Knowledge on variations in the reproductive modes, karyotypes, and mtDNA sequences of Lacerta (Zootoca) vivipara made headway but the morphological differences between any forms or populations remain unclear. That is why we studied different patterns of morphological variability using nine biometrics and 10 meristic variables on 242 common lizards: 119 oviparous (French, Spanish, and Slovenian), 114 viviparous (French, Bulgarian, and Russian), and nine hybrids. Our analyses confirm, for each population, the existence of a clear sexual dimorphism. Observed differences between reproductive strains (oviparous vs. viviparous) could not be connected immediately with the reproductive mode. Results of comparison between regions correspond to the geographical origin of the samples. We observe three clusters: western (Pyrenees and France), Slovenian, and eastern (Bulgaria, Russia, and Siberia). Comparisons of samples defined by their karyotypes are very similar. L. (Z.) v. carniolica subspecies is different for a majority of the studied variables. Our results show the special interest of the Russian samples but do not support the validity of the sachalinensis subspecies. The absence of clear relation between morphological and genetic structure of the species reveals that samples of the “complex” of common lizards are very closely related and have likely relatively recently diverged.
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274Variation in reproductive traits (sexual maturity, clutch size, clutch weight, mean egg mass, newborn weight) was studied during a four year period in a population of the live-bearing lizard Lacerta vivipara. Sexual maturity was associated with attaining a minimum body size. Clutch size increased with female body length and litter weight increased with clutch size. A major component of the within year variation in these reproductive traits was attributable to female size. Analysis of successive clutches in individual females indicated that a significant fraction of the variation in litter size adjusted for female length, was due to consistent differences between individuals Newborn weight varied within and among litters, but no relations between hatchling mass or mean egg mass in a litter and other traits were detected Size-adjusted reproductive performances remained constant during the course of this study, even though environmental conditions (weather factors, food availability) varied annualiy Observed among year variations in reproductive characteristics were attributable to differences in the body size distributions of the adult females
Although the European common lizard, Lacerta 6i6ipara, is among the most common Eurasian reptile species, we know little about how these lizards cope with very low temperatures. In this study we examined microenvironmental conditions, body temperature, behavior, and cold strategies to see whether strategies of freezing and supercooling, while normally considered to be mutually exclusive, may in fact be adopted simultaneously by the common lizard. Following up on an earlier study of a lowland population, this time we used a mountain population (850 m) to discover differences in overwintering strategies between the two populations. Differential scanning calorimetry conducted during the hibernation period (vs. the activity period) showed that the blood of highland lizards had an increased ability to resist ice formation, confirming an ecophysiological effect most likely mediated by physical properties of the blood. Mean blood glucose level of unfrozen L. 6i6ipara in the field increased significantly (about fourfold) from 8.5±0.7 mmol l-1 in September to 33.2±5.6 mmol l-1 in March. The blood glucose level then experienced a significant decline as it fell to 6.2±0.8 mmol l-1 after hibernation in April. Glucose, in conclusion, seems to play a role of cryoprotectant rather than antifreeze.
The geographical variation of Ibero-Pyrenean Zootoca vivipara (JACQUIN, 1787) is studied. Multivariate analyses show a differentiation of central and western Cantabrian samples, mainly based on specific pileus scales configuration, especially in males, whereas in females there seems to be a considerable morphological overlap with female specimens of other areas. Univariate statistics clusters Cantabrian and Basque Country (s lat.) specimens more closely, with Pyrenees specimens slightly more differentiated, a pattern fairly coincident with the results of genetic studies. Oviparous Cantabro-Pyrenean populations are described as a new subspecies: Zootoca vivipara louislantzi ssp. nov.. They differ from other subspecies in various traits and are characterized by the following combination of characters: morphologically (decreased collar and supralabial scales counts, increased numbers of lamellae under 4th toe, lack of the discontinuous wide white-bordered vertebral band and also lack of yellow colored bellies in females), osteologically (tendency toward reduction of presacral vertebrae), karyologically (W-sex chromosome uniarmed) and genetically (Nei’s genetic distance of 0.102 and the diagnostic alleles ATA-150 and ATA-200; and also 1.3 (± SD 0.5)% of sequence divergence in 16S rRNA and 1.8 % (range: 1-2.6%) in cytochrome b). Biometric and meristic characteristics of the new subspecies as a whole, and separately for its main range areas are given.
