeria (38), the Queen Charlotte Islands,
Canada (41,42), Scotland (17,14), and Syria (27). These do not create
problems of identification because of their geographic distance, but
populations with high frequences of zero-plated specimens and low
mean plate counts occur in other southern California streams. Miller
and Hubbs (38) reported a number of populations besides the one in the
type locality in Soledad Canyon (36) in which zero-plated specimens
constitute a substantial fraction of the population: 1) the Santa
Maria River, about 2 miles from the ocean and two other streams in the
drainage, the Huasna River and Alamo Creek; 2) the Mohave River at
Victorville and near the fish hatchery; 3) the Los Angeles, San
Gabriel and Santa Ana Rivers, three rivers on the Los Angeles plain
where the sticklebacks are extinct, and 4) some northern tributaries
of the Santa Clara River. Subsequent surveys have discovered
substantial frequencies of zero-plated sticklebacks in populations
from 1) San Francisquito Canyon, another northern tributary to the
Santa Clara River (01), 2) the Sisquoc River, tributary to the Santa
Maria River (03), 3) San Antonio Creek, a small coastal stream, Santa
Barbara County (03), 4) Holcomb Creek, in the Mohave River drainage
(09), 5) Pine Valley Creek in San Diego County (21), 6) in the
Baldwin Lake area, San Bernardino County (34), and 7) in the South
Fork of the San Jacinto River, Riverside County (04). In all of these
Taxonomy - 2 (DRAFT) - Taxonomy
Species STICKLEBACK, THREESPINE, UNARMORED
Species Id ESIS251007
Date 14 MAR 96

southern California populations, the frequency of zero-plated
specimens is lower and the mean plate count is higher than in G. a.
williamsoni from Soledad Canyon, and Miller and Hubbs (22,21) have
concluded that those they reported are introduced and introgressed by
plated G. a. microcephalus (= freshwater, low morph of Hagen and
Gilbertson 1972). Additional populations with substantial frequencies
of zero-plated sticklebacks are likely to be discivered in southern
California.
The existence of zero-plated sticklebacks elsewhere in southern
California, besides the type locality in Soledad Canyon, raises the
important issue of whether they represent a monophyletic group or
complete plate loss has evolved more than once. The existence of
zero-plated sticklebacks in distant localities makes multiple origin
of complete plate loss plausible. In the absence of morphological
comparisons based on more than just plate counts, this question could
be answered. However, Buth (13) preformed an electrophortic analysis
of variation at eight gene pool loci which encode enzymes. Based on
phylogentic analysis he concluded that G. a. williamsoni from the type
locality in Soledad Canyon, Los Angeles County and from a tributary
stream, San Fracisquito Canyon, represent a monophyletic group and
that all other populations with zero-plated sticklebacks are more
closely related to G. a. microcephalus, the low plated freshwater
subspecies of Miller and Hubbs (38). Buth concluded, "A taxonomy that
recognizes only evolutionary units does not allow the application of
the name G. a. williamsoni to the San Antonio Creek population".
Based on Buth's (13) cladogram, this conclusion must be extended to
populations in the Santa Maria River drainage, and the Holcomb Creek
population appears to be an intergrade derived by the introduction
from the lower Santa Clara River. Buth (13) did not examine samples
from other populations in southern California with substantial
frequencies of zero-plated sticklebacks, and one must not assume that
they are part of a monophyletic group with G. a. williamsoni until
evidence to support that view is developed.
Another finding of practical importance in Buth's (13) study is
the existence of two alleles at the Adenosine deaminase (Ada-A,
Enzyme Commission Number 3.5.4.4) locus which are unique to G. a.
williamsoni from the Santa Clara River east of Ventura-Los Angeles
County line (including Soledad Canyon, but not San Francisquito
Canyon). Compared to the mobility of the common allele, which is
monomorphic in all other samples, these alleles had mobilities of 91
and 105 per cent. However, Buth (13) noted that this enzyme looses
activity rapidly when frozen, and it would be best to use
freshly-killed specimens for critical comparisons. In the absence of
reliable morphological criteria, "Ada-A" presents the best available
method for recognizing G. a. williamsoni.
Despite the difficulty of recognizing G. a. williamsoni using
morphologiacl criteria, its taxonomic history is reasonably simple.
The unarmored threespine stickleback was described by Girard in 1854
using specimens from the Soledad Canyon (known to him as William's
Pass), Los Angeles County, California. According to Ross (46), Jordan
and Hubbs (22) were the first authors to reduce this taxon to a
subspecies status and propose the trinomial Gasterosteus aculeatus
williamsoni. Hay (19) considered a Miocene stickleback from the
Taxonomy - 3 (DRAFT) - Taxonomy
Species STICKLEBACK, THREESPINE, UNARMORED
Species Id ESIS251007
Date 14 MAR 96

Truckee Formation, Nevada to be a subspecies of the unarmored
threespine stickleback, and named it Gasterosteus williamsoni
leptosomus. In 1908, Jordan pointed out that G. w. leptosomus was a
junior synonym to Gasterosteus doryssus, but did not comment on
possible relationships with G. a. williamsoni. In 1909 Regan compared
specimens apparently from the lower Santa Clara River (36) to
specimens from the Santa Ana River, which he named Gasterosteus
santae-annae. These forms were recognized until at least 1925 (25).
However, Bertin (12) lumped them as Gasterosteus aculeatus, an
approach that Hubbs (22) endorsed in the absence of adequate knowledge
of geographical variation within the taxon. The earliest recognition
of Gasterosteus aculeatus williamsoni as a subspecies was published by
Miller (36). Miller and Hubbs (38) recognize three eastern Pacific
basin subspecies of G. aculeatus, including G. a. williamsoni.
The type specimen, and others are housed at the Smithsonian
Institute, Washington, D.C.. A diagram comparing Gasterosteus
aculeatus williamsoni with two closly related types is located in
Miller's (37) work.

Taxonomy - 4 (DRAFT) - Status
Species STICKLEBACK, THREESPINE, UNARMORED
Species Id ESIS251007
Date 14 MAR 96

STATUS

Coded Status

E: Federal Endangered

COMMENTS ON STATUS -
U.S. STATUSES AND LAWS:
The unarmored threespine stickleback (Gasterosteus aculeatus
williamsoni) has been designated as Endangered 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 subspecies has this
status wherever found including the State of California.
This subspecies 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.
USFS -Responsible for the law enforcement/protection of this
species with applicable State and Federal laws on
public lands under their control. Also responsible
for management/recovery on Forest Service lands. The
Forest Service is responsible for integrating
management, protection, and conservation of Federally
listed species into the Forest Planning process
(36 CFR 219.19 and 219.20). Management practices that
would cause detrimental changes in water temperature
Status - 1 (DRAFT) - Status
Species STICKLEBACK, THREESPINE, UNARMORED
Species Id ESIS251007
Date 14 MAR 96

or composition, water course blockage, or sediment
deposits within 100 feet of the edges of perennial
streams, lakes or other bodies of water are prohibited
(36 CFR 219.27(e)).

