Behavioral Ecology Advance Access originally published online on October 24, 2007
Behavioral Ecology 2008 19(1):61-66; doi:10.1093/beheco/arm100
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Effect of UV-reflecting markings on female mate-choice decisions in Cosmophasis umbratica, a jumping spider from Singapore
a Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543 b College of Life Sciences, Hubei University, Wuhan 430062, Hubei, China
Address correspondence to: D. Li. E-mail: dbslidq{at}nus.edu.sg.
Received 17 October 2006; revised 26 July 2007; accepted 23 September 2007.
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ABSTRACT |
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Earlier studies have shown that Cosmophasis umbratica, a jumping spider from Singapore, is sexually dimorphic in the reflectance of ultraviolet (UV) (males, but not females, have UV-reflecting markings). Here we present the first experimental evidence that the male's UV markings influence mate choice of C. umbratica females. When presented with males whose appearance was manipulated by the use of a UV-blocking filter, females spent more time watching UV+ males (i.e., males with UV present) and less time watching UV– males (UV absent). We also manipulated the levels of male brightness by using 2 UV-transmitting neutral density filters and showed that UV reflectance was used specifically for hue discrimination instead of being used for detecting differences in brightness alone. This is not only the first strong evidence of UV influence on female mate-choice decisions for a spider but also the best experimental demonstration of color vision, whatever the wavelength.
Key words: color vision, Cosmophasis umbratica, female mate choice, jumping spiders, sexual selection, ultraviolet.
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INTRODUCTION |
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TOPABSTRACTINTRODUCTIONMETHODSRESULTSDISCUSSIONFUNDINGREFERENCES |
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The males of many animal species have colorful ornamentation that is based in part on reflectance in the ultraviolet (UV, wavelengths < 400 nm). For birds (Maier 1993
; Bennett et al. 1996, 1997; Andersson and Amundsen 1997; Hunt et al. 1997, 1998, 1999; Andersson et al. 1998; Johnsen et al. 1998; Maddocks et al. 2001; Pearn et al. 2001; Siitari et al. 2002), fishes (Garcia and de Perera 2002; Kodric-Brown and Johnson 2002; Smith et al. 2002; Rick et al. 2006; but see White et al. 2003), and reptiles (Fleishman et al. 1993), numerous studies have shown that the male's UV markings influence female mating preference or mate choice, but the role of UV markings in invertebrate courtship is poorly understood (see Arikawa et al. 1987; Brunton and Majerus 1995; Robertson and Monterio 2005).
The Salticidae is the largest spider family (Platnick 2007), and these spiders are characterized by unique, complex eyes and vision based on exceptionally high spatial acuity (Land 1969a, 1969b, 1985; Blest et al. 1990). Salticid eyes are also known to support color vision (Devoe 1975; Yamashita and Tateda 1976; Peaslee and Wilson 1989; Nakamura and Yamashita 2000), and there are UV-sensitive photoreceptors in the retinas of the salticid's large, forward-faced principal eyes (Land 1969b; Blest et al. 1981). Salticids are known for their especially elaborate courtship behavior (Jackson 1982; Jackson and Pollard 1997), and the males of many species have strikingly colorful markings that are displayed to the watching female. However, there is only one salticid species, Cosmophasis umbratica, for which UV reflectance and the ability to see UV have been demonstrated experimentally (Lim and Li 2006a, 2006b, 2007; for a review see Taylor and McGraw 2007).
Cosmophasis umbratica is common on sunlit vegetation (i.e., an open habitat) in Singapore (Lim and Li 2004). The males’ abdomens are mostly black but with iridescent white lines running anterior to posterior. There are complex iridescent markings, some of which are structural (Land et al. 2007), on various parts of the male's body, but especially on the top and sides of the carapace and on the sides of leg femora (Lim and Li 2006b). Females, however, do not reflect UV (Lim and Li 2006b). From earlier work, we know that UV reflectance varies considerably among males (Lim and Li 2006b) and changes with age and prior feeding history (Lim and Li 2007), and these findings are the rationale for a question that we investigate here. Does UV reflectance affect the mating preference of female C. umbratica?
