Low but genetically variable male mating ability in a tropical Drosophila despite fitness benefits of remating

摘要: Abstract Male mating success is a key source of variation in fitness, particularly organisms where males can mate multiply and there potential for high variance reproductive success. Males should therefore produce large numbers gametes to capitalise on all opportunities mating. In addition, strong selection male reduce genetic traits relative other traits. Despite this, the tropical Australian fruitfly Drosophila birchii show significant their remating resulting number offspring. We quantified latency, duration productivity D. males, 30 isofemale lines collected from across two elevational gradients (20 – 1100 m), when they were given with up four females consecutively. rates low compared species (only 14 27% achieved fourth ∼1 day). Mean also approximately doubled successive copulations. However, although produced progressively fewer offspring than male’s first mating, it consistently increased overall Critically, we found no reduction (male) derived these later matings, indicating sustained cumulative fitness benefit remating. Heritable was observed (H2 = 0.035 0.292) except evidence divergence trait means elevation. The surprisingly restricted ability may be explained by female encounter rate due species’ densities field, possibly combined cost sperm (or ejaculate) production.