The annotated budak: How long can it last?

The brevity of low spring tides and the lengthening shadow of coastal improvement connive to make each intertidal walk a race against time and the terror of charting the possible final moments of a living shore. We know too little about even the most common and charismatic creatures that cling to the few remaining coastlines where the sea has not been buried alive under a wall of concrete or carpet of litter. There is also the nagging thought that every hopeful stoop over each shifting plain might yield a multitude of missed links, even on untamed slivers of sand too small to be remarkable but too large to be understood and forgotten.

Save fair Eunice whose jaws inspire palpable fear and trembling, or those with showy fans or flat beds of electric colour, most worms arouse rather little. Only hungry fish and the hungry who fish harbour a tangible interest in the millions of thin-bodied animals that tunnel through mud and sand, revealing themselves only by chance and wasting no time in vanishing out of sight. Many of these creatures are distant cousins of earthworms and leeches and languish near the bottom of the food chain. But on occasion, one might catch sight of a snippet of bright colour threading over the silt like a neon twine.

With neither segments nor the swirling parapods of ragworms, these are nemerteans or ribbon worms, a branch of animals as far apart from polychaetes as dung beetles are from ducks. For all their reedy dimensions, their phylum boasts some of the longest members of the animal kingdom. One species from Norway, Lineus longissimus, is known to reach 30 metres with taller tales of 60-metre monsters. The worms are just 5-10 mm wide and consist of little more than a digestive tube with a mouth on one end and anus on the other. This structural simplicity, however, does not deter the animal from crude behaviour, for they possess a long organ known as an eversible proboscis. Like a sock puppet, this proboscis is turned inside-out when the ribbon worm encounters small prey. Venomous barbs at the end of the organ dispatch the victims before they have time to ponder the indignity of dying in the hands of a killer that has neither hands nor much of a brain in its head. The proboscis is prehensile and even species who endanger themselves by insisting on living in urban wetlands can't resist flashing out this rude member repeatedly at nubile biology students. And should some outraged maiden attempt to severe all contact with the creature, the cut pieces simply grow into new worms as long as each fragment is about half as long as the diameter of the body. What a pleasure it must be to spring to new life after dozens of little deaths from strokes of passionate fury...