Does multiple paternity improve fitness of the frog Crinia georgiana?

In the Australian myobatrachid frog Crinia georgiana simultaneous polyandry occurs in about half of all matings, which leads to multiple paternity, bu t reduced fertilization success and occasional female mortality. Multiple p aternity may provide benefits to females that compensate for these costs, f or example, through enhanced genetic diversity of a clutch. In nature, embr yos and tadpoles of C. georgiana develop in shallow, temporary pools and ma y be exposed to fluctuating water levels and the risk of desiccation betwee n rain events. Fertilization by genetically diverse sires may act as a bet hedge against these conditions. To evaluate this hypothesis, females were a rtificially mated with one or two males in the held and eggs and larvae rea red in the laboratory under constant or fluctuating developmental condition s. Experiment 1 exposed embryos from single- and multiple-paternity clutche s to conditions where eggs were completely covered during development or eg gs sat in air on a moist substrate. Experiment 2 exposed freshly hatched la rvae from single- and multiple-paternity clutches to constant wet condition s, where larvae were completely covered, or fluctuating wet conditions, whe re larvae ranged from being completely submersed to partially exposed over a 13- day cycle. We measured mean performance and best performance as alter nate measures of genetic benefits. There were no effects of paternity on pe rcent survival, to hatching, time to hatching, body size at hatching, perce nt survival to metamorphosis, time to metamorphosis, or body size at metamo rphosis. We also analyzed variance within clutches as a measure of genetic diversity. Again there were no predictable effects of multiple paternity. P olyandry does not appear to provide any genetic benefits that compensate fo r the high costs of polyandry in this species.