The tambaqui (Colossoma macropomum) is a native species known for its tasty meat and adaptability, being the most commercialized in Brazil. Supplementing the cryopreservation medium with antioxidants, such as sulfated polysaccharides (SP) found in macroalgae, can protect spermatozoa and improve results. The study evaluated the effects of adding SP extracted from seaweeds (Kelps sp and Solieria filiformis) to the cryodiluent medium.
The project, approved by the Ethics Animal Research Committee of the State University of Ceará (number 09279405/2021), involved 24 male Tambaqui, sexually mature, weighing around 5 kg. The males received an intracoelomic application of Ovopel® (0.3 pellet/kg BW). Semen (over 80% motility) was collected to form eight pools, diluted (1:9 semen:diluent), and frozen in a solution with powdered coconut water (ACP-104) and 10% DMSO. That solution was supplemented with varying SP concentrations from seaweeds (0.1-0.75 mg/mL). Controls used an unsupplemented solution. Samples were sealed in 0.25 mL straws, equilibrated at 10°C for 10 minutes, frozen in liquid nitrogen vapor (−170°C) and stored (−196°C). After 45 days, samples were thawed at 45°C for 8 seconds. Data were expressed as mean ± standard deviation, and analyzed for significance using Kruskal-Wallis test followed by Dunn’s post-test (P < 0.05).
The table 1 presents the shows the parameters analyzed for different groups treated with varying concentrations of seaweed-derived SP (Kelps sp and S. filiformis). Among the groups treated with S. filiformis, the concentration of 0.50 mg/ml obtained better results in the analyzed parameters. The group treated with 0.10mg/ml of Kelps sp. showed the best results in terms of motility, VCL and DNA integrity, indicating that this group had the best performance among the tested groups across multiple parameters. It is possible to conclude that the addition of sulfated polysaccharides promoted an improvement of the analyzed sperm parameters.