Anuran Vocal Communication: Effects of Genome Size, Cell Number and Cell Size.

Significant variation in genome size occurs among anuran amphibians and can affect cell size and number. In the gray treefrog complex in North America, increases in cell size in autotriploids of the diploid (Hyla chrysoscelis) altered the temporal structure of mate-attracting vocalizations and auditory selectivity for these properties. Here, we show that the tetraploid species (Hyla versicolor) also has significantly fewer brain neurons than H.

Parallel changes in mate-attracting calls and female preferences in autotriploid tree frogs.

For polyploid species to persist, they must be reproductively isolated from their diploid parental species, which coexist at the same time and place at least initially. In a complex of biparentally reproducing tetraploid and diploid tree frogs in North America, selective phonotaxis--mediated by differences in the pulse-repetition (pulse rate) of their mate-attracting vocalizations--ensures assortative mating. We show that artificially produced autotriploid females of the diploid species (Hyla chrysoscelis) show a shift in pulse-rate preference in the direction of the pulse rate produced by males of the tetraploid species (Hyla versicolor).