Валуев В.А. // Материалы по флоре и фауне Республики Башкортостан. Выпуск XV (декабрь) Уфа. РИЦ Баш ГУ, 2017, стр. 3 - 9

Ярцев В. В., Куранова В. Н., Абсалямова Е. Н. // Современная герпетология. 2019. Т. 19, вып. 1/2. С. 56–67

Широко распространенные виды пресмыкающихся характеризуются репродуктивной пластичностью, которая проявляется также в вариабельности репродуктивных циклов. Для понимания специфики репродуктивного цикла самцов Zootoca vivipara в азиатской части ареала исследованы самцы томской популяции вида (окрестности г. Томска, юго-восток Западной Сибири), отловленные с апреля по июль 2017 г. ( = 27). Проанализирована динамика гонадосоматического индекса (ГСИ), относительной массы жировых тел (ОМЖТ), площади семенного эпителия (ПСЭ), уровня тестостерона в сыворотке крови (УТ), соотношение числа сперматогенных клеток в семенниках и наличие сперматозоидов в придатках семенника, а также определен возраст методом скелетохронологии. У самцов после выхода из зимовки (конец апреля) в семенниках зарегистрировано большое количество сперматоцитов. К началу мая отмечено увеличение ГСИ, ОМЖТ, ПСЭ, УТ, а также формирование максимального пула сперматид. В ходе размножения (май – начало июня) ГСИ, ОМЖТ, ПСЭ, УТ резко уменьшаются, при этом сперматозоиды появляются как в семенниках, так и в их придатках. В середине июня отмечено начало нового цикла сперматогенеза (пролиферация сперматогониев). С этого периода до июля ГСИ,ОМЖТ, ПСЭ увеличиваются вместе с ростом числа сперматоцитов. Общая длительность сперматогенного цикла в исследованной популяции составляет около 12 месяцев, но он характеризуется сжатыми сроками спаривания и связанными с этим процессами сперматогенеза в сравнении с европейскими популяциями вида.

Эпова Л.А., Куранова В.Н., Ярцев В.В. // Вестник Томского государственного университета. Биология. 2020. № 50. С. 79–100

Для выявления специфики горных популяций широкоареального вида пресмыкающихся – Zootoca vivipara – проанализированы различные аспекты ключевого процесса, обеспечивающего их существование в экстремальных условиях, – размножения. В весенне-осенние периоды 2012–2016 гг. исследованы популяции вида подгольцового и горнолесного поясов западного макросклона центральной части хребта Кузнецкого Алатау (54–55° N, 87–88° E, юго-восток Западной Сибири). Выявлено, что длительность активного периода составляет 85–152 суток и зависит от высоты местности и погодных условий года наблюдений. Фенологические фазы репродуктивного периода, половые циклы самцов и самок отличаются временными характеристиками, корректируемыми условиями среды конкретного высотного пояса: сокращение сезона активности Z. vivipara при продвижении в горы сопровождается более поздним возрастом наступления половой зрелости самцов и самок. Для сезонной динамики относительного объема семенников характерны высокие значения параметра в периоды выхода из зимовки, размножения и к концу сезона активности. Размеры семенников коррелируют с длиной тела самцов (p<0,01). У самок вителлогенез отмечен после выхода с зимовки, овуляция и оплодотворение – в мае – начале июня, беременность, роды – в третьей декаде июля – августе. Выявлены более широкая вариабельность плодовитости размножающихся самок разного возраста и высокая средняя плодовитость самок в низкогорье и среднегорье по сравнению с высокогорьем. Среднемноголетняя популяционная плодовитость самок всех высотных поясов – 7,3 (7,1–7,6), что на 1,2 выше, по сравнению с равнинными популяциями вида юго-востока Западной Сибири и в целом по ареалу (p<0,001). Размах внутрипопуляционной изменчивости плодовитости в горах (3– 11) ниже, чем на равнине (2–12). Выявлена связь длины и массы самок с размером выводка (p<0,01).

