Investigating the effect of spirulina and marigold on growth indicators, immunity and astaxanthin content in zebrafish (Danio rerio) tissue.

In this study, the impact of marigold and spirulina, both in isolation and in conjunction with one another, was analyzed on several indicators relating to growth, immunity, survival, and levels of astaxanthin present in zebrafish tissue. 120 zebrafish were randomly allocated to 10 litre aquariums across four different treatment groups (with three replications in each group, each containing 30 fish). The control diet is based on the basic diet, the second treatment diet contains 25 g/kg of spirulina powder (SP) on the basic diet, the third treatment diet contains 25 g/kg of marigold powder (MG) on the basic diet, and the fourth treatment diet It also contains 25 grams of marigold powder (MG) and 25 grams of spirulina (SP+MG)/kg of the basic feed. At the end of the experiment, some immune indicators and astaxanthin were checked in the tissue. The results of this study show the significant effect of spirulina (SP), marigold powder (MG), and the combination of spirulina and marigold powder (SP+MG) on immunity, and astaxanthin. Especially the marigold and the combined treatment of spirulina and marigold showed better performance (P<0.05). respectively, SP+MG and MG treatment significantly increased total protein, lysozyme, and astaxanthin in fish tissue, and the highest amount of IgM was observed in MG treatment (P<0.05). However, no significant difference was observed in relation to growth and survival.