Effect of variant ovarian fluid on sperm performance and egg fertilization rates of Arctic charr (Salvelinus alpinus L.)

Abstract: Successful in vitro fertilization in aquaculture is highly dependent on the method used to handle or treat the eggs and milt. As such it is of paramount importance that timely evaluation of the methods is conducted to enhance hatchery productivity and reduce the cost of production. In this study, three methods of handling eggs of Arctic charr in Sweden were evaluated, with the objective of ascertaining the importance of retaining the ovarian fluid in the egg batch. Further, activation of fish sperms with a commercial activator, ActiFishᵀᴹ, was tested to compare the fertilization rates, in a bid to overcome the current low egg fertilization and hatching rates among farmed Arctic charr. Variation of the volumetric amount of the ovarian fluid did not yield dissimilar fertilization rates. As such, tempering with the volume of the ovarian fluid under the current study did not affect the performance of the sperms and consequent fertilization rates. Further, no differential fertilization rates were recorded for the sperm extender and freshwater. However, positive relationships were recorded for fertilization rate and sperm velocity (VCL). The study contends that high and successful fertilization rates are likely to be obtained with or without the ovarian fluids under in-vitro fertilization of Arctic charr eggs.