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Thread: UV Sunlight Exposure Affects On Koi

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    Daihonmei MikeM's Avatar
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    UV Sunlight Exposure Affects On Koi

    In a thread about winter feeding, Yerrag led us into discussing the effects of UV radiation on koi. It is a topic that deserves a thread of its own so additional information can be posted together over time, especially since there are a good number of scientific studies (although using other fish species as subjects). So, I'm starting a separate thread, beginning with Yerrag's initial post:

    YERRAG: As I read thru Ray Peat's old newsletters, I'd like to share one excerpt from a newsletter entitled "Carbon Monoxide:Cancer Hormone?:

    Unsaturated fatty acids are now clearly identified as a "target" of ultraviolet radiationdamage in skin cells, and increasingly they are seen to be involved in toxic injury and stress injury. Radiation absorbed anywhere in a cell can start a peroxidation chain reaction, causing widespread damage, which can include the inactivation of important enzymes...

    I can't help but think about the effect of our koi lacking the protection offered by saturated fats. In feeding koi unsaturated fats, we are probably making our koi more vulnerable to the effects of UV exposure from sunlight.

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    Daihonmei MikeM's Avatar
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    MCA: All the more important to put a pergola or roof over the concrete display pond and put koi in a mud pond over the summer. The turbid water in a mud pond will provide lots of UV protection.

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    Daihonmei MikeM's Avatar
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    YERRAG:

    [Originally Posted by MCA... All the more important to put a pergola or roof over the concrete display pond and put koi in a mud pond over the summer. The turbid water in a mud pond will provide lots of UV protection.]

    I agree. To the point that it shouldn't be considered optional to have a pergola, or a shade sail, especially for koi ponds that are very much exposed to sunlight, on months where the sunlight is harsh and direct.

    Still, I'd like to see some koi food made with coconut oil, instead of fish oil. But the danger of this food is that the koi keeper should understand the food is not meant to be fed on cold seasons, as the saturated fat solididfes and could solidify. Since koi are cold-blooded, they have no way to increase their temperature to keep the coconut oil from solidifying.

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    Daihonmei MikeM's Avatar
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    MIKEM: I would hesitate to take any research focused on how humans digest and assimilate nutrient, and apply it to fish. For example, the system of the fish results in excess energy being stored as 'fish oil'. Mammals tend to store excess energy in saturated fats to a much higher degree.

    The idea that harmful UV targets unsaturated fatty acids in the skin layers does seem transferable. That is a very interesting and leads to more questions. To what extent are unsaturated fatty acids stored in the exposed areas of a koi? What is the effect of the mucus coat? (And, what is the effect on the mucus coat?) Is the risk different for doitsu than wagoi? .... This could be an area of inquiry that helps explain hikkui, and someday might lead to figuring out why some koi seem genetically inclined to get hikkui.

    Yerrag, do you have more info on the UV/unsaturated fatty acids interactions?

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    Daihonmei MikeM's Avatar
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    SACICU:


    [Quote Originally Posted by MikeM View Post

    I would hesitate to take any research focused on how humans digest and assimilate nutrient, and apply it to fish. For example, the system of the fish results in excess energy being stored as 'fish oil'. Mammals tend to store excess energy in saturated fats to a much higher degree.

    The idea that harmful UV targets unsaturated fatty acids in the skin layers does seem transferable. That is a very interesting and leads to more questions. To what extent are unsaturated fatty acids stored in the exposed areas of a koi? What is the effect of the mucus coat? (And, what is the effect on the mucus coat?) Is the risk different for doitsu than wagoi? .... This could be an area of inquiry that helps explain hikkui, and someday might lead to figuring out why some koi seem genetically inclined to get hikkui.

