Jemez Feral Guppies; McCauley Springs, New Mexico
Jemez
feral male
© Alan S. Bias – Feb. 17, 2017
Permission granted for nonprofit
reproduction or duplication of photos and text in entirety with proper credit
for learning purposes only.
NOTE: All photos by author or Tom Coggins with express permission.
INTRODUCTION
Nestled high in the Jemez Mountains
of Sandoval County, New Mexico, at an elevation of around 7350’ (2240.28
meters) reside one of the most unique and oldest established feral populations
of Poecilia reticulata in North America.
This self-sustaining population is not only a jewel for livebearer
enthusiast tanks, but the focus of much formally published research. As with most thermal spring environments
throughout the United States, conditions can be rather harsh for a species
evolved in a tropical setting. Overall, size of habitable range is
normally limited by temperature extremes, predation, and water chemistry to the
first few pools near issuing thermal source.
In others habitation will extend downstream to a point where minimum
survivable temperatures are no longer maintained during winter extremes.
While published research indicates a stocking date ca. 1975
or before of “feeder Guppies”, Jemez has varying sources suggesting initial
dates of introduction ranging from the late 1940's - 1960's. This
coincides with most North American feral populations. Based on known genotype
and phenotypical expressions, the Jemez population is unique in that individuals
express little indication of founding members deriving from modern Domestic
Guppy strains. While likely not
wild-caught, they show little in the way of domestication. Since their introduction having evolved into
an interesting study population for researchers and breeders alike.
ENVIRONMENTAL CONDITIONS
Prior
published testing U.S. Geological Survey at McCauley Springs revealed a thermal
discharge rate of between 310 - 400 gpm.
The same study indicated an average discharge temperature of between
30.6 - 31.6*C. Specific Conductance
ranged between 160 - 180 S/cm.
Analysis
of tritium levels at McCauley Springs were indicative of water entering the
ground prior to 1953, though also suggestive of some water entering post this
date. Water is circulated in the upper
1500’ of the ancient Valles Caldera moat and heated by geothermal heat flux
common in the region. While many springs
in the regions are much hotter, McCauley is generally considered a “Warm
Spring”, with dilution in ground water supply, having a pH of 8.0 and
corresponding lower levels of most minerals.
My Jemez study
population derive from a large collection of individuals on July 15, 2016. Guppy
habitation was limited primarily to the first two pools after thermal
discharge. Greater numbers of Poecilia reticulata and Gambusia geserei reside
in the first pool, as compared to the second. Average depth of poos was around
3 feet at center with shallow edges. Water
leaving the McCauley Spring Stream flows into the East Jemez River, before entering
the Jemez River proper. Water
temperature on the date of collection was just over 32.2*C at spring source,
with slightly varying pH readings of 8.0+.
Water temperature in the first habitable pool was over 31.1*C, with a
noticeable drop in the second pool. Each
pool was strewn with sand and rock of varying size. An abundance of plant growth resembling Naja
Grass (Najas guadalupensis) and algae was present in the first pool, while lower
pools lacked vegetation.
The indicated pool temperature is
considered within “habitable range” for Poecilia reticulata, though it is
nearing the upper maximum limit. Extreme
limit need not be “lethal” in immediate fashion to result in long-term
repercussions. Male guppies have been
demonstrated to have preference for slightly lower temperatures (24.5*C) vs.
females (28.2*C) for optimal development of secondary sexual characters; in the
form of color ornaments and gonopodia.
Lower temperatures can result in delayed maturation, and higher
temperatures in deformity. Further
studies support a reduction in overall body mass, growth, reproduction and
locomotion, in both sexes, for individuals reared long-term in temperatures in
excess of 30*C.
McCauley
Springs pool, photo courtesy of Tom Coggins
Just as temperature restricts these
feral populations, so does predation. At McCauley predation in the first
two pools is limited to resident non-native Gambusia geserei, birds,
crustaceans, and insects. The
presence of Gambusia affinis in other locations is known to greatly restrict
feral juvenile Guppy population levels. Native
species of Rio Grande Sucker, Longnose Dace and Flathead minnow are found in the
East Fork of the Jemez River, well below the restricted Poecilia reticulata
zone of habitation.