Willem Bonnaffe, Melissa Martin, Marianne Mugabo, Sandrine Meylan, Jean-François Le Galliard // Ecology and Evolution. 2018; 8: 12299–12307

The understanding of developmental patterns of body coloration is challenging because of the multicomponent nature of color signals and the multiple selective pressures acting upon them, which further depend on the sex of the bearer and area of display. Pigmentary colors are thought to be strongly involved in sexual selection, while structural colors are thought to generally associate with conspecifics interactions and improve the discrimination of pigmentary colors. Yet, it remains unclear whether age dependency in each color component is consistent with their potential function. Here, we address lifelong ontogenetic variation in three color components (i.e. UV, pigmentary, and skin background colors) in a birth cohort of common lizards Zootoca vivipara across three ventral body regions (i.e. throat, chest, and belly). All three color components developed sexual dichromatism, with males displaying stronger pigmentary and UV colors but weaker skin background coloration than females. The development of color components led to a stronger sexual dichromatism on the concealed ventral region than on the throat. No consistent signs of late-life decay in color components were found except for a deceleration of UV reflectance increase with age on the throat of males. These results suggest that body color components in common lizards are primarily nonsenescent sexual signals, but that the balance between natural and sexual selection may be altered by the conspicuousness of the area of display. These results further support the view that skin coloration is a composite trait constituted of multiple color components conveying multiple signals depending on age, sex, and body location.

J. Cote, J.-F. Le Galliard, J.-M. Rossi & P. S. Fitze // J . Evol. Biol. 21 (2008) 1165–1172

Colouration may either reflect a discrete polymorphism potentially related to life-history strategies, a continuous signal related to individual quality or a combination of both. Recently, Vercken et al. [J. Evol. Biol. (2007) 221] proposed three discrete ventral colour morphs in female common lizards, Lacerta vivipara, and suggested that they reflect alternative reproductive strategies. Here, we provide a quantitative assessment of the phenotypic distribution and determinants of the proposed colour polymorphism. Based on reflectance spectra, we found no evidence for three distinct visual colour classes, but observed continuous variation in colour from pale yellow to orange. Based on a 2-year experiment, we also provide evidence for reversible colour plasticity in response to a manipulation of the adult population sex ratio; yet, a significant portion of the colour variation was invariant throughout an adult female’s life. Our results are thus in agreement with continuous colour variation in adults determined by environmental factors and potentially also by genetic factors.

Patrick S. Fitze, Julien Cote, Luis Martin San-Jose, Sandrine Meylan, Caroline Isaksson, Staffan Andersson, Jean-Marc Rossi, Jean Clobert // PLoS ONE 4(4): e5111

Under chronic stress, carotenoid-based colouration has often been shown to fade. However, the ecological and physiological mechanisms that govern colouration still remain largely unknown. Colour changes may be directly induced by the stressor (for example through reduced carotenoid intake) or due to the activation of the physiological stress response (PSR, e.g. due to increased blood corticosterone concentrations). Here, we tested whether blood corticosterone concentration affected carotenoid-based colouration, and whether a trade-off between colouration and PSR existed. Using the common lizard (Lacerta vivipara), we correlatively and experimentally showed that elevated blood corticosterone levels are associated with increased redness of the lizard’s belly. In this study, the effects of corticosterone did not depend on carotenoid ingestion, indicating the absence of a trade-off between colouration and PSR for carotenoids. While carotenoid ingestion increased blood carotenoid concentration, colouration was not modified. This suggests that carotenoid-based colouration of common lizards is not severely limited by dietary carotenoid intake. Together with earlier studies, these findings suggest that the common lizard’s carotenoid-based colouration may be a composite trait, consisting of fixed (e.g. genetic) and environmentally elements, the latter reflecting the lizard’s PSR.

Melissa Martini, Sandrine Meylan, Doris Gomez and Jean-Francois le Galliard // Biological Journal of the Linnean Society, 2013, 110, 128–141

Lizards display structural and pigment-based colorations, and their visual system is sensitive to wavelengths of 300–700 nm. However, few studies in squamate reptiles have quantified interindividual colour variation that includes the structural ultraviolet (UV) component (300–400 nm). In the present study, we investigated variability of a ventral UV/yellow–red ornamentation in the common lizard Zootoca vivipara, including an analysis of spatial distribution, as well as sex and age differences. We also investigated whether the expression of coloration is related to body size and condition. Our analyses revealed two distinct patches: a gular patch with a strong UV reflectance and a belly patch with a dominant yellow–red reflectance. Males displayed a less saturated throat coloration with higher UV chroma and UV hue, and had a redder but duller belly coloration than females. Yearlings had less elaborate ornaments than adults, although they already displayed a yellow–red sexual dichromatism on the belly. UV sexual dichromatism was only apparent in adults as a result of a weaker UV reflectance in females, suggesting potential fitness costs of a bright UV coloration in that sex. Different colour traits were related to body size in both sexes, as well as to body condition in males. We discuss the potential evolutionary scenarios leading to the maintenance of this ornament in common lizards.

