Application of different activating solutions to in vitro fertilization of crucian carp, Carassius carassius (L.), eggs

Within the study, the in vitro fertilization (ivF) in crucian carp, Carassius carassius (L.), with the use of three activating solutions (AS) [reverse osmosis water (RO), Woynarovich (WS) and Billard (BS) solutions] as well as the period of the capacity of eggs to be fertilized (up to 180 s post-egg-activation) in those solutions. Moreover, CASA analysis of sperm motility was conducted with each AS. In control groups (0 s), the highest (P < 0.05) fertilization rate (93.2 %) was observed with WS. The application of RO and BS affected lower (P < 0.05) embryo survival (63.5 and < 5 %, respectively). High fertilization rate (over 90 %) was recorded up to 30 (RO) and 90 s (WS) post-egg-activation. Progressive sperm motility (pMOT) was high (over 48 %) in all treatment groups up to 30 s. In RO and WS groups, pMOT significantly decreased (P < 0.05) after 45 s post activation. BS affected pMOT over 10 % up to the 165 s. No differences (P > 0.05) between the groups were found considering the curvilinear velocity (VCL) 15 s post-sperm-activation. Between 30 and 135 s, the lowest (P < 0.05) VCL after application of RO was noted. The highest VCL (P < 0.05) up to 135 s was noted after application of BS and WS. All AS activated crucian carp sperm. The lowest fertilization rate was noted when BS was used, despite the high pMOT and VCL. It suggest that the AS which activates the sperm properly may not activate the eggs probably due to high osmolality of BS (262 mOsm kg(-1)). Because eggs retained the longest period of activity in WS, this AS is suggested for ivF in crucian carp.