Skin colour changes in ornamental koi (Cyprinus carpio) fed different dietary carotenoid sources
| dc.contributor.author | Tan, Phaik Shiang | |
| dc.date.accessioned | 2014-11-04T02:54:27Z | |
| dc.date.available | 2014-11-04T02:54:27Z | |
| dc.date.issued | 2006 | |
| dc.description | Master | en_US |
| dc.description.abstract | Koi value increases with intensity of skin colour. Fish coloration and pigmentation is due to absorption and deposition of carotenoids. Fishes are unable to synthesize their own carotenoids and therefore these must be included in their diet. Three trials were undertaken to investigate skin colour changes in ornamental koi (Kohaku) by feeding a dietary carotenoid supplement of algal (Haematococcus pluvialis or Spirulina) or palm carotenoid (powder and oil form). Diets containing synthethic carotenoids (Astaxanthin or Canthaxanthin) and a control diet with no carotenoids added were used for comparison. In the first experiment, koi (12.89 + 0.02g) were fed diets supplemented with carotenoid sources at a level of 100ppm. The experiment was conducted in a static water system for a period of 10 weeks. Koi fed with diets supplemented with carotenoids exhibited better body coloration than those fed the control diet without added carotenoids. Growth performance of koi were affected by the dietary carotenoids source. Koi fed diets supplemented with spirulina or Carosol respectively, showed higher growth than koi fed other diets. There were differences (P< 0.05) in skin total carotenoid and individual carotenoid types in the skin, muscle and liver of koi. The total carotenoids on the skin of koi fed with Spirulina or Carophyll Pink supplemented diets showed significantly higher value, 12.08mg kg-1 and 11.76mg kg-1, respectively. Visual observations of the morphology of chromatophores on the scale of koi fed with different diet were done under high power light microscope. In the second experiment, koi (254.89 + 16.82g) were fed diets fortified with carotenoids at a level of 250ppm or 500ppm, respectively. The experiment was conducted in static water system for a period of 8 weeks. Growth performances of koi were not affected by the addition of carotenoids to their diet. Koi fed added dietary carotenoids exhibited better body coloration than koi fed the control diet with no added carotenoids. Colour parameter such as L*, c* and h* were measured using a Minolta Colour Reader (CR-100) at three different colour regions (white, orange and red) on the koi body. Based on the CIELCH colour scale (CIE, 1976), L* indicates Lightness, C* indicates chroma and h* indicates the hue angle. Koi fed diets supplemented with 500ppm Carophyll Pink or Spirulina increased their redness. Some of the head region of koi fed carotenoids supplemented at 500ppm turned yellowish and this indicated an overdose of dietary carotenoids. There were significant differences (P< 0.05) in total carotenoid and individual carotenoid types deposited in koi gonad and blood serum. The total carotenoids concentrations in blood serum and gonad of the koi fed 250ppm Spirulina supplemented diet were the highest. In the third experiment, koi (49.36 + 0.32g) were fed diets fortified with carotenoid sources at a level of 250ppm in a water flow through system for a period of 12 weeks. Growth performances of the koi were not affected by the addition of carotenoids to their diet. There were no significant differences (P> 0.05) in total carotenoid on the skin of all the koi. However, there were significant differences (P< 0.05) in individual carotenoid types of koi fed different diets. The astaxanthin content of koi fed diets supplemented with 250ppm Carophyll Pink was significantly higher than diet supplemented with 250ppm Carophyll Red or Caromin throughout the feeding trial. Colour parameter (L*, a*, b*, c* and h*) were measured at the left dorsal regions. L* indicated Lightness, a* indicates red-green chromaticity and b* indicates yellow-blue chromaticity (CIELAB, 1976). There were significant differences (P<0.05) for L* and b* of koi skin. In conclusion, certain dietary carotenoids may affect or increase the growth performances and colouration in koi. Koi pigmentation depends on proper carotenoid source (synthetic or algal) with suitable carotenoid levels (100-250ppm) and appropriate feeding period (8-12 weeks) which are the crucial factors for better colouration and growth performances of koi. | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/365 | |
| dc.language.iso | en | en_US |
| dc.subject | Biological Science | en_US |
| dc.subject | Ornamental koi | en_US |
| dc.subject | Carotenoid | en_US |
| dc.title | Skin colour changes in ornamental koi (Cyprinus carpio) fed different dietary carotenoid sources | en_US |
| dc.type | Thesis | en_US |
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