EFFECT OF ILLUMINATION ON GROWTH AND BEHAVIOUR OF GUPPY, POECILIA RETICULATA

The guppy, Poecilia reticulata, is a model for many ichthyological studies. The effect of light on juvenile growth has been studied on the Poecilia reticulata. Studies have been conducted in twenty-liter aquariums. For experiments on the fish arbitrary choice of light intensity (light transmission behavior), it was used radiant pans of organic glass 150 x 15 x 15 cm divided by transparent semi-partitions into ten communicating compartments. The specific growth rate has been determined after the experiments. It increases with the light level increasing. The growth rate is minimal at 0 lx in all series of experiments. It was shown that the sharpest increase in the specific growth rate of guppies occurred when the illumination changed from 0 to 200 lx. A further increase in the intensity of illumination practically did not affect the growth of guppies. Also, the guppy juvenile behavior has been studied in special trays at different light from 3200 to 5900 lx. The motor activity of guppies increases by 30% in lightgradient conditions. The frequency (25 sec) and length of guppies stay (28.3 sec) are the highest in the compartment with 4700 lx. The preferential light zone expands if the juveniles are starving. As the period of starvation increased, guppies began to swim almost equally often and linger in different light zones. Thus, high light conditions stimulate the search behavior and activity of guppies. To grow guppies in production conditions, high illumination is necessary.