Javascript Disabled Detected

You currently have javascript disabled. Several functions may not work. Please re-enable javascript to access full functionality.

My fish are tilted 10 degrees to the right...

Started by Guest_Usil_* , Dec 22 2011 04:26 PM

Next

Please log in to reply

21 replies to this topic

#1 Guest_Usil_*

Guests

Posted 22 December 2011 - 04:26 PM

For the past week when I come into my home office in the morning I have noticed that my sunfish are all listing to the right by about 10 degrees. When I first noticed this it was in the hybrid but I have seen others do this when they are out in front of the tank. This morning I see all three of them lined up in front and all looking out the front waiting for the Food-God. All were tilted to the right by the same angle (about 10 degrees). It looked really weird. This only happens in the morning. Other times in the day they are in normal upright positions.

My only take on this is that the sun is in their eyes at this time of morning as the window to the right of them is fully open to light and the sun is passing in front of the window at exactly that time in the morning and streams a lot of light across the front of the tank. When the sun gets in at a certain angle they angle their bodies by 10 degrees to avoid the direct sunlight streaming into their right eye.

Does this seem like a rational explanation? Anyone else think of a better explanation?

Has this been observed by others?

I will try to take a picture of this tomorrow morning.

Usil

Edited by Usil, 22 December 2011 - 04:34 PM.

Back to top

#2 Guest_az9_*

Guests

Posted 22 December 2011 - 08:12 PM

It's an earthquake warning!

Sorry couldn't resist. Can you cover the window temporarily to test you hypothesis?

Back to top

#3 Guest_frogwhacker_*

Guests

Posted 22 December 2011 - 08:20 PM

I have observed my male longear doing this at times, and I've witnessed other Lepomis' doing this in the wild(both singularly and in plural), but I've really never seen or thought of an explanation for it. I haven't noticed it with my rock bass or SMB except when they're hiding under something low. Although Lepomis' are the only fish I've seen doing this in the open, this is only my limited observations, so it's entirely possible that others do it too. Sorry I couldn't be of more help, but I can tell you that your fish aren't alone in this practice.

Steve.

Back to top

#4 Guest_Yeahson421_*

Guests

Posted 22 December 2011 - 08:24 PM

All of my fish do this, and I've never known why. The only fish I've never seen do it are darters, but that's because they are always on the bottom.

Back to top

#5 Guest_Usil_*

Guests

Posted 22 December 2011 - 10:43 PM

Since others have observed this can you tell me if window light might be the reason? If no window light but still see the tilting what could this be?

I will try to take pictures of this tomorrow morning and also close the blinds and see the effect.

Usil

Back to top

#6 Guest_Ken_*

Guests

Posted 22 December 2011 - 10:49 PM

For the past week when I come into my home office in the morning I have noticed that my sunfish are all listing to the right by about 10 degrees. When I first noticed this it was in the hybrid but I have seen others do this when they are out in front of the tank. This morning I see all three of them lined up in front and all looking out the front waiting for the Food-God. All were tilted to the right by the same angle (about 10 degrees). It looked really weird. This only happens in the morning. Other times in the day they are in normal upright positions.

My only take on this is that the sun is in their eyes at this time of morning as the window to the right of them is fully open to light and the sun is passing in front of the window at exactly that time in the morning and streams a lot of light across the front of the tank. When the sun gets in at a certain angle they angle their bodies by 10 degrees to avoid the direct sunlight streaming into their right eye.

Does this seem like a rational explanation? Anyone else think of a better explanation?

Has this been observed by others?

I will try to take a picture of this tomorrow morning.

Usil

Does the temp in the office automatically drop over night? Are they tilting towards or away from the light. If it is away could they be trying to create a greater exposure to the sun for heat? Though beiung coldwater I wouldn't expect that. Just a thought.

Back to top

#7 Guest_Usil_*

Guests

Posted 22 December 2011 - 11:11 PM

The water temperature is stable at about 70. They are tilting towards the light and the window which would decrease the amount of light hitting them. This morning the bluegill, the longear and the hybrid redear/green were all lined up about 6 inches away from each other all facing me looking at me at my desk and all tilted the same 10 degrees. It was strange.

Usil

Edited by Usil, 22 December 2011 - 11:11 PM.

Back to top

#8 Guest_Usil_*

Guests

Posted 22 December 2011 - 11:22 PM

I got an idea. You know when you tilt a picture on the wall to spoof a friend. Maybe they got together and said, Hey! lets freak out the Food-Good, just do what I do...

