Effect of exposure of sturgeon roe to low-intensity laser radiation on the hardiness of juvenile sturgeon

Abstract

We present data on the effect of polarized laser radiation in the near IR region of the spectrum with wavelength 808 nm on the resistance of juvenile sturgeon to oxygen deficiency in the habitat when the fertilized roe are briefly exposed to radiation in the organogenesis stage. The magnitude of the stimulating effect depends on the exposure time (t) and power density (P) of the radiation and also on its modulation frequency (F). For optimal irradiation parameters (cw mode, P = 2.9 mW/cm 2 , t = 60 sec), the hardiness of the juveniles increases by a factor of ~1.5 compared with the control group. The maximum differences in the sensitivity of embryos to cw and pulsed radiation are observed for F = 1 Hz; as the modulation frequency increases up to F = 50 Hz, the magnitude of the photobiological effect approaches a level typical for cw exposure. We show that the duration of the dark period (pause time) between pulses is the critical parameter determining the dependence of the stimulating effect on the modulation frequency. We discuss questions concerning use of the indicated physical factor in the technology for raising sturgeon under industrial fish farming conditions. Introduction. Economically sound technologies for industrial raising of valuable fish species (sturgeon, salmon, whitefish) have attracted the attention of an increasing number of fish farms [1][2][3]. In this case, fish farming efficiency is mainly determined by the hardiness of the juvenile at the time it is released into artificial and natural bodies of water, in which it is subject to the effect of diverse biotic and abiotic habitat factors. The concentration of dissolved oxygen is an important factor in an aquatic environment, which fluctuates significantly both under artificial conditions and under farm conditions for raising a standard fish juvenile. When there is a deficiency of oxygen dissolved in the water, for the farm-raised juvenile we may observe a number of morphological deviations: head deformities, microcephaly (reduced brain size), underdeveloped gills, defects in the olfactory organs, etc. Most often, such a fish considerably lags behind normally developing individuals in size-weight parameters [1]. Furthermore, a significant deficiency of oxygen dissolved in the water can cause large-scale kills of fish fry. This is why development of methods for improving the resistance of juvenile fish to oxygen deficiency is an important problem in modern fish farming practice. There are quite good grounds for the interest of ichthyologists [4][5][6][7][8][9][10][11] in the stimulating effect of optical (including laser) radiation, which has been successfully used for a long time for treatment of human diseases [12,13], treatment and stimulation of weakened animals [14,15], and also for stimulation of plants [16,17]. However, attempts to use laser radiation in the red region of the spectrum (helium-neon laser, λ = 632.8 nm) in fish farming have shown that its effect on sturgeon and stellate sturgeon either proves to have (de-

Influence of coherence low intensity optical radiation and radiation periodicity on enzyme activity of embryos of rainbow trout (Oncorhynchus mykiss, Walbaum, 1792)

“…Based on the presented data and also on data obtained previously 2,3,4 we conclude that among the resonant and nonresonant photophysical processes (orientational effect of light, effect of gradient forces, dipoledipole interactions, thermooptic processes) capable of inducing photo biological effects dependent on such laser-specific characteristics as polarization and coherence, the determining influence in the processes studied in this work comes from the orientational effect of light and dipole-dipole interactions. And the orientational effect can appear for anisotropic media with liquid-crystal type ordering (especially domains in membranes and multiple-enzyme complexes) both under conditions when there is no resonant absorption and for weakly absorbing structures, and can initiate a change in their conformations and accordingly their functional characteristics.…”

“…As our long-term studies have shown, laser radiation, as well as the radiation of super-bright LEDs, has a stimulating effect on fish and their sexual products (caviar and sperm), as well as on the development of gullet crustaceans. 2,3,4 Our previous studies were based on the effect of optical radiation on bioobjects within a single exposure. The question of the most favorable periods of repeated exposure to optical radiation, in which the maximum effect on aquaculture objects is manifested, remains open.…”

Effects of Photobiomodulation on Daphnia magna Straus and their Sensitivity to Toxicant

“…So, by the example of three cyanobacterial strains, it was shown that the response of organisms to pollution of freshwater aquatic ecosystems with zinc is highly dependent on the light level (50). It is known that very low-intensity laser radiation can significantly affect the development of living systems (1,5,(51)(52)(53)(54). In (29), a low-intensity laser preradiation protector effect was found: The pre-exposure of a small region of the mice skin surface to low-intensity helium-neon laser light markedly decreased the toxic effect of lipopolysaccharide.…”

“…Photobiomodulation (PBM), also known as low-level laser therapy (LLLT), which involves exposing biological objects to monochromatic (laser) or nonmonochromatic (LED) visible or near-infrared light, has been actively developed over the past few decades. Numerous studies have been conducted in order to reveal the mechanism of action, to develop treatment methods and to find out safe treatment modes at the level of both cells (1-3) and various organisms (4)(5)(6). It has been demonstrated that PBM, depending on the physical impact parameters and the condition of the biological object, has a positive or negative, stimulating, overwhelming or regulatory effect on both prokaryotic and eukaryotic organisms (3,(7)(8)(9)(10)(11).…”

“…It is known that low-intensity laser and LED irradiation can have a protective effect on organisms under certain conditions (22)(23)(24)(25). Laser radiation in the near-infrared region increases the resistance of sturgeon fry to oxygen deficiency (5). The protective effect of infrared radiation against damage induced by ultraviolet radiation was studied in (26).…”