Spirulina for Fish

Spirulina For Nutrition

Spirulina for Fish

I have used Spirulina as a health tonic since 1998. We have been feeding our Koi spirulina mixed with wheat germ for enhanced colour as well for improved health.

Here is an article from the Yorkshire Koi Society by Grant Fujita

The first part of this article comes from Koi January 1978, when it was found that Spirulina had some beneficial effects to Koi (fish) when added to their food. 20+ years on and much more research has been carried out on this algae and some of the findings are detailed in the second part of this article.

Spirulina 1978 by Grant Fujita

Recently, a new Koi food has been found to have some positive effect on the colour of Nishikigoi. The food is an algae called Spirulina. Spirulina has been tested and cultivated in Marine Life testing laboratories in Nigata. Spirulina has been found to have a high content of the carotenoid colour pigment, which is very effective on the colour of Nishikigoi. For a long time, Spirulina, as food, has been cultivated in the Republic of Chad in Central Africa.

Analysis of Spirulina

71% protein, 8% fat, 16% carbohydrate, plus vitamins, a chlorophyll and carotenoid. Sprirulina was found to have a higher protein contend, better digestibility and had other ingredients good for Koi, compared to Chlorella another algae used as Koi food. Spirulina is also easy to cultivate and harvest.

Algae – Spirulina – Main carotenoid ingredient – Zeaxanthin
Algae – Chlorella – Main carotenoid ingredient – Lutein.

In a test on Goldfish, redness can be divided into two main colour pigments. Astacanthin for red and Lutein for yellow. It was found that Zeaxanthin became the red colour pigment Astaxanthin. Lutein or yellow colour pigment will not change to Astaxanthin. The test showed that the red colour on the Goldfish or Koi is Astaxanthin. Zeaxanthin enters the fish body and becomes Astaxanthin.

Spirulina has a large content of Zeaxanthin, which becomes the red pigment Astaxanthin. It was thought that Spirulina would have a positive effect on the colour of Nishikigooi. Dr. Hiroshi Yasumasa at the University of Tokyo performed a test in which Lutein and Zeaxanothin with Astacanthin were mixed with Koi food and fed for 35 days. The results are as follows:

The experiment showed that Zeaxanthin (Astaxanthin) heightens not only red colour but also the white colour. In Japan, there is a place called Ishiwa, which is well known for the beautifully coloured Koi. Recent research has shown that the reason for the colour heightened Koi was the presence of algae, which is similar to Spirulina, upon which the Koi fed. Further research will be conducted to verify this fact.