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: California
DESIGNATED STATUS: Endangered
ADMINISTRATIVE AGENCY: California Department of Fish and Game
STATE STATUTE: California Endangered Species Act; Fish and Game
Code Chapter 1.5, Article 1, Section 2050.

INTERNATIONAL STATUSES, TREATIES, AND AGREEMENTS:
The IUCN Red Data Book lists the unarmored threespine stickleback
as Endangered (1977 edition). This species is also listed by the
U.S. in the Convention on Nature Protection and Wildlife Preservation
in the Western Hemisphere Annex, 1970.

ECONOMIC STATUSES:
None.

70/08/25:35 FR 13519/13520 - Proposed Listing.
70/10/13:35 FR 16047/16048 - Listed as Endangered.
79/05/21:44 FR 29566/29577 - Five Year Review.
85/07/22:50 FR 29901/29909 - Five Year Review.

Status - 2 HABITAT ASSOCIATIONS

HABITAT - AQUATIC
INLAND AQUATIC

LAND USE -
Residential
Cropland and Pasture
Orchards, Groves, Vineyards, Nurseries,
Mixed Rangeland
Streams and Canals
Reservoirs

NATIONAL WETLAND INVENTORY CODES

NWI NWICLS NWIMOD NWISPEC

Lacustrine, limnetic UB
Riverine, intermittent UB2
Riverine, intermittent SB2
Riverine, intermittent BB2
Riverine, intermittent AB1
Riverine, lower perennial UB4
Riverine, lower perennial UB3
Riverine, lower perennial UB2
Riverine, lower perennial SB4
Riverine, lower perennial SB3
Riverine, lower perennial SB2
Riverine, lower perennial RS1
Riverine, lower perennial RB1
Riverine, lower perennial BB2
Riverine, lower perennial AB5
Riverine, lower perennial AB2
Riverine, lower perennial AB1
Lacustrine, limnetic UB
Riverine, intermittent UB2
Riverine, intermittent SB2
Riverine, intermittent BB2
Riverine, intermittent AB1
Riverine, lower perennial UB4
Riverine, lower perennial UB3
Riverine, lower perennial UB2
Riverine, lower perennial SB4
Riverine, lower perennial SB3
Riverine, lower perennial SB2
Riverine, lower perennial RS1
Riverine, lower perennial RB1
Riverine, lower perennial BB2
Riverine, lower perennial AB5
Riverine, lower perennial AB2
Riverine, lower perennial AB1

COMMENTS ON HABITAT ASSOCIATIONS -
Although Wootton (52,53) provides generally applicable
information on the ecology of threespine sticklebacks, the southern
California populations are at the southern extreme of the species
range, and may exhibit ecological peculiarities. Thus, studies of the
ecology of the Soledad Canyon, Los Angeles County (01) and San Antonio
Creek, Santa Barbara County populations (23) provide valuable
background on habitat associations and preferences. G. a. williamsoni
Habitat Associations - 1 from Soledad Canyon and other populations with high frequencies of
zero-plated specimens occur in shallow (< 1 m deep) coastal streams
often flowing through riparian woodlands within xeric mixed rangeland.
The streams always have a very low gradient, and usually do not
support trout (Salmo gairdneri) or speckled dace (Rhinichthys
osculus), which often occur in higher gradient reaches of the same
drainages, sometimes along with low plated sticklebacks. Zero-plated
sticklebacks often coexist with the arroyo chub (Gila orcutti) and
mosquitofish (Gambusia affinis). In Soledad Canyon, they also occur
with Santa Ana sucker (Catostomus suntaanae) or its hybrids with
the Owens sucker (C. fumeiventris) (07). In the San Antino Creek
(Santa Barbara County) sticklebacks coexist with prickly sculpin
(Cottus asper) and, near the mouth, with staghorn sculpin (Leptocottus
armatus) and the tidewater goby (Eucyclogobius newberryi) (23).
Records of sympatry of other fish species with sticklebacks may be
obtained from the catalogue records of the fish collection of the
National History Museum of Los Angeles County, for the Santa Clara
River, from Bell (07) and for San Antino Creek from Irwin (23).
According to Baskin (01), the Soledad Canyon population of "G. a.
williamsoni appears to prefer areas of moderate flow with vegetation
for cover. Riffles and ponds are the major habitats available, and
sticklebacks tend to be most numerous in small ponds with moderate
flow. They are absent from pools which lack a flow, and from streams
with a gradient greater than 170 ft/mile. Most breeding takes place
in small, man-made pools. These sticklebacks have a high reproductive
capacity but appear to be limited by available breeding habitat."
Aquatic vegetation in which the sticklebacks may take cover include
recumbent, submerged and emergent vascular plants, and filamentous
algae. Although they are most abundant in small impoundments, behind
natural obstacles (i.e. submerged logs) or culverts under roads, they
also may be abundant along riffles if filamentous algae or emergent
marginal vegetation is present. Natural cover includes stream banks,
rocks, sunken logs and, most importantly, vegetation (vascular plants
and filamentous algae) (01). Fry generally are found in vegetation,
and presumably depend on it for protection from predatory fishes and
invertebrates. Thus, Baskin (02) estimated that 1,650 specimens
occurred in an impoundment measuring about 17 x 28.5 m, and that 56
occurred in a 5 m section of stream. Breeding was observed only in
impoundments, except on one riffle where a patch of vegetation formed
a still-water area in mid-stream. However, it was difficult to make
observations on riffles, and riffles with well-developed marginal
vegetation probably are important sites of breeding and shelter for
fry and subadults. Baskin (02) reported that small fry tend to
aggregate in warm shallow margins of impoundments. Irwin's (23)
results for San Antonio Creek sticklebacks are consistent with
Baskin's (01) observations. Clearly, natural pools or impoundments
through which the flow is maintained enhance habitat quality for these
sticklebacks.
It is worth noting that Baskin (01) observed that sticklebacks
in the upper Santa Clara River occurred in intermittant sections of
stream, which they may reach by active (04) and passive dispersal.
Intermittant reaches of stream may contain water and dessicate on
both a seasonal basis and in the summer on a daily basis. Large
numbers of sticklebacks may occur in intermittant habitat (01),
especially in years following extensive winter flooding.
The range of physical conditions experienced by populations with
zero-plated sticklebacks have been reported by Baskin (01,02) and
Irwin (23). G. a. williamsoni in Soledad Canyon generally occupies
water around 20 deg Celsius, pH 7.4 to 8.4, about 7 ppm oxygen and
conductivity was 575 to 750 micro-ohms square cm. In San Antonio
Creek (23) the seasonal range of temperature was 9 to 24 deg Celsius,
Habitat Associations - 2 dissolved oxygen concentration was 3.4 to 14 ppm, conductivity was
1000 to 2700 micro-ohms square cm. Sticklebacks generally are
euryhaline fishes and tolerate a wide range of salinities, though
Heuts (20) found lower-plated European Gasterosteus to be less
tolerant of elevated salinity. Feldmeth and Baskin (16) observed a
critical thermal maximum of 34.6 deg Celsius in G. a. williamsoni
acclimated to 22.7 deg Celsius, and it is not stressed at dissolved
oxygen concentrations above 3 ppm. Baskin (01) reported a large
number of water chemistry and limnological values for Soledad Canyon,
but the effects of other environmental parameters on unarmored
threespine sticklebacks are not known.
Studies of diatom diversity indicate that the Santa Clara River
was relatively clean in 1973 (01).
Of concern within the Soledad Canyon area is the present rate
of water draw-down and conversion of this mixed rangeland, all caused
by increasing agricultural development (i.e. citrus orchards,
vineyards, nuts, and a wide range of other vegetable crops) and
possibly by future construction of residential developments. If the
current rate of growth in agriculture and urbanization continues,
the unarmored threespine stickleback's exhistence may be something of
the past.