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METHODS |
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Study subjects
Subadult males and females (i.e., individuals one molt away from becoming adults) of C. umbratica were collected in Singapore and subsequently maintained individually in transparent cylindrical cages (diameter x height: 6.5 x 8.5 cm), with opaque dividers between cages to ensure visual isolation from neighboring conspecific individuals in a laboratory with controlled environmental conditions (relative humidity: 80–85%; temperature: 25 ± 1 °C; light regime: 12:12 h; lights on at 08:00 h). Basic maintenance procedures were as described in earlier studies (see Lim and Li 2004
, 2006b). In addition to the standard overhead lighting, we also provided light from full-spectrum (i.e., 300–700 nm) fluorescent tubes (Arcadia Natural Sunlight Lamp, Croydon, UK) for 4 h daily (09:00–11:00 h; 16:00–18:00 h), the rationale for this being that, during periods of peak activity (mornings and late afternoons), C. umbratica's natural habitat is shrubs exposed to sunlight (Lim and Li 2004), and we wanted to simulate the daylight conditions applicable in this habitat. All spiders were fed twice a week on a diet of houseflies (Musca domestica), fruit flies (Drosophila melanogaster), and small instars of crickets (Acheta domestica) (Lim and Li 2004).
Experimental apparatus
We adopted a dichotomous choice design for the experiments. Our testing apparatus was constructed entirely of glass (Figure 1), which facilitated video recording of interactions between individuals and also permitted the maximum transmission of full spectrum light (300–700 nm) that came from 10 Voltarc Ultra Light tubes (110 W each, powered by a 120 V 50/60 Hz electronic ballast; SUPER-TEK, Naturallighting.com, Houston, TX) and 3 additional UV light–emitting dark tubes (Hitachi BL/B, 20 W), each powered by a 230 V 50/60 Hz electronic ballast, all of which were suspended about 150 cm above the apparatus (Figure 1). The mate-choice apparatus consisted of 1 chamber ("female chamber"; L x B x H = 7.6 x 2.5 x 2.5 cm) that held a female, and another 2 chambers (L x B x H = 7.6 x 2.5 x 2.5 cm; "male chambers") each of which contained a size-matched courting male. An opaque (black) piece of cardboard was placed between the 2 males’ chambers so that the 2 males could not see each other, all the while allowing intersexual communications to take place. A black curtain surrounded the whole setup. All interactions were video recorded using a high-definition digital video cameras (Sony HDV 1080i) that was placed in front of the setup through a slit in the black curtain, minimizing disturbance of the spiders. As it was important to determine the direction of a female's attention regardless of its position, a transparent glass slide was fixed at an angle (45°) above the female chamber (Figure 1), such that the video recordings of both the female and her reflection were done at the same time. Video playbacks of all interactions, set at highest image resolutions per frame, were subsequently analyzed blindly with respect to the treatments (software, Studio DV Plus, Pinnacle Systems Inc., Mountain View, CA) at a resolution of 25 frames per second.
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General experimental protocol
There were 2 experiments, with Experiment 1 being designed to investigate whether UV reflectance influenced mate choice by females of C. umbratica and Experiment 2 being designed to investigate whether females relied specifically on hue discrimination, as opposed to the perception of differences in brightness.
The 2 males used in any given choice test were of similar age for all trial conditions (see below). Only virgin adult males (N = 15) and females (N = 20) (age, 14–26 days after maturation, mean ± standard error [SE]: 19.4 ± 1.0 day) were used in trials, as this allowed us to rule out the possibility that previous encounters with conspecific males or females was influencing test outcomes.
Body mass (with a resolution of 0.001 g) of individual males was obtained prior to mate-choice tests. After each test, body lengths (carapace and abdomen lengths) were obtained by first immobilizing each spider using CO2 and then using a micrometric scale for measurement under a microscope.
Experiment 1: effects of UV reflectance
We used a horizontally positioned UV wavelength–blocking filter (Photonitech Pte. Ltd., Singapore) for creating lighting conditions that were distinctly different for the 2 male chambers in each test (Figure 2): UV+ (i.e., filter absent) and UV– (i.e., filter present). With this experimental design, we could ascertain whether females responded differently depending on whether a male was in the UV+ or UV– condition. Whether UV+ was on the right or the left side was determined for each test at random.
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For each test of mate assessment by a female, there were 2 control trials, one immediately before (control 1) and one immediately after (control 2) the test. Each control lasted for 5 min, and during the control only the female was present (no males in the male chambers). These controls enabled us to rule out the possibility that females had any distinct preference for the left versus the right male chamber independent of males being present (i.e., we controlled for the possibility that females were simply choosing between lighting conditions instead of choosing between males that differed in UV characteristics.
