Study On The Feeding, Oxygen Consumption And Excretion Of Styela Clava

A common adhering organism in the northern sea area of our country, Styela clava, was researched to determine the influence of itsfeeding , biological oxygen consumption and excretion on cage-cultured species. An indoor static closed system was employed in this experiment. In addition, experiments were conducted to determine the oxygen consumption rates in different body weights, temperatures, salinities, pH and ambient oxygen pressures of starving Styela clava, to determine the relationships among body weight, temperatures and ammonia excretion rate, to determine the relationship between body weight and oxygen consumption rate of feeding Styela clava, to determine the feeding rates of different body weights Styela clava on seven species of algae and the relationship between food density and feeding rate. The results are:The feeding rates of different standards Styela clava to seven species algae increase with the increase of Styela clava standards at 21℃. Feeding rate varies with the density of algae. Styela clava tends to select larger size algae.Temperature and body weight influence oxygen consumption rate remarkablely. The oxygen consumption rate of Styela clava increases with temperature increasing in the water temperature range of 12~28℃. The oxygen consumption rate has a negative relationship to body weight of Styela clava . The relationships between body weight (W) and oxygen consumption rate (Y) can be expressed as Y=0. 093 W-0.249 (R2=0. 9726) and Y=0. 0935 W0.747 (R2=0. 9985), respectively. Ambient oxygen pressure has some influence on the oxygen consumption rate, but the diversity is not remarkable (P<0.05). The oxygen consumption rate reaches peak at salinity 32 and pH7. The oxygen consumptionrate of fed Styela clava is higher than starving one remarkablely (P<0.05) .Temperature influences ammonia excretion rate per unit body weight remarkablely (P<0.01). The relationship between body weight and ammonia excretion rate and the relationship between temperature and ammonia excretion rate can all be expressed as a bell-like curve. Ammonia excretion rate per individual increases with the increase of body weight at 24°C, and the regression equation is On =5. 46 WO.825(R2=0. 9874). Ammonia excretion rate per unit body weight decreases with the increase of body weight, and the regression equation is Qn =141. 25W-0.325(R2=0.9242). Body weight influences ammonia excretion rate remarkablely (P<0. 01). The 0: N value increases with the increase of body weight, but the diversity is not remarkable (P<0.05).Styela clava is a common adhering organism in sea farming area of Shan dong province. This research deals with the characters of its oxygen consumption, feeding and excretion, which has important significance to adhering organism prevention and control and provides scientific basis for effective adhering organism preventing measures.