Habitat Associations - 3 (DRAFT) - Food Habits
Species STICKLEBACK, THREESPINE, UNARMORED
Species Id ESIS251007
Date 14 MAR 96

FOOD HABITS

TROPHIC LEVEL -
CARNIVORE

LIFESTAGE FOOD FOOD PART
General Detritus
General Worms
General Fish
General Zooplankton
General Crustaceans
General Molluscs
General Detritus
General Worms
General Fish
General Zooplankton
General Crustaceans
General Molluscs

Food Habits - 1 (DRAFT) - Environment Associations
Species STICKLEBACK, THREESPINE, UNARMORED
Species Id ESIS251007
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
G Human Association: Farm ponds
G
G
G Aquatic Features: Pool areas
G Terrestrial Features: Downed logs
G Human Association: Farm ponds
G

Environment Associations - 1 (DRAFT) - Life History
Species STICKLEBACK, THREESPINE, UNARMORED
Species Id ESIS251007
Date 14 MAR 96

LIFE HISTORY

FOOD HABITS:
Wootton (52,53) provides a review of the food of Gasterosteus
aculeatus, and studies of diet in G. a. williamsoni from Soledad
Canyon (01) and in the San Antonio Creek population (23) are
available. Prey are eaten whole. Baskin's (01) results for Soledad
Canyon population are given as percent occurrence of prey types in
stickleback stomachs in the "dry season". The most commonly occurring
forms are mayfly larvae (Ephemeroptera, 71%), Ostracoda (51.4%), fly
larvae (Diptera, 37.2%), unidentified insect parts (23.2%), snails
(Gastropoda, 19.7%), unidentified organic matter (18.6%), aphids
(Aphididae, 15.8%), Daphnia (15.0%), nematodes (12.1%), and beetles
(Coleoptera, 10.8%). Irwin (23) reports very detailed results. Space
does not permit detailed review of his results, and citing them out
of context would be misleading. Fifteen categories of food items were
reported, and their importance in the diet and use relative to
availability (electivity) varied greatly among four seasonal samples.
Both drift and benthic prey were taken, dependence on these categories
varied seasonally. A major item in the diet are chironomids, which
occur in a high frequency of stomachs most of the year and may
constitute 50% of the contents. Small crustaceans constitute a
moderately important food source year round, but in contrast to
Baskin's (01) results, mayflies never occur in more than about 15% of
the stomachs. Thus, results of the two studies agree in some respects
and contrast in others. However, they show clearly that these
sticklebacks depend almost exclusively on aquatic animal matter for
food and are opportunistic feeders that will accept a wide range of
food types. Stickleback eggs were found in 12 per cent of the
stickleback stomachs examined. All of these stickleback eggs were in
males (49).
Neither author reported the size of specimens used in stomach
content analysis, but presumably adult and large sub-adult fish were
used. Wooton (53) reported that diet changes with fish size in lake
sticklebacks, and this shift must occur in southern California
sticklebacks. An important element in this shift is from smaller to
larger individuals of the same prey species.

HOME RANGE/TERRITORY:
Threespine sticklebacks typically exhibit classic male
reproductive territoriality (52,53). Reproductively mature males,
which exhibit red and blue (or sometimes pale blue) nuptial
coloration, establish territories on the bottom near cover (usually
vegetation) in places where current is negligible (01,04). The
probability of eggs hatching increases with increased cover (47,48).
The territories are established and held by means of actual combat at
first and later by ritualized display, which predominates in agonistic
interactions once territories are established.
Baskin (01) reported on territorial male G. a. williamsoni from
Soledad Canyon, and observed that on average, males nested 63 cm from
cover (bank or vegetation), territories were 71 cm in diameter (a
value comparable to that of Wootton (52) but greater than that of
Kynard (28,29), based on much larger samples), nests (on bottom) were
Life History - 1 (DRAFT) - Life History
Species STICKLEBACK, THREESPINE, UNARMORED
Species Id ESIS251007
Date 14 MAR 96

in 22 cm of water, and flow at nests was 0.02 m/sec. The need for
large territories with negligible flow at nests may severely limit
suitable breeding territory. The shallow water in which nests are
located renders them vulnerable to slight decreases in water level.
Additional cover (e.g., flower pots) could increase the egg survival
(47,48) and probably recruitment.
Generally females and nonreproducting individuals swim in loose
schools, but Larson (56) inferred the existence of feeding territories
in a lake population of G. aculeatus. This has not been observed
elsewhere.

PERIODICITY:
G. a. williamsoni and other populations with zero-plated
sticklebacks exhibit relatively weak seasonality of feeding and
reproduction. Feeding seasonality was discussed in the above section
on FOOD HABITS. Irwin (23) observed substantial feeding throughout
the year, but prey species varied considerably. Baskin (01,02) found
that some breeding occurs all year, but is significantly higher
between January and October. Irwin (23) concluded that recruitment
in San Antonio Creek occurs from May through September. The highest
natural adult mortality in San Antonio Creek occurs in May and June,
and flood-induced juvenile mortality was high in February (though this
must vary among years). It is known that photoperiod, temperature,
and food availability influence reproduction in Gasterosteus (52,53)
and apparently these factors are sufficiently favorable most of the
year in southern California to permit some reproduction.
Wootton (52,53) reported on reproductive cycle of female G. a.
aculeatus during the breeding season. Assuming a three-month breeding
season in his population, females can spawn about every fifth day.
However, this period depends on temperature and occurs in well fed
females; reduced ration will increase the interspawning interval.
At about 21 deg Celsius, Kynard (28) observed the following male
reproductive cycle: up to 2 days for nest building, about 5 days for
egg brooding and 6 or 7 days for defense of the fry; a total of 13-14
days. However, Moodie (39) observed a male breeding cycle of about
18 days in a cooler lake. Thus, the male breeding cycle in warmer
southern California habitats might be shorter. It is not known how
many cycles males can complete in a season.
Diurnal periodicity occurs in other G. aculeatus populations
(52,53), and presumably in unarmored threespine sticklebacks as well.
G. aculeatus is less trappable at night, and presumably less active
(54). Although sticklebacks may feed at night, they tend to keep
the stomach full during the day, and stomach content volume tends to
decline over night. In some cases, they exhibit a slight crepuscular
feeding pattern. Although Worgan and Fitzgerald (54) observed low
night time stomach contents in female G. aculeatus, but nesting males
never had much food in the gut. Although the amount of time spent by
males fanning is constant throughout a 24 hour period, fanning bouts
are longer at night.

