Lizard common

ILLUSTRATION 6 Although amber fossils most commonly contain flies, animals as large as lizards have been found. 

Thoen, C., Bauwen, D., and Verheyen, R. F. (1986). Chemoreceptive and behavioral responses of the common lizard, Lacerta vivipara, to snake chemical deposits. Animal Behaviour 34,1805-1813. 

Exenatide (synthetic exendin-4, from the saliva from a lizard), which has a 53% overlap with glucagon-like peptide-1 and which also binds to the glucagon-like peptide-1 receptor, has been investigated in a placebo-controlled study for 28 days in 116 patients with type 2 diabetes in addition to a sulfonylurea or metformin (1). The most common adverse effects were nausea (mostly only in the first week) and mild to moderate hypoglycemia, for which no treatment was needed. 

Feeding commences after mating. Their diet is mostly small mammals and reptiles, particularly mice, voles and common lizards. They also take fledgling birds, and occasionally frogs. Vipers can swim well, but this is generally a much rarer... 

Important drugs have been derived from two plants common in the woodlands of the eastern United States. One is etoposide (an anticancer drug) based on the podophyllotoxin found in Podophyllum peltatum,415 The second is sanguinarine (from Sangulnarla canadensis), which is used for treatment of periodontal disease. A common fence lizard of the western United States, Sceloporus occidentalis, has something in the blood that kills the bacteria responsible for Lyme disease.416... 

In an effort to test the system and to generate preliminary data on the toxicity of munition compounds to reptiles, acute oral toxicity studies on TNT, DNT, and RDX were conducted using Western fence lizards (S. occidentalis) [60], All three compounds were administered via gavage in a com oil vehicle. Table 7.1 shows the median lethal dose (LD50) for lizards orally exposed to these common munition compounds. Based on these data, RDX is relatively more toxic to fence lizards than TNT and DNT. Males appear more sensitive to RDX than females, while females are more sensitive to DNT than males, although generalizations on the relative sensitivity of males and females should be approached with caution. Overall, these data suggest that RDX is most toxic, and DNT and TNT are less toxic. 

Apart from the underlying principles, there are the questions of how the data are obtained and their limitations. With the phenetic method, characters used are those for which it is possible to make the necessary quantitative measurements. With the cladistic method, it is rarely possible to determine each branch point, especially where convergent evolution has occurred. The phenetic method produces a practical classification but lacks the deeper philosophical justification of the cladistic method. However, both methods often give similar results, but differences arise, as in the example in Fig. 1.2. Although the crocodile and lizard show greater morphological similarity to one another than to the bird, birds and crocodiles have more recent common ancestors than crocodiles and lizards. 

Thoen, C., Bauwens, D. Verheyen, R.F. 1986. Chemoreceptive and behavioural responses of the common lizard Lacerta vivipara to snake chemical deposits. Anim. Behav., 34, 1805—1813. 

While vision is commonly rated as the dominant sensory mode in reptiles (i.e., Madison, 1977), we believe this is an impression based primarily on work with terrestrial lizards, snakes and tortoises which may not apply as well to the aquatic members of the class. Much more research needs to be done with aquatic and marine snakes and turtles whose habitats provide poor visual, but excellent chemical cueing characteristics. 

Figure 5.4. A common lizard scaled linearly to gigantic size. Scene from The Giant Gila Monster (1959). Movie Still Archives.

To determine whether viviparous lizards (L. vivipara) show innate responses to chemical cues from predatory snakes from birth, or learn them through experience, the preceding experiments were duplicated (Van Damme et al. 1995). Seventeen juvenile common lizards (L. vivipara) were exposed to a clean cage or to a cage that had previously housed the lizard-eating adder V. berus) or smooth snake (C. austriaca). Juveniles that had never been exposed to predator chemical cues before behaved like the animals used in the previous study by Thoen et al. (1986). One difference in the behavior of juvenile and adult lizards... 

Monier, S. Samadi, M. Prunet, C. Denance, M. Laubriet, A. Athias, A. Berthier, A. Steinmetz, E. Jurgens, G. Negre-Salvayre, A. Bessede, G. Lemaire-Ewing, S. Neel, D. Gambert, R Lizard, G. Impairment of the cytotoxic and oxidative activities of 7 beta-hydroxycholesterol and 7-ketocholesterol by esterification with oleate. Biochem. Biophys. Res. Common. 2003, 303, 814-824. 

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