    Yerrag, do you have more info on the UV/unsaturated fatty acids interactions?]


    https://www.ncbi.nlm.nih.gov/pubmed/20653882


    The effect of UV radiation (UVR) on juvenile Atlantic salmon (Salmo salar) was assessed by measuring the fatty acid (FA) profiles of muscle, dorsal and ventral skin, and ocular tissues following 4-month long exposures to four different UVR treatments in outdoor rearing tanks. Fish were fed two different diets (Anchovy- and Herring-oil based) that differed in polyunsaturated fatty acid (PUFA) concentrations. Anchovy-fed salmon had higher concentrations of ALA (alpha-linoleic acid; 18:3n-3), EPA (eicosapentaenoic acid; 20:5n-3) and DPA (docosapentaenoic acid, 22:5n-3) in their muscle tissues than fish fed the Herring feed. Fish subjected to enhanced UVB levels had higher concentrations of LIN (linolenic acid, 18:2n-6) and ALA, total omega-6 FA and SAFA (saturated fatty acids) in their tissues compared with fish in reduced UV treatments. Concentrations of ALA, LIN, GLA (gamma-linolenic acid; 18:3n-6), EPA, PUFA and total FA were higher in ventral skin of fish exposed to enhanced UVB compared with fish in reduced UV treatments. Salmon exposed to reduced UV weighed more per-unit-length than fish exposed to ambient sunlight. The FA profiles suggest that fish exposed to UV radiation were more quiescent than fish in the reduced UV treatments resulting in a buildup of catabolic substrates.

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    Daihonmei MikeM's Avatar
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    Very interesting! Thank you, Sacicu.

    I wish I had time now to read up on the subject. Need to find a couple of days to devote to it. ....Maybe someone will and post a summary sooner??

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    Oyagoi yerrag's Avatar
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    As a recent convert to Ray Peat's ideas and writings, I have turned away from the idea that polyunsaturated fats are essential to our health, an idea that is not backed by science but heavily masqueraded as science by marketers through media misinformation. To such extent that conventional medical wisdom considered saturated fat to be unhealthful, while it considers polyunsaturated fats (PUFA) to be essential (EFAs). This thinking has led to us to avoid saturated fats, Sometime around the eighties or nineties, CSPI (The Center for Science in the Public Interest), a shill organization, successfully made McDonald's shift from using beef tallow to vegetable oil - from healthful saturated fats to unhealthful PUFAs. This is but one example of our skewed perception of what food is unhealthful and healthful. To say this misrepresentation by industry has affected our health greatly is an understatement.

    But this forum is about koi. And certainly our choice of oils for our koi is affected by how we view our use of fats and oils for our own consumption.

    Last yaar, around this time, I fed my koi the leftover ground flaxseed and hempseed hearts that were used in making blended food for my late father, who was on PEG and had to be tube fed blended food. At that time, I still considered the PUFAs from flax and hemp to be healthful. There were around 2-3kgs of these. It may or may not be coincidental that 2 months later my yamabuki died. But if my pond were so well-maintained that time I could blame the death on the hempseeds and flaxseeds. More likely, it was a combination of different factors that led to my koi dying. But I can't help but think that the PUFAs could have weakened the immune system of my koi, and could have contributed to its death. I thought this deserves some mention, even if it is merely anecdotal, and that there are other factors involved.

    It would be nice if we could do some testing as a group. And it doesn't have to be start with a reformulated koi. Low-oil koi food can be supplemented with diced coconut meat and fed to koi. I don't know if you could get mature coconuts in the US, as the coconuts I see there are the young coconuts where you get coconut water or juice from. The flesh of the mature coconut is where coconut oil is derived from, and it is the flesh that needs to be removed from the shell and diced. It's a lot of work, and I wouldn't recommend it. The next best thing would be dessicated coconut, which come in flake form. You may be able to find it in supermarkets or ethnic Asian grocery stores.

    One thing I noticed about feeding coconut flesh to koi is that the ammonia waste is reduced coming from koi. My guess is that the koi readily uses up the oil for its energy needs, and has less need for metabolizing protein, so that the ammonia by-product from protein metabolism is lessened.

    One concern is that oil forms a slick on the water surface, so you don't want to overdo it. Oil film on the water surface can interfere with the effectivity of aeration in oxygenating the water. So, be forewarned. Another concern is what happens to all that oil. It helps that every I put em-1 beneficial microorganisms in my pond, primarily for algae control. It also helps balance the good and bad bacteria in the pond, keeping for example the pond floor waste from putrefying. Instead of putrefying, the waste ferments and doesn't give off the foul odor indicative of bad bacteria from the putrefaction process. But the microorganisms can also consume the excess oils, so it would address the concern of excess coconut oil in the pond.