PHENOTYPICAL OBSERVATIONS
Collected fish
showed no signs of parasitic infestation, nor have subsequent captive
raised. This population may still retain genetic predisposition for
resistance. Further benefit is derived in
the form of constant high water temperature beyond 28.9*C, which is lethal to
Ichthyobodo necator (Costia). Individuals pretty much match descriptions
of published research by Nicoletto & Kodric-Brown (See: Scientific Study Excerpts). Overall individuals are very
reflective with minimal ornamental orange spotting in those collected, and F1
offspring.
Jemez
feral male foraging
Captive bred F2
and F3 show an expected increase in both red and yellow color ornaments in males,
when reared with no predation. Spotting
remains very distinct, with circular patches surrounded by iridophore /
leucophores circular rings. Also, noted
is an increase in upper and lower sword ornaments with minimal extension.
Nearly all
collected males and offspring are hyaline dorsal. Some express black
melanophores in the dorsal, but not the O. Winge trait known as Maculatus.
The majority of males express basic wild-type oval-tail, a percentage small top-sword
with minimal extension, and the remainder rudimentary flag-tails. A very reflective iridophore ring surrounds
primary ectopic melanophore “eye spots” in the anterior body. Violet-blue
iridophore pattern is present, in nearly all males in the body, to include long
linear patches.
Potential extreme temperature issues
manifest in two forms in collected individuals:
size and shape. Size reduction is
evident both sexes collected at McCauley Springs. However, this condition did not completely
manifest in F1 offspring reared under cooler temperatures. Males and females showed dramatic increase in
size under optimum temperature and feeding regimen. Though size disparity remained between the
sexes, with females expressing a proportionally larger increase in overall
size.
A high percentage
of collected females expressed little or no tapering of posterior peduncle,
likely as a result of high environmental temperatures in the first pool.
This “thickness” has alleviated somewhat in captive raised fish, though in general
thickness in female body form is much greater than many wild or captive bred
populations. Males in turn, have
demonstrated just the opposite.
Collected males demonstrate a “linear and lanky” appearance, despite low
velocity water conditions. Captive
reared, to a high degree, are much more robust in body type. In general, the overall body size has increased
and lengthened in both males and females.
Jemez
Springs feral male
All fish appear
to be heterozygous or homozygous Purple Body Mutation (Pb). Lifespan appears longer
than some feral populations I have worked with, and consistent with others. Research indicates they have evolved over
multiple generations under limited predation on a diet consisting mostly of
algae. Jemez males phenotypically resemble
the Kemp 2008 Quare study population in many ways, and likely demonstrate the
same fairly low UV peaks. Melanophore ornaments are both circular and
linear, with the latter more predominant. Good fertility is evident, with
moderate size litters of 15-30 fry. Based on breeding results this
population shows little, if any, sign of additional infusion from other sources
since initial stocking(s). All research papers seem hesitant to cite
stocking date earlier than late 1960-70’s. From what I have informally
gathered and observed, it seems likely an earlier stocking date is more than plausible.
A percentage of
males express Iridescens (Ir); “reflective dorsal spot”. This in itself is
suggestive of a much earlier stocking date. Ir was present in early
breeder tanks 1920-40’s and prior to modern collections of Poecilia reticulata
wingei (to include those known as Endler’s Livebearer).
Iridescent
Male with Reflective Dorsal Spot
All females are
color tail / neutral oval-tail, with the exception of limited purple-blue
iridophores (Pb expression) &/or yellow xanthophore in the form of Flavis (Fla) in the caudal base.
Females express much in the way of reflective qualities, as found in
males, as compared to many other feral populations or wild populations. Including purple-blue iridophores, heavy
reticulation, and black striping on anterior shoulders along the lateral line.
This is suggestive of “overall” Jemez reflectivity stemming from X-link
&/or autosomal modes of inheritance.
Population appears homozygous grey, in wild caught and in captive bred
to date.
Jemez
feral females
Surprisingly, this population does
not exhibit a very high "fright or flight" response to human traffic
or movement from above, and is known for gathering around bathers entering the
pools in large schools. Under high
temperature parameters this increased mobility may be indicative of low
predation levels on adults (Gambusia geserei predation limited to juveniles)
&/or low satiation levels (limited food resources in small area of
habitation) for the group constituents as a whole. Collected individuals easily settle into
captivity in uncovered tanks with high water levels. Readily respond to feeding, and unlike
Poecilia reticulata wingei variants, take little notice during tank
maintenance. Though interestingly, when
removed and confined to small tanks during photography, males expressing near
wild-type color ornaments exhibit higher levels of agitation and continuous
movement, as opposed to those expressing increased color / pattern arising from
lack of predation in captive rearing.
