Two sexes respond equally to food restriction in a sexually dimorphic but not body mass dimorphic jumping spider

To avoid predation, many animals mimic behaviours and/or coloration of dangerous prey. Here we examine potential sex-specific mimicry in the jumping spider Habronattus pyrrithrix . Previous work proposed that males' conspicuous dorsal coloration paired with characteristic leg-waving (i.e. false antennation) imperfectly mimics hymenopteran insects (e.g. wasps and bees), affording protection to males during mate-searching and courtship. By contrast, less active females are cryptic and display less leg-waving. Here we test the hypothesis that sexually dimorphic dorsal colour patterns in H. pyrrithrix are most effective when paired with sex-specific behaviours. We manipulated spider dorsal coloration with makeup to model the opposite sex and exposed them to a larger salticid predator ( Phidippus californicus ). We predicted that males painted like females should suffer higher predation rates than sham-control males. Likewise, females painted like males should suffer higher predation rates than sham-control females. Contrary to expectations, spiders with male-like coloration were attacked more than those with female-like coloration, regardless of their actual sex. Moreover, males were more likely to be captured, and were captured sooner, than females (regardless of colour pattern). With these unexpected negative results, we discuss alternative functional hypotheses for H. pyrrithrix colours, as well as the evolution of defensive coloration generally.

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Photoperiod Influences the Effects of Exercise and Food Restriction on an Antigen-Specific Immune Response in Siberian Hamsters

Endocrinology ◽

10.1210/en.2003-1035 ◽

2004 ◽

Vol 145 (2) ◽

pp. 556-564 ◽

Cited By ~ 17

Author(s):

Staci D. Bilbo ◽

Randy J. Nelson

Keyword(s):

Body Mass ◽

Food Restriction ◽

Severity Of Illness ◽

Reproductive Function ◽

Delayed Type Hypersensitivity ◽

Siberian Hamsters ◽

Trade Offs ◽

Access To Food ◽

Short Days ◽

Activity Condition

Abstract Environmental conditions influence the onset and severity of illness and infection and may compromise survival. Energetically challenging conditions during winter may directly induce death through hypothermia, starvation, or shock. The ability to forecast and prepare for the arrival of challenging conditions associated with winter (e.g. low temperatures, decreased food) likely confers survival advantages. Siberian hamsters (Phodopus sungorus) stop reproduction and reduce body mass (∼25%) during short, winter-like day lengths, resulting in energetic savings. Hamsters also increase circulating glucocorticoids and lymphocytes (e.g. T cells, NK cells), and exhibit enhanced antigen-specific delayed-type-hypersensitivity (DTH) responses in the skin during short days (SDs). We tested the hypothesis that Siberian hamsters use SD lengths to signal the onset of winter to mediate the energetic trade-offs among body mass, reproductive function, and immune function. Long-day (LD; 16 h light, 8 h dark) and SD (8 h light, 16 h dark) hamsters were either food restricted (25%) or provided ad libitum (ad lib) food for 4 wk; half of all hamsters in each food condition had voluntary access to a running wheel, and half remained sedentary. SD hamsters enhanced DTH responses compared with LD hamsters under sedentary ad lib conditions. Exercise enhanced DTH in LD hamsters regardless of food intake. Furthermore, food-restriction did not significantly influence DTH in LD hamsters. In contrast, food-restriction suppressed DTH in SD hamsters regardless of activity condition, and exercise modestly enhanced DTH only in SD hamsters with ad lib access to food. In sum, moderate energetic deficiency suppressed DTH in SD (but not LD) hamsters, and this suggests that hamsters may have evolved to enhance immune responses during winter in preparation for increased metabolic stressors.

