Effect Of Glucose, Sucrose And NaCl To Embryo Development Of Zebrafish

Is pure fresh water the ideal condition for living of fresh water fish? Does suitable concentration of inorganic salts, nutritional substances or neutral organic substances, and increase of osmotic potential have any obvious effects to fish living or embryo development? These kinds of questions remain largely unknown. Embryonoic period of fish is most sensitive to environmental changes. Observing the effect of environmental change to fish embryo development is a short cut for investigation of environmente effect on fish. In the present experiments, we let early zebrafish embryos (about two hours after fertilization) develop in different solutions of sallt, glucose or sucrose of different concentrons. In questing for whether a suitable concentration of these materails could improve fish embryo development quality, and/or increase developing speed, we observed embryo development speeds, hatch time and morphological condition and movement type of the embryos, and swimming habitor of the larvae, and compared with those developed in freshwater control. Results showed that salt, glucose and sucrose solutions in certain concentrations can quicken embryo develop speed, and shorten hatch time. Larvae hatched from these treated embryos, in certain concentrations, showed normal morphology and swimming behavior. Especially in 2% sucrose and 1.5% glucose, significantly decreased the hatching time of fish embryos. But as the concentration of glucose solution increased, death rate of the embryos became significantly higher, and embryo morphology was also affected. Whereas death rate did not become significantly higher as the concentration of sucrose solution increased up to 8%. So we can conclude that suitable concentrations of salt, sucrose and glucose solutions significantly accelerated zebrafish embryo development. But high concentration of glucose solution significantly affected normal development of zebrafish embryos. Higher concentrations of sucrose did not show such significantly effect on zebrafish embryo development. It may be the reason for the same weight/volume ratio of sucrose is lower in mol concentration than that of glucose, and sucrose solution give out lower osmotic potential than that of glucose. Lower concentration solutions of sodium chloride increased embryo developmental speed, but higher high concentration solutions of sodium chloride significantly affected embryo development, even some embryos can hatch, their morphology were usually abnormal, and dead within a day.