Are discus and Sunfish similar?

[brewmaster15]

Now before anyone goes off the deep end here... I know Sunfish and discus are totally unrelated...But... They physically resemble each other very closely. This is sometimes called "convergent evolution" .Its when 2 totally unrelated species evolve in similar habitats and evolve to look similar because of it. Nature abounds with examples of this.

So why mention it here...

I remember countless fishing trips ..as the sunrises you go down to the slow moving rivers and lakes with the old fishing rod, The sun lightly dances on the water. You look into the water to see sunfish hanging lazzily in the sunlight, apparantly enjoying the warmth. At least thats what I thought then.. That they were soaking up the warmth being cold blooded.... and that may have been it, but often in the summer there is no real difference to a lakes daytime temp and night time temp..the water holds the heat well. So if not for warmth what were they doing it for. Many animals generate vitamen D with sunlight...do they? I haven't got the answer. Maybe there is a therapeutic effect on fish as well as people with it. What I did note though was ... sunfish , bluegills etc would even leave the spawning nest to get into that sunny spot of water in the am. I have seen bass, pickerel and even trout do this...but sunfish more than others.

So where do the discus come into this . well this morning I did a nice water change on my heckels tank, and they pretty much hang out in the far corner when I do this. I finished the wc, and went on to the next tanks... a few minute latter, and the 4 heckels are in the corner of the tank in a patch of sunlight that was only about a foot square. It streams in thru a small basement window for a short time in the am. Its the only tank in the fishroom that does it. Odd I thought...so much for Discus not liking to be in the open and in the sunlight. Though I don't doubt that in the wild and even in our brightly fluorescent lit tanks they hide under driftwood and plants.. I do wonder though if in the early morning in the amazon, the discus are like their unrelated cousins and like to soak up some sun...if not for vitamen production , maybe for some undiscovered biological purpose.


Over the next few days I think I may get a reptile spot light and equip it with the special daylight bulbs that are used to bring out colors in reptiles. I think I will place it over a corner of the tank and see if my other discus avoid it or are drawn to it in the am. Interestingly enough... The heckels I have in this tank, are in tap water, and where many have noted Heckels color fade with time, I have seen these intensify...or maybe I just got too much sun and am imagining it.
-al

[Tristanyyz]

Brewmaster,

You have seen a picture of my tank. I showed it to you during a treatment of a wild with fungus, who is all better now...thank you.

Well my tank gets natural sunlight usually late afternoons. I used to close the curtains to block out the sunlight but one day I happened to notice how much my discus love huddling together in the sun. Normally they spend most of their time hanging out on the opposite side of the tank, say one third of the tank. Why do they hang out just one one side of the tank? Who knows, two of my biggest wilds hang out there and guard the big drift wood that is there. So anyways, its rare to see them on the other side of the tank closest to the window. A few go over at a time, usually the pigeons, looking for a worm or two. However when the section of the tank is filled with natural light from the window, they are all over there huddled together, whether the aquarium lights are on or off, doesnt matter, they seem to enjoy the sun.

[Jason]

very cool observation and theory!

sunlight may be usefull for alot of biological functions we dont know about.

I've seen my discus align their bodies in a sunbeam in such a way as to expose their whole side to the sun and also in a way as to limit how much sun was able to hit their bodies. that could have more to do with how they use the sun to figure out up from down etc.

[discuskrib]

definately sounds like one of the more interesting experiments done here.

perhaps fish can sense a temperature difference, even if ever so slight. could be like sitting in your car with the a/c on high and you still feel the sunlight hitting your arm when it's near the window and out of the shade.

maybe fish like to sunbathe just like people do.

vitamin D and melatonin production are 2 cellular functions people get out of it. would be interesting to find out if discus also produce vitamins when exposed to sunlight. maybe fish also have an equivalent to melatonin.

looking forward to hearing your results Brew!

JimmyL - have you run across any studies like this?

[ChloroPhil]

That's interesting though I guess not very surprising. One of the tanks at the store gets a lot of evening sun and they fish seem to do better at that time. Perhaps like discuskrib said, they like to sunbathe, especially the wild caught who have grown up getting sun.

Al,

How about trying that sunlamp trick with both domestic and wild fish? I'd be interested to see how it turns out.

