Abstract
The rainbow trout (Oncorhynchus mykiss) is one of the most commercially sought-after freshwater fish species and one of the most farmed in the world. On the other hand, aquaculture breeding frequently results in outbreaks of infectious diseases and pests, and compromises the production and welfare of fish. Arthrospira platensis (known as "Spirulina") has been used as a supplement in diets to enhance fish welfare in recent years because of its beneficial properties. This study aimed to assess the possible protective effects of Arthrospira platensis on rainbow trout specimens exposed to three different doses of the toxicant CdCl(2). The experiment was carried out using five experimental treatments of 40 individuals each: control group; group II (0.2 mg CdCl(2) per kg of commercial fish feed); group III (0.2 mg Kg(-1) of CdCl(2) plus 2.5 g per kg of A. platensis); group IV (0.2 mg Kg(-1) of CdCl(2) plus 5 g per kg of A. platensis); group V (0.2 mg Kg(-1) of CdCl(2) plus 10 g per kg of A. platensis). During the experiment, dietary supplementation of A. platensis normalized all serum and blood parameters altered by the presence of CdCl(2). A. platensis also had a protective effect on markers of oxidative stress.