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MERAV SEIFAN ARIEL GILAD KEREN KLASS YEHUDAH L. WERNER 《Biological journal of the Linnean Society. Linnean Society of London》2009,97(2):275-288
Recent arguments in the literature prompted us to compare methods for assessing sexual dimorphism in body proportions of lacertid lizards, using Acanthodactylus boskianus . Although expressing body-part measurements as proportional to head length was the most effective method, we recommend using trunk length for the baseline as a general method for lizards. We also argue that, when aiming to assess sexual dimorphism in body proportions of lizards, if the context is ecological, all available adults should be included. However, for morphology and taxonomy, small sub-samples of the largest individuals that maximally express their genetic morphological potential should be used. In A. boskianus , the sexual dimorphism of mensural characters in adults was typical: males were larger, with relatively larger head and appendages. However, the ontogeny of this dimorphism was unusual in that the differences existed already in youth and thereafter persisted isometrically. The sexual dimorphism of meristic characters was male-biased in numbers of femoral pores and of caudal vertebrae, and female-biased in numbers of ventral plates along the trunk and of precaudal vertebrae. Size dimorphism may conceivably play a role in sex recognition because two potential visual cues (i.e. size dimorphism and dichromatism) appear to complement each other. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society 2009, 97 , 275–288. 相似文献
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Pedro Galán 《Ecography》1997,20(2):197-209
This paper presents data on aspects of the reproductive ecology of a population of Podarcis bocagei in northwestern Spain, as monitored over a two-year period (1990–1991) Data were obtained principally on the basis of mark-recapture experiments, but also from laboratory hatching studies Mating took place between the end of March and July During the laying period, from May to July, 8 5% of reproductive females produced three clutches, 52 1% two clutches, and 39 4% one clutch In general, single clutches were produced by small females Only a small proportion of large females produced three clutches Mean clutch size was 4 8 eggs (range 4–7) in May, 4 3 (2–6) in June and 3 9 (2–4) in July There was sigmficant variation in the mean snout-to-vent length (SVL) of females laying in each month of the season Both clutch size and mean single-egg volume increased with mother's SVL There was a significant partial correlation between egg volume and clutch size when both mother's SVL and month of laying were held constant There was no significant between-year variation in clutch size, breeding females' SVL, egg weight or relative clutch mass A delay in the timing of reproductive events in one year (1991) is attributable to adverse weather conditions during early spring Hatching occurred between July and September Hatch success (as estimated in 1989, 1990 and 1991 from natural nests at the study site) was high, ranging from 83% in 1991 to 91% in 1989 The mean SVL of female hatchlings was greater than that of male hatchlings By contrast, adult females had lower mean SVL than adult males 相似文献
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Acanthodactylus is a widespread lacertid genus including about thirthy species whose systematics remains much debated.The present study is aimed at improving the taxonomic status of the Tunisian species whose geographical distribution and ecological requirements have been studied elsewhere. Allozymic variation at 22 loci was scored in 14 populations for a total of 249 individuals. High genetic variability is confirmed in all samples; it is higher in species displaying a wide bioclimatic habitat range. No reduction of genetic variability was observed in two insular populations.Any interspecific hybrid could be detected from our genetic data, even in sympatric areas arguing in favor of specific status of four taxons in Northern, Central and Southern Tunisia.Phylogenetic relationships are discussed on the basis of UPGMA and Fitch-Margoliash procedures applied to the genetic distances matrix and centered data analysis of allozyme frequencies. 相似文献
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Müller J 《Journal of morphology》2002,253(1):43-50
The skull of the poorly known Asia Minor lacertid lizard Parvilacerta parva is described. In comparison to other palaearctic lacertids, Parvilacerta parva displays several peculiar traits such as a large braincase, a short parietal table, closed post-temporal openings, reduced ossification, or a large lacrimal. Many features are related to the small size of Parvilacerta parva and are of apparently heterochronic nature, as they can also be found in certain ontogenetic stages of other lacertid species. Small size and heterochrony even seem to be factors involved in the less-developed sexual dimorphism of Parvilacerta parva. The described morphology is interpreted to be related to a life history strategy in r-selecting, semiarid environments. 相似文献
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The kinematics of drinking of Lacerta viridis were analysed. A drinking bout is composed of four phases: approach, immersion, emersion and withdrawal. The tongue and gravity are central to moving water through successive compartments of the buccal cavity and into the oesophagus. Upon the basis of formifunction analysis of water intake and transport, a kinematic model of drinking in lizards is proposed. 相似文献
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In some vertebrate taxa, pheromones provide important information about species, sex, reproductive condition, kinship, and even individual identity. Because they possess highly developed nasal chemosensory systems, lizards are capable of many chemical discriminations, but many aspects of their pheromonal communication remain poorly understood even in major families. We report that males of a lacertid lizard, Podarcis muralis, are capable of differential response to surface chemical cues from conspecific males and females, from gravid and nongravid females, and from conspecific females and females of the closely related sympatric congener, P. bocagei carbonelli. In 60 sec trials in which stimuli from the femoral, cloacal, lateral, and upper body surfaces were presented to males on cotton swabs, males tongue-flicked at significantly higher rates to stimuli from conspecific females than males, from conspecific nongravid than gravid females, and from conspecific than heterospecific females. Responses to stimuli from conspecific males did not differ from those to distilled water. Together with previous findings that males can distinguish between chemical cues from familiar and unfamiliar males, these findings suggest that pheromones provide male P. hispanica important information regarding the presence of sexual rivals and the reproductive condition of potential mates without visually encountering other lizards. A growing body of literature indicates that lacertids are capable of sophisticated pheromonal discriminations that may play important roles in their social behavior. 相似文献
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S. Carranza D. J. Harris E. N. Arnold V. Batista J. P. Gonzalez de la Vega 《Journal of Biogeography》2006,33(7):1279-1288
Aim To determine genetic substructuring within the lacertid lizard Psammodromus algirus . To compare levels of variation across a geological barrier, the Strait of Gibraltar, and to compare this against the known age of the barrier using a molecular clock hypothesis. To compare the effect of the barrier within this species with previously published data from other organisms.
