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Fish in aquarium

  1. Apr 20, 2007 #1
    Do fish care about what the environment outside the tank they are in looks and sounds like? Do they know they are in a tank?
  2. jcsd
  3. Apr 20, 2007 #2
    Feel free to correct this anyone:
    I have read that a goldfish's memory is such that when it swims completely around the bowl back to the starting point, it cannot remember ever having been there before. If this is so, then I would think they are unaware that they are in a tank.

    I don't know if they care about the external environment.
  4. Apr 20, 2007 #3
    Fish do have a long term memory of sorts and can remember things if the same thing occurs repeatedly but as Type 7 says i doubt they care what their view is like
  5. Apr 20, 2007 #4
    I'm glad you said 'occurs repeatedly' because I remember when I was a child I lived near a lake and an old man (probably old as I am now) used to feed the fish from his dock every day at the same time. The fish would gather together in the same spot at the correct time each day. Maybe that's memory.
  6. Apr 20, 2007 #5
    The short term memory thing is a myth. While gold fish don't have as good a memory as, say, a dog, they are not are not in a state of "dementia" either. An animal that can't remember ANYTHING is a dead animal.

    Fish can be taught patterns (like where food is placed) and remember them for days. They have even been reported to be able to recognize their owner.

    As for if they care about the aesthetics of their surroundings... I don't think we know that. Maybe research should be done in animals to see if they have a sense of "beauty." ... scan their brains in different-looking environments and see if they feel more pleasure around certain colors or shapes (if they find them beautiful).

    That should be interesting research.
    Last edited: Apr 20, 2007
  7. Apr 20, 2007 #6


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    I've never understood why anyone gives the slightest thought to trhis silly myth that fish have no memory. Is there anyone of us who hasn't seen fish all congregate looking for food when someone approaches the tank? Of COURSE they have a memory!

    As far as the tank's outside goes, fish that are not happy will be stressed by lots of movement too near the tank.
  8. Apr 20, 2007 #7


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    You can tell they know what the outside environment is if you watch how they react to what's outside the tank. If there is a sudden movement near the outside, they will all swim away from it. If you have a male betta, and put a mirror outside the tank, it will try to fight with itself (not recommended to try it and stress the fish).

    As Dave points out, yes, fish also have memories. You can train them if you really want to, and they certainly do learn where to look for the food at feeding time.

    Do they know they are in a tank? Well, they probably do know that they bump their nose into a solid wall every time they try to swim past a certain point. I don't know if that matters in any way to them, or if they just turn around and go another way.

    With any captive or domestic animal, the more you enrich their environment with things that make it more like their natural environment, or more interesting, the healthier and less stressed they are. A goldfish swimming around a barren bowl is probably pretty stressed. If you instead give it places to hide and swim through, and plants, companions, etc., then it can express more of its normal behaviors and be less stressed.
  9. Apr 21, 2007 #8
    I think this is an example of people believing what they want to believe to salve their consciences. It's okay to confine a fish to a bowl if it has no awareness that it is so confined. Here's another one I've heard: It's okay to hook fish because they do not feel pain. And as for mammals, it's okay to do whatever the hell we want to them, because they have no emotional sensitivity.