MIGRATION PATTERNS:
Although seasonal migrations are well documented for some
threespine stickleback populations and the physiological basis for
Life History - 2 (DRAFT) - Life History
Species STICKLEBACK, THREESPINE, UNARMORED
Species Id ESIS251007
Date 14 MAR 96

such migrations is well known (52,53), freshwater sticklebacks,
including those in southern California are not known to undertake
migrations. However, they actively disperse as the aquatic habitat
expands in the late fall (04) and they apparently are washed
downstream during flooding (01,23,04).

COVER/SHELTER REQUIREMENTS:
As noted in the section on territoriality, male sticklebacks
prefer (31) cover in vegetation, can establish denser breeding
territories and experience greater reproductive success when cover is
available (47). Natural cover includes stream banks, rocks, sunken
logs and, most importantly, vegetation (vascular plants and
filamentous algae (01). Fry generally are found in vegetation, and
presumably depend on it for protection from predatory fishes and
invertebrates.

REPRODUCTIVE SITE REQUIREMENTS:
As noted in sections "HOME RANGE/TERRITORY" and "COVER/SHELTER
REQUIREMENTS", the reproductive site requirments of Gasterosteus
aculeatus have received a great deal of attention (52,53). In
general, the males tend to establish territories and build nests on
the bottom in shallow, still water near cover. The nests normally
are constructed of decaying aquatic plant fibers, but males appear
to accept a wide range of vegetaion types for nest construction.
Nests generally are constructed in or near vegetation, and males are
known to prefer nesting sites within vegetation (31). A shallow pit
(about 1 cm deep) is dug in sandy muddy substrate. It has been shown
in marine G. aculeatus that increased cover permits greater efficiency
of conversion of eggs to fry by males (47,48). Male G. a. williamsoni
will nest in very shallow water (<20 cm), and although deep habitat
generally is not available to southern California sticklebacks,
G. aculeatus prefers to nest on bottom 45-85 cm deep over 15-45 cm
deep sites (31). Even though southern California stream sticklebacks
nest only in virtually still water (01), they appear to require some
circulation, which sometimes includes flow of ground water through
surface pools (04). Lindsey (32) found that English stream
G. aculeatus had the highest rate of hatching and successful
development between 20 and 24 deg Celsius, but optimum temperature for
development was negatively associated with lateral plate number.
During the reproductive season, females feed actively and invest
heavily in the production of eggs (53). Thus, no novel resources
(just more food) are required by females during the breeding season.
Fry move from the protection of their father's guarded
nest to aquatic vegetaion, often in very shallow water, presumably
for protection. They also tend to occur in relatively warm water
(01), which however is not near the critical thermal maximum for G. a.
williamsoni from Soledad Canyon (16).

REPRODUCTIVE CHARACTERISTICS:
The reproductive biology of threespine sticklebacks is
exceptionally well known (52,53). Malcolm (34) presently is studying
behavior of Gasterosteus from the Baldwin Lake area, but his research
is in progress (Summer 1985). Generation time for southern
Life History - 3 (DRAFT) - Life History
Species STICKLEBACK, THREESPINE, UNARMORED
Species Id ESIS251007
Date 14 MAR 96

California sticklebacks is one year and few if any individuals survive
to breed a second year (01,04,23). As noted in the sections above
males establish territories in shallow water with negligable flow (but
some circulation) near cover (01). A nest is constructed of aquatic
vegetation fibers in a shallow (about 1 cm deep) pit that the male
digs. Once the male creeps through, the nest, he will begin to court
females. Males court females using the "zig-zag dance", "dorsal
pricking", and a variety of displacement activities such as "creeping
through", "fanning" and "gluing". A receptive female responds with a
"heads up", and the male leads her back to the nest. He "shows" her
the nest entrance, and the female enters. He vibrates his snout
against her exposed tail, stimulating her to release her eggs, and
then he drives her out of the nest and territory. He then enters the
nest to fertilize the eggs. The courtship sequence takes from a few
minutes to at least an hour, depending on female receptivity, male
motivation and distractions. The female plays no role in
post-fertilization care of zygotes, and a number of females may be
courted within about 24 hours, before the male enters the parental
phase (refer below, "PARENTAL CARE"). The actual number of broods
produced by males and clutches produced by females per year is not
known, but under favorable conditions (suitable territories, about
20 deg Celsius, and abundant food), Gasterosteus males complete the
breeding cycle in 13-14 days (28,29), and females may produce a
brood every 5 days on average (53). Some reproduction may occur
from January through October in Soledad Canyon (01,02) and from May
through September in San Antonio Creek (23). The breeding season
is much longer and the generation time in these sticklebacks is
shorter than reported in the literature for more northerly
populations, but these parameters probably vary with latitude.

PARENTAL CARE:
As noted above, only males provide parental care. At about 21
deg Celsius (a temperature close to that prevailing in southern
California in the summer), eggs take about 5 days to hatch and males
guard the fry for about 6 days (28,29). Parental care includes
"fanning" of the eggs, without which survival is certainly lower (48)
and possibly nil (35,28,29), and they provide defense of eggs and fry
against predators. Males may capture fry in their mouths and return
them to their nest. No further association between males and young
is known. Eggs are large. Fry use yolk for a day or two after
hatching, and then become more active and begin to feed (52,53).

POPULATION BIOLOGY:
The population biology of G. a. williamsoni and other stream
sticklebacks is not well understood because of serious problems of
sampling quantatively, obtaining objective estimates of different
size class frequencies, observing them without disturbance, and
habitat heterogeneity. Wootton (53) presented an excellent review
of current knowledge of the population biology of threespine
sticklebacks, and aspects of the phenology, demography, microhabitat
distributions and environmental tolerances of southern California
populations with high frequencies of zero-plated specimens are in
Baskin (01,02), Baskin and Feldmeth (16), and Irwin (23). G. a.
Life History - 4 (DRAFT) - Life History
Species STICKLEBACK, THREESPINE, UNARMORED
Species Id ESIS251007
Date 14 MAR 96