Usil

Edited by Usil, 22 December 2011 - 11:22 PM.

Back to top

#9 Guest_smilingfrog_*

Guests

Posted 23 December 2011 - 04:10 AM

My only take on this is that the sun is in their eyes at this time of morning as the window to the right of them is fully open to light and the sun is passing in front of the window at exactly that time in the morning and streams a lot of light across the front of the tank. When the sun gets in at a certain angle they angle their bodies by 10 degrees to avoid the direct sunlight streaming into their right eye.

Does this seem like a rational explanation? Anyone else think of a better explanation?

Has this been observed by others?

I will try to take a picture of this tomorrow morning.

Usil

If I am reading this correctly, they are leaning toward the light? If so, I have observed a similar behavior of fish orienting themselves to light on night dives. I was introduced to what my dive instructor referred to as "fish tipping" when I did my first night dive. We would find a sleeping fish, shine a flashlight directly down on it then very slowly tilt the light to one side. Many times the fish will keep its back to the light and we could get them to tip over onto their side. Sunfish seemed particularly prone to this behavior, the majority of bluegills and rockbass we tried it on would tip.
They may be orienting themselves to the light, in a natural setting the light is always going to come from the surface, and while it may not come straight down, it won't come as much from the side as it does through a window and the side of the aquarium.
On the other hand, I also had a spotfin shiner that lost an eye. When I would come home from work late at night and turn on the light, it would swim fully on its side next to the bottom with the eye facing down, presumably to block the bright light. After several minutes as it became accustomed to the light it would swim in a normal position. Your fish, as you suggested, might just be trying to keep the bright light out of their eyes as well.

Back to top

#10 Guest_mywan_*

Guests

Posted 23 December 2011 - 09:13 AM

Interesting. I'm starting to suspect it's a predator avoidance mechanism. It would work a lot like the sharp angles of stealth bombers to avoid radar reflections. Light hitting them straight on the side runs the risk of acting like a flash signal, like a mirror reflection used for signaling, to get predators attention. Light reflected off steeply angled sides of their body would reflect at far more diffuse angles and become too dispersed to give their positions away to predators. A lot like trying to use a mirror to reflect light directly away from the light source, it doesn't work very well past a certain angle.

Edited by mywan, 23 December 2011 - 09:14 AM.

Back to top

#11 Michael Wolfe

Board of Directors

North Georgia, Oconee River Drainage

Posted 23 December 2011 - 09:39 AM

Interesting. I'm starting to suspect it's a predator avoidance mechanism. It would work a lot like the sharp angles of stealth bombers to avoid radar reflections. Light hitting them straight on the side runs the risk of acting like a flash signal, like a mirror reflection used for signaling, to get predators attention. Light reflected off steeply angled sides of their body would reflect at far more diffuse angles and become too dispersed to give their positions away to predators. A lot like trying to use a mirror to reflect light directly away from the light source, it doesn't work very well past a certain angle.

I was thinking the same thing... by tilting towards the light they would cast the smallest shadow below them... and have the least likelihood of having the sunlight illuminate their large round sides...

In my opinion this is also why sunfish turn and face you all the time, even in the wild... it is not because they are all that interested or expect food... it is because a sunfish that is facing you head on is much harder to see than one that shows you his profile. Rule number one: don't get dead...

Either write something worth reading or do something worth writing. - Benjamin Franklin

Back to top

#12 Guest_gerald_*

Guests

Posted 23 December 2011 - 10:15 AM

Yup, lots of fish tilt toward non-vertical light, especially deep-bodied species like sunfish, angelfish, silver dollars, etc.
I think it's mainly a defense against attack from above: herons, kingfishers, cormorants, raccoons.

Back to top

#13 Guest_mywan_*

Guests

Posted 23 December 2011 - 05:06 PM

If fish maintain an orientation with respect to light sources as a camouflage I wonder if you could use a flood light with a color or wavelength of light that would make fish stand out without them responding to it. This should be possible even if it requires glasses with lenses made of nonlinear optical components to make the light visible to you. Spectroscopic profiles might even be useful in species identification, much like we use spectroscopy to see what stars are made of. It might even be useful for spotting certain kinds of fungal or bacterial skin infections. With a sufficiently powerful spectroscope over a wide enough band of wavelengths it may even be possible to detect the abundance of specific proteins in their slim coat. No need to get that expensive for a lot of more basic information with spectroscopic fish profiling.

