Love dart

A love dart (also known as a gypsobelum) is a calcareous or chitinous dart-like structure used as part of the mating behavior of some hermaphroditic land snails and slugs. The dart is typically stabbed into the body of the prospective mate during courtship, and the injection of mucus associated with the dart can increase the success of fertilization.

The exact function and effectiveness of love darts are complex and debated, and can vary significantly between species. In general, the injected mucus contains hormones or other substances that manipulate the recipient's physiology. This can lead to several effects, including:

• Increased sperm survival: The mucus can alter the recipient's reproductive tract to improve sperm storage and reduce sperm digestion.
• Reduced sperm digestion: The mucus can neutralize or reduce the effect of enzymes in the recipient that break down sperm.
• Increased paternity: By manipulating the recipient's physiology, the dart-shooting snail can increase the likelihood that its sperm will fertilize the eggs.

The love dart itself does not directly fertilize the eggs. Instead, it serves as a delivery mechanism for the mucus that influences the recipient's reproductive system. The process is often reciprocal, with both snails attempting to stab each other with love darts. The success of dart shooting can influence mate choice and fertilization outcomes. Despite its name, the "love dart" behavior can sometimes cause injury to the recipient snail.