    Still, I may be jumping the gun. MikeM, who will run with what piques his interest, will have more to share about saturated fats for koi after he does more research. From the way he digs up all stuff on algae, I'm sure this will have the makings of another good thread.

  8. #8
    Daihonmei MikeM's Avatar
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    LOL.... It may be a very long time! The effects of UV is the subject of tens of thousands of studies. Simply winnowing them down to ones of possible relevance to koikeeping is a huge task. Hopefully I will find some academic article summarizing research results relating to fish. Meanwhile, keep in mind that the oils/fats consumed are not necessarily as important as the oils/fats produced by the fish.

    That said, there is some suggestion that fish oil consumption can increase toleration of UV exposure:

    J Invest Dermatol. 1995 Oct;105(4):532-5.

    Dietary fish oil reduces basal and ultraviolet B-generated PGE2 levels in skin and increases the threshold to provocation of polymorphic light eruption.

    Rhodes LE1, Durham BH, Fraser WD, Friedmann PS.

    Abstract

    The sunburn response is markedly reduced by dietary fish oil rich in omega-3 polyunsaturated fatty acids. Because prostaglandins mediate the vasodilatation, we examined the effect of fish oil on ultraviolet (UV) B-induced prostaglandin metabolism. In addition we assessed the potential photoprotective effect of fish oil in light-sensitive patients. Thirteen patients with polymorphic light eruption received dietary supplements of fish oil rich in omega-3 polyunsaturated fatty acids for 3 months. At baseline and 3 months, the minimal erythema dose of UVB irradiation was determined, and a graded UVA challenge given to a forearm to assess the threshold dose for papule provocation. Suction blisters were raised on the other forearm, on control skin, and on skin irradiated with four times the minimal erythema dose of UVB 24 h previously, and blister fluid prostaglandin E2 was measured by radioimmunoassay. Following 3 months of fish oil, the mean minimal erythema dose of UVB irradiation increased from 19.8 +/- 2.6 to 33.8 +/- 3.7 mJ/cm2 (mean +/- SEM), p < 0.01. The UVA provocation test was positive in 10 patients at baseline, and after 3 months nine of these showed reduced sensitivity to papule provocation, p < 0.001. Before fish oil, PGE2 increased from 8.6 (SEM 2.1) ng/ml in control skin to 27.2 (11) ng/ml after UVB, p < 0.01. Following 3 months of fish oil, PGE2 decreased to 4.1 (1) and 9.6 (2.4) ng/ml in control and irradiated skin, respectively, p < 0.05. Reduction of UV-induced inflammation by fish oil may be due, at least partially, to lowered prostaglandin E2 levels. The photoprotection against UVA-provocation of a papular response suggests a clinical application for fish oil in polymorphic light eruption.


    ....Do not give up on fish oil too soon, Yerrag.

  9. #9
    Jumbo sacicu's Avatar
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    Quote Originally Posted by yerrag View Post
    As a recent convert to Ray Peat's ideas and writings, I have turned away from the idea that polyunsaturated fats are essential to our health, an idea that is not backed by science but heavily masqueraded as science by marketers through media misinformation. To such extent that conventional medical wisdom considered saturated fat to be unhealthful, while it considers polyunsaturated fats (PUFA) to be essential (EFAs). This thinking has led to us to avoid saturated fats, Sometime around the eighties or nineties, CSPI (The Center for Science in the Public Interest), a shill organization, successfully made McDonald's shift from using beef tallow to vegetable oil - from healthful saturated fats to unhealthful PUFAs. This is but one example of our skewed perception of what food is unhealthful and healthful. To say this misrepresentation by industry has affected our health greatly is an understatement.

    But this forum is about koi. And certainly our choice of oils for our koi is affected by how we view our use of fats and oils for our own consumption.

