Matriline effects on metamorphic traits in a natural system in the European common frog (Rana temporaria)

Abstract

Successful reproduction is an important determinant of the fitness of an individual and of the dynamics of populations. Offspring of the European common frog (Rana temporaria) exhibit a high degree of variability in metamorphic traits. However, environmental factors alone cannot explain this phenotypic variability, and the influence of genetic factors remains to be determined. Here, we tested whether the maternal genotype influences developmental time, body size, and body condition of offspring in a forest pond in Germany. We collected fertilized eggs from all 57 clutches deposited in the pond. We used multilocus genotypes based on seven microsatellite loci to assign metamorphosed offspring to mothers and to determine the number of fathers for a single matriline. We tested the influence of genetic effects in the same environment by comparing variability of metamorphic traits within and between full‐sib offspring grouped to matrilines and tested whether multiple paternity increases the variability of metamorphic traits in a single matriline. The variability in size and body condition was higher within matrilines than between them, which indicates that these traits are more strongly influenced by environmental effects, which are counteracting underlying genetic effects. The developmental time varied considerably between matrilines and variability increased with the effective number of fathers, suggesting an additive genetic effect of multiple paternity. Our results show that metamorphic traits are shaped by environmental as well as genetic effects.

Drop dead! Female mate avoidance in an explosively breeding frog

“…Direct benefits, such as increased fertilization success by larger or size-assorted males have been disproved; in fact, fertilization success has been found to be independent of size assortment [ 32 ]. We also detected a high rate of multiple paternity in our study population (80% [ 33 ]), probably due to ‘stray sperm’, which would minimize the potential adaptive effects of precopulatory female mate choice.…”