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21 March 2016 Application of the Gompertz Function in Studies of Growth in Dusky Salamanders (Plethodontidae: Desmognathus)
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Gompertz growth functions were fitted to skeletochronological data sets of three species of desmognathine salamanders from an assemblage (Wolf Creek) in the Cowee Mountains of southwestern North Carolina. The results were compared to earlier evaluations of growth in desmognathines from a nearby assemblage (Coweeta) in the Nantahala Mountains. In two of the species, Desmognathus quadramaculatus and D. monticola, larger adult body sizes were attained at Coweeta than at Wolf Creek, whereas adult body sizes of the third species, D. ocoee, were similar in the two populations. Growth in both standard length (snout–vent length) and body mass were evaluated. The early phases of growth, prior to sexual maturation, were similar in the larger D. quadramaculatus and the smaller D. monticola, and higher in both species than in the even smaller D. ocoee. In all three species, growth rates tended to be higher in the Coweeta populations than in those at Wolf Creek. The inflexions of the Gompertz curves for body mass versus age, representing the maximum rates of growth, occurred at or near the age of first reproduction, which is expected, given the tendency for growth to slow at sexual maturation in desmognathines and other salamanders. The results support earlier findings that differences in adult body size between D. quadramaculatus and D. monticola are mainly effects of differences in age at sexual maturation, modulated by a difference in propagule size, as opposed to growth differences. However, the difference in adult size between these species and D. ocoee are joint effects of smaller propagule size, lower growth rate, and earlier maturation in the latter species.

Richard C. Bruce "Application of the Gompertz Function in Studies of Growth in Dusky Salamanders (Plethodontidae: Desmognathus)," Copeia 104(1), 94-100, (21 March 2016).
Received: 29 November 2014; Accepted: 1 March 2015; Published: 21 March 2016