    Last yaar, around this time, I fed my koi the leftover ground flaxseed and hempseed hearts that were used in making blended food for my late father, who was on PEG and had to be tube fed blended food. At that time, I still considered the PUFAs from flax and hemp to be healthful. There were around 2-3kgs of these. It may or may not be coincidental that 2 months later my yamabuki died. But if my pond were so well-maintained that time I could blame the death on the hempseeds and flaxseeds. More likely, it was a combination of different factors that led to my koi dying. But I can't help but think that the PUFAs could have weakened the immune system of my koi, and could have contributed to its death. I thought this deserves some mention, even if it is merely anecdotal, and that there are other factors involved.

    It would be nice if we could do some testing as a group. And it doesn't have to be start with a reformulated koi. Low-oil koi food can be supplemented with diced coconut meat and fed to koi. I don't know if you could get mature coconuts in the US, as the coconuts I see there are the young coconuts where you get coconut water or juice from. The flesh of the mature coconut is where coconut oil is derived from, and it is the flesh that needs to be removed from the shell and diced. It's a lot of work, and I wouldn't recommend it. The next best thing would be dessicated coconut, which come in flake form. You may be able to find it in supermarkets or ethnic Asian grocery stores.

    One thing I noticed about feeding coconut flesh to koi is that the ammonia waste is reduced coming from koi. My guess is that the koi readily uses up the oil for its energy needs, and has less need for metabolizing protein, so that the ammonia by-product from protein metabolism is lessened.

    One concern is that oil forms a slick on the water surface, so you don't want to overdo it. Oil film on the water surface can interfere with the effectivity of aeration in oxygenating the water. So, be forewarned. Another concern is what happens to all that oil. It helps that every I put em-1 beneficial microorganisms in my pond, primarily for algae control. It also helps balance the good and bad bacteria in the pond, keeping for example the pond floor waste from putrefying. Instead of putrefying, the waste ferments and doesn't give off the foul odor indicative of bad bacteria from the putrefaction process. But the microorganisms can also consume the excess oils, so it would address the concern of excess coconut oil in the pond.

    Still, I may be jumping the gun. MikeM, who will run with what piques his interest, will have more to share about saturated fats for koi after he does more research. From the way he digs up all stuff on algae, I'm sure this will have the makings of another good thread.
    I doubt just 2 to 3 kilos of flaxseeds and hempseeds will cause problems but then again while both of these have high polyunsaturated fats, both can cause also side effects on some humans like diarrhea, low blood pressure, etc. Not much data with regards to its effect on carp or koi though.

    I am also not sure the beneficial effects of coconut meat on koi as so far you have not conclusively show what coconut meat does for koi. I do know coconut meat spoils easily and while it may cause lesser ammonia uneaten food captured in the filter may spoil at a faster rate compared to commercial feeds with food grade preservatives.

  10. #10
    Oyagoi yerrag's Avatar
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    Quote Originally Posted by sacicu View Post
    I doubt just 2 to 3 kilos of flaxseeds and hempseeds will cause problems but then again while both of these have high polyunsaturated fats, both can cause also side effects on some humans like diarrhea, low blood pressure, etc. Not much data with regards to its effect on carp or koi though.

    I am also not sure the beneficial effects of coconut meat on koi as so far you have not conclusively show what coconut meat does for koi. I do know coconut meat spoils easily and while it may cause lesser ammonia uneaten food captured in the filter may spoil at a faster rate compared to commercial feeds with food grade preservatives.
    Someone here has two ponds to make experiments with :-) You might want to do some experiments?

    There is plenty of fiber in coconut meat. In fact, coconut meat has plenty of both soluble and insoluble fiber. So it is expected that there would be much mechanical waste. It is a good trade-off for me though. The increase in mechanical waste is easily filtered mechanically, as these are large clumps. It has never been a problem to me. But when the consumption of coconut meat allows the koi to easily metabolize their oils for energy and leads to less use of protein for metabolism to produce energy, less ammonia is produced. Two benefits result - more protein is reserved for use in the koi's growth, and there is less work for the biological filter. Looking at the larger picture, koi development is enhanced as growth factors are enhanced thru more efficient use of protein for growth and through better water parameters.

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