Some local lads have started fishing on the canal. The likelihood of these young scallywags having a licence to do so is slim, but likewise their level of success when it comes to catching anything seems equally dubious. I have observed them occasionally, waving rods across the water to no success, but this week I came across three of them at the side of the water, making loud retching noises and shouting.
As someone not long out of the mainstream classroom, it is something of a habit to pause and query the antics of young teenagers, so I stopped and observed the melodrama.
“We’ve caught a carp!” one of them shouted, somewhat unnecessarily, given the fact that I was standing less then a metre away from the unfortunate creature. It looked more like a pike to me, but I wasn’t going to argue. Whatever the species, it was very, very dead.
“Okay,” I said, cautiously.
“It STINKS!” said another boy, in between making gagging noises.
“Well, boys,” I said. “If it smells bad, I wouldn’t eat it if I were you.”
“We’re not going to eat it!” said the first boy, his tone making it clear that the very suggestion was utterly ludicrous.
“So what are you going to do with it?” I asked.
“Take a picture of it and then throw it back,” said one of them, like this was the most obvious thing in the world and I was from outer space.
“Well, I’m not sure I approve of this,” I said, in my best middle-aged woman voice. “You’ve just killed a creature for no good reason.”
“We didn’t kill it!” said the first boy, incredulously. “It was already dead!”
I sighed. Of course it was. The boys had somehow dragged a long-dead, semi-rotten fish out of the canal and were very excited about the whole business. How else does one spend a Sunday afternoon when one is thirteen, I suppose? Ah, those halcyon days. I decided I had little to contribute to the situation and I left them to it.
Pike or carp? I pondered absent-mindedly, as I made my way home. Fish names are something of a sore spot for me. There is an interminable list of them that crossword setters like to make use of in their clue-constructions. Whenever I see the word “fish” embedded in a clue, my heart sinks. I swear, you can string any handful of letters together and it will turn out to be an obscure species of fish: from ayu to ziega, amur to zingel, if there’s a fish involved in a crossword, then I’m on a hiding to nothing.
Whether the unfortunate beast was indeed a pike or a carp, it seemed obvious on reflection that it had been dead for some considerable time. Not only were the boys’ fishing skills and equipment highly unlikely to have extended to such a princely catch, the creature itself was stiff and motionless. Do fish go through rigor mortis like mammals? I wondered. Now, there’s something to Google. In a flash, I remembered that the treatise on which my PhD was based at one point likens something to “a fish out of water”. I recall going down something of a rabbit hole, as I found myself pondering how much the ancient writers knew about what happens to fish when they’re out of water. Sure, they would have observed what a fish does when this happens, but what did they conclude was going on? I remember asking Professor Bob Sharples, an expert in the field of ancient thought and something of a walking encylopaedia, whether he knew of any mentions of the topic in the Greek and Latin corpus. “Indeed!” he said. “In fact, Theophrastus wrote a whole treatise called On Fish. I wrote an article about it five years ago.” Of course he did. How foolish of me not to know this.
There seems to have been something of a discussion in the ancient world about how fish respire. Aristotle observed that fish died quickly when removed from water and inferred that water must contain a life-sustaining substance that was analogous to air on land. He noted that fish possess gills instead of lungs and correctly proposed that these organs play a role similar to breathing in humans and other land-based animals. Aristotle also distinguished between different aquatic animals, and seems to have understood that creatures such as dolphins and whales have to surface for air, whereas fish use their gills to extract what they need directly from the water. The much less famous Theophrastus (the subject of my Professor’s article and Aristotle’s successor as head of the Lyceum) seems to have taken quite an interest in fish. He observed that fish depend on the continuous flow of water through their gills and that stagnation or poor water quality can harm them.
Roman naturalists, including Pliny the Elder, inherited and popularised this understanding. They also observed that gills serve as the essential respiratory structures of fish and that water somehow provides the equivalent of atmospheric air. While none of these men could have known about oxygen or understood the biochemical processes of respiration, they did accurately describe the observable mechanics: water passing over the gills. These observations laid the groundwork for the later scientific recognition of the fact that fish extract dissolved gases from water. The ancient thinkers demonstrated a surprisingly advanced understanding for their time, the kind of understanding that comes from empirical observation and underpins the modern scientific method.
To conclude my canalside meanderings, it is coincidental that fish are something of a hot-button topic inside our own household this week, as my husband is currently resurrecting our long-disused fish tank. It already looks marvellous, a veritable panorama of underwater plants, but is yet to welcome its piscine resident as the water quality needs to be perfect and the tank needs to be a properly functioning eco-system before it can sustain life reliably. My husband is not the kind of man to bung a fairground fish in a plastic bag: he takes his responsibility as the prime mover very seriously. I am told that we will have one solitary fish, because it will be one of those fish that likes to fight other fish. A pugnacious pollock. A bellicose barracuda. I am looking forward to seeing it, staring out of the tank like a prize boxer eyeballing his opponent before the fight.