RESEARCH STUDY EXCERPTS
Kodric-Brown (1989) utilized 2 study populations, Paria wild [Trinidadian]
and Jemez feral [McCauley Springs, NM]. McCauley Springs feral
express reduced orange spotting in comparison to other populations. Not
surprisingly, it was reported “Females from the Jemez population showed
significant disagreement in their preferences for individual males.”
Jemez males exhibit increased iridophore spotting (blue and white), and
increased circular and linear melanophore spots. Jemez males are very
iridescent purple-blue, often expressing: Iridescens (Ir), (Winge 1922b;
See also: Iridscens (Ir), Blacher 1928; Smargd
Iridescens (SmIr), Dzwillo 1959; Blue Iridescent Spot, Kottler
2013; Reflective Dorsal Spot (RDS), Bias 2013).
The wild type guppies used in this study were from a third
generation laboratory colony derived from a feral population located in the
McCauley hot spring in the Jemez Mountains of New Mexico. This population has
been there for at least 16 years (R. Thorn-hill, personal communication). All
fish appeared to be in good physical condition. The three male tail types used
were upper sword, flag, and round... …These three tail types are common in the
McCauley springs population (personal observation). (Nicoletto 1991).
Offspring reared in the laboratory encountered different
environmental conditions from their field-caught sires. A laboratory
environment, with its abundant food and constant conditions, may have permitted
the expression of ornaments in male offspring that were present, but not
expressed, in field-caught sires… …In other words, in the laboratory
environment we may find an uncoupling of ornamentation and constitution, so
differences in the ornamentation of offspring of different sire types were not
observed. The uncoupling argument may also explain why the offspring of
preferred males were not more ornamented than the offspring of non-preferred
males as both the Fisherian and adaptive models predict. (Nicoletto 1995)
In this study, the field-caught sires had significantly fewer
orange spots with less relative area than their laboratory reared sons…
…and the heritability estimate for orange was not significantly different from
zero, indicating little or no heritability. This suggests that the sires may
have been unable to express their orange ornamentation because of adverse
environmental conditions. The environment of the Jemez Mountain sires is highly
oligotrophic and the fish feed primarily on algae. I examined the gut contents
of 27 guppies in 1987 from the Jemez population and found all to contain algae,
and only one large female contained a single unidentified insect.
Although nothing is known about the development of orange ornamentation in
guppies reared exclusively on a diet of algae, they are known to have slower
growth rates than guppies fed Daphnia or Tetramin (Dussault & Kramer 1981). (Nicoletto 1995)
Guppies used in this study were the laboratory-born offspring of
field-caught guppies from a feral population located in McCauley Hot Spring in
the Jemez Mountains of New Mexico. This population has lived in the
spring for at least 23 years (Koster W, personal communication). These fish are
descendants of domesticated "feeder guppies" that are somewhat
similar in appearance to wild-type guppies (Nicoletto, 1993), but they are
probably not as variable (Endler JA, personal communication). (Nicoletto 1996)
Jemez males had significantly more iridescent coloration (x =
29.6%, SE= 11.40) than Trinidad males (x = 4.380, SE = 4.45). Jemez males also
had two types of iridescent spots, blue and white, whereas Trinidad males only
had white spots. There were no significant differences between Trinidad and
Jemez males for the percent of their bodies covered with orange or black color
spots... Both Trinidad and Jemez females preferred males with high display
rates, but differed in the relative visually-preferred males. (Kodric-Brown 1996)
Jemez females preferred males with larger areas of carotenoid
spots, and pattern complex-ity. Female choice of males with complex color
patterns may, in part, explain the high degree of disagreement among the Jemez
females in their choices of males. However, complexity of the color pattern did
not seem to be an important factor in the PCA analy-sis. (Kodric-Brown 1996)
Guppies used in these experiments were descendants from a feral
population in McCauley Hot Spring in the Jemez Mountains of New Mexico. This
population has lived in the spring for at least 24 years. These fish are
descendants of ‘feeder guppies’ that are similar in appearance to wild-type
guppies, although they may be more variable in their mate preferences
(Nicoletto 1993, Kodric-Brown & Nicoletto 1996). Mating preferences
of this population have been extensively studied. Females differentially
respond to males with high display rates (Nicoletto 1993) and to displays of
longer duration (Nicoletto 1996). Jemez females also respond preferentially to
males with more complex ornamentation and more orange color on their body
(Nicoletto 1993). However, courtship vigor is correlated with carotenoid
pigmentation, and when the variance in display rate is statistically controlled
the preference for males with more orange color disappears. In this
respect Jemez guppies differ from other guppy populations (Endler 1980, 1983,
Endler & Houde 1995, Houde 1987, 1988, Kodric-Brown 1985, 1989). (Nicoletto & Kodric-Brown 1999)
Jemez males also have extensive iridescent ornamentation.