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A Predator's Perspective of the Accuracy of Ant Mimicry in Spiders

Psyche A Journal of Entomology ◽

10.1155/2012/168549 ◽

2012 ◽

Vol 2012 ◽

pp. 1-5 ◽

Cited By ~ 11

Author(s):

Ximena J. Nelson

Keyword(s):

Batesian Mimicry ◽

Sexually Dimorphic ◽

Oecophylla Smaragdina ◽

Jumping Spider ◽

Behavioural Characteristics ◽

Ant Mimicry ◽

Signal Accuracy

Among spiders, resemblance of ants (myrmecomorphy) usually involves the Batesian mimicry, in which the spider coopts the morphological and behavioural characteristics of ants to deceive ant-averse predators. Nevertheless, the degree of resemblance between mimics and ants varies considerably. I usedPortia fimbriata,a jumping spider (Salticidae) with exceptional eyesight that specialises on preying on salticids, to test predator perception of the accuracy of ant mimicry.Portia fimbriata’s response to ants (Oecophylla smaragdina), accurate ant-like salticids (Synageles occidentalis), and inaccurate ant-like salticids (females ofMyrmarachne bakeriand sexually dimorphic males ofM. bakeri, which have enlarged chelicerae) was assessed.Portia fimbriataexhibited graded aversion in accordance with the accuracy of resemblance to ants (O. smaragdina>S. occidentalis> femaleM. bakeri> maleM. bakeri). These results support the hypothesis that ant resemblance confers protection from visual predators, but to varying degrees depending on signal accuracy.

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Effects of age and feeding history on structure-based UV ornaments of a jumping spider (Araneae: Salticidae)

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2006.0020 ◽

2006 ◽

Vol 274 (1609) ◽

pp. 569-575 ◽

Cited By ~ 30

Author(s):

Matthew L.M Lim ◽

Daiqin Li

Keyword(s):

Mate Choice ◽

Food Deprivation ◽

Spectral Intensity ◽

Sexually Dimorphic ◽

Jumping Spider ◽

Structural Coloration ◽

Spectral Reflection ◽

Male Age ◽

Uv Coloration

Recent studies have shown for birds that females sometimes choose mates on the basis of condition-dependent variation in ultraviolet (UV, less than 400 nm) ornamentation, but there have been few comparable studies on invertebrates. Yet many invertebrates have UV structural coloration. Here, we investigate Cosmophasis umbratica , a jumping spider (Araneae: Salticidae) that has sexually dimorphic UV-iridescent ornamentation, and we provide evidence that male UV coloration is condition dependent in this species. Spectral-reflection patterns change with male age and prior feeding history. The position of the UV band (i.e. UV hue) of the carapaces of younger (field-collected as subadults and matured as adults in laboratory) males shifted, relative to older (field-collected as adults) males, significantly towards longer wavelengths. Food deprivation significantly decreased the spectral intensity of the abdomen, but not the carapace. Questions concerning the mechanisms by which UV ornaments change are highlighted, as are hypotheses concerning the role of condition-dependent UV variation in male–male competition and as a criterion used by females when making mate-choice decisions.

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The jumping spider Saitis barbipes lacks a red photoreceptor to see its own sexually dimorphic red coloration

The Science of Nature ◽

10.1007/s00114-021-01774-6 ◽

2021 ◽

Vol 109 (1) ◽

Author(s):

Mateusz Glenszczyk ◽

David Outomuro ◽

Matjaž Gregorič ◽

Simona Kralj-Fišer ◽

Jutta M. Schneider ◽

...

Keyword(s):

