Dart shooting influences paternal reproductive success in the snail Helix aspersa (Pulmonata, Stylommatophora)

Although animal courtship behaviors are generally understood within the con text of sexual selection, the relevance of many sexual behaviors to sexual selection, and vice versa, remains unexplained. For example, the adaptive f unction of the "love dart" used in the precopulatory behavior of hermaphrod itic land snails is only now becoming apparent. Contrary to previous assump tions, dart shooting is unlikely to function as a stimulus for copulation. In searching for a more ultimate explanation of the dart's function, we tes ted whether variation in dart shooting influences reproductive fitness in H elix aspersa. Individual mother snails were mated sequentially to two poten tial fathers. Dart shooting was closely observed and quantified for all pai rings, and percentages of offspring sired by each potential father were det ermined using allozymes. The results indicate that snails that shoot darts effectively have significantly greater paternal reproductive success than s nails that shoot poorly. In contrast, there was no significant effect of ma ting order on either dart shooting or paternal reproductive success.