The effect of magnetic field on permeability of egg shells of salmonid fishes

Abstract

. 2007. The effect of magnetic field on permeability of egg shells of salmonid fishes. Acta Ichthyol. Piscat. 37 (2): 129-135.Background. The effect of the magnetic field on fish egg shells has not attracted major interest of researchers, even though it could have been predicted that such effect may be vital to fish embryogenesis. One of the hitherto-neglected aspects of the magnetic field action of fish eggs are the changes in the egg shell permeability and possible alteration of the process of embryogenesis. Studying this process and learning the associated phenomena may be important in explaining cases of substantial mortality of the embryos. Materials and Methods. Fish eggs (Atlantic salmon, Salmo salar L.; sea trout, Salmo trutta L.; and rainbow trout, Oncorhynchus mykiss (Walbaum, 1792) and isolated egg shells, in a custom-made osmometer setups, were subjected to the action of a stable magnetic field (2 mT). The ultrastructure of the egg-shells was studied using a scanning electron microscope (JEOL JSM 6100). Results. Stable magnetic field (2 mT), affecting fish eggs, caused statistically significant increase in the egg-shell permeability to water, in the period of the egg activation (and also less distinct increase during the entire embryogenesis). Conclusion. Weak, stable magnetic field increases egg-shell permeability to water affecting water management processes in fish eggs, during incubation. This phenomenon may have practical implications for fish hatcheries.

The effect of static magnetic field on melanophores in the sea trout (Salmo truttam.truttaLinnaeus, 1758) embryos and larvae

“…Here we describe the effect of static magnetic field on melanophores during embryonic and larval development of the sea trout (Salmo trutta m. trutta L.). As opposed to the previously studied fish species, we observed differences in the timing and development of embryos incubated in magnetic field, among others thickness and permeability of egg envelopes (Sadowski et al 2007). The sea trout is of great economic importance and all studies contributing to better knowledge of its complicated embryonic development may prove useful in practice of protection and restitution of the species in the Polish rivers.…”

The Effect of an Anthropogenic Magnetic Field on the Early Developmental Stages of Fishes—A Review

“…Initially, the egg envelope is permeable, so that the egg placed in water, whether fertilized or not, absorbs water. As a result, perivitelline space is formed between the envelope and the egg cell (yolk cell sphere surrounded by cytoplasm with the haploid nucleus); it is filled with fluid that contains not only water but also cortical alveoli with hydrophile substances [ 25 , 26 , 27 ].…”

“…Osmometric measurements of egg envelopes of the sea trout, Atlantic salmon ( Salmo salar L.), and rainbow trout in an SMF of 2 mT revealed changes in their permeability. The quantity of water passing through the envelopes placed on the osmometer collars in the SMF increased significantly; the field of this intensity caused an increase in permeability after egg activation during the formation of perivitelline space [ 26 ].…”

Magnetic field effect on melanophores of the European whitefish Coregonus lavaretus (Linnaeus, 1758) and vendace Coregonus albula (Linnaeus, 1758) (Salmonidae) during early embryogenesis

“…Juvenile fishes were reported to change directional responses (Quinn & Groot 1983). Magnetic field was observed to prolong sperm motility Formicki 2008;Formicki et al 2015), to slow down water absorption by fish eggs (Formicki et al 1993;Sadowski et al 2007), to accelerate cardiac contractions in embryos and larvae (Winnicki et al 2004), and to increase the respiration rate (Formicki & Perkowski 1998). Magnetic fields were also observed to affect the orientation of embryos (Tański et al 2005) as well as that of larvae and adults (Walker et al 2002;Formicki et al 2004a,b).…”