Reasonable Assumption ◽

Sexually Dimorphic ◽

Sexual Signaling ◽

Jumping Spider ◽

Maximal Sensitivity ◽

Green Sensitivity ◽

Ill Posed ◽

Human Eyes ◽

Black Color ◽

Red Coloration

AbstractExamining the role of color in mate choice without testing what colors the study animal is capable of seeing can lead to ill-posed hypotheses and erroneous conclusions. Here, we test the seemingly reasonable assumption that the sexually dimorphic red coloration of the male jumping spider Saitis barbipes is distinguishable, by females, from adjacent black color patches. Using microspectrophotometry, we find clear evidence for photoreceptor classes with maximal sensitivity in the UV (359 nm) and green (526 nm), inconclusive evidence for a photoreceptor maximally sensitive in the blue (451 nm), and no evidence for a red photoreceptor. No colored filters within the lens or retina could be found to shift green sensitivity to red. To quantify and visualize whether females may nevertheless be capable of discriminating red from black color patches, we take multispectral images of males and calculate photoreceptor excitations and color contrasts between color patches. Red patches would be, at best, barely discriminable from black, and not discriminable from a low-luminance green. Some color patches that appear achromatic to human eyes, such as beige and white, strongly absorb UV wavelengths and would appear as brighter “spider-greens” to S. barbipes than the red color patches. Unexpectedly, we discover an iridescent UV patch that contrasts strongly with the UV-absorbing surfaces dominating the rest of the spider. We propose that red and black coloration may serve identical purposes in sexual signaling, functioning to generate strong achromatic contrast with the visual background. The potential functional significance of red coloration outside of sexual signaling is discussed.

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Effects of food restriction on body mass, energy metabolism and thermogenesis in a tree shrew (Tupaia belangeri)

10.1101/478487 ◽

2018 ◽

Author(s):

Xue-na Gong ◽

Hao Zhang ◽

Di Zhang ◽

Wan-long Zhu

Keyword(s):

Food Intake ◽

Metabolic Rate ◽

Body Mass ◽

Food Restriction ◽

Tree Shrew ◽

Tree Shrews ◽

Tupaia Belangeri ◽

Brown Adipose ◽

Food Shortages ◽

Ad Libitum

AbstractThis study investigates the energy strategies of a small mammal in response to food shortages as a function of food restriction (FR), metabolic rate and ambient temperature. We subjected tree shrews (Tupaia belangeri) to FR and measured body mass, survival rate, resting metabolic rate (RMR), nonshivering thermogenesis (NST) and cytochrome c oxidase (COX) activity of brown adipose tissue (BAT). Cold-exposed animals restricted to 80% of ad libitum food intake had significantly increased RMR and NST and decreased body mass and survival rates compared with those kept at room temperature on the same FR level. Animals classified has having a high RMR consumed 30.69% more food than those classified as having a low RMR, but showed no differences in body mass or survival when restricted to 80% of ad libitum food intake. These results indicate that tree shrews, known for their relatively high metabolic rates, are sensitive to periods of FR, which supports the metabolic switch hypothesis. Our findings are also consistent with the prediction that small mammals with food hoarding behaviors, like tree shrews, may have a lower tolerance for food shortages than non-hoarding species.

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Predatory response to changes in camouflage in a sexually dimorphic jumping spider

Journal of Arachnology ◽

10.1636/hi13-02.1 ◽

2013 ◽

Vol 41 (3) ◽

pp. 381-386 ◽

Cited By ~ 5

Author(s):

Maciej Bartos ◽

Katarzyna Szczepko ◽

Marzena Stanska

Keyword(s):

Sexually Dimorphic ◽

Jumping Spider ◽

Predatory Response

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Effects of food restriction on body mass, thermogenesis and serum leptin level inApodemus chevrieri(Mammalia: Rodentia: Muridae)

Italian Journal of Zoology ◽

10.1080/11250003.2013.796409 ◽

2013 ◽

Vol 80 (3) ◽

pp. 337-344 ◽

Cited By ~ 6

Author(s):

W. L. Zhu ◽

Y. Mu ◽

H. Zhang ◽

L. Zhang ◽

Z. K. Wang

Keyword(s):

Body Mass ◽

Food Restriction ◽

Serum Leptin

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Defending body mass during food restriction in Acomys russatus: a desert rodent that does not store food

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00156.2005 ◽

2006 ◽

Vol 290 (4) ◽

pp. R881-R891 ◽

Cited By ~ 27

Author(s):

Roee Gutman ◽

Itzhak Choshniak ◽

Noga Kronfeld-Schor

Keyword(s):

