On Being A Tube Worm

This is only going to involve a bit of light zoölogy.

That illustration above, of a polychæte worm called Chætopterus, looks quite fierce and jagged. In fact these animals are entirely innocuous to humans and we rarely encounter them, but I have at times become inordinately focussed on them. Although this is not really about them, they’re worth considering, so I’ll go into a bit of detail.

Any number of species of animal sit around all the time not doing very much, particularly in the sea and to a lesser extent in the much harsher environment of freshwater rivers, lakes and ponds. There’s no particular reason to single Chætopterus in this respect. It just happens to be one of those countless animals whose lifestyle involves doing very little other than filtering food out of water. The picture shows such a worm in a state it would rarely be in while alive, because in its burrow its chætæ would be lying flat against its sides, and they are by no means sharp or offensive weapons. It lives in a mucus-lined U-shaped burrow in mud or sand, although some of them live under rocks. The middle section has fans which draw sea water down towards them and the front makes a bag of mucus in which a bolus of food is formed, which it passes down its back towards its mouth. The current it creates also enables it to breathe, just as a fish’s gills exchange dissolved gases in a current. It’s completely blind, but oddly it also glows blue when disturbed. Any consciousness it has does not include the luminescence, so it can’t perceive that it does this and there’s no possibility of it being a signal between individuals of the same species. There are a couple of small species of crab who tend to share its burrow and they can’t live anywhere else.

Really, the point is not the animal itself, as it’s only one of many sessile organisms who do nothing but filter feed on the bottom of bodies of water. In some cases this is extreme, in the sense that they actually live kilometres down on the abyssal plains of the oceans, but on the whole their lives seem quite simple compared to our own. They just suck and eat. In the case of Chætopterus they also have separate sexes, but even simultaneous hermaphrodites generally benefit as a species from combining their gametes with other individuals. It is worth asking how a sexual animal that just lies there all day can reproduce and whether this contributes to the richness of their life experience. Females release a chemical which stimulates the males to release sperm, which in turn stimulates the females to release eggs. In both cases this is done by rupturing the body wall, so in a sense both sexes explode with pleasure, and we might imagine this as orgasmic. The gametes then combine in the water, becoming planktonic larvæ, most of whom are presumably eaten, possibly by adults of the same species. Being a tube worm is not like being human. The presumed death of the parent worms conveniently gets them out of the way for the next generation, preventing them from hogging resources such as food and substrate, and is pretty normal for thousands of animal species. It means that they are all absentee parents and orphans, and they substitute parental care with prodigious physical reproduction.

It seems to be an easy life. It also seems to be the kind of life which, if lived by a human being, would lead to our swift demise. There are trivial ways in which this is true: for instance, obviously no human is going to live very long buried in the seabed trying to breathe water. However, on the whole it’s a very inactive life, and although there are overuse injuries, often acquired by athletes, humans more often suffer as a result of physical inactivity or disuse: “use it or lose it”. In the richer parts of the planet, many health problems are associated with not doing very much physically, although the situation is very different in the global South, and has historically been elsewhere. Yet there are many animals who do best when left alone.

In a way, the life of a polychæte worm buried in silt all her adult life is idyllic. On the other hand, harnessing the probably instinctive taboos humans have about mucus, what she’s “actually” doing is very similar to picking her bogies and eating them, because the dust we inhale which gets trapped in our nostrils by the mucus and is then sometimes disposed of by people “picking their nose and chewing it” as the song has it, is how she keeps body and soul together. An odd thought in a way, and also a disgusting one. She also lives in a tube of congealed mucus. There’s another question here. Is this tube to be considered part of the animal’s body or is it just a container? Also, if it’s the latter, it could be considered to be clothing for worms in a way, so humans are not the only clothed species, although caddis fly larvæ cases are a lot closer to what we do.

The inevitable issue of consciousness arises. As a panpsychist, I am going to say that of course this species is conscious. There’s even a central nervous system including a brain. Some polychætes, notably peacock worms, react a hundred times faster than we can, which makes them superior in that one respect. I don’t know if this is true of parchment worms (which is what they’re called because of the texture of their tubes) as they don’t seem to need to respond so quickly to a stimulus. Their companion crabs use their burrows to hide from predators, so it’s probably quite a dull life from that perspective too. Nonetheless they can sense the pheromones in the water, seem to make some kind of decision as to when to release them, also choose when to move the lump of food and mucus towards their mouths and do something which results in them glowing blue when they’re threatened, although that could in theory be passive. There also seems to be some awareness of the passage of time, or of the right conditions coming about, in the female initiation of the reproductive sequence. However, thinking of our own puberty, although there is a correspondence between life events and hormonal changes, they aren’t, at least straightforwardly, under conscious control. The endocrine system has parallels to the nervous system and even uses some of the same compounds such as adrenalin, but only one appears to involve consciousness clearly. All that said, maybe there’s a shadowy, or not so shadowy, consciousness within our endocrine and immune systems, and maybe they’re even linked to what we think of as our nervous system-based consciousness. After all, almost nobody who remembers or experiences it would say puberty doesn’t pack an emotional punch, and this is just one example of a hormonal event, albeit a near-universal one.