Location The Iberian Peninsula and North Africa.
Methods Partial sequences from the mitochondrial cytochrome b , 12S rRNA and 16S rRNA genes were obtained from 101 specimens belonging to the subfamily Gallotiinae and used in this study. The data set was aligned using C lustal X and phylogenetic trees produced using both maximum-parsimony and maximum-likelihood methods. Maximum likelihood estimates of divergence times for the combined data set (12S + 16S + cytochrome b ) were obtained after discovery of lineage rate constancy across the tree using a likelihood ratio test.
Results Psammodromus algirus contains divergent eastern and western mtDNA clades within the Iberian Peninsula. The western clade has northern and southern lineages in Iberia and one in North Africa. This phylogeographical pattern indicates that the lizard invaded North Africa after the opening of the Strait, presumably by natural rafting.
Main conclusions As in several other species, current patterns of genetic diversity within P. algirus are not directly related to the opening of the Strait of Gibraltar. Widespread sampling on both sides of the barrier is necessary to determine its effect on species in this area accurately. 相似文献
Location The Iberian Peninsula and North Africa.
Methods Partial sequences from the mitochondrial cytochrome b , 12S rRNA and 16S rRNA genes were obtained from 101 specimens belonging to the subfamily Gallotiinae and used in this study. The data set was aligned using C lustal X and phylogenetic trees produced using both maximum-parsimony and maximum-likelihood methods. Maximum likelihood estimates of divergence times for the combined data set (12S + 16S + cytochrome b ) were obtained after discovery of lineage rate constancy across the tree using a likelihood ratio test.
Results Psammodromus algirus contains divergent eastern and western mtDNA clades within the Iberian Peninsula. The western clade has northern and southern lineages in Iberia and one in North Africa. This phylogeographical pattern indicates that the lizard invaded North Africa after the opening of the Strait, presumably by natural rafting.
Main conclusions As in several other species, current patterns of genetic diversity within P. algirus are not directly related to the opening of the Strait of Gibraltar. Widespread sampling on both sides of the barrier is necessary to determine its effect on species in this area accurately. 相似文献
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Du WG Feng JH 《Journal of experimental zoology. Part A, Ecological genetics and physiology》2008,309(3):138-146
How fluctuating temperatures influence reptilian embryos and hatchlings has attracted increasing scientific attention, but is poorly known. We conducted an incubation experiment with a factorial design of two mean temperatures (24 vs. 28 degrees C) and three diel thermal fluctuations (0, +/-3, +/-6 degrees C) to determine the effects of diel thermal fluctuations and mean temperature on incubation duration and hatchling phenotypes. Both diel thermal fluctuations and mean temperature significantly affected incubation duration, but not hatching success. Incubation duration increased with increasing temperature fluctuations at a mean temperature of 24 degrees C, but not at a mean temperature of 28 degrees C. The significant interaction between diel thermal fluctuations and mean temperature on hatchling morphology indicated that the effect of thermal fluctuations depended on the mean temperature. Hatchling mass differed significantly between 24+/-6 and 28+/-6 degrees C, but not between the two constant temperatures or the temperatures with +/-3 degrees C fluctuations. At a mean temperature of 24 degrees C, the effect of thermal fluctuations on hatchling size was marginally significant, with relatively large hatchlings at the constant temperature; at a mean temperature of 28 degrees C, thermal fluctuations had no impact on hatchling size. The locomotor performances were significantly affected by mean temperature rather than diel thermal fluctuations. Therefore, diel thermal fluctuations around a given mean temperature do not affect hatchling phenotypes in a relatively large magnitude, but the influence of diel thermal fluctuations may differ with changing mean temperatures. 相似文献
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Tail autotomy, the self-induced tail separation from the body, is a common and effective antipredator mechanism in lizards. In this study, we examine the muscle energetics of tail shedding in six lacertid lizard species (Podarcis erhardii, Podarcis peloponnesiaca, Podarcis muralis, Podarcis gaigeae, Podarcis milensis, and Lacerta graeca) from the northeast Mediterranean region. Very long periods of postautotomy tail movement were demonstrated for all species (range=6-8 min), and differences among species were not statistically significant. Postautotomy tail movement, powered by anaerobic muscle activity, resulted in a strong increase in lactate concentrations and a concomitant depletion of muscle glycogen of exhausted tails relative to resting tails. No significant differences were found in either lactate or glycogen concentrations among the species examined. Duration of movement was negatively correlated with final lactate concentrations. The lack of differentiation in postautotomy energetic physiology in this group of species that have evolved under very different predation environments indicates that postautotomy muscle metabolism involves an overall conservative suite of characters. 相似文献