williamsoni in Soledad Canyon and a population in San Antonio Creek
mostly consume diverse aquatic arthropods, which should be sufficently
abundant as long as habitat quality is maintained (01,23).
Sticklebacks require vegetation or other structure as cover in quiet
water for reproduction (30,31,48,47), and the young often are most
abundant in cover (01,08). Adult unarmored threespine sticklebacks
in Soledad Canyon apparently are not subject to significant predation
by fishes or other native predatory vertebrates (07,04), but the
introduced African clawed frog (Xenopus laevis), which may pose a
threat (50), has been present in its drainage for some time, and has
been spreading in recent years (51). Except for San Antonio Creek,
where the prickly sculpin (Cottus asper), a known stickleback
predator (40) and Holcomb Creek, where rainbow trout (Salmo gairdneri)
(09), also a stickleback predator (52) occur, other populations with
zero-plated specimens are not eaten by fishes. A variety of
cosmopolitan aquatic insects (e.g., belostomatids, odonates, Ranatra)
take juvenile and occasionally adult sticklebacks (52,53). Garter
snakes (Thamnophis couchi hammonidi) (11), herons and belted
kingfishers (04) feed on sticklebacks in southern California.
There have been no reports of disease in southern California
sticklebacks (though it would be difficult to detect), but males
occasionally develop cutaneous infections late in the breeding
season (04).
Southern California sticklebacks used as prey by birds frequently
develop infestations of the Coelomic tapeworm (Schistocephalus
solidus), which destroy their reproductive potential. The
ectoparasitic copepod (Lernaea cyprinacea) which often includes fatal
secondary infections, also could adversely affect stickleback
populations (52). Winter flooding in southern California may wash
sticklebacks from permanent to intermitant reaches of stream, where
they are stranded (01,04). Irwin (23) concluded that winter flooding
is a major source of mortality in San Antonio Creek, and this
conclusion is consistent with observations in the Santa Clara River
(01,04). The quantitative effects of these sources of mortality are
unknown.
Threespine sticklebacks have an excellent potential for recovery
after population decline (28,29). Females from other populations
have produced an average of 973 eggs per season under optimal
laboratory conditions (53), and the young are relatively precocious.
Males did seem to be a limiting factor on recruitment in a Santa
Clara River system population (18), but availability of suitable
nesting sites might limit the number of reproducing males. However,
males often have fewer eggs than they seem capable of brooding (28,
29), so number of nesting males may not limit recruitment even if many
mature males fail to obtain nests.
Southern California sticklebacks live through the breeding season
after they hatch, during which they reproduce and die (01,23).
The sites in which Baskin (02) estimated densities probably were
chosen because they contained abundant sticklebacks, and the densities
estimated in the pool (1,650 specimens in a 17 x 28.5 m pool) and the
riffle (5 m long) represented optimistic objectives for populations
under management.

Life History - 5 (DRAFT) - Life History
Species STICKLEBACK, THREESPINE, UNARMORED
Species Id ESIS251007
Date 14 MAR 96

SPECIES INTERRELATIONSHIPS:
Stream populations of threespine sticklebacks appear to depend
strongly on aquatic vegetation for cover for nesting males and as a
refuge for fry (52,53,01). The species of aquatic vegetation or even
the growth form do not appear to be important. Submerged, emergent
and recumbent vegetation all seem to be acceptable as long as they
provide cover and do not fill the water column so completely that
night-time respiration depleates oxygen content of the water. Oxygen
depletion does not appear to be a problem at all times (01,02), but
at times when the stream desiccates forming small remnant pools oxygen
depletion does play a major factor in survival (04).

OTHER LIFE HISTORY DESCRIPTORS:
None.

Life History - 6 (DRAFT) - Management Practices
Species STICKLEBACK, THREESPINE, UNARMORED
Species Id ESIS251007
Date 14 MAR 96

MANAGEMENT PRACTICES

RESULT MANAGEMENT PRACTICE

Beneficial Controlling/Restricting Off-Road Vehicles
Beneficial Maintaining/Controlling Water Flow
Beneficial Controlling water levels
Beneficial Maintaining undisturbed/undeveloped areas
Beneficial Land Acquisition
Beneficial Controlling pollution [thermal, chemical, physical]
Beneficial Controlling/Restricting Pesticide Use
Beneficial Controlling/Restricting Herbicide Use
Beneficial Controlling/Restricting Agricultural Practice
Beneficial Maintaining undisturbed/undeveloped areas
Beneficial Reforestation
Beneficial Transplanting wild animals
Beneficial Restricting Poaching
Beneficial Controlling/Removing Exotic Vertebrates
Adverse Dissolved Oxygen Reduction
Existing Dissolved Oxygen Reduction
Adverse Hybridization
Existing Hybridization
Adverse Off Road Vehicles
Existing Off Road Vehicles
Adverse Predation
Existing Predation
Adverse Rural Residential/Industrial Areas
Existing Rural Residential/Industrial Areas
Adverse Recreational development
Existing Recreational development
Adverse Highway/Railroads
Existing Highway/Railroads
Adverse Siltation
Existing Siltation
Adverse Groundwater drawdown
Existing Groundwater drawdown
Adverse Irrigating
Existing Irrigating
Adverse Dredging
Existing Dredging
Adverse Developing/maintaining stream bank vegetation
Existing Developing/maintaining stream bank vegetation
Adverse Applying pesticides
Existing Applying pesticides
Adverse Environmental Contamination/Pollution
Existing Environmental Contamination/Pollution
Adverse Exotic/Feral/Introducted Species
Existing Exotic/Feral/Introducted Species
Adverse Competition
Existing Competition
Adverse Erosion
Existing Erosion
Adverse
Management Practices - 1 (DRAFT) - Management Practices
Species STICKLEBACK, THREESPINE, UNARMORED
Species Id ESIS251007
Date 14 MAR 96

RESULT MANAGEMENT PRACTICE

Existing
Adverse Harvesting
Existing Harvesting
Beneficial Controlling/Restricting Off-Road Vehicles
Beneficial Maintaining/Controlling Water Flow
Beneficial Controlling water levels
Beneficial Maintaining undisturbed/undeveloped areas
Beneficial Land Acquisition
Beneficial Controlling pollution [thermal, chemical, physical]
Beneficial Controlling/Restricting Pesticide Use
Beneficial Controlling/Restricting Herbicide Use
Beneficial Controlling/Restricting Agricultural Practice
Beneficial Maintaining undisturbed/undeveloped areas
Beneficial Reforestation
Beneficial Transplanting wild animals
Beneficial Restricting Poaching
Beneficial Controlling/Removing Exotic Vertebrates
Adverse Dissolved Oxygen Reduction
Existing Dissolved Oxygen Reduction
Adverse Hybridization
Existing Hybridization
Adverse Off Road Vehicles
Existing Off Road Vehicles
Adverse Predation
Existing Predation
Adverse Rural Residential/Industrial Areas
Existing Rural Residential/Industrial Areas
Adverse Recreational development
Existing Recreational development
Adverse Highway/Railroads
Existing Highway/Railroads
Adverse Siltation
Existing Siltation
Adverse Groundwater drawdown
Existing Groundwater drawdown
Adverse Irrigating
Existing Irrigating
Adverse Dredging
Existing Dredging
Adverse Developing/maintaining stream bank vegetation
Existing Developing/maintaining stream bank vegetation
Adverse Applying pesticides
Existing Applying pesticides
Adverse Environmental Contamination/Pollution
Existing Environmental Contamination/Pollution
Adverse Exotic/Feral/Introducted Species
Existing Exotic/Feral/Introducted Species
Adverse Competition
Existing Competition
Adverse Erosion
Existing Erosion
Management Practices - 2 (DRAFT) - Management Practices
Species STICKLEBACK, THREESPINE, UNARMORED
Species Id ESIS251007
Date 14 MAR 96

RESULT MANAGEMENT PRACTICE

Adverse
Existing
Adverse Harvesting
Existing Harvesting

COMMENTS ON MANAGEMENT PRACTICES -
The biology of Gasterosteus aculeatus williamsoni makes it
more vulnerable to extinction than any typical stickleback population.
However, its endemism and proximity to expanding metropolitan Los
Angeles have rendered it particularly vulnerable. Specific threats
have been outlined in Miller (37), the Recovery Plan (49), and Ono
(44). Factors that have brought it to its current endangered status
include the following:

