ИСТИНА

The mechanisms of spectral sensitivity formation of Mysis relicta were studied by whole-eye electroretinography (ERG) and microspectrophotometry (MSP) techniques [Jokela-Määttä et al., 2005; Abu Khamidakh et al., 2010; Demchuk et al., 2012; Zak et al., 2013; Donner et al., 2016]. It has been shown that M.relicta is dichromatic animals with LWS- and MWS-cells. It is assumed that different proportions of LWS- and MWS-visual pigments may underlie the spectral sensitivity variability of different populations of M. relicta. In addition, it is revealed that the microvilli of LWS- and MWS-cells have different light polarization sensitivity and are located in different rhabdom layers. It is shown that the ERG-spectral sensitivity has a longer wavelength position than the absorption spectra of the visual pigments due to the fact that the xanthomatine screening pigment is located between the crystalline cones of the cornea. At the same time, M.relicta does not have carotenoid intraocular filters, which are widespread in marine Сrustacea. The most clearly described system of spectral sensitivity is manifested in the shrimps of Lake Pyhäjärvi. These animals have the spectral sensitivity in the red region of their natural light environment due to the prevalence of LWS P560 cells in combination with a corneal xanthomatine cut-off filtration for wavelengths shorter than 550 nm. There are preliminary ERG-data on reciprocal relationships between LWS- and MWS-cells. The conducted researches formed the basis of the current grant between the Russian Foundation for Basic Research and the Finnish Academy of Sciences "Mechanisms and time scales of eye adaptation to changes in habitat in the Arctic on the example of relics of the glacial period – shrimps of the genus Mysid."