| JR: Very helpful thoughts. As you know, my personal knowledge of fish grown outside Florida is limited. I cannot say that I have ever seen beni better in a Florida-grown koi than in the best shipped into Florida from Japan or cooler climes. Typically, the Florida-grown reds have a worn look, at least in comparison. However, I've got to recognize that there are not many koikeepers in Florida with high quality fish. I have seen pretty good reds on fish kept by the most skilled whose water quality is consistently excellent, despite exposure to heat. I think those reds would likely be better in cooler temps. My take on it is that very good quality Hi can withstand the high temperatures, at least for several years, if other stresses are minimal, but lesser quality Hi is more challenged by the stress and the constant growth. It may seem a bit strange to some to think of good growth as a stressor, but in regard to color I think it can be, simply because the metabolism is utilizing every source of nutrition for growth. Pigment does not get the opportunity to consolidate as regularly as in a cooler climate.
Hudi & dtbh: I am not aware of a test for silica in water. Sandy soils generally have high silica content. It has been observed by some in Japan that areas with sandy soils are better for expression of Sumi. Hard water is often mentioned as bringing out Sumi, but there is a theory that it is not the hardness per se, but silica associated with hard water that brings out the Sumi. So, I was wondering about that idea and whether it was a factor in your experiences with Utsuri. The warm temperatures may have negative effects, but be offset by other water quality factors. If so, your experiences might not be the same as koikeepers in other places with similar weather conditions, but different geology.
Above I posted a picture of a young Showa taken after 4 months of rapid growth in my pond. Sumi is coming in thick and heavy, and the Hi is stretched rather thin. I'll try to get around to taking another picture of her to see how another 3 months has affected her. |