The role of these iridescent colors in mate choice is unknown. They may
function in long-distance attraction of females (Endler 1983). In this study
females did not respond to differences in the blue treatment, and this is
consistent with some previous studies using live males (Nicoletto 1993, 1995).
However, in a study of mate preferences by Kodric-Brown & Nicoletto (1996)
a Principal Component analysis showed that some females in this population
preferentially responded to males with extensive iridescent ornamentation.
Iridescent blue and/or violet coloration also seems to be an important
criterion in mate choice of several populations of Trinidadian guppies (Endler
& Houde 1995). (Nicoletto
& Kodric-Brown 1999)
Fish used in our experiments were laboratory-reared, first
generation descendants of females caught at McCauley Spring in the Jemez
Mountains near Albuquerque, New Mexico. The population was established by
introduction approximately 30 yrs previously. It experiences low predation
pressure, since there are no piscivorous fish. Males are highly ornamented,
with large areas of the body and fins covered with red and yellow (carotenoid),
black (melanin), and iridescent (mostly blue and white) spots. Females prefer
males with complex color patterns, large areas of carotenoid pigment, and high
display rates (Nicoletto 1993, 1995). (Kodric-Brown 2001)
Jemez females mature much later than females from Trinidadian
populations that experience low predation and high adult survivorship.
Typically, less than half of the Jemez females mated to males at 3–4 months old
produced broods, whereas females from Trinidad were fully sexually mature at
that age (Reznick et al. 1996). We chose 6-mo-old females because at that age
all are mature and can produce a brood. At 12 mo, all Jemez females are still
reproductively active. In the laboratory, Jemez females senesce and begin to
die at an age of 18–24 mo. Senescence is characterized by smaller brood size or
cessation of reproduction. Although we have no information about the age
of females in Jemez Springs, gravid females of the size class of our
laboratory-reared 12-mo-old females are quite numerous. (Kodric-Brown 2001)
Age had a significant effect on female responsiveness to the
showy male image. Six-month-old virgin females spent significantly more time
viewing the image of the showy male than 12-mo-old virgin females. A greater
number of females preferred the showy male at the age of 6 mo[nths] than at 12 mo[nths] or
after mating and producing a brood... Thus, female preference for showy males
decreased with age. Mating experience had no effect on the responses of females
to showy males. Twelve-month-old virgin females and postpartum females spent
approximately equal amounts of time viewing both showy and plain males. (Kodric-Brown
2001)
Our results document changes in female responsiveness based on
one criterion, male ornamentation, specifically the area of carotenoid spots.
The intensity and size of carotenoid spots are important criteria for female
choice in all populations of guppies examined to date, including laboratory
stocks (e.g., Farr 1980; Kodric-Brown 1993), naturalized populations (e.g.,
Nicoletto 1993; Brooks and Caithness 1995), and native populations in Trinidad
(e.g., Endler and Houde 1995). However, our results should not be taken to
imply that older females are incapable of discriminating among males and do not
show preferences for particular male traits. Because we tested only the area of
carotenoid spots, we cannot rule out mate choice based on other criteria, such
as other pigment patterns or courtship displays. Females from the Jemez
population do show strong preferences for vigorously displaying males
(Nicoletto 1993, 1995). So older females may well select males based primarily
on the vigor and duration of courtship displays rather than carotenoid
pigments… Our results have important implications for studies of
sexual selection. They suggest that criteria for mate choice may change with
female age, thus altering selection for multiple male secondary sexual traits,
including male courtship tactics. If older females are less responsive to male
morphological traits, such as carotenoid color spots, then males might
compensate in their courtship tactics and engage in more vigorous displays.
