I went to the beach today at lunch, and for reasons best left unexplored here, my mind was on sex. Walking down the trail, I saw two snails engaged in what could only be sex, but it sure didn't look like any sex I'd ever seen. The snails appeared to be joined by some sort of tubes that came from each of them. They were motionless, and the rock below them was covered in a white slimy material. Ok, call me sick, but I found this pretty interesting, so I came back and started researching snail sex. Here's what I found out. It's pretty cool.
Most snails are hermaphroditic, having both male and female sex organs. This dual set of genitals is located right behind the head on the snail. When two snails meet, the encounter begins with caresses and kisses. Yes, snails do have lips. Soon, the snails' genitals become swollen, and before long the two snails are engaging in what one article called “lip-genital atrium behavior”. Honest, I'm not making this stuff up. So far it sounds pretty romantic and gentle, eh? Well..now things get rough. A half hour or so after initial contact the two snails push against each other and each releases a "love dart", a centimeter long hollow calcareous lancehead with four blades into the body of the other. The snails shoot for the tender flesh right behind the genitals, but their aim isn't always perfect. The sex continues with each snail injecting sperm into the other. (And all over the rock, if that stuff on the rock was what it looked like)
The question that remains to be answered about snail sex is....What is the dart for? Snails are quite promiscuous and may mate several times a week, however only one dart is produced each week. Successful mating does not depend on accurate dart placement, or even on there being a dart at all. Some scientists theorized that the dart dissolved inside the body of the snail, furnishing calcium needed for successful egg development. This was also proved false, as few darts remain in the body long. Latest research seems to indicate, however, that when a dart is accurately placed, mucous covering the darts sends the mate’s female reproductive tract into rhythmic contractions. The contractions draw the spermatophore (a membrane covered package of sperm) into the reproductive tract and allows the sperm to escape before the enzymes there digest it. As snails are sexually adventuresome and often mate with several partners before any eggs are fertilized, dart placement may be a factor in determining which partner passes on his genes.
And you thought snail sex was boring.