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P. Vandewalle § A. Chikou † P. Lalèyé † E. Parmentier F. Huriaux B. Focant ‡ 《Journal of fish biology》1999,55(4):795-808
The inception and development of the cartilaginous cephalis skeleton of Chrysichthys auratus is described from hatching to about 18 days post-hatching. At hatching, no skeletal structure is present. Not until day 3 do clearly delimited cranial primordia become apparent. As in many siluriforms, the neurocranium is platybasic from the start, the suspensorium constitutes, with Meckel's cartilage and the hyoid bar, a single cartilaginous element, and the junction between the front and rear of the neurocranium is complete on day 4. By day 8 the quadratomandibular joint has formed and the tectum posterius has appeared. Cartilage reduction first affects the trabecular bars, then, markedly, the visceral arches. By day 18 the braincase floor has almost disappeared. 相似文献
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Chemical communication in the lacertid lizard Podarcis muralis: the functional significance of testosterone 下载免费PDF全文
Chemical signals are essential for intersexual communication in many animals, including lizards. While faeces have been suggested to contain socially relevant chemical stimuli, epidermal gland secretions are generally believed to be the leading source of chemosignals involved in lizard communication. Early research has shown that sex hormones affect epidermal gland activity, with androgens stimulating gland/pore size and/or gland productivity. However, the functional significance of hormone‐induced glandular activity in lizard chemical communication remains unclear. In this study, we manipulated testosterone (T) concentrations in male Podarcis muralis lizards. While T‐supplementation did not change pore size, it did increase secretion production substantially. Chemosensory tests showed that female conspecifics tongue‐flick at a higher rate and more quickly towards the secretion of males with experimentally increased T levels than towards the secretion of control males, suggesting that females can discriminate between males with dissimilar T levels based on chemical cues of secretion alone. Based on the scent of faeces, however, females were unable to discriminate between males with differential T levels. Also, females reacted more quickly when offered larger amounts of secretion – irrespective of whether secretions were obtained from control or T‐increased males. This result indicates that secretion quantity affects chemosignal detectability in Podarcis muralis. 相似文献
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Sharon DownesDirk Bauwens 《Animal behaviour》2002,63(6):1037-1046
Podarcis sicula of Italian origin has expanded its range along the Adriatic coast of Croatia, apparently replacing the autochthonous species P. melisellensis by competitive exclusion. We used an experimental approach on newborn lizards to test the hypothesis that direct behavioural interference occurs between P. sicula and P. melisellensis, whereby the former obtains an advantage over the latter. Brief encounters betweenP. sicula and P. melisellensis were more aggressive and more likely to result in clear dominant-subordinate relationships than were brief encounters between pairs of conspecific P. melisellensis. When they cohabited for 3 weeks, individuals in heterospecific pairs were less likely to occupy a thermal microhabitat simultaneously than individuals from homospecific pairs. Contrasts of individuals in heterospecific pairs showed that behavioural interference was asymmetric in favour of P. sicula. During brief encounters P. sicula were more aggressive and dominant than P. melisellensis opponents. When the two species cohabited for longer periodsP. sicula used better, and P. melisellensis poorer, thermal microhabitats than when reared in isolation. In addition, P. sicula grew faster, and P. melisellensis slower, than in isolation. These within-species shifts in microhabitat use and growth were not evident for homospecific pairs living together. Thus, our observations indicate that asymmetric aggressive interactions between hatchlings of our study species reduce an important fitness component (i.e. growth rate) of P. melisellensis. These findings are consistent with the hypothesis that direct behavioural interference by P. sicula is the mechanistic basis of the competitive exclusion ofP. melisellensis . Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved. 相似文献
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