The individual test female remained in the female chamber during the entire testing period (control 1, test for assessment, control 2), each control lasting for 5 min and the test for assessment lasting for 10 min. Immediately before control 1 began, the female was kept in the female chamber for 5 min to acclimate, with the opaque screen hiding the male chambers from view (Figure 1). We started control 1 by lifting the screen. We returned the screen after control 1 ended and gave the female another 5-min acclimation period before lifting the screen and letting the test of assessment begin. Another 5-min acclimation was provided in the same way between the end of the test and control 2.
During the 5-min acclimation period between control 1 and the test of assessment, with the male chambers out of the female's view, 2 size-matched males (mean ± SE mass: 0.017 ± 0.001 g, mass range: 0.010–0.029 g, paired t-test: t19 = –0.454, P = 0.655; mean body length: 6.5 ± 0.1 mm, body length range: 5.7–7.7 mm, paired t-test: t19 = 0.564, P = 0.579) were put in the apparatus, one per male chamber (which of the 2 males that went into chamber on right-hand side determined at random). As our criterion of using size-matched males meant that we did not have enough individual males in the laboratory culture for restricting each individual male to a single test, 12 of the 15 males were used more than once, with the following breakdown: used once, N = 3; twice, N = 6; 3 times, N = 1; 4 times, N = 4; and 6 times, N = 1; average 3 times). However, no 2 males were ever paired together in more than one test and, whenever males were reused, they were never used more often than once per week (i.e., males were maintained for a further week isolated from conspecifics). No individual female was used more than once for either experiment. There were 20 trials.
As with most salticids that have been studied (Jackson and Pollard 1997; but for a possible exception, see Clark and Uetz 1993), there are no distinctive displays by which C. umbratica females signify that they have decided to mate with a particular male. In general, salticid courtship rarely resembles a chain of stereotypical steps leading up to mating, appearing more typically to be a prolonged negotiation between the male and female (Jackson and Pollard 1997). For a displaying male, the initial challenge seems to be keeping the female interested in his displays for long enough to persuade her to mate.
During the tests for assessment, the data we recorded pertained to the male's success at achieving this critical first requirement for mating success, gaining and keeping the female's attention. Two variables were considered, 1) the time the female spent in front of each male chamber and 2) the time the female spent watching the male (i.e., female attention; Hebets and Maddison 2005; Elias et al. 2006), where "watching the male" was defined as time when she had the gaze of the corneal lenses of her anterior median eyes oriented directly toward a male, regardless of the female's position (see Figure 1). The first of these 2 variables was also considered during the controls.
Three lines of evidence support our interpretation of a female's gaze as being indicative of the female’s attention being on a particular male. First, we used observable differences in the locomotion and body postures of females in the absence or presence of conspecifics. During normal locomotion in the absence of conspecifics, females usually adopt a stop-and-go gait (Lim and Li 2004). However, on visual recognition of a conspecific male, females usually adopt a hunched posture with bent abdomen (Lim and Li 2004), with the carapace facing the direction of the nearby male. In fact, by subtle movements of the carapace toward the direction of the male, the male revealed that females were observing the male's movements while maintaining the hunch posture. Secondly, the use of a UV-transmitting glass, positioned at 45° to the horizontal plane above the female chamber (Figure 1), allowed an additional view from the "top" (i.e., video recording from dorsal view of female chamber). This dorsal view, together with the frontal view of the video camera, provided further aid in confirmation of a female's directional gaze. Finally, the use and position of a high-definition digital video recorder equipped with a 20x optical zoom lens, together with an ability to view a video frame captured at 25 frames per second, all facilitated a clear and close-up video recordings of all male–female interactions (i.e., frontal and dorsal views).
The dominant display postures of C. umbratica males during courtship are arched posturing and flexed-up abdomen (Lim and Li 2004). We recorded how much time each male spent in these postures during the 10-min test period because we needed to check for the possibility that the different lighting conditions caused males to change their display posture and movement pattern, thereby providing females with potential assessment cues other than the UV reflectance of the male's ornaments.