The SF writer Philip K. Dick introduced the concept of “zebra”. Based on the idea that zebra stripes are a form of camouflage, which they probably aren’t, PKD conjectures that although we may be aware of camouflage which works well to fool other species into not noticing particular organisms, there could also be a successfully camouflaged entity which completely deceives all human beings. Although it’s almost impossible for this to be a scientific possibility, because the idea is that it is in principle impossible to observe this entity, nothing seems to rule it out, and there’s also an element of humility in the idea that we humans may be as subject to being deceived as any other animal. There are very clear examples where we know we’re being fooled some of the time, as with the likes of flatfish and cuttlefish who can change colour and hide themselves visually, and the way cricket chirps seem to come from a different direction than the actual cricket is a similar happenstance, but the rational possibility exists that there could be something we will never see or know about. Our sensory world is quite restricted in various ways, notably due to our practically non-existent sense of smell, and it seems feasible that a dog, for instance, would be able to smell our fear or a change in odour when we get certain types of cancer. We don’t know what tricks or senses are possible which are not available to us. Hence what are the chances that, just as Chætopterus glows blue when threatened, presumably scaring off some potential predators, we also have an adaptation which serves a function for us but of which we are completely unaware, even in principle? It needn’t be something particularly exotic. Maybe we emit an aversive odour when we’re afraid which deters predators, and dogs can smell it but are not averted.

Carefree lives are probably rare, and I’m thinking of all animal lives here, possibly more than that. I was clearing up some lumber earlier and a spider fled across one of the planks. I think it would be a failure of empathy to deny she was afraid. Whether that’s actually so is another matter, but the benefit of the doubt should be exercised on most occasions. If you see an animal of whatever size or phylum moving as fast as they can away from an obvious threat, it makes sense that that’s how they’re feeling. I could go on, but I won’t. The observation was once made to me that in the past, every human adult’s life involved being afraid, hungry and tired almost all the time, and the same still applies to the rest of the animal kingdom. I’m not entirely sure this is true of humans because they were on top of things, but it does occur to me that childbirth and parenting of small children at least seems to resemble that more closely than most of the rest of human life in an industrial or post-industrial society for most White able-bodied wealthy (etc) humans.

There used to be a pair of wood pigeons which nested in a sycamore tree outside our house. During discomfortable conversations with Sarada I used to look at them and imagine they had an easy, simple, happy relationship raising chicks and letting them free into the adult world. They came back at least once. Then it became clear that the sycamore was sending roots under the neighbours’ house and causing damage, and it was deemed that the tree be felled. This was not while they were nesting in it, but it occurred to me that they might return to their haunt the next year and find it gone, so their life wasn’t really as blissful as all that, thanks partly to us. Probably most of a wood pigeon’s life is nasty and miserable. The average lifespan of the species in the wild is three years, but they can live for more than seventeen in captivity, demonstrating the difference between potential and reality. A house mouse can be expected to live an average of eighteen weeks but could live to be a year and a half. I don’t know if these figures are skewed by infant mortality. This was probably never true of humans or their childhoods would have to have been a lot shorter than they generally are, but it shows how hard life generally is.

But the thing is, maybe life for humans is supposed to be hard. Not for us that nice cosy mucus-coated burrow in the mud. Something about our very existence might have to be difficult for us to live at all. When I consider our granddaughter, I’m acutely aware that she is happy and carefree much of the time, or so I imagine, but thinking back at my own childhood I can remember that at the age of ten I traced back what I worried about and found that worry had been my constant companion for as long as I could remember. That might be me of course, but I don’t think childhood is the happiest time of most people’s lives, or rather, I don’t think childhood is usually happy. It might be that adulthood has more potential for happiness but maybe it doesn’t get realised. Nor do I think poverty is the sole culprit here because many wealthy people are thoroughly miserable, not necessarily because of their wealth but because that’s what life is like. On the other hand, maybe that’s just what we’re supposed to believe because human life could be a whole lot better but it isn’t, though not because of non-human influences.

They shoot horses. I don’t honestly believe it’s kinder to do so because there are examples of horses who were able to recover from serious limb injury, but it is also true that to a considerable extent a horse is a running being, and not being able to do so is psychologically and physically injurious. Humans need to be good at being human, but it isn’t always clear what that involves. We don’t, then, benefit from living in slimy holes on the sea bed, but what do we benefit from?

I’m not totally clear what I’m getting at here. Maybe I should’ve thought about it a bit longer, or maybe you can tell me.