1. Channelization which eliminates: (a) still water habitat needed for
breeding (64); and (b) aquatic vegetation that shelters fry and
generally increases flow velocity faced by weak-swimming
sticklebacks (01).
2. Ground and surface water use (drawdown), which decreases available
habitat, and ultimately causes elimination of riparian vegetation.
3. Introductions of exotic aquatic organisms. Miller (37) and Baskins
(01) suggested that introduced mosquito fish (Gambusia) might
compete with sticklebacks for food. Sunfish apparently caused
extinction of a Gasterosteus population in Washington (30,31), and
thus pose a potential threat if introduced. However, they do
coexist with sticklebacks in other southern California streams
(04). Appearance of the African clawed frog (Xenopus laevis) in
the Soledad Canyon area may pose a threat. It was described as a
voracous nonspecific feeder (50), and it recently has been
spreading in southern California and in the Soledad Canyon area.
Other predatory fishes that tolerate warm water could have
contributed to reduction of stickleback populations.
4. Industrial and residential (urban) construction has several
potential indirect impacts. It increases pressure for
channelization of seasonally flooded streams and for ground and
surface water diversion. It also increases the potential for toxic
spills and runoff of pesticides, for eutrophication due to sewage
leaching and fertilizer runoff, and for increase runoff which may
scour habitat, cause siltation of still water areas, and wash
sticklebacks into areas of intermittant stream beds. Increased
human population density also increases the probability of
introductions of exotic species.
5. Agricultural development in southern California also has a number
of impacts. It often depends on use of limited local supplies of
ground water, resulting in loss of habitat, it may result in
release of leached nutrients or inorganic toxins, increased erosion
and siltation (both are caused by present agricultural practices
and clearing of new lands for pasture and field). Siltation causes
habitat distruction by covering the bottom and pools with fine
sediment or completely filling in pools. Both aspects cause
Management Practices - 3 (DRAFT) - Management Practices
Species STICKLEBACK, THREESPINE, UNARMORED
Species Id ESIS251007
Date 14 MAR 96

detrimental habitat distruction that in turn effects this species
reproduction (i.e. destroys breeding grounds).
6. The development of recreational parks in Soledad Canyon may
affect the stream through grading, and use of off-road vehicles
along and in the stream may adversely affect sticklebacks by
eliminating aquatic and riparian vegetation.
7. A southern Pacific Railroad route runs through Soledad Canyon,
including the area immediately upstream of the most upstream
population of G. a. williamsoni, and a chemical spill from a train
has the potential to eliminate the unarmored threespine stickleback
from the type locality.
8. Excessive growth of aquatic vegetation (caused by many factors,
such as: fertilizer inflow from nearby agriculture and mild
siltation, both of which increase available nutrients) may reduce
dissolved oxygen through plant respiration and decomposition.

Populations of G. aculeatus with high frequencies of zero-plated
individuals were once abundant in low gradient reaches of the Los
Angeles, San Gabriel and Santa Ana Rivers (15,36,37) and have been
eliminated by some combination of the factors listed above. This
restriction of the range of sticklebacks in southern California
provided the original impetus for placing the subspecies in Endangered
status. They also may have been extirpated in other streams before
discovery. For example, small numbers of sticklebacks, some
zero-plated, were found in the South Fork of the San Jacinto River,
Riverside County (04). However, the low gradient reaches of the San
Jacinto River in the San Jacinto Valley, which probably provided
suitable habitat, have long since dried up, apparently because of
groundwater exploitation (55). If sticklebacks occurred there, they
probably had high frequencies of zero-plated individuals and have
disappeared before being detected.
Items 1,3,4,6 and 7 above, are particularly serious problems in
Soledad Canyon, possibly the only habitat of true G. a. williamsoni
(and thus the place where conservation efforts should be most intense.
These factors are a persistant threat to the population that may
require regulatory attention into the foreseeable future.
All southern California populations of Gasterosteus, regardless
of their morphology or precise taxonomic status will be threatened
by both agricultural and urban development. Inhabitation of such
small aquatic habitat patches, characteristic of southern California
drainages, renders sticklebacks there vulnerable to even more
environmental distrurbance.
G. a. williamsoni and other populations with zero-plates face two
additional environmental threats. Members of these populations can
hybridize with more highly armored sticklebacks (46), and introduction
of such sticklebacks to their habitats could result in introgression.
In addition, predatory fishes tend to prey selectively on G. aculeatus
with plate counts other then seven per side (10), and introduction of
predatory fishes to the habitats of populations with zero-plated
individuals might result in their extinction or in selective loss of
specimens with other plate counts.

Management Practices - 4 (DRAFT) - Management Practices
Species STICKLEBACK, THREESPINE, UNARMORED
Species Id ESIS251007
Date 14 MAR 96

APPROVED PLAN:
U.S. Fish and Wildlife Service. 1985. Unarmored Threespine
Stickleback (Revised). U.S. Fish and Wildl. Serv., Portland, OR.,
80 pp.

The primary objective of the Unarmored Threespine Stickleback
Recovery Plan is to restore the species to a self-sustaining
population and reclassify from Endangered status to Threatened.

The recovery plan activities necessary to acheive the reclassification
criteria are to:

1. Restore and maintain essential and existing habitat at optimum
conditions (i.e. maintain water table, maintain water flow, control
industrial/urban/agricultural development, prevent siltation
caused by many of the abive activities, and also control such
activities as pesticide/herbicide mis-use and exposure to other
pollutants detrimental to this species existence);
2. Identify essential habitat, and determine need for acquistion;
3. Preserve and protect stickleback populations, and review status,
habitat requirements, and distribution of populations;
4. Protect stickleback populations by preventing the introduction of
exotic organisms, removing the exotic predators, preventing illegal
take, implementing measures as a contigency to protect the
sticklebacks from extinction, and monitoring populations;
5. Establish viable populations at other sites;
6. Implement an information and education program, (a) to inform
public about Unarmored threespine stickleback distribution,
identification, and legal status; (b) install informational signs
to prevent habitat degradation (i.e. Off-road vehicles, overpumping
of groundwater, flooding from irrigation discharge, etc.);
(c) provide information regarding recovery; and (d) encourage
public support of recovery efforts.;
7. Enforce laws and regulations which provide legal protection to UTS
populations and habitat.