Heart Rate ◽

Oxygen Consumption ◽

Body Temperature ◽

Energy Expenditure ◽

Body Mass ◽

Food Restriction ◽

Daily Torpor ◽

Spiny Mice ◽

Desert Rodent ◽

Initial Decrease

Golden spiny mice, which inhabit rocky deserts and do not store food, must therefore employ physiological means to cope with periods of food shortage. Here we studied the physiological means used by golden spiny mice for conserving energy during food restriction and refeeding and the mechanism by which food consumption may influence thermoregulatory mechanisms and metabolic rate. As comparison, we studied the response to food restriction of another rocky desert rodent, Wagner’s gerbil, which accumulates large seed caches. Ten out of 12 food-restricted spiny mice (resistant) were able to defend their body mass after an initial decrease, as opposed to Wagner’s gerbils ( n = 6). Two of the spiny mice (nonresistant) kept losing weight, and their food restriction was halted. In four resistant and two nonresistant spiny mice, we measured heart rate, body temperature, and oxygen consumption during food restriction. The resistant spiny mice significantly ( P < 0.05) reduced energy expenditure and entered daily torpor. The nonresistant spiny mice did not reduce their energy expenditure. The gerbils’ response to food restriction was similar to that of the nonresistant spiny mice. Resistant spiny mice leptin levels dropped significantly ( n = 6, P < 0.05) after 24 h of food restriction, and continued to decrease throughout food restriction, as did body fat. During refeeding, although the golden spiny mice gained fat, leptin levels were not correlated with body mass ( r2 = 0.014). It is possible that this low correlation allows them to continue eating and accumulate fat when food is plentiful.

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Body mass and attractivity of female offspring are negatively affected by food restriction of meadow vole (Microtus pennsylvanicus) dams during lactation

Behaviour ◽

10.1163/1568539x-00003219 ◽

2014 ◽

Vol 151 (12-13) ◽

pp. 1847-1868 ◽

Cited By ~ 4

Author(s):

Ramona M. Sabau ◽

Lyndsey Pierson ◽

Michael H. Ferkin

Keyword(s):

Body Mass ◽

Sexual Behaviour ◽

Food Restriction ◽

Female Offspring ◽

Microtus Pennsylvanicus ◽

The Body ◽

Male Offspring ◽

Meadow Vole ◽

Body Weights ◽

And Control

The environment experienced by pups during lactation (nutrition and maternal behaviour) can contribute not only to sexual development, but also to individual differences in offspring sexual behaviour. We tested the hypothesis that female offspring of meadow vole dams (Microtus pennsylvanicus) that were 30% food restricted (FR) during days 1–7 of lactation (FR 1–7), days 8–14 of lactation (FR 8–14), or days 15–21 of lactation (FR 15–21) show negative effects on their food intake, growth, and the three components of sexual behaviour (attractivity, proceptivity and receptivity) as compared with female offspring of control dams. With the exception of age 29 days or age 34 days, the body weights of female offspring of FR 1–7 dams and FR 8–14 dams between days 21 and 48 were lower than the body weights of female offspring of FR 15–21 dams and those of control dams. Female offspring of FR 1–7 dams maintained a lower body weight than the other female offspring throughout the study. Female offspring of FR 8–14 and FR 15–21 dams produced odours that were less attractive to males than odours produced by those of FR 1–7 and control dams. Female offspring of FR dams and control dams did not differ in their measures of proceptivity and receptivity. However, the total amount of time allocated for copulation by males was shorter for those males that were paired with female offspring of FR 1–7 dams than it was for those that were paired with the female offspring of FR 8–14, FR15–21, and control dams. The results of this study, coupled with those found in a study conducted on the male offspring of FR dams, indicate that for female offspring days 1–7 and for male offspring days 8–14 of lactation are the time periods during which food restriction of dams had the greatest impact on deficits in sexual behaviour and body mass in meadow voles.

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