It's a tale as old as time: Snail is born with genetic mutation. Snail cannot mate. Scientists turn to social media to find the snail a mate. Scientists find two possible mates for the lonely snail. Those other two snails mate instead. The lonely snail remains lonely.
OK, so, it's not really the stuff of a Disney romance, but it is real life. All of this happened to one very lonely snail in England. The snail's name is Jeremy, and this is Jeremy's story.
A search for love
Jeremy is a rare find among the garden snails you've probably seen countless times but probably never paid much attention to. The shell of nearly every garden snail you'll come across coils to the right, in a clockwise direction. Jeremy's shell, however, coils to the left, in a counter-clockwise direction. And you may be saying to yourself, "Well, that's not that big a deal. The shells go in opposite directions, so what?"
The "so what" is that because Jeremy's shell coils in the opposite direction of practically every other snail he will ever come across, he will never be able to mate with them. You see, Jeremy is truly a mirror of most garden snails. Not only does its shell coil in the opposite direction, but its sex organs are also on the left side. Since they're on the left side and almost every other snail's organs are on the right, the organs won't line up, and the snails will be unable to mate and reproduce.
Under ordinary circumstances, this would have left Jeremy out in the cold, unlikely to have ever found a mate. However, in the autumn of last year, a retired scientist from England's Natural History Museum found Jeremy on a compost heap in a London park. Knowing that a researcher at the University of Nottingham was interested in snail genetics — indeed, the researcher had worked with a team on a study that had identified the genetics involved in snail twist direction — the scientist collected Jeremy and mailed the snail off to Nottingham.
Jeremy arrived in the care of that researcher, Angus Davison, an associate professor and reader in evolutionary genetics at Nottingham, and not long after that, Davison put Jeremy on a dating app. That dating app just happened to be the whole internet. Davison sent out the call across press outlets and social media for anyone, anywhere, to take a gander at the snails they see, and if they happen to spot a similarly lefty snail, to let Davison know.
This broad online dating search wasn't in vain. Two potential mates for Jeremy were found. One was a snail named Lefty, from a snail enthusiast in Ipswich, England, while another snail, eventually named Tomeu, was discovered by a Spanish snail farmer who worked at a restaurant that specialized in, well, snails. Tomeu was about to be cooked when the farmer noticed the shell coiling to the left.
Both Lefty and Tomeu were sent off to Davison so that, hopefully, one of the snails would hit it off with Jeremy.
All's fair in love and snails
At this point, you're probably curious as to the mechanics of snail mating. As Davison explains to NPR, snails stab one another with "love darts" — awww! — that are actually just calcium spears that are used to transfer hormones between each snail. As snails are male and female at the same time, they can both fertilize and then reproduce. Snails can also reproduce on their own, but Davis explained that this happens "very rarely" and "they'd much prefer to mate with another snail."
So, with all that in mind, let's pick up Jeremy's story where we left off.
Lefty arrived before Tomeu did, and Lefty and and Jeremy seemed to make a mating connection. There was "gentle biting" and other activities that are the equivalent of snail flirting and foreplay, but Lefty and Jeremy never actually mated before Tomeu's arrival.
Once Tomeu came onto the scene, Davison and his team refrigerated all three snails for the winter to simulate a typical hibernation cycle, and then, come spring, they were taken out of the fridge and allowed to interact. And here's where things go south for Jeremy.
Lefty and Tomeu woke up with a great deal more energy than Jeremy, and the two snails mated multiple times and produced three clutches of eggs between them. The first batch of eggs resulted in more than 170 tiny baby snails. The other two clutches should hatch soon.
Jeremy is described as "shell-shocked" by the apparent reversal of fortunes. All this media attention and not one love dart from either of the would-be suitors.
Lefty has returned to Ipswich, but there is still hope for Jeremy and Tomeu to mate.
Right shell or left shell?
Given all that all this attention on Jeremy, Lefty and Tomeu is based on their shells, Davison and his team were naturally curious and excited about which direction the offsprings' shells would coil. How many of the baby snails would have left-twisting shells like their parents?
Zero, it turns out. Of the more than 170 baby snails produced so far, not a single one has exhibited a left-coiling shell.
Davison, however, wasn't surprised by the shells' directions.
"The fact that the babies developed right-coiling shells may be because the mother carries both the dominant and recessive versions of the genes that determine shell-coiling direction. Body asymmetry in snails is inherited in a similar way to bird shell colour — only the mother’s genes determine the direction of the twist of the shell, or the colour of a bird egg. It is far more likely that we will get to see left-coiling babies produced in the next generation or even the generation after that."
So, hopefully, when Jeremy and Tomeu mate — we're rooting for you, Jeremy! — their offspring and the offspring of Tomeu and Lefty will produce some more left-coiling shelled snails.