I would like to start a conversation about what it means to be a fish. For that, we have to know what a fish is thinking. Most of us, including myself, are not fish, and hopefully, we are a little more intelligent. Or are we?
I certainly can not read a fish's mind, but I have been cohabiting with them for about 70 years. As a little boy, I used to sleep on piles of halibut and other fish in my Dad's fish
market. I am sure I smelled a bit.
Fish are very attuned to their surroundings, much more than we are to our terrestrial landscape.
Humans can only move on one plane as we must stay firmly anchored to the ground. Even if we are in a plane or boat, we need a floor to walk on. OK, a very few of us flew in space, but I’m not counting them but when we start keeping fish in space, we can have a conversation about that.
Fish can move in many different planes and unlike us, can also move up and down. Most fish do have a problem moving backwards but that is not a huge problem unless they inadvertently swim into a tight pipe or hole in a rock.
But fish have something none of us have. A lateral line. That thin line of slightly different scales that start near the eye and goes back across the fishes back to it’s tail.
You can easily see it on this red anthias
And this fluke
This line of fluid filled cells allows the fish to have built in sonar much more sensitive than a modern submarine. Robert Straughn, (The Father of Salt Water Fish Keeping) called it “remote feel” and is much more important to the fish than even its’s eyesight.
Fish can get along just fine with one eye, and many fish can live totally blind. Remember, the vast majority of the oceans are much deeper than light penetrates.
This “remote feel” tells the fish about it’s surroundings including behind it. If you look at fish long enough in a tank, you will notice that they never crash into the glass, not even in total darkness and remember, the fish can’t see the glass just as we can’t see it as we look through it. The fish know it’s there, can see through it but I am sure it frustrates them as they can’t swim through it. We can't catch a fish with a net unless we cheat and corner it against a rock. The fish knows exactly where that net is even if it is behind it.
Some fish when we put them in a tank, notably puffers or boxfish constantly swim up and down the glass trying to get through. Some of those fish will keep that up even while their eye is getting abraded from the growth on the glass.
The fish can also sense the water surface and substrate. They know they are swimming in 18” of water and constantly keep trying to get to deeper water. If you took a fish from our tank and put it back into the sea in shallow water, the first thing it will do is head to deep water.
Fish also have no noses or lungs as we do. Our noses have hairs in them to filter out most larger particles and our esophagus have cilia to help push out debris or pathogens. We can also cough if we suck in a bug or shoe, Fish can’t.
Fish breathe water through their head and the water exits through their gills which is also in their head. They have no such filters as we do and whatever is in the water, goes through the fishes gills and any chemicals in the water is also in the fishes bloodstream.
Unlike us, fish don’t choke as they can swallow and breathe at the same time—unless it is a Great White Shark and it has an accountant stuck in its jaws.
Everything in the sea wants to eat anything smaller and fish know this, but they don’t swim in fear of getting eaten. They go about their day looking for either food or a good looking fish to mate with and only become alarmed if they sense a larger creature near them. Then they scramble for cover.
As a SCUBA diver, I spent many hours underwater, much of it here in New York, hunting lobsters. A large number of dives were at night, but even in the day, the visibility in New York waters is measured in inches. I was not afraid to dive at night, but I did get a little “edgy” after I surfaced in total darkness and my boat was quite far away so I had to swim on the surface carrying lobsters or speared fish. (I never got bitten by a shark but I am not an accountant, their favorite food).
We fret if we get a new fish and it won’t eat anything. If we Humans were collected on Earth and taken in a dark Styrofoam box to another planet and put in a clear enclosure surrounded by water as we were being ogled at by the same-looking huge creatures that caught us while we were minding our own business hanging out in some grungy bar, then given some slimy food we have never seen before, I doubt we would eat either.
Of course, if we were taken by similar-looking creatures as we are and put into a condo on a beach someplace, then fed with something we are used to like Hostess Twinkies, Eskimo Pies and beer and kept at 75 degrees near a TV, we may get along just fine.
Fish need to feel as if they are “home” and fed things they ate in the sea or a reasonable facsimile. Many of us insist on feeding dry foods but that is akin to eating cardboard and fish don’t want it but if forced to eat it, many will. They don’t care how many vitamins and minerals it has on the label or how nice looking the French Angel on the can is.
They also need a place to hide from us because I’m sure that if fish can’t see us, they are happier, just like when I was SCUBA diving, if I saw a 783 pound barracuda swimming a few feet from me and smiling, I would be afraid, very afraid.
Most fish will also eat just about anything living and smaller than they are and if they can see it move, they will like it better. Living or fresh food in the sea is all loaded with bacteria, viruses, fungi, and parasites. Fish eat that with every meal and have no problems with it and will not become infected with disease. It’s what fish do and their immune system is perfectly suited to handle those things as they were made to injest those things. The fish in the sea are immune to all those things because by design they have to be. All that fresh food they are eating is loaded with living bacteria which is what lives in the fishes gut and tells the immune system what to be on the lookout for to keep the fish healthy.
It is also loaded with fish oil which is mostly vitamin A.
The gut bacteria in fish control immunity almost 100%, so when we medicate a fish with almost anything, that medication goes through the fish's blood system and also kills its gut bacteria. Even if it doesn’t kill it, it disrupts it.
If we kill the bacteria, the viruses will take over and if we kill the bacteria, the parasites can take over because they all live in harmony to keep each other in check.
Fish are also afraid of anything pure white and shiny (can you say PVC) If that is all they have to hide in, they will, but they will not be happy as you can tell by the expression on their face and if they could scream, they would. If you feel the need to put a fish in a bare tank, I think clay bricks with homes in them like sold in Home Depot would feel much more natural to fish.
Stress is the biggest killer of captive fish and we can not eliminate stress all together but we can lessen it to a degree and if we do, our fish will have a much better chance of living their full presumed lifespan as stress also hinders it’s immune system but I don’t want to go into that now as I am exfoliating (whatever that is)
