The effect of static magnetic field on Danube huchen, Hucho hucho (L.) sperm motility parameters

The distribution range of Danube huchen, Hucho hucho (L.) in Polish waters is decreasing, and is currently only 25 to 30% of its original area. Since few data are available concerning Danube huchen, it is necessary to develop a better understanding of its reproduction to improve artificial spawning in hatcheries. Eight sperm motility parameters were assessed using CASA after short-term storage in a static magnetic field. The effect of magnetic field exposure on spermatozoa at fertilization and on sperm morphology (SEM) was also examined. Static magnetic fields had a positive effect on sperm motility parameters, including VCL, which determines fertilization effectiveness; values for this parameter after a 24 h exposure period to fields of different intensity were as follows: 1 mT - 110.09 μm s^-1; 5 mT - 111.65 μm s^-1; 10 mT - 152.10 μm s^-1; control - 102.09 μm s^-1. Egg fertilization rates of spermatozoa held for 24 hours in fields of 1mT was 71.32%, 5mT - 58.23%, and 10mT - 59.99%, and in the control - 32.60%. The mean length of spermatozoa was 27.14 ±0.22 μm; the head was elongate; length without the neck was 2.80 ±0.19 μm; the width was 2.0 ±0.08 μm. This study suggests that the method of exposing sperm to magnetic fields might, after more extensive studies, could be used for short-term sperm storage.