[brewmaster15]

I'll give it a shot and let you know.

Heres an interesting Vitamin D fact...

http://www.diet-and-health.net/Nutrients/Calciferol.html


Vitamin D is only found naturally in fish, fish oils and fats.


Unfortunately I haven't found anything yet on exactly how the fish produce it!

-al

[Paulio]

I remember reading info on a web page about actinic lamps and Discus. I will try to find a link for it but it was basicaly about aiding in Vitamin use. I never tried it out because I dont like the way it exagerates color. My fish like to get a little sun too though.

Paul

[Paulio]

Sorry to be so lazy but maybe if we all read through some of this the important links will make it back ::)

http://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=Discus%2Bactinic%2Bvitamin+d

Now before anyone goes off the deep end here... I know Sunfish and discus are totally unrelated...But... They physically resemble each other very closely. This is sometimes called "convergent evolution" .Its when 2 totally unrelated species evolve in similar habitats and evolve to look similar because of it. Nature abounds with examples of this.

So why mention it here...

I remember countless fishing trips ..as the sunrises you go down to the slow moving rivers and lakes with the old fishing rod, The sun lightly dances on the water. You look into the water to see sunfish hanging lazzily in the sunlight, apparantly enjoying the warmth. At least thats what I thought then.. That they were soaking up the warmth being cold blooded.... and that may have been it, but often in the summer there is no real difference to a lakes daytime temp and night time temp..the water holds the heat well. So if not for warmth what were they doing it for. Many animals generate vitamen D with sunlight...do they? I haven't got the answer. Maybe there is a therapeutic effect on fish as well as people with it. What I did note though was ... sunfish , bluegills etc would even leave the spawning nest to get into that sunny spot of water in the am. I have seen bass, pickerel and even trout do this...but sunfish more than others.

So where do the discus come into this . well this morning I did a nice water change on my heckels tank, and they pretty much hang out in the far corner when I do this. I finished the wc, and went on to the next tanks... a few minute latter, and the 4 heckels are in the corner of the tank in a patch of sunlight that was only about a foot square. It streams in thru a small basement window for a short time in the am. Its the only tank in the fishroom that does it. Odd I thought...so much for Discus not liking to be in the open and in the sunlight. Though I don't doubt that in the wild and even in our brightly fluorescent lit tanks they hide under driftwood and plants.. I do wonder though if in the early morning in the amazon, the discus are like their unrelated cousins and like to soak up some sun...if not for vitamen production , maybe for some undiscovered biological purpose.


Over the next few days I think I may get a reptile spot light and equip it with the special daylight bulbs that are used to bring out colors in reptiles. I think I will place it over a corner of the tank and see if my other discus avoid it or are drawn to it in the am. Interestingly enough... The heckels I have in this tank, are in tap water, and where many have noted Heckels color fade with time, I have seen these intensify...or maybe I just got too much sun and am imagining it.
-al


Hi, Al: I've been through this forum over and over and it will practically take me longer than a year to read everything. But I found your inquiry here and want to agree with you (along with those members who replied). Curious, did you set up that actinic lighting as yet? I did not read your resolve, if any, concerning the outcome. I noted that everytime I change water my discus heads to the corners that has the most lighting. My tank is about 3 feet from the outdoor where I dump the dirty water outside (to fertilize the flowerbeds). And, this is the side they cling to and without fail. It's amazing to see this.

Perhaps they are sundwellers. 8) 8) 8) **Angie**

[jim_shedden]

Al : Something that I find very interesting is the following:
Being that I fish for a living I am very observent of the conditions around me. One thing that is obvious to me is that when there is a transition on the shoreline such as rock to weeds it very often relates out into the water as well. These are very often "fish holding" locations. This also works with sunlight. If you come across an area that has shade and sunlight generally you will find the fish on the edge in the shade. The same thing happens with current. Look for the fish on the edge of the current or the back eddy. Rarely will they ever be in the current. They wait for their prey to come down and then dash in to capture it and then get out. They want to expend the least amount of energy as possible. Look in your tank and notice where the discus congregate.......it will generally be away from the current. I have 2 tanks that get direct sunlight in the morning. The larger discus, particularly the wilds will be on the edge.