Indeed, male guppies have been reported to increase their courtship displays toward
larger, and presumably older, females (Baerends et al. 1955; Houde 1997). (Kodric-Brown 2001)
When females were presented with 'mixed signals,' namely dull
males courting intensely, and males with orange coloration and low levels of
courtship, there was no significant difference in the time they spent with each
image, because females varied in their preferences for each image. These
results are consistent with the interpretation that the dynamic (courtship
display) and the static signals (orange color) are equally attractive. Our
results also support an alternative interpretation, namely that females of this
population show individual preferences in the relative ranking of these two
traits: some may show a preference for orange color, while others may base
their preference on display rate. The observed patterns are also consistent
with those found in a previous study of Jemez guppies using live males, where
females differed in their preferences for male ornaments (carotenoid and
iridescent spots (Kodric-Brown and Nicoletto 1996). (Kodric-Brown 2001)
To determine whether predation pressure affects female
preference for males with UV-reflective colour patterns, we compared the
responses of Jemez females with those of Quare females. The Jemez females were
from a population of naturalized guppies in McCauley spring located in the
Jemez Mountains of New Mexico, U.S.A. The Jemez population was introduced into
the spring over 30 years ago, and since then has had no piscivorous
predators. (Kodric-Brown
2001)
Male UV Reflectance Patterns Colour patterns of Jemez males showed UV-reflective components that
covered 4–31% of the body area. Most, but not all, of the iridescent colours
also reflected below 400 nm (near UV and UV). Among the iridescent colours,
white and purple strongly reflected below 400 nm, but green and blue did not.
Gold (yellow–orange) also showed a UV component. Generally, the area of UV
reflectance closely matched the area of iridescence visible in longer
wavelengths. Although the overall colour pattern was the same when viewed in
the visible and the short wavelengths, certain aspects of the pattern were more
noticeable in the UV wavelengths. Melanin (black) spots surrounded, either
completely or partially, by a ring of iridescent white, and gold spots next to
black areas provided a striking contrast in the UV. (Kodric-Brown 2001
Jemez females Responses to male pairs matched for all colours. Females spent almost twice as long
observing a male behind the UVT partition as they did the same male viewed
behind the UVB partition. These results suggest that females not only respond
to the UV-reflective components of the male colour patterns, but that these
components contribute to the overall attractiveness of a male. Responses
to male pairs differing in UV reflectance area. Females, when given a
choice between pairs of males that were matched for carotenoids and iridescence
but differed in UV reflectance, consistently chose the male of the pair behind
the UVT partition. Difference in the time females spent with the more
ornamented male of the pair was positively correlated with the difference in
the area of UV reflectance between the pairs. These results indicate that
females respond to the area of a male’s colour pattern that reflects UV
wavelengths. Responses to male pairs differing in carotenoid
area. There was no effect of treatment (UVT versus UVB) on female
responses to male pairs that differed in the area of carotenoids but were
matched for area of iridescence and UV reflectance. Similarly, there was
no positive correlation between the time females spent with the more ornamented
male of the pair when he was behind the UVT partition. Jemez females
Responses to the UV-reflective components of male colour patterns. Females
from both populations spent longer viewing males when the males were placed
behind the UVT partition than when the same males were placed behind the UVB
partition. Jemez and Quare females responded in a similar way to manipulations
of the UV-reflective component of male colour patterns. Predation level
thus does not seem to affect female responses to UV-reflective components of
male colour patterns. (Kodric-Brown 2001).
Conclusions
Jemez Feral
Guppies continue to offer researchers an ongoing opportunity to study an
evolving population within the confines of North America. They also offer breeders a unique set of
“genetic tools” for use in Domestic breeding programs.
My initial test
outcrosses are only in early stages.
