A few weeks ago the CFZ took delivery of a small shipment of live eels, which would otherwise have ended up on someone’s plate. The eels themselves had apparently been destined for halal supermarkets, despite eels being a non-halal meat (halal food laws forbid the consumption of carnivores and consumers of carrion). As well as saving the lives of these fascinating fish, our main reason for acquiring eels is so that we can observe the fish first hand. Jon and Richard have suggested that sterile eels, that live longer and grow much larger than an eel would normally grow, could be the basis for many lake monster sightings in places like Loch Ness and the Lake District. There is some good supporting evidence for this theory, or certainly that eels in captivity live longer and grow larger than their wild counterparts; Blackpool Tower Aquarium is home to two very large common eels that have lived most of their lives in captivity.
When the eels arrived they were not in the best of condition; all of them had white spot, two of the eels were dead and one had had the end of its tail bitten off quite badly. Jon and I named the remaining 6 eels with names including Eel-ly Jenkins and Ben Eel-ton; the name I gave to the injured eel was Eel-ton John. For the first few days the eels refused to eat any of the tasty morsels I dangled before their mouths and Jon and I started to get worried. Had the stress of their transport left the poor little fellows so perturbed that they had lost all interest in sustenance? Thankfully I had the brainwave of turning all their tank lights off at 6pm so it would be darker in their tanks in the evening when they were fed and this seemed to solve the problem so soon the eels were eating up earthworms with some determination.
Once we had treated the white-spot all was well… until Saturday night, anyway. The other eels had started to gang up on poor Eel-ton John and his manky tail, probably calculating that if they took out the weakest of their number this would mean more food for them. In order to put a stop to intra-specific competition like this, my first course of action was to increase the amount of food and place it in more locations. The eels, however, just ignored the extra worms and continued picking on Eel-ton John, still reasoning ‘Saturday night’s all right (for fighting)’. All the while Eel-ton John was picking up more scratches, getting stressed and his tail had no chance to fully heal. In fact, out of all the eels Eel-ton John was still the only one showing any sign of infection when the white-spot had cleared up in all the others. Jon and I decided that the only sensible course of action was to remove him from the communal eel tank so he could be put into a smaller tank on his own and would have a chance to heel without any more bullying.
While I caught Eel-ton John, cryptozologist Jon scoured the internet and his books for suggestions to aid the eel’s recovery. The eel took a while to catch, but when I finally managed to catch him he looked much worse than he had through the tank's glass. I thought to myself it’ll be a miracle if he’s 'still standing' this time tomorrow. As far as the eel’s treatment, Jon and I eventually settled upon making his water slightly brackish as this should have a detrimental effect on any fungi, but be well within acceptable limits for the eel. We added 3 teaspoons of salt for each gallon of water in his tank and put the salt into a one and a half pint measuring jug and poured half a pint of the mixture into his tank at 12-hour intervals. This seems to be working rather well and after only a day in the slightly salted water he has perked up a lot and is enjoying all the worms he’s being fed. Eel-ton John’s tail looks better already and without the bullying from the others he’ll be less stressed and better able to fight off any infections in the future.
When the eels arrived they were not in the best of condition; all of them had white spot, two of the eels were dead and one had had the end of its tail bitten off quite badly. Jon and I named the remaining 6 eels with names including Eel-ly Jenkins and Ben Eel-ton; the name I gave to the injured eel was Eel-ton John. For the first few days the eels refused to eat any of the tasty morsels I dangled before their mouths and Jon and I started to get worried. Had the stress of their transport left the poor little fellows so perturbed that they had lost all interest in sustenance? Thankfully I had the brainwave of turning all their tank lights off at 6pm so it would be darker in their tanks in the evening when they were fed and this seemed to solve the problem so soon the eels were eating up earthworms with some determination.
Once we had treated the white-spot all was well… until Saturday night, anyway. The other eels had started to gang up on poor Eel-ton John and his manky tail, probably calculating that if they took out the weakest of their number this would mean more food for them. In order to put a stop to intra-specific competition like this, my first course of action was to increase the amount of food and place it in more locations. The eels, however, just ignored the extra worms and continued picking on Eel-ton John, still reasoning ‘Saturday night’s all right (for fighting)’. All the while Eel-ton John was picking up more scratches, getting stressed and his tail had no chance to fully heal. In fact, out of all the eels Eel-ton John was still the only one showing any sign of infection when the white-spot had cleared up in all the others. Jon and I decided that the only sensible course of action was to remove him from the communal eel tank so he could be put into a smaller tank on his own and would have a chance to heel without any more bullying.
While I caught Eel-ton John, cryptozologist Jon scoured the internet and his books for suggestions to aid the eel’s recovery. The eel took a while to catch, but when I finally managed to catch him he looked much worse than he had through the tank's glass. I thought to myself it’ll be a miracle if he’s 'still standing' this time tomorrow. As far as the eel’s treatment, Jon and I eventually settled upon making his water slightly brackish as this should have a detrimental effect on any fungi, but be well within acceptable limits for the eel. We added 3 teaspoons of salt for each gallon of water in his tank and put the salt into a one and a half pint measuring jug and poured half a pint of the mixture into his tank at 12-hour intervals. This seems to be working rather well and after only a day in the slightly salted water he has perked up a lot and is enjoying all the worms he’s being fed. Eel-ton John’s tail looks better already and without the bullying from the others he’ll be less stressed and better able to fight off any infections in the future.
1 comment:
This has been my favorite hypothesis from the CFZ.
Have you considered sterilizing these eels, just so you could see if they really do get that much larger?
My take on the big eels is that European eels historically were larger than they are now. They are heavily over-fished species. And one thing we know about over-fished species is that the actual size of the fish seems to be greatly reduced over time. Maybe there were historically unexploited populations of eel in the remote lakes, which were then spotted by tourists and other people who weren't sure what they were. Because the average person had only seen the eels from the exploited populations, they were unaccustomed to the larger size of these eels in the lakes and thought they were monsters.
The reason why they get smaller because of overfishing is that we tend to take the large ones, and there is selective pressure on the populations to become small. If you're small, you live to breed.
I also wonder if maybe Conger eels are coming into some of these areas that are close to the sea. Conger eels are bigger than the Anguilla species.
European eels are considered critically endangered by the IUCN. Norway has banned fishing them. Pollution with PCB's is now thought to be a major cause of their decline. And an eel with that sort of toxicity could never reach its full potential as an organism-- including reaching its full size potential.
Keep exploring this hypothesis. It's got me quite intrigued.
Post a Comment