Interpopulation variability in growth and puberty rates in male moor frogs (Rana arvalis Nilsson, 1842)

Abstract

The age distribution, body size, and annual growth rates in amphibians inhabiting three water reservoirs of different hydrochemical compositions have been analyzed to identify the interpopulation characteristics of the growth and puberty rates in the moor frog males. Altogether, 117 pubescent males at the age of 2 to 6 years old were studied. It has been determined that the ambient surface water salinity in the Middle Urals in the springtime is at the level of 150 mg/dm³. The interannual variations in salinity in the analyzed water reservoirs are related to the changes in the sulphate concentration. It has been noted that a water salinity of approximately 300 mg/dm³ during the spawning season is not a negative factor limiting growth of the moor frog. The relatively early pubertal maturation of the male moor frog can be observed under close-to-optimal conditions and is followed by the redistribution of the energy cost for the reproductive process advantages, along with a delay in the growth of the amphibians.