Melissa Martin, Jean-François Le Galliard, Sandrine Meylan and Ellis R. Loew // The Journal of Experimental Biology (2015) 218, 458-465

Male and female Lacertid lizards often display conspicuous coloration that is involved in intraspecific communication. However, visual systems of Lacertidae have rarely been studied and the spectral sensitivity of their retinal photoreceptors remains unknown. Here, we characterise the spectral sensitivity of two Lacertid species from contrasting habitats: the wall lizard Podarcis muralis and the common lizard Zootoca vivipara. Both species possess a pure-cone retina with one spectral class of double cones and four spectral classes of single cones. The two species differ in the spectral sensitivity of the LWS cones, the relative abundance of UVS single cones (potentially more abundant in Z. vivipara) and the coloration of oil droplets. Wall lizards have pure vitamin A1-based photopigments, whereas common lizards possess mixed vitamin A1 and A2 photopigments, extending spectral sensitivity into the near infrared, which is a rare feature in terrestrial vertebrates. We found that spectral sensitivity in the UV and near infrared improves discrimination of small variations in throat coloration among Z. vivipara. Thus, retinal specialisations optimise chromatic resolution in common lizards, indicating that the visual system and visual signals might co-evolve.

Melissa Martin,Sandrine Meylan, Claudy Haussy, Beatriz Decencière, Samuel Perret and Jean-François Le Galliarda // Behavioral Ecology (2016), 27(1), 262–270

Ultraviolet (UV) colors are visual signals potentially involved in territorial conflicts. However, the role of UV signals remains unclear relative to the prior resident effect and familiarity with the opponent, and the reliability of UV signals is still controversial. Male common lizards Zootoca vivipara exhibit substantial variation in the reflectance of their throat UV color patch. We tested whether UV reflectance was correlated with indicators of individual condition. We further manipulated throat UV reflectance of resident and intruder lizards and staged repeated encounters in the laboratory during the mating season. We found no evidence of condition dependence of the UV colors expression. During the first encounter among unfamiliar males, a reduction of UV reflectance of 1 of the 2 opponents influenced agonistic behaviors and the contest outcome, such that there was a significant advantage for residents over intruders. This advantage disappeared when both opponents were UV reduced. During the subsequent encounters among familiar males, fighting was more aggressive when opponents displayed similar UV signals, but UV signals did not influence the contest outcome. These results demonstrate that UV reflectance acted as a badge of status in male common lizards whose effects on the behavioral response were modulated, but not overridden, by the prior resident effect and by the familiarity effect. Male–male interactions are therefore mediated by UV signaling and competition for mates should play a major role in the evolutionary maintenance of this ornament. We discuss putative functions and reliability of UV signals.

Luis M. San-Jose, Fernando Granado-Lorencio, Barry Sinervo, and Patrick S. Fitze // The American Naturalist, Vol. 181, No. 3 (March 2013), pp. 396-409

Carotenoids typically need reflective background components to shine. Such components, iridophores, leucophores, and keratin- and collagen-derived structures, are generally assumed to show no or little environmental variability. Here, we investigate the origin of environmentally induced variation in the carotenoid-based ventral coloration of male common lizards (Lacerta vivipara) by investigating the effects of dietary carotenoids and corticosterone on both carotenoid- and background-related reflectance. We observed a general negative chromatic change that was prevented by b-carotene supplementation. However, chromatic changes did not result from changes in carotenoid-related reflectance or skin carotenoid content but from changes in background-related reflectance that may have been mediated by vitamin A1. An in vitro experiment showed that the encountered chromatic changes most likely resulted from changes in iridophore reflectance. Our findings demonstrate that chromatic variation in carotenoid-based ornaments may not exclusively reflect differences in integumentary carotenoid content and, hence, in qualities linked to carotenoid deposition (e.g., foraging ability, immune response, or antioxidant capacity). Moreover, skin carotenoid content and carotenoid-related reflectance were related to male color polymorphism, suggesting that carotenoid-based coloration of male common lizards is a multicomponent signal, with iridophores reflecting environmental conditions and carotenoids reflecting genetically based color morphs.

Luis M. San-Jose, Katleen Huyghe, Johan Schuerch and Patrick S. Fitze // Biological Journal of the Linnean Society, 2017, XX, 1–13.

