NATURAL VARIATION IN THE APPENDICULAR SKELETON OF TRITURUS-CARNIFEX (AMPHIBIA, SALAMANDRIDAE)

Intraspecific variation in the appendicular skeleton of two geographic ally isolated populations of Triturus carnifex, one from northern Ital y (Rosate, Milano) and one from central Italy (Bagnaia, Perugia), has been studied. A total of 1,746 forelimbs and 830 hindlimbs were examin ed. Forelimb skeletal variability was much greater in the Rosate than the Bagnaia population. Skeletal variants were present in 36.3% and 13 .5% of the forelimbs, respectively, or in 54.7% and 22.7% of the netws (P < 0.0001). There were no predominant skeletal variants in Bagnaia, while in the Rosate population, the majority of the variants consiste d of fusion of radiale and prepollicis and of phalangeal formula 1-2-3 -2. Hindlimb skeletal variability was similar in the two populations a nd appeared to be much lower than that of the forelimb, with highly si gnificant differences in the frequency of basipodium variants within t he Rosate population and in the frequency of acropodium variants in bo th populations. Skeletal variants were present in about 9% of the hind limbs, or in about 12% of the newts from either population. At present , no conclusion can be drawn about the mechanisms, genetic and/or epig enetic, underlying the skeletal variability observed in the Triturus c arnifex from northern and central Italy. (C) 1996 Wiley-Liss, Inc.