Management Practices - 5 (DRAFT) - References
Species STICKLEBACK, THREESPINE, UNARMORED
Species Id ESIS251007
Date 14 MAR 96

References

***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCURRENCE *****

01 Baskin, J.N. 1974. Survey of the unarmored threespine stickleback
(Gasterosteus aculeatus williamsoni) in the upper Santa Clara River
drainage. Final Rep. for Bur. of Sport Fish. and Wildl. Contract
No. 14-16-001-5387SE. U.S. Fish and Wildl. Serv., Wash., D.C.,
iii + 66 pp.
02 Baskin, J.N. 1975. Biology and habitat of the unarmored
threespine stickleback (Gasterosteus aculeatus williamsoni) in
the upper Santa Clara River, California. Contract AB-27. Calf.
Dept. of Fish and Game, Sacramento, CA. iv + 28 pp.
03 Baskin, J.N. and M.A. Bell. 1976. Unarmored threespine
stickleback survey and report. Contr. No. 39-5495, U. S. Dept.
of Agric., Forest Serv., Pasadena, CA., 47 pp.
04 Bell, M.A. 1974-1979. Unpubl. data. Field note book. Dept. of
Ecol. and Evolution, State Univ. of New York, Stoney Brook.
05 Bell, M.A. 1975. The distribution and systematics of the
unarmored stickleback, Gasterosteus aculeatus williamsoni (Girard),
in the Santa Clara River system. Contract No. AB-23, Calf. Dept.
of Fish and Game, Sacramento, CA., 18 pp.
06 Bell, M.A. 1976. The evolution of phenotypic diversity in
threespine sticklebacks (Gasterosteus aculeatus). Ph.D.
Dissertation, Univ. of Calif., Las Angeles, Calf.
07 Bell, M.A. 1978. Fishes of the Santa Clara River system, southern
California. Nat. Hist. Mus., Los Angeles Co. Contrib. Sci.
295:1-20.
08 Bell, M.A. 1979. Low plate morph of the threespine stickleback
breeding in salt water. Copeia 1979:529-533.
09 Bell, M.A. 1982. Melanism in a high elevation population of
Gasterosteus aculeatus. Copeia 1982:829-835.
10 Bell, M.A. 1984. Evolutionary phenetics and genetics: the
threespine stickleback, Gasterosteus aculeatus, and related
species. In: Turner, B.J. Evolutionary Genetics of Fishes, New
York, Plenum. pp. 431-528.
11 Bell, M.A. and T.R. Haglund. 1978. Selective predation of
threespine sticklebacks (Gasterosteus aculeatus) by garter snakes.
Evol. 32:304-319.
12 Bertain, L. 1925. Recherches bionomiques, biometriques et
systematiques sur les Epinoches (Gasterosteides). Ann. Inst.
Oceanogr. Monaco 2:1-204.
13 Buth, D.G. 1984. Genetic affinities of freshwater populations of
Gasterosteus aculeatus williamsoni. Job Order 40-91T5-0-974, U.S.
Forest Serv., Pasadena, CA., 67 pp.
14 Campbell, R.N. 1985. Morphological variation in the threespine
stickleback (Gasterosteus aculeatus) in Scotland. Behaviour 93:
161-168.
15 Culver, G.B. and C.L. Hubbs. 1917. The Fishes of the Santa Ana
system of streams in southern California. Lorquinia 1:82-83.
16 Feldmeth, C.R. and J.N. Baskin. 1976. Thermal and respiratory
studies with reference to temperature and oxygen tolerance for the
unarmored stickleback Gasterosteus aculeatus williamsoni Hubbs.
References - 1 (DRAFT) - References
Species STICKLEBACK, THREESPINE, UNARMORED
Species Id ESIS251007
Date 14 MAR 96

Bull. So. Calif. Acad. Sci. 75:127-131.
17 Giles, N. 1983. The possible role of calcium levels during the
evolution of phenotypic diversity in Outer Herbridean populations
of the threespine stickleback, Gasterosteus aculeatus. J. Zool.
London 199:535-544.
18 Haglund, T.R. 1981. Differential reproduction among lateral plate
phenotypes of Gasterosteus aculeatus, the threespine stickleback.
Ph. D. diss., Univ. of Calif., Los Angeles.
19 Hay, O.P. 1907. A new fossile stickleback fish from Nevada.
Proc. U.S. Nat. Mus. 32:271-273.
20 Heuts, M.J. 1947. Experimental studies on adaptive evolution in
Gasterosteus aculeatus L. Evolution 1:89-102.
21 Hubbs, C.L. 1973. Pers. comm. Enclosed in: Memorandum on source
of stock of sticklebacks in Pine Valley Creek, San Diego County,
CA. (March 1973). Hubbs Library, Scripps Inst. of Ocean.,
La Jolla, CA.
23 Irwin, J.F. 1982. The distribution and natural history of the
unarmored threespine stickleback. Gasterosteus aculeatus
williamsoni (Girard) in San Antonio Creek, California. Contr. No.
11310-1289-80, U.S. Fish and Wildl. Serv., Sacramento, CA.
i + 52 pp.
24 Jordan, D.S. 1908. Note on a fossile stickleback from Nevada.
Smith. Misc. Coll. 52:117.
25 Jordan, D.S. 1925. Fishes. Appleton, New York, xv + 773 pp.
26 Jordan, D.S., and C.L. Hubbs. 1925. Record of fishes obtained by
D.S. Jordan in Japan, 1922. Mem. Carnegie Mus. 10:93-346.
27 Krupp, F., and B.W. Coad. 1985. Notes on a population of the
threespine stickleback, Gasterosteus aculeatus, from Syria.
Senckenbergiana Biol. 66:35-39.
28 Kynard, B.E. 1978. Breeding behavior of a lacustrine population
of threespine sticklebacks (Gasterosteus aculeatus L.). Behavior
67:178-202.
29 Kynard, B.E. 1978. Nest desertion of male Gasterosteus aculeatus.
Copeia 1978:702-703.
30 Kynard, B.E. 1979. Population decline and change in frequencies
of lateral plates in threespine sticklebacks (Gasterosteus
aculeatus). Copeia 1979:635-638.
31 Kynard, B.E. 1979. Nest habitat preference in low plate morphs in
threespine sticlebacks (Gasterosteus aculeatus). Copeia 1979:
525-528.
32 Lindsey, C.C. 1962. Experimental study of meristic variation in
a population of threespine sticklebacks, Gasterosteus aculeatus.
Can. J. Zool. 40:271-312.
33 MacLean, J.A. 1980. Ecological genetics of threespine
sticklebacks in Heisholt Lake. Can. J. Zool. 58:2026-2039.
34 Malcolm, J. 1985. Pers. comm. Letter to: M.A. Bell (June 1985),
Dept. of Bio., Univ. of Redlands, Redlands, Calf.
35 McPhail, J.D. 1969. Predation and the evolution of a stickleback
(Gasterosteus). J. Fish. Res. Bd. Can. (now Can. J. Fish. Aquat.
Sci.) 26:3183-3208.
36 Miller, R.R. 1960. The type locality of Gasterosteus aculeatus
williamsoni and its significance in the taxonomy of California
sticklebacks. Copeia 1960:348-350.
References - 2 (DRAFT) - References
Species STICKLEBACK, THREESPINE, UNARMORED
Species Id ESIS251007
Date 14 MAR 96