Experiment 2: effects of UV luminance
Using of a filter that blocked UV wavelengths, we examined in Experiment 1 the effects of the presence and absence of UV wavelengths on female mate choice. However, the presence of the UV-blocking filter not only removed UV but also inevitably reduced overall quantum flux (or, more or less, what is usually meant by brightness; see Bennett et al. 1996) across the whole wavelength range (300–700 nm). This meant that C. umbratica females might have been expressing preference for males with overall brighter appearance (UV+) over less bright males (UV–) because a UV-blocking filter effectively blocked out photons that would have been present in the absence of the filter. This suggests an alternative hypothesis for findings in Experiment 1. Instead of the female discriminating between the presence and absence of UV, females do not discern UV from other wavelengths and instead are influenced by only the slight change in brightness (i.e., Experiment 1 is not sufficient for revealing whether it is the hue of the light, instead of only its brightness, that matters to the spider). Experiment 2 addresses this issue by following the same procedure used in Experiment 1 except that, instead of simply having the UV filter (UV– vs UV+), we used 2 neutral density filters, ND1 and ND2 (Kodak neutral density Wratten gelatin 0.10 and 0.20 filters, respectively). These filters alter luminance (achromatic brightness) that was independent of hue between 300 nm in the UV and 700 nm in the human-visible range (Figure 2). Because all transmitted wavelengths were equally reduced, the shape of the transmission spectra (i.e., the hue of the transmitted light) of both filters remained the same; the only difference was the intensity of transmitted light (Figure 2). We carried out 20 trials using the spiders (males: N = 15; female: N = 20) used in Experiment 1. As in Experiment 1, the male identity and the number of times a particular male that was reused were as in Experiment 1.
Data analyses
All behavioral data were tested for normality using the Kolmogorov–Smirnov test before statistical analyses. Normally distributed data were analyzed with parametric statistical tests. Otherwise, nonparametric statistics were used. As data on the time spent by females in front of male chambers for the 2 controls in both Experiments 1 and 2 were not normally distributed, we analyzed these data using Wilcoxon signed-rank tests. Because most of males were reused during the mate-assessment phase in both Experiments 1 and 2 and in order to minimize the risk of pseudoreplication, we introduced male identity as a random factor and performed linear mixed models (generalized linear mixed model) on the time spent by female in front of males, the time spent by females watching each of the 2 males, and the time spent by males displaying in the assessment tests. Binomial tests (null hypothesis: 50–50 chance of choosing either males) were performed to determine whether females more often chose (definition: spent more time watching) the UV+ or the UV– male or chose the ND1 or the ND2 male. All statistical tests were as in Zar (1996). All data are presented as means ± SE.
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RESULTS |
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Experiment 1: effects of UV hue
How much time females spent near either of the 2 male chambers was not significantly different from how much time females spent near the other male chamber during control 1 (Wilcoxon signed-rank test, Z = –1.024, N = 20, P = 0.306), control 2 (Z = –0.653, N = 20, P = 0.513), or the mate-assessment test (F1,31 = 0.543, P = 0.467) (Figure 3a). However, females watched UV+ males significantly longer than they watched UV– males (F1,38 = 9.149, P = 0.004) (Figure 3b). Females chose UV+ males significantly more often than UV– males (18 out of 20; binomial test, P < 0.001). How much time UV+ males spent displaying was not significantly different from how much time UV– males spent displaying (UV+: 5.7 ± 1.5 s, UV–: 3.1 ± 0.9 s; F1,38 = 2.122, P = 0.153).
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Experiment 2: effects of UV luminance
How much time females spent near ND1 was not significantly different from how much time they spent near ND2 (control 1: Z = –0.486, N = 20, P = 0.627; mate-assessment test: F1,38 = 0.124, P = 0.727; control 2: Z = –0.664, N = 20, P = 0.506), nor were there significant difference in how long females watched ND1 and ND2 males (F1,38 = 1.868, P = 0.180) (Figure 4) or in how much time males spent displaying in ND1 and ND2 (F1,38 = 1.082, P = 0.305).
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DISCUSSION |
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TOPABSTRACTINTRODUCTIONMETHODSRESULTSDISCUSSIONFUNDINGREFERENCES |
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Cosmophasis umbratica males have markings that reflect in UV (Lim and Li 2006b
), and our findings here show that UV reflectance is salient to females. How much time females spent watching displaying males was reduced when we added a filter that removed UV. More specifically, the wavelength range of UV (i.e., 300–400 nm) was present under UV+ but absent under UV– conditions. Although the filter we used also slightly lowered the quantum influx (roughly, "brightness") of the male, the findings from Experiment 2 did not support an alternative hypothesis for our findings in Experiment 1. That is, our experiments using different neutral density filters provided no evidence that C. umbratica females were being influenced solely by subtle differences in brightness. It is notoriously difficult to get unambiguous evidence of hue discrimination in nonhuman animals (e.g., Gregory 1998), but our findings strongly suggest that hue (the presence vs absence of UV, in this instance), not simply brightness differences in the 300–700 nm range, influenced female mate-choice decisions.