Yet, based on observations of my ½ dozen feral breeding colonies a host
of potential benefits are possible in outcross offspring for color, pattern and
reflection. It is rare for breeders to identify
a breeding population or strain of Poecilia reticulata with the reflective
qualities and pattern expression exhibited in Jemez, outside of selectively
bred Swordtail strains or from infusions of P. reticulata wingei variants. While published research as quantified Jemez
ornamental traits along scientific standards, little has been documented along
breeder recognized traits and mode of inheritance.
Acknowledgements
Many thanks to my friend, and fellow
collector / breeder Tom Coggins (Missouri) for this recent collection.
Tom went out of his way to not only make this collection in New Mexico,
but deliver them in entirety two weeks later at my Southern WV home.
References:
Dzikowski, R., Hulata,
G., Karplus, I., & Harpaz, S. (2001). Effect of temperature and dietary
l-carnitine supplementation on reproductive performance of female guppy
(Poeciliareticulata). Aquaculture, 199(3), 323-332.
Gibson, M. B., &
Hirst, B. (1955). The effect of salinity and temperature on the pre-adult
growth of guppies. Copeia, 1955(3), 241-243.
Gillooly, J. F., Brown,
J. H., West, G. B., Savage, V. M., & Charnov, E. L. (2001). Effects of size
and temperature on metabolic rate. science, 293(5538), 2248-2251.
Johansen, P. H., &
Cross, J. A. (1980). Effects of sexual maturation and sex steroid hormone
treatment on the temperature preference of the guppy, Poecilia reticulata
(Peters). Canadian Journal of
Zoology, 58(4),
586-588.
Kodric-Brown, A., &
Nicoletto, P. F. (1996). Consensus among females in their choice of males in
the guppy Poecilia reticulata. Behavioral
Ecology and Sociobiology, 39(6),
395-400.
Kodric‐Brown,
Astrid, and Paul F. Nicoletto. "Age and experience affect female choice in
the guppy (Poecilia reticulata)." The
American Naturalist 157.3
(2001): 316-323.
Kodric-Brown,
A., & Nicoletto, P. F. (2001). Female choice in the guppy (Poecilia
reticulata): the interaction between male color and display. Behavioral Ecology and Sociobiology, 50(4), 346-351.
Kodric-Brown,
A., & Johnson, S. C. (2002). Ultraviolet reflectance patterns of male
guppies enhance their attractiveness to females. Animal Behaviour, 63(2), 391-396.
Kodric-Brown, A., &
Johnson, S. C. (2002). Ultraviolet reflectance patterns of male guppies enhance
their attractiveness to females. Animal
Behaviour, 63(2),
391-396.
Muñoz, N. J., Breckels,
R. D., & Neff, B. D. (2012). The metabolic, locomotor and sex-dependent
effects of elevated temperature on Trinidadian guppies: limited capacity for
acclimation. Journal of
Experimental Biology, 215(19),
3436-3441.
Nicoletto,
P. F. (1993). Female sexual response to condition-dependent ornaments in the
guppy, Poecilia reticulata. Animal
Behaviour, 46(3),
441-450.
Nicoletto, P. F. (1995). Offspring quality and female choice
in the guppy, Poecilia reticulata. Animal
Behaviour, 49(2),
377-387.
Nicoletto, P. F. (1996). The influence of water
velocity on the display behavior of male guppies, Poecilia reticulata. Behavioral Ecology, 7(3), 272-278.
Sublette, E. J., Hatch, D. M., & Sublette, M. (1990). The fishes of New Mexico.
University of New Mexico Press.
Trainer, F. W., Rogers, R. J., & Sorey, M. L. (2000). Geothermal Hydrology of Valles
Caldera and the Southwestern Jemez Mountains, New Mexico (No. 2000-4067). US Department of the
Interior, US Geological Survey; Information Services [distributor]
USDA 2002, East Fork
Jemez Wild and Scenic River Management Plan, US Dept. of Agriculture, Forest
Service. Jemez Ranger Dist., Santa Fe
National Fores, Sandoval County, New Mexico.
WEETMAN,
D., ATKINSON, D., & CHUBB, J. C. (1999). Water temperature influences the
shoaling decisions of guppies, Poecilia reticulata, under predation threat. Animal behaviour, 58(4), 735-741.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Show seasons around the world are getting ready to kick off. Support them with your entries.
Make some time to attend one. Great chance to meet some breeders in person...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~
