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Joined: May 2014
Posts: 3,864 Likes: 298
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OP
Joined: May 2014
Posts: 3,864 Likes: 298 |
There are a lot of fish facts, and fish myths. So I'd like to ask if this is fact, or myth... Does sunlight hurt the eyes of fish because they have no eyelids? I've heard that is why feeders should be set in morning & evening, rather than the middle of the day. But is it true? PS If anyone wishes, they are welcome to ask further fact or myth questions in this thread. But first, what about fish eyes?
7ac 2015 CNBG RES FHM 2016 TP FLMB 2017 NLMB GSH L 2018 TP & 70 HSB PK 2019 TP RBT 2020 TFS TP 25 HSB 250 F1,L,RBT -206 2021 TFS TP GSH L,-312 2022 GSH TP CR TFS RBT -234, 2023 BG TP TFS NLMB, -160
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Joined: Jan 2009
Posts: 28,534 Likes: 841
Moderator Ambassador Field Correspondent Lunker
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Moderator Ambassador Field Correspondent Lunker
Joined: Jan 2009
Posts: 28,534 Likes: 841 |
I don't know about "hurt" but I think the preference of fish is to be in more shaded water for feeding. Looking up at the sky shouldn't be any different for them than for us.
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Joined: Mar 2005
Posts: 21,497 Likes: 266
Moderator Hall of Fame 2014 Lunker
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Moderator Hall of Fame 2014 Lunker
Joined: Mar 2005
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Fish eyes do not work like ours (color , rods and cones etc.). Their senses are developed for water not air so all of them are different. I will try to find some more info.
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Joined: Apr 2002
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Moderator Ambassador Field Correspondent Lunker
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Moderator Ambassador Field Correspondent Lunker
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Since fish do not have eye lids and most do not have an adjustable iris (most with a fixed pupil) they regulate the amount of light entering the eye by moving deeper or shallower. In humans and many other animals the pupil size (opening) is adjusted by the iris (colored part of the eye).
Last edited by Bill Cody; 06/18/17 01:40 PM.
aka Pond Doctor & Dr. Perca Read Pond Boss Magazine - America's Journal of Pond Management
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Joined: May 2014
Posts: 3,864 Likes: 298
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OP
Joined: May 2014
Posts: 3,864 Likes: 298 |
Thanks for all the replies! Like most freshwater fishermen, I long ago realized that calm sunny days were usually not good for the bite, except during early spring when the water is cold. Normally low light conditions, such as caused by waves, clouds, dawn or dusk, are best.
Guess I'm mostly curious about why. Is it easier to catch prey under low light conditions? Do bright conditions limit their eyesight, or maybe even hurt their eyes? Don't know if there's been a lot of research on the subject, but ...
7ac 2015 CNBG RES FHM 2016 TP FLMB 2017 NLMB GSH L 2018 TP & 70 HSB PK 2019 TP RBT 2020 TFS TP 25 HSB 250 F1,L,RBT -206 2021 TFS TP GSH L,-312 2022 GSH TP CR TFS RBT -234, 2023 BG TP TFS NLMB, -160
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Joined: Jul 2005
Posts: 4,596 Likes: 36
Lunker
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Lunker
Joined: Jul 2005
Posts: 4,596 Likes: 36 |
Fish eyes do not work like ours (color , rods and cones etc.). Their senses are developed for water not air so all of them are different. I will try to find some more info. In general fish are near sighted and their eyes are much more sensitive to light than ours. I have read that LMB have eyes that are five times more senstive than ours. In addition color vision in fish is much different than ours and can vary quite a bit between different types of fish. LMB have two cones (color recpetors) attached per nerve while we only have one. Fish that live in the deeper depths of the ocean can have five or more cones attached per nerve. Water does filter out certain wavelengths of color as depth changes.
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Joined: Jul 2005
Posts: 4,596 Likes: 36
Lunker
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Lunker
Joined: Jul 2005
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Joined: Jun 2012
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Joined: Jun 2012
Posts: 2,058 Likes: 7 |
I have an LED company. I worked with a lettuces producer to grow lettuces with dark leaves. The key was UV light. We added some UV and infrared LEDs to the mix. Long story long I had an extra light so we added it over top of a 38 gallon bow front fish tank with live plants. My thoughts were that the plants would just love the light and grow like crazy. Well to my dismay the plants all melted in two days and the platys went completely blind. Their eye clouded over and never repaired. Most died because they could not see to eat. The light only ran for 8 hours a day 4 two off 4 again.
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Joined: Jan 2011
Posts: 534 Likes: 76
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Joined: Jan 2011
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Bummer for sure. I take it the lettuce grew well? So why would aquatic organisms respond so differently to UV? UV is used to treat drinking water in some cases. I'm now really curious what happens here.
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Joined: Mar 2005
Posts: 21,497 Likes: 266
Moderator Hall of Fame 2014 Lunker
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Moderator Hall of Fame 2014 Lunker
Joined: Mar 2005
Posts: 21,497 Likes: 266 |
Yes there is some indication that some fish may see in the UV spectrum. LMB have better low light vision than BG so they have the advantage in hunting in low light. LMB also hunt at night while BG are mostly dormant.
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Joined: Jun 2012
Posts: 2,058 Likes: 7
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Joined: Jun 2012
Posts: 2,058 Likes: 7 |
Bummer for sure. I take it the lettuce grew well? So why would aquatic organisms respond so differently to UV? UV is used to treat drinking water in some cases. I'm now really curious what happens here. The UV gave the right lettuce the deep red or purple colours. This fella was growing, washing, packaging into clam shells for Wendy's fast food salads. They wanted that dark colour for their salad mix. The LED over HPSodium gave a 90% increase in germination and 10X less power consumption. We ended up with UV lights in T5's. Basically a T5 with out much phosphorus in it to colour up the lettuce. I am not sure if it was the UV or the infrared. Infrared is really bad for our eyes as well as UV.
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