THE EFFECTS OF VARIOUS SALINITY AND TEMPERATURE CONDITIONS ON THE GROWTH RATE OF LEPRALIA PALLASIANA MOLL. COLONIES (Vliyanie Uslovii Razlichnoi Solenosti i Temperatury na Temp Rosta Kolonii Korkovoi Mshanki Lepralia Pallasiana Moll.),

The paper discusses experiments on the reaction of the bryozoan Lepralia pallasiana to variations of water salinity and temperature. The effect of salinity variations on the species was investigated in containers containing Black Sea water with normal salinity (18 o/oo) and reduced salinities 14, 12 and 10 o/oo at the usual temperature in summer (20-24C). The effect of temperature variations on the species was investigated in winter at temperatures 25, 15 and 10C in waters having the salinities of 18, 14, 12, and 10 o/oo. On the basis of the tests it was disclosed that within the salinity range from 18 to 12 o/oo at the usual summer temperature the growth of the bryozoans can be considered as normal, whereas with the salinity of 10 o/oo the growth and gemmation ceases. As to the variations in temperature, it was found that at 15C the growth is greatly retarded and at 10C it ceases. The combined effect of variations in salinity and temperature increased the retardation of growth so that the growth rate of L. pallasiana at a salinity reduced to 12 o/oo and temperature to 15C was 14 times slower than at 25C, but at 10 o/oo and 15C it was 30 times slower than at 18 o/oo.