Findings from our controls provided no evidence that C. umbratica females were expressing preference simply for a particular light condition (i.e., presence or absence of UV in Experiment 1 and brighter or dimmer light environments in Experiment 2), as there was no significant difference in how much time the female spent near one versus the other chamber when no male was present (i.e., controls 1 and 2 in both experiments). It may be surprising that there was no discernible effect of the experimental conditions on the time spent close to each male despite there being such a strong effect on how much time females spent looking at males during the mate-assessment phase. Proximity to a particular male is frequently used as a criterion for detecting mate choice in animal studies (e.g., Houde 1997). However, the exceptional spatial acuity of salticid eyes (Land 1985; Harland and Jackson 2002) and knowing that facility with which salticids can, by sight and from a considerable distance, discriminate between different kinds of prey, suggest that salticids are animals that can readily discriminate, by sight and from considerable distances, between different potential mates. This may be why, for salticids, close proximity does not work so well as a criterion for ascertaining mate-choice decisions.
In many animals, there may be a tendency for females to spend more time watching males that are displaying more actively (Slagsvold and Viljugrein 1999; but see Siitari et al. 2002), but we found no significant differences in the time spent by male displaying under the different light conditions. Evidently, C. umbratica females spent longer time watching UV+ males than UV– males because they could see UV reflectance from male markings, not because males displayed more actively under UV.
The reflectance spectra of male C. umbratica comprised primarily of 2 reflection bands: one within human-visible wavelengths, and the other in the UV spectral range (Lim and Li 2006b). Although the results here indicate that C. umbratica females can discriminate between males that differ in their UV reflection, whether UV wavelengths, compared with other wavelengths to which salticids are sensitive, are more important in female mate choice in C. umbratica remains unexplored. This is because color manipulation via optical filters altered mainly UV wavelengths and not other human-visible (400–700 nm) wavelengths, to which jumping spiders are also visually sensitive. Interestingly, the palps of C. umbratica females have a UV-induced bright green fluorescence that is absent in males (Lim et al. 2007). Behavioral evidence shows that the female's green fluorescence is important for inducing male courtship behavior (Lim et al. 2007). Because salticid eyes are known to be sensitive to UV and to green wavelengths (Devoe 1975; Blest et al. 1981; Peaslee and Wilson 1989), perhaps further studies of the mate-choice decisions of C. umbratica females should consider the significance of UV and green, as well as other wavelengths.
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FUNDING |
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National University of Singapore ARC (R-154-000-140-112 to D.L.) and National Natural Science Foundation of China (NSFC) (30470229).
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ACKNOWLEDGEMENTS |
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We thank Poh Moi Goh for rearing the houseflies and fruit flies. Comments and suggestions from Lian Pin Koh and Tien Ming Lee greatly helped to improve the manuscript. The experiments comply with the "Principles of Animal Care," publication No. 86-23 (revised 1985) of the National Institute of Health, and also with the current laws of Singapore and China.
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REFERENCES |
|---|
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TOPABSTRACTINTRODUCTIONMETHODSRESULTSDISCUSSIONFUNDINGREFERENCES |
|---|
Andersson S, Amundsen T. Ultraviolet colour vision and ornamentation in bluethroats. Proc R Soc Lond B Biol Sci (1997) 264:1587–1591.
Andersson S, Örnborg J, Andersson M. Ultraviolet sexual dimorphism and assortative mating in blue tits. Proc R Soc Lond B Biol Sci (1998) 265:445–450.
Arikawa K, Inokuma K, Eguchi E. Pentachromatic visual system in butterfly. Naturwissenschaften (1987) 74:297–298.[CrossRef][Web of Science]
Bennett ATD, Cuthill IC, Partridge JC, Lunau K. Ultraviolet plumage colors predict mate preferences in starlings. Proc Natl Acad Sci USA (1997) 94:8618–8621.
