Influência de polissacarídeos sulfatados sobre a motilidade e morfologia espermática pós descongelação de Prochilodus brevis / (Influence of sulfated polysaccharides on post-thawing sperm motility and morphology of Prochilodus brevis

ABSTRACT

This research aims to verify the influence of sulfated polysaccharides, extracted from the skin of tilapia, on the after thawing motility and morphology of P. brevis sperm. For this, 17 males were hormonally induced to reproduce, through the application of two doses of pituitary carp extract, 0.4 and 4.0mg kg-1. After the seminal collection, objective analyzes were performed and samples with motility greater than 80% were selected to form the pools. Then, the pools were frozen in solution supplemented, or not, with different concentrations of glycosaminoglycans (GAGs) 0 (control); 0.5; 1.0; 1.5; 2.0; 2.5; 3.0; 3.5; 4.0; 4.5 or 5.0mg mL-¹ (total of 10 treatments). The samples were placed in 0.25 mL French straws and submitted to an equilibrium time of 10 minutes at 4 ºC. Then, they were kept in the dry shipper for 15 minutes and finally stored in liquid nitrogen. After 15 days, samples were thawed in a water bath at 30 ºC for 16 seconds and evaluated for sperm motility and morphology. Thus, it was observed that the increase in GAGs caused a decrease in sperm motility, however the control and the concentration of 0.5mg mL-¹ presented very similar data. On the other hand, no decrease in normal sperm was observed with an increase in the concentration of GAGs. Therefore, it is concluded that the lowest concentration of GAGs is the most adequate to supplement the sperm freezing medium.