Cupid’s Arrow: It’s a snail love story

Editor’s Note: This is an excerpt from ‘The Harmony of Bees and Other Charms of Creepy Crawlies’ by Ranjit Lal—who writes about natural history, animals and the environment with great verve and charm. Here he explains the charming and rather complicated love life of snails. This excerpt has been republished with permission of Speaking Tiger Books.

You know, life gets complicated enough when you develop a crush on someone and are not quite sure that person fancies you in return. But the love life of some snail species goes much beyond just that! You see, in these species, each snail is both boy-snail and girl-snail at the same time! And well, when they want to have baby snails—that’s when things get properly weird. 

First, of course, they have to meet each other. They use their lower pair of tentacles to detect each other’s delectable perfumes. The top longer pair of tentacles have a mustard seed sized pinpoint eye, which doesn’t see that well, and snails are deaf. Their lower shorter pair of tentacles feels the ground as they make their way to one another. 

Once they are convinced that they are of the same species and kind of like one another, they begin courting, coming closer to each other, touching tentacles, and even kissing. They take their time about this from a couple of hours to maybe half the day. What they’re actually trying to do is to manoeuvre themselves into a suitable position, for something truly shocking to follow. Because now it’s almost time for them to actually make out! 

Now, boy snail wants to have babies with girl snail. Well, just when you think all is lovey-dovey between them, what do they do? They get up close, almost bumping chests like sportspersons do, and from their necks, pfft! shoot out a harpoon or ‘love dart’ crafted out of calcium or chitin, the size of a fingernail into each other. (Apparently this is where we got the idea for Cupid’s arrow.) 

Often they’re not very careful about their aim and may seriously injure their partners or miss completely, which happens maybe 30% of the time. The shooting of darts and harpoons is of course a very boy thing to do, and it is indeed done at the initiative of the boy half of the snails. Some say that the snails being shot thus find it pleasurable, some say it’s painful and they try to avoid it but who really knows? After shooting each other they come together and make out. But still all is not hunky dory…. 

When said boy snail shoots his dart, this is what he has in mind for his relationship with girl snail: she should have only his babies. Girl snail (or for that matter all girl snails) however, would rather make out with as many boy snails as possible to have a variety in her children, which would improve their chances of survival. Her internal plumbing is specially designed to actually kill off or digest as many of the boy snail’s wriggling sperm (more than 99%) before they can reach the safety of a special pouch, where they may be stored and used to fertilise eggs. 

To do this, they have to pass through a very long tunnel and bypass a nasty container where sperm is digested, an obstacle course, rather like the police roadblocks and diversions we find everywhere. The hormonal chemicals in the boy snail’s dart prevent the digestion of as many as possible of his sperm, so that they reach the safety of the pouch intact in maximum numbers. It’s thought that the boy snail which gets in his harpoon first, or has the bigger, sharper harpoon, has a better chance to make babies than one who is slower on the draw… 

So it seems that boy snail and girl snail are working at cross purposes: boy snail wants as many babies as possible, on the condition they must be only his (so only his magnificent genes get passed on), and girl snail also wants to have babies, but by different papas so there’s a better chance of her babies surviving. (If it was to be only one partner for her and he turned out to have wacko genes, where would that leave her and her babies?)... 

Once they have mated, the mama goes off and digs a shallow pit in which to lay and bury her eggs. But can you imagine the conversation between a mama snail and her babies, when she tries to explain the facts of life to them just before they set off into the world on their own?... Luckily for mama snails, they trundle off before their babies hatch and can ask such awkward questions.