The Secret Sex Life of Certain Salacious Shellfish

2002/3 - Tony Stevens

At first sight one might wonder what sort of sex life can shellfish have? After all most of them don't get about much. But there must be some reason why oysters spend their entire adult life in beds. For a start, it is impossible to generalise when talking of shellfish, there are far too many to do that. There are over a thousand known species of freshwater mussel alone. Some shellfish are very mobile but by far the largest group are literally tied to one place when they become adults. The 'Beard' on the edible mussel firmly anchors it down; the 'foot' of an oyster serves the same purpose. The barnacle, after gaily swimming around in its' youth, decides it's time to settle down and actually cements itself, head down to the nearest rock, or for those still with a sense of wanderlust, to a passing ocean liner. The barnacles belong to a sub-class of molluscs known as 'Cirripedes'. This not a Glaswegian term for a person wearing a wig, It refers to the now obsolete legs, which have evolved into 'Cirri', feathery appendages that now draw food into the 'mouth' of the barnacle. For all the above creatures, their days of wandering are over. Now, as everyone knows, being tied down at home can severely curtail your social life, not to mention your sex life, particularly so if your spouse is a cross dresser, or worse, (But more of that later). Not for the first time do we find that supposedly purely human activities have been anticipated by the animal kingdom, however with both the participants being tied down the attractions of bondage must be limited.

The shellfish's answer to the problem is to have a sex change. Now I'm not talking about wife swapping, although in some quiet backwater, who knows what might go on. I refer to a gender change in an individual. Shellfish are past masters at this and display great ingenuity in the methods they use. Some oysters regularly change their sex once or twice a year, this is technically known as 'Rhythmical consecutive hermaphroditism', (So now we really know who invented the rhythm method of birth control.) Some change with age, starting as males when young and immature and as they reach maturity gradually becoming female, which echoes the views of many women. Various species of oysters exhibit this tendency. So it would be quite possible for one oyster to approach another and tell him that he's becoming an old woman in his old age, and be completely correct.

If this were to occur in humans I for one would find it most unsettling. How long would the transition period last? Would the physical changes be in step with the mental ones, or would one lag the other? If one had to endure this process regularly, I think my favourite period would be when I had a woman's' body but still possessed a mans' mind, that would be the best of both worlds. The biological reason for this sex change behaviour is that whatever the sex of your immediate neighbours, (the only ones you can reach), eventually you will be compatible, unless you both change sex at the same time. Barnacles are particularly susceptible to this problem. They, having cemented themselves to one location and seeing the ladies nearby, also cemented head down, gaily waving their legs in the air must be particularly provocating. To aid them in their quest barnacles have developed a sexual organ six times their own length. To translate this into human terms, this would be thirty-six feet long for a six-foot man. This would be entirely superfluous for humans, (No matter what some might say, although it might provide a really novel means of performing the Indian Rope Trick), but it is essential for the barnacle. The barnacle inserts this organ into the carapace of the adjacent barnacles to see if they are currently male or female. This is particularly important since, in human terms, his neighbour, who he had known previously as Kylie Minouge might now turn out to be Arnold Schwarzenegger and strongly object to being groped in this manner.

In other varieties of barnacles the male is very much smaller than the female. At the end of his free-swimming period, the immature male attaches himself to the carapace of the female, virtually as a parasite. Apart from mating with her he also persistently steals food from her. Once again nature has forestalled the human phenomena of a 'Toy-boy' being a parasite on women.
I often try to put myself in the position of the creatures discussed above. How would I feel if I were subjected to the same processes? If I found that one of my parents, happily married for years had undergone a sex change and I now have two mothers, or even two fathers. Would their marriage still be legal, or would it be retrospectively annulled, would I even still be considered legitimate? All these questions run through my brain endlessly without answer, because there can be none. It does however give a whole new insight into the origins of the abusive term 'Shellfish Bastard'.
Some limpets exhibit another type of sex change. They tend to congregate in large clusters. If there is an even mix of males and females then all is well but if the number of females reduces, or even disappears altogether, then some of the males start exhibiting female characteristics, a situation very similar to that existing in some of H.M. Prisons today.

There is also another solution adopted by some house bound shellfish. This is to be both male and female at the same time. These creatures produce both sperm and eggs simultaneously, so that whatever the sex of a nearby mollusc, they can be accommodated. In the absents of any 'takers' these shellfish can mate with themselves, totally without any outside intervention. Genetically this is not a good idea as a regular occurrence as it reduces the gene pool and causes severe inbreeding and associated genetic defects. This may also be the reason why shellfish have no eyes. If the old saying is to be believed, they did all go blind many millions of years ago.

Finally, despite intense research (Well, I had a quick browse on the internet), I cannot find an answer to the question; 'what do Oysters eat for an aphrodisiac?'