Effects Of UV-B Radiation On Experimental Population Dynamics And Interspecific Competition Of Two Species Of Marine Rotifers (B. Plicatilis & B. Urceus)

A detailed literature review of ecophysiology effects of UV-B radiation on zooplankton was undertaken, and a series of indoor experiments were conduced to investigate the effects of UV-B radiation on the lethal effect, feeding and feeding selectivity, population dynamics, population growth and competition of two species of marine rotifers (Brachionus plicatilis and Brachionus urceus)at the level of individual and population, to supply experimental base for aquatic ecosystem with changes in global climate and provide the science foundation which built the indices system on denoting UV-B radiation of Ecotoxicology. The results were summarized as follows:2.1 The lethal effect of UV-B radiation on two species of marinerotifers (B. plicatilis & B. urceus)This paper reported the acute lethal effect of UV-B radiation on two species marine rotifers (Brachionus plicatilis and Brachionus urceus), and expected to elucidate the effects of UV-B radiation on marine ecological system and provide the science foundation which built the indices system on denoting UV-B radiation of Ecotoxicology. The results showed that the UV-B radiation was very harmful to rotifers and could make acute lethal effect on them when the UV-B radiation intensity achieved some threshold. Moreover, the 24, 48 and 96h LD₅₀ of UV-B radiation for Brachionus plicatilis were 4.393, 2.694 and 1.720kJ/m2 respectively while for Brachionus urceus were 5.856, 4.516 and 1.730kJ/m² respectively. However, both of the two rotifer species have the same acute lethal intensity threshold of UV-B radiation of (50±10)μW/cm². Furthermore, in the range of experimental radiation dose, the...