Although the signalling role of melanin-based coloration has been largely debated, an increasing number of studies support its relationship to different fitness-related traits. However, whether melanin-based coloration could also function as an indicator of performance has been barely explored despite the influence that performance has on fitness. We investigated the relationship between melanin-based coloration and bite force and sprint speed in male common lizards, Zootoca vivipara. Melanin-based coloration predicted performance, being positively and negatively related to bite force and sprint speed. The association between melanin-based coloration and bite force is mediated by positive associations between coloration and head and body size. We did not find an association between coloration and any morphological traits determining sprint speed and the driver of the encountered negative association remains unknown. The observed opposite relationships between coloration and performance traits suggests the existence of costs (e.g. darker males may have higher predation because of lower sprint speeds) and/or alternative performance strategies, which is congruent with disruptive selection on sprint speed in juvenile common lizards. Our findings suggest that melanin-based coloration could indicate performance capacity, a hypothesis that deserves further attention considering that, as shown here, more intense coloration may not necessarily reflect a better overall performance.

E. Vercken, M. Massot, B. Sinervo & J. Clobert // EUROPEAN SOCIETY FOR EVOLUTIONARY BIOLOGY. 2006. 20 ( 2007) 221–232

Within-sex colour variation is a widespread phenomenon in animals that often plays a role in social selection. In males, colour variation is typically associated with the existence of alternative reproductive strategies. Despite ecological conditions theoretically favourable to the emergence of such alternative strategies in females, the social significance of colour variation in females has less commonly been addressed, relative to the attention given to male strategies. In a population of the common lizard, females display three classes of ventral colouration: pale yellow, orange and mixed. These ventral colours are stable through individual’s life and maternally heritable. Females of different ventral colourations displayed different responses of clutch size, clutch hatching success and clutch sex-ratio to several individual and environmental parameters. Such reaction patterns might reflect alternative reproductive strategies in females. Spatial heterogeneity and presence of density- and frequency-dependent feedbacks in the environment could allow for the emergence of such alternative strategies in this population and the maintenance of colour variation in females.

Jessica Vroonen, Bart Vervust, Raoul Van Damme // Amphibia-Reptilia 34 (2013): 539-549

In many animals, aspects of colouration are hypothesized to convey information on the body condition or quality of individuals. This idea has been tested primarily for the carotenoid-based component of body colouration. The significance of other pigments in this context has received far less attention. In the common lizard, Zootoca vivipara, the degree of black patterning on the ventrum and throats is sexually dimorphic and varies considerably among individuals. In this study, we examine whether this melanin-based component of body colouration may reflect individual differences in quality (SVL, condition, immune response).We find that males (but not females) with a higher degree of ventral patterning mount a stronger phytohemagglutinin-induced immune response. The amount of black patterning does not correlate with body size, body condition, aspects of dorsal colouration or parasite load. We conclude that in male Zootoca vivipara, melanin-based ventral colouration may signal an aspect of immune capacity to sexual rivals or potential partners.

Evgeny S. Roitberg, Valentina F. Orlova, Nina A. Bulakhova, Valentina N. Kuranova, Galina V. Eplanova, Oleksandr I. Zinenko, Oscar Arribas, Lukas Kratochvíl, Katarina Ljubisavljeviс, Vladimir P. Starikov, Henk Strijbosch, Sylvia Hofmann, Olga A. Leontyeva, Wolfgang Böhme // Ecology and Evolution. April  2020; Volume 10, Issue 8: 1–31.

Reproductive mode, ancestry, and climate are hypothesized to determine body size variation in reptiles but their effects have rarely been estimated simultaneously, especially at the intraspecific level. The common lizard (Zootoca vivipara) occupies almost the entire Northern Eurasia and includes viviparous and oviparous lineages, thus representing an excellent model for such studies. Using body length data for >10,000 individuals from 72 geographically distinct populations over the species' range, we analyzed how sex-specific adult body size and sexual size dimorphism (SSD) is associated with reproductive mode, lineage identity, and several climatic variables. Variation in male size was low and poorly explained by our predictors. In contrast, female size and SSD varied considerably, demonstrating significant effects of reproductive mode and particularly seasonality. Populations of the western oviparous lineage (northern Spain, south-western France) exhibited a smaller female size and less female-biased SSD than those of the western viviparous (France to Eastern Europe) and the eastern viviparous (Eastern Europe to Far East) lineages; this pattern persisted even after controlling for climatic effects. The phenotypic response to seasonality was complex: across the lineages, as well as within the eastern viviparous lineage, female size and SSD increase with increasing seasonality, whereas the western viviparous lineage followed the opposing trends. Altogether, viviparous populations seem to follow a saw-tooth geographic cline, which might reflect the nonmonotonic relationship of body size at maturity in females with the length of activity season. This relationship is predicted to arise in perennial ectotherms as a response to environmental constraints caused by seasonality of growth and reproduction. The SSD allometry followed the converse of Rensch's rule, a rare pattern for amniotes. Our results provide the first
evidence of opposing body size—climate relationships in intraspecific units.