Document Type : Research Paper
3- Department of Fisheries, Lahijan Branch, Islamic Azad University, Lahijan, Iran
The present study aimed to determine the effect of lucantin red and yellow and astaxanthin on growth, hematological and immunological parameters, and coloration of the tiger oscar (Astronotus ocellatus). To this end, 120 fingerlings of tiger oscar were equally and randomly divided into 12 aquariums. The fish were fed with experimental diets for 8 weeks. Treatments included diets containing no pigment (control), lucantin red, lucantin yellow, and astaxanthin, with three replicates apiece. At the end of the trial, growth factors, hematological and immunological parameters, and coloration were measured and the obtained data were statistically analyzed. The results showed that there is a significant difference between the control group and other treatments fed with pigments in terms of growth factors (p<0.05). However, no significant difference was found between treatments fed with pigments in this regard (p>0.05). The results indicated no significant difference between treatments in hematological parameters (p>0.05). The results demonstrated that there is a significant difference between the control group and other treatments in terms of lysozyme activity. In addition, a significant difference was observed between treatments 1 and 3 in this regard (p<0.05). However, there was no significant difference between treatments in other immunological parameters (total immunoglobulin, IgM). The statistical analyses suggested no significant difference between experimental treatments in terms of total carotenoids in the blood (p>0.05). Statistical analysis of color intensity variation revealed a significant difference between the control group and other treatments (p<0.05). The study findings showed that lucantin red and yellow and astaxanthin can improve growth factors and coloration and increase lysozyme activity in tiger oscar.