Bennett ATD, Cuthill IC, Partridge JC, Maier EJ. Ultraviolet vision and mate choice in zebra finches. Nature (1996) 380:433–435.[CrossRef]
Blest AD, Hardie RC, McIntyre P, Williams DS. The spectral sensitivities of identified receptors and the function of retinal tiering in the principal eyes of a jumping spider. J Comp Physiol A Neuroethol Sens Neural Behav Physiol (1981) 145:227–239.[CrossRef]
Blest AD, Ocarroll DC, Carter M. Comparative ultrastructure of Layer-I receptor mosaics in principal eyes of jumping spiders—the evolution of regular arrays of light guides. Cell Tissue Res (1990) 262:445–460.[CrossRef][Web of Science]
Brunton CFA, Majerus MEN. Ultraviolet colors in butterflies—intraspecific or inter-specific communication. Proc R Soc Lond B Biol Sci (1995) 260:199–204.
Clark DL, Uetz GW. Signal efficacy and evolution of male dimorphism in the jumping spider, Maevia inclemens. Proc Natl Acad Sci USA (1993) 90:11954–11957.
Devoe RD. Ultraviolet and green receptors in principal eyes of jumping spiders. J Gen Physiol (1975) 66:193–207.
Elias DO, Hebets EA, Hoy RR. Female preference for complex/novel signals in a spider. Behav Ecol (2006) 17:765–771.
Fleishman LJ, Loew ER, Leal M. Ultraviolet vision in lizards. Nature (1993) 365:397.[CrossRef]
Garcia CM, de Perera TB. Ultraviolet-based female preferences in a viviparous fish. Behav Ecol Sociobiol (2002) 52:1–6.[CrossRef][Web of Science]
Gregory RL. Eye and brain: the psychology of seeing. (1998) 5th ed. Princeton (NJ): Princeton University Press.
Harland DP, Jackson RR. Influence of cues from the anterior medial eyes of virtual prey on Portia fimbriata, an araneophagic jumping spider. J Exp Biol (2002) 205:1861–1868.
Hebets EA, Maddison WP. Xenophilic mating preferences among populations of the jumping spider Habronattus pugillis Griswold. Behav Ecol (2005) 16:981–988.
Houde AE. Sex, color, and mate choice in guppies. (1997) Princeton (NJ): Princeton University Press.
Hunt S, Bennett ATD, Cuthill IC, Griffiths R. Blue tits are ultraviolet tits. Proc R Soc Lond B Biol Sci (1998) 265:451–455.
Hunt S, Cuthill IC, Bennett ATD, Griffiths R. Preferences for ultraviolet partners in the blue tit. Anim Behav (1999) 58:809–815.[CrossRef][Web of Science][Medline]
Hunt S, Cuthill IC, Swaddle JP, Bennett ATD. Ultraviolet vision and band colour preferences in female zebra finches, Taeniopygia guttata. Anim Behav (1997) 54:1382–1392.
Jackson RR. The behavior of communicating in jumping spiders (Salticidae). In: Spider communication: mechanisms and ecological significance—Witt PN, Rovner JS, eds. (1982) Princeton (NJ): Princeton University Press. 213–247.
Jackson RR, Pollard SD. Jumping spider mating strategies: sex among cannibals in and out of webs. In: Mating systems in insects and arachnids—Choe J, Crespi B, eds. (1997) Cambridge: Cambridge University Press. 340–351.
Johnsen A, Andersson S, Örnborg J, Lifjeld JT. Ultraviolet plumage ornamentation affects social mate choice and sperm competition in bluethroats (Aves: Luscinia s. svecica): a field experiment. Proc R Soc Lond B Biol Sci (1998) 265:1313–1318.
Kodric-Brown A, Johnson SC. Ultraviolet reflectance patterns of male guppies enhance their attractiveness to females. Anim Behav (2002) 63:391–396.[CrossRef][Web of Science]
Land MF. Movements of the retinae of the principal eyes of jumping spiders (Salticidae: Dendryphantinae) in relation to visual stimuli. J Exp Biol (1969a) 51:471–493.
Land MF. Structure of the retinae of the eyes of jumping spiders (Salticidae: Dendryphantinae) in relation to visual optics. J Exp Biol (1969b) 51:433–470.
Land MF. The morphology and optics of spider eyes. In: Neurobiology of arachnids—Barth FG, ed. (1985) Berlin: Springer-Verlag. 53–78.