37 Miller, R.R. 1961. Man and the changing fish fauna of the
American Southwest. Pap. Mich. Acad. Sci., Arts, Lett. 1960,
46:365-404.
38 Miller, R.R. and C.L. Hubbs. 1969. Systematics of Gasterosteus
aculeatus, with particular reference to intergradation and
introgression along Pacific Coast of North America: a commentary
on a recent contribution. Copeia 1969:52-69.
39 Moodie, G.E.E. 1972. Morphology, life history and ecology of an
unusual stickleback (Gasterosteus aculeatu) in the Queen Charlott
Islands, Canada. Can. J. Zool. 50:721-732.
40 Moodie, G.E.E. 1972. Predation, natural selection and adaptation
in an unusual threespine stickleback. Heredity 28:155-167.
41 Moodie, G.E.E., and T.E. Reimchen. 1973. Endemism and
conservation of sticklebacks in the Queen Charlotte Islands. Can.
Field-Nat. 87:173-175.
42 Moodie, G.E.E., and T.E. Reimchen. 1976. Phenetic variation and
habitat differences in Gasterosteus populations of the Queen
Charrlotte Islands. Syst. Zool. 25:49-61.
43 Nelson, J.S. 1971. Comparison of the pectoral and pelvic
skeletons and some other bones and their phylogentic implications
in the Aulorhynchidae and Gasterosteidae (Pisces). J. Fish. Res.
Bd. Can. 28:427-442.
44 Ono, R.D., J.D. Williams and Wagner. Vanishing Fishes of North
America. Stone Wall Press, Wash., D.C., xii + 257.
45 Regan, C.T. 1909. The species of threespine sticklebacks
(Gasterosteus). Ann. Mag. Natur. Hist. Ser. 8., 4:435-437.
46 Ross, S.T. 1973. Systematics of Gasterosteus aculeatus (Pisces:
Gasterosteidae) in central and southern California. Nat. Hist.
Mus. Los Angeles Co. Contrib. Sci. 243:1-20.
47 Sargent, R.C. 1982. Territory quality, male quality, courtship
intrusions, and female nest-choice in the threespine stickleback,
Gasterosteus aculeatus. Anim. Behav. 30:364-374.
48 Sargent, R.C., and J.B. Gebler. 1980. Effects of nest site
concealment on hatching success, reproductive success, and paternal
behavior of the threespine stickleback, Gasterosteus aculeatus.
Behav. Ecol. Sociobiol. 7:137-142.
49 Sasaki, S., J.N. Baskin, B. Beall, J.A. St. Amant, C.C. Swift and
M.A. Bell. 1977. Recovery Plan for the Unarmored Threespine
Stickleback. Goleta, CA. Calf. Dept. of Fish and Game, Goleta.
60 pp.
50 St. Amant, J.A. and F.G. Hoover. 1973. African clawed frog,
Xenopus laevis (Daudin), established in California. CA. Fish
and Game 59:151-153.
51 Swift, C.C. 1985. Pers. comm. Nat. Hist. Mus. of Los Angeles Co.,
Los Angeles, CA.
52 Wootton, R.J. 1976. The Biology of the Sticklebacks. NY Academic
Press, x + 385 pp.
53 Wootton, R.J. 1984. A functional biology of sticklebacks.
Univ. Calif. Press, Berkeley. 265 pp.
54 Worgan, J.P., and G.J. FitzGerald. Diel activity and diet of three
sympatric sticklebacks in tidal marsh pools. Can. J. Zool. 59:
2375-2379.
55 Ziegler, L.B. 1971. Pers. comm. Conversation with M.A. Bell
References - 3 (DRAFT) - References
Species STICKLEBACK, THREESPINE, UNARMORED
Species Id ESIS251007
Date 14 MAR 96

References - 4 (DRAFT) - References
Species STICKLEBACK, THREESPINE, UNARMORED
Species Id ESIS251007
Date 14 MAR 96

(1971). San Jacinto, CA.
56 Larson, G.L. 1976. Social behavior and feeding ability of two
phenotypes of Gasterosteus aculeatus in relation to their spatial
and trophic segregation in a temperate lake. Can. Jour. Zool.
54:107-121.

***** REFERENCES FOR N-OCCURRENCE NARRATIVE ONLY *****

01 Baskin, J.N. 1974. Survey of the unarmored threespine stickleback
(Gasterosteus aculeatus williamsoni) in the upper Santa Clara River
drainage: Final Report for Bureau of Sport Fish. and Wildl.
Contr. No. 14-16-001-5387SE. U.S. Fish and Wildl. Serv., Wash.,
D.C., iii + 66 pp.
02 Baskin, J.N. and M.A. Bell. 1976. Unarmored threespine
stickleback survey and report. Contr. No. 39-5495. U. S. Dept.
of Agric., Forest Serv., Pasadena, Calf. 47 pp.
03 Bell, M.A. 1974-1979. Unpubl. data. Field notebook. Dept. of
Ecol. and Evolution, State Univ. of New York, Stoney Brook.
04 Bell, M.A. 1975. The distribution and systematics of the
unarmored stickleback, Gasterosteus aculeatus williamsoni (Girard),
in the Santa Clara River system. Contr. No. AB-23, Calif. Dept.
of Fish and Game, Sacramento. 18 pp.
05 Bell, M.A. 1976. The evolution of phenotypic diversity in
threespine sticklebacks (Gasterosteus aculeatus). Ph.D.
Diss., Univ. of Calf., Los Angeles.
06 Bell, M.A. 1982. Melanism in a high elevation population of
Gasterosteus aculeatus. Copeia 1982:829-835.
07 Buth, D.G. 1984. Genetic affinities of freshwater populations of
Gasterosteus aculeatus williamsoni. Job Order 40-91T5-0-974. U.S.
Forest Serv., Pasadena, Calf., 67 pp.
08 Culver, G.B. and C.L. Hubbs. 1917. The Fishes of the Santa Ana
system of streams in southern California. Lorquinia 1:82-83.
09 Hubbs, C.L. 1973. Pers. comm. Enclosed in: Memo on source
of stock of sticklebacks in Pine Valley Creek, San Diego Co.,
CA. (March 1973). Hubbs Library, Scripps Inst. of Ocean.,
La Jolla, Calf.
10 Malcolm, J. 1985. Pers. comm. Letter to: M.A. Bell (June 1985),
Dept. of Bio., Univ. of Redlands, Redlands, Calf.
11 Miller, R.R. 1960. The type locality of Gasterosteus aculeatus
williamsoni and its significance in the taxonomy of California
sticklebacks. Copeia 1960:348-350.
12 Miller, R.R. and C.L. Hubbs. 1969. Systematics of Gasterosteus
aculeatus, with particular reference to intergradation and
introgression along Pacific Coast of North America: a commentary
on a recent contribution. Copeia 1969:52-69.
13 Regan, C.T. 1909. The species of threespine sticklebacks
(Gasterosteus). Ann. Mag. Natur. Hist. ser. 8, 4:435-437.
14 Sasaki, S., J.N. Baskin, B. Beall, J.A. St. Amant, C.C. Swift and
M.A. Bell. 1977. Recovery Plan for the Unarmored Threespine
Stickleback. Calf. Dept. of Fish and Game, Goleta. 60 pp.
15 Ziegler, L.B. 1971. Pers. comm. Conversation with M.A. Bell
(1971). San Jacinto, CA.
References - 5 (DRAFT) - References
Species STICKLEBACK, THREESPINE, UNARMORED
Species Id ESIS251007
Date 14 MAR 96

References - 6