Here is a tutorial on Raman spectroscopy:
http://depts.washing...an-Tutorial.pdf

For more generalized spectroscopic profiling the fluorescence issue wouldn't be as big a deal since it would merely represent part of the fishes profile. Remote monitoring systems could contain a lot more information than what can be achieved with standard remote camera systems, or even be used to help determine when to have the camera turned on.

Back to top

#14 Guest_FirstChAoS_*

Guests

Posted 23 December 2011 - 06:28 PM

Interesting. I'm starting to suspect it's a predator avoidance mechanism. It would work a lot like the sharp angles of stealth bombers to avoid radar reflections. Light hitting them straight on the side runs the risk of acting like a flash signal, like a mirror reflection used for signaling, to get predators attention. Light reflected off steeply angled sides of their body would reflect at far more diffuse angles and become too dispersed to give their positions away to predators. A lot like trying to use a mirror to reflect light directly away from the light source, it doesn't work very well past a certain angle.

Interesting, Now I wonder if fish have stealth features that deflect vibrations too to avoid lateral line detection.

Josh

I wonder if anyone in ancient Greece ever decided to get buried with a seine instead of the traditional two coins.

Back to top

#15 Guest_az9_*

Guests

Posted 25 December 2011 - 12:34 PM

All I know is my bluegills and yellow perch fish freak more from the red light that precedes the flash than the flash itself when I take a picture of them with my digital camera in my grow out tanks. They definitely do not like the red light!

Back to top

#16 Guest_frogwhacker_*

Guests

Posted 25 December 2011 - 02:33 PM

All I know is my bluegills and yellow perch fish freak more from the red light that precedes the flash than the flash itself when I take a picture of them with my digital camera in my grow out tanks. They definitely do not like the red light!

Just out of curiosity one time, I tried a red laser pointer with my fish. It seemed to cause 'freak out mode' with all of them. It even sent the minnows into a panic. It almost appeared as if it was painful so I didn't continue, but I did give them all the one time through just to see. Interestingly, the least affected by it was the SMB. This probably wasn't a real responsible action for a fish keeper, but my sporadic bursts of intrusive curiosity are quite minimal compared to the pampering they normally receive.

Steve.

Back to top

#17 Guest_az9_*

Guests

Posted 25 December 2011 - 06:27 PM

Just out of curiosity one time, I tried a red laser pointer with my fish. It seemed to cause 'freak out mode' with all of them. It even sent the minnows into a panic. It almost appeared as if it was painful so I didn't continue, but I did give them all the one time through just to see. Interestingly, the least affected by it was the SMB. This probably wasn't a real responsible action for a fish keeper, but my sporadic bursts of intrusive curiosity are quite minimal compared to the pampering they normally receive.

Steve.

I know I won't do it again as I don't need stressed fish damaging themselves against the tank walls. I go out of my way not to spook them and even get down on my hands and knees to crawl below a window that creates a shadow over the one tank if walk past it normally. The shadow really freaks them too.

I have shade cloth over both basement room windows which allows just enough light in. I also have shade cloth over each doorway of each doorless room of the basement, of which there is one tank in each room. I also have shade cloth blocking the hallway to these rooms as it's open to my shop and I like to get started working before it's light in the morning. Otherwise the light going on freaks them.

I tried dimmer lights but don't like the idea of having lights on all the time, and they sometimes suddenly go out if turned too low and sometimes if you try to slowly turn them on they won't turn on at the dim end of the spectrum.

Edited by az9, 25 December 2011 - 06:28 PM.

Back to top

#18 Guest_Usil_*

Guests

Posted 01 January 2012 - 01:01 PM

I tried to get all three but when I got closer to the aquarium this morning, two of them left. Here is the hybrid tilted to the right. The bluegill next to him was also tilted before he moved. They only do this in the morning when the light is coming through the window strongly. The tank is getting plant cluttered. I need to do some serious plant control. I think that the LED lights have worked out too well. I am going to cut back the number of hours they are on.

Posted Image

Usil

Edited by Usil, 01 January 2012 - 01:07 PM.

Back to top

#19 Guest_FirstChAoS_*

Guests

Posted 01 January 2012 - 01:18 PM

Could be a dominance display, at times I seen sunfish swim up to each other and lean like that before one chases the other off as if they are sizing each other up.

Back to top

#20 Guest_Usil_*

Guests

Posted 01 January 2012 - 01:39 PM

If only one did it that might be true but all of them do it side by side. I have never seen any outwardly aggressive movement when they do this and after the sun leaves the window they resume normal upright positions.

Usil