    As for awareness of the evironment outside the tank, now you have me thinking in terms of prey instincts. Fish near the edge of a lake will scatter at your approach or if any shadow falls over them. Aquarium fish should have the same instinct, although some either have it to a lesser degree or have become inured to sudden movement nearby (koi seem awfully calm). Fish in a lake will stay in an area that has tree branches overhead. This protects them from hawks, etc. and maybe the shady area is cooler. But I've seen them spread out more when a rain cloud obscures the sun. I'm thinking that their awareness might be limited to a perception of light (and shade) and to movement. I'm just speculating.
  10. Apr 21, 2007 #9
    I've heard that fish are sensitive to gravity and don't know which way up to swim in zero gravity environment.I wonder if fish like oxygen bubbles just for breathing - perhaps they like being massaged by the moving bubbles!
    What is the ideal fish size to tank size ratio - do fish get stressed out and "lonely" in tanks that are too big?
    Last edited: Apr 21, 2007
  11. Apr 21, 2007 #10
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  12. Apr 21, 2007 #11
    Erm I'm not quite sure how to answer the *original* question, I'm not going to make up anything that sounds scientific because I really don't know ...
    but to answer Rothiemurchus' question "What is the ideal fish size to tank size ratio - do fish get stressed out and "lonely" in tanks that are too big?" , then I can say ...
    the bigger the tank the better. For more than one reason.
    First of all - I'm not quite sure why , but in a bigger tank, fish are less likely to catch diseases and consequently, die.
    If I were a fish, alone in a tank i'd feel just as lonely in a small tank or a big one. Just in a big one I'd have more territory. To stop fish being lonely I guess the best thing is have more than one together . But, be careful when choosing , as some types of fish "don't get on well with others" and might start attacking some ; I've read about it and seen it happen, unfortunately ...
    I hope my answer was helpful to you. Sorry I can't work out the answer for if fish care about their environment...
  13. Jul 12, 2007 #12
    This year I did my year 10 science project on fish and their memory. I can definately tell you that fish have a working memory and they can go 3 months without triggering their memory and remember certain sounds and signs. [ I did this by playing classical music and heavy metal music in their tank and then feeding them at different parts of the tank, it took my angel fish 5 "lessons" to figure out the music and it took my gold fish 14 "lessons" to figure out the music. So gold fish arent completely simple but there just no too smart.

    To answer the question on what is a safe fishtank size to keep a certain amount of fish in:
    you must find the length of the tank. Using the measurement of the tanks length then find the approxiamate length of all the fish in your tank, if the length of all the fish exceeds the length of the tank then there could be problems with over crowding, but if you give the fish proper places to hide and proper vegetation then they should be fine if there are a few more centiemtres of fish then tank.

    Also to answer the actual question if the fish care about their environment out side the tank, i believe that they do. The fish seem to be timid when there is lots of movement out side the tank and they seem to get stressed by lots of loud sounds.
    Last edited: Jul 12, 2007
  14. Jul 12, 2007 #13


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    I don't know if this applies to other than carp (including goldfish), but they will cease growing when they reach the size that is suitable for the tank. Can't say as I've ever heard of one shrinking to fit a tank that's already too small, though.
    Neat information about measuring them, Tommy. I never heard of that before.
  15. Jul 12, 2007 #14


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    I've never heard of length being used. The usual method is one inch of fish per gallon.
  16. Jul 13, 2007 #15


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    That's interesting. Ceteceans (whales) evolved from 15 foot long dog-like mammals. The length of their body was so great that they continually sought out food in swamps and shallow water to support its weight and awkwardness. Continually dunking their heads in water over a few million years (from 25 million years ago) slowly saw natural selection select the animals with nostrils that were higher up the skull than the others. Slowly, (again) the mammal ended up in open water, swimming more and rarely making land fall.

    At some point (maybe a few million years of this) they detached as land mammals and the nostrils ended up on the top of the head (through natural selection)...... eventually, as a fully fledged marine mammal the early whales began to grow to enormous sizes simply because there were no restrictions.... (water displacement, gravity etc....) in their environment. Then we get examples like the Blue Whale (redonculously humungous). (Very distant relation to the Blue Heeler breed of dog:rolleyes:)
  17. Jul 13, 2007 #16


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    Which makes one wonder why there were much, MUCH larger animals roaming about that didn't have this happen.

    If 'bodies of a certain size need water to support them' is a strong evolutionary driver, then how did apatosaurs, seismosaurs and their ilk manage just fine?
  18. Jul 13, 2007 #17


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    A monstrously large tail was selected as an offset to their enormous structure... ?... just a guess. This was accompanied by a ganglion bundle of nerves in the CNS near the "lower" spinal area that acted as a controller for the tail. Much like a train with a long payload has secondary engines.

    The apatos and others had a long time to evolve in any direction to suit thier size. I wouldn't be surprised if the mososaurs and elasmosaurs were perhaps evolved from land based dinosaurids.

    After 40 million years of mammalian evolution... perhaps this was how it turned out. The long almost 400 million years of dinosaurid evolution had its mechanisms of selection and then there was a (reportedly) 99% extinction rate that included plants etc as well (bolide interuptus) From there we had 40 million years of evolution before the dog-like cetecean arose. Each case of natural selection has its own distinct fingerprint and logic, if you can call it that... is my guess.
    Last edited: Jul 13, 2007
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