Land MF, Horwood J, Lim MLM, Li D. Optics of the ultra-violet reflecting scales of a jumping spider. Proc R Soc Lond B Biol Sci (2007) 274:1583–1589.[Medline]
Lim MLM, Li D. Courtship and male-male agonistic behaviour of Cosmophasis umbratica Simon, an ornate jumping spider (Araneae: Salticidae) from Singapore. Raffles Bull Zool (2004) 52:435–448.
Lim MLM, Li D. Behavioural evidence of UV sensitivity in jumping spiders (Araneae: Salticidae). J Comp Physiol A Neuroethol Sens Neural Behav Physiol (2006a) 192:871–878.[CrossRef][Web of Science][Medline]
Lim MLM, Li D. Extreme ultraviolet sexual dimorphism in jumping spiders (Araneae: Salticidae). Biol J Linn Soc (2006b) 89:397–406.[CrossRef][Web of Science]
Lim MLM, Land MF, Li D. Sex-specific UV and fluorescence signals in jumping spiders. Science (2007) 315:481.
Lim MLM, Li D. Effects of age and feeding history on structure-based UV ornaments of a jumping spider (Araneae: Salticidae). Proc R Soc Lond B Biol Sci (2007) 274:569–575.[Medline]
Maddocks SA, Bennett ATD, Hunt S, Cuthill IC. Context-dependent visual preferences in starlings and blue tits: mate choice and light environment. Anim Behav (2001) 63:69–75.[CrossRef][Web of Science]
Maier EJ. To deal with the invisible—on the biological significance of ultraviolet sensitivity in birds. Naturwissenschaften (1993) 80:476–478.[CrossRef][Web of Science]
Nakamura T, Yamashita S. Learning and discrimination of colored papers in jumping spiders (Araneae, Salticidae). J Comp Physiol A (2000) 186:897–901.[CrossRef][Web of Science][Medline]
Pearn SM, Bennett ATD, Cuthill IC. Ultraviolet vision, fluorescence and mate choice in a parrot, the budgerigar Melopsittacus undulatus. Proc R Soc Lond B Biol Sci (2001) 268:2273–2279.[Medline]
Peaslee AG, Wilson G. Spectral sensitivity in jumping spiders (Araneae, Salticidae). J Comp Physiol A Neuroethol Sens Neural Behav Physiol (1989) 164:359–363.[CrossRef][Medline]
Platnick NI. The world spider catalogue, version 8.0. (2007) [Internet] [cited 2007 July 20]. Available from: http://research.amnh.org/entomology/spiders/catalog/index.html.
Rick IP, Modarressie R, Bakker TCM. UV wavelengths affect female mate choice in three-spined sticklebacks. Anim Behav (2006) 71:307–313.[CrossRef][Web of Science]
Robertson KA, Monterio A. Female Bicyclus anynana butterflies choose males on the basis of their dorsal UV-reflective eyespot pupils. Proc R Soc Lond B Biol Sci (2005) 272:1541–1546.[Medline]
Siitari H, Honkavaara J, Huhta E, Viitala J. Ultraviolet reflection and female mate choice in the pied flycatchers, Ficedula hypoleuca. Anim Behav (2002) 63:97–102.[CrossRef][Web of Science]
Slagsvold T, Viljugrein H. Mate choice copying versus preference for actively displaying males by female pied flycatchers. Anim Behav (1999) 57:679–686.[CrossRef][Web of Science][Medline]
Smith EJ, Partridge JC, Parsons KN, White EM, Cuthill IC, Bennett ATD, Church SC. Ultraviolet vision and mate choice in the guppy (Poecilia reticulata). Behav Ecol (2002) 13:11–19.
Taylor LA, McGraw KJ. Animal coloration: sexy spider scales. Curr Biol (2007) 17:R592–593.[CrossRef][Web of Science][Medline]
White EM, Partridge UC, Church SC. Ultraviolet dermal reflexion and mate choice in the guppy, Poecilia reticulata. Anim Behav (2003) 65:693–700.[CrossRef][Web of Science]
Yamashita S, Tateda H. Spectral sensitivities of jumping spider eyes. J Comp Physiol A Neuroethol Sens Neural Behav Physiol (1976) 105:29–41.[CrossRef]
Zar JH. Biostatistical analysis. (1996) 3rd ed. Upper Saddle River (NJ): Prentice-Hall Inc.
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