Separate and combined effects of Spirulina platensis and Pot Marigold (Calendula officinalis) powder on the growth performance, carcass composition, intestinal enzyme activities, immune response, and antioxidant defense in Macro fish (Labidochromis caerul

This study investigated the impact of Spirulina platensis and pot marigold (Calendula officinalis) powder both individually and in combination, on various aspects of growth performance, carcass composition, immune response, intestinal enzymes, antioxidant defence, and astaxanthin levels in Macro fish (Labidochromis caeruleus) tissue. 240 Macro fish, with an average weight of 3.68±0.1 g, were randomly assigned to 12 aquariums, which were then divided into four treatment groups, as follows: control (standard feed without additives), SP (25 g/kg Spirulina powder added to the basal diet), MG (25 g/kg pot marigold powder added to the basal diet), and SP+MG (25 g of C. officinalis powder and 25 g of Spirulina per kg of basal diet). Within each group, three replications of 60 fish were maintained. The combination of SP and MG showed superior results in terms of specific growth rate (SGR), final weight, weight gain, and astaxanthin content. Furthermore, the SP+MG treatment led to improvements in hematological parameters (lymphocyte percentage, red blood cells (RBC) count, and hematocrit level) and immune factors (IgM concentration, total protein level, and lysozyme activity). It also increased crude protein levels in the carcass and antioxidant enzyme activities (catalase, superoxide dismutase, and glutathione peroxidase). Notably, the digestive enzyme activity in the SP+MG treatment differed significantly from the other groups. These findings suggest that the combined use of S. platensis and Pot Marigold powder could be a beneficial feed supplement in the diets of L. caeruleus.