High Speed Snail

It was a cold rain sodden morning (well I am in the UK) and I had to run some errands in my car. Looking out through my side window I discovered that I had a hitchhiker. There was a small snail sliding slowly through the rain drops.

I drove to my next destination very carefully, especially when cornering, wishing I had a sign, “Snail on board” so that other drivers would understand my caution. The mucus was strong in this one, he held on.

Thanks to a very knowledgeable chap on Twitter @BrianE_Cambs I later found out that my stowaway was a girdled snail, Hygromia cinctella. These snails originated in the Mediterranean region and are believed to have been introduced to the UK around 1950. Since the 1970s they have spread rapidly throughout the UK probably in plant pots, on animals and judging by this one by our road transport system. Although they are an invasive species they don’t seem to have caused any harm. Surprisingly given where they originate from they are active in cold weather, which is no doubt why this one was exploring my car on a chilly morning.

The last whorl of their shell is sharply keeled and often white giving rise to their descriptive name of girdled snail. The shell can be different colours, is slightly translucent and striated.

They are one of the species of snail that employ love darts during their courtship. Snails are hermaphrodites, having both male and female reproductive organs which are situated in their heads. The love dart, or gypsobelum to give it its boring name, is comprised of calcium carbonate. It is stored in a muscular sac. It is fired into the other snail prior to mating and has been known to pierce organs or even go right through the victim’s head! The purpose of the dart seems to be as a delivery system for allohormone laden mucus. This chemical triggers biophysical changes in the recipient snail so that when  sperm is later transferred from the darting snail it is able to fertilize the eggs rather than being digested. This is very much an over simplification of a very complicated system, but you get the idea. Maybe Cupid’s arrows were dreamed up by a Greek fond of watching snails mate.

Hygromia cinctella love dart. By Joris M. Koene and Hinrich Schulenburg [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)%5D, via Wikimedia Commons

I digress! I’m sure you are all wondering if the snail managed to cling on. He made it to the next stop. The flash lighting up the raindrops with the dark background make him look as though he has gone into space.

I am happy to say that the motoring mollusc made it back safely and was transferred to some shrubbery to live out his life at a snail’s pace.

I was struck by the shell markings and fancy I see a leaf pattern.