Motility activation and subpopulation analysis in Solea senegalensis spermatozoa
Computer Assisted Sperm Analysis (CASA) has been successfully applied in the study of fish sperm motility. Once these spermatozoa are characterized it is possible to group in homogeneous subpopulations with similar motility patterns. This analysis could have further implications for the selection of appropriate husbandry conditions during reproductive season. Solea senegalensis sperm was colleted weekly from 44 fish during May-July. The effect of pre-dilution solutions and the composition of the motility activating solutions were analyzed. Also, the effect of seawater osmolarity was analyzed in male populations maintained in contact with females and isolated. The analyses demonstrated the existence of a heterogeneous sperm population in all samples. The subpopulations pattern varied with time and activating treatment. Sperm predilution in a non-ionic solution prior to the activation of sperm produced the highest percentages of motile spermatozoa. Female interaction revealed no significant effect on the sperm motility parameters analysed.