Chung, D.J.D. 1987. Courtship and dart shooting behaviour of the land snail, Helix aspersa. Veliger 30: 24-39.
The function of reciprocal 'love dart' exchange between pairs of terrestrial snails during courtship has long puzzled researchers. In an attempt to understand this phenomenon Chung tried to answer the question, "Does dart receipt have a stimulatory effect on courtship behavior?"
Helix snails are simultaneous hermaphrodites with complex mating rituals. One stage of reproduction is dart shooting, the function of which has never been discovered. In the past, it was generally assumed that the receipt of a dart somehow "stimulated" cooperative courtship behavior.
In this study, detailed behavioral observations were made on 100 pairs of snails through all stages of reproduction. Chung found that snails that received a dart had a significantly lower rate of attempted copulation than those that had not received a dart. This suppressed rate of attempted copulation was interpreted as indicating that dart reception physically injured the receiving animals. In some case the injury led to cessation of courtship. He also found that dart reception was not a prerequisite for completion of courtship and copulation as snails not receiving a dart attempted copulation at the same rate as those who received a dart.
He concluded that dart receipt has no obvious stimulatory effect on the reproductive behavior of Helix aspersa. Finally he suggests that dart shooting may have evolved as an anti-cheating device or as a device used in coercion due to the pain a dart wound can inflict.
(248 words)
Back to Zool 250 Home Page