Rough-skinned newt

Radiation adversely affects limb regeneration of amphibians, alters DNA metabolism, and increases the frequency of chromosomal aberrations and liver lesions (Table 32.25). In some species of amphibians and reptiles, as in many mammals, mortality rates after acute exposure to radiation do not stabilize within 30 days — effectively invalidating the conventional LD50 (30-day postexposure) value. In the rough-skinned newt (Taricha granulosa), for example, the minimal LD50 dose at 200 days after irradiation was 2.5 Gy, compared with 350 Gy at 30 days (Willis and... 

Snakes, 2 species, 3-4 Gy, single acute exposure Rough-skinned newt, Tarichagranulosa] single acute exposure LD50, 90 days after exposure 3... 

The level of tetrodotoxin in the skin of a particular female rough-skin newt correlates with that in her eggs. The amounts in the eggs of one clutch vaiy little, hut there is considerable variation between clutches. These findings suggest that the mother passes on the toxin to her eggs. As the amount of toxin is not correlated with egg size, it may not be transferred automatically (passively) with maternal resources to the egg. Rather, the mother may exert some control over the amount allocated to the eggs (Hanfin etal., 2003). 

Hanfin, C. T., Brodie, E. D., Ill, and Brodie, E. D., Jr. (2003). Tetrodotoxin levels in eggs of rough-skin newt, Taricha granulosa, are correlated with female toxicity. Journal of Chemical Ecology 29,1729-1739. 

The retention of selected isotopes by amphibians and reptiles is quite variable. For example, whole-body retention of after intraperitoneal injection in the rough-skinned newt showed two distinct loss components with biological half-lives of 2 and 210 days. The slower component accounted for 26% of the administered activity thyroid contained 78% of the total and clearly accounted for the long-term component (Willis and Valett 1971). However, similar studies with 1 and the leopard frog showed three distinct loss components (0.1 day 1.4 to 2.9 days 44.3 to 69.4 days) loss of each component was greater at 25°C than at 10°C. Also, the fast component probably represented plasma clearance through urinary excretion (Willis and Valett 1971). 

A rough-skinned newt Taricha granulos. Photograph hyE.R Degginger. The National Audubon Society CoHec on/Photo Researchers, Ina Reproduced by permission. 

California newt, Tarichia torosa, 118 Eastern newt, Notophthalmus viridiscens, 710 Rough-skinned newt, Taricha granulosa. 111 Triturus spp., 132, 665... 

In the rough-skinned newt Taricha granulosa, arginine vasotocin (AVT) plays important roles in reproduction. It elicits oviposition in the female (Moore, Wood Boyd,... 

Rough-skinned newt - http //commons.wikimedia.org/wiki/ File Rough-skinned newt (Taricha granulosa).JPG... 

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