盐度对波部东风螺幼虫存活、生长及变态的影响

采用突变和渐变两种实验方法检验了盐度对波部东风螺幼虫存活、生长和变态的影响。这两个实验，在盐度21．0－27．5的范围内，幼虫均有较高的存活率、变态率和较快的生长速度。其中，在盐度24．0处，幼虫的存活率和变态率都最高，生长速度也最大。不管盐度如何，幼虫较快的生长速度总是和自发变态前较短的浮游期联系的，尽管渐变盐度没能使幼虫的存活率、变态率、生长速度、变态个体的大小以及浮游期的长度得到显著的改变，却明显地加宽了幼虫存活和变态的盐度范围。渐变盐度的实验方法优于突变盐度的实验方法。

Effects of salinity on larval survival,growth and metamorphosis of

Effects of salinity on larval survival, growth and metamorphosis of Babylonia formosae habei were examined by using two experimental approaches,gradually changed and abruptly changed. In both experiments, larval survival rates and metamorphosis rates were higher and larval growth were faster in salinity from 21.0 to 27.5. Moreover, the highest rates of both survival and metamorphosis which were observed was at salinity 24.0,so was the fastest growth rate. Regardless of salinity, faster growth was associated with a shorter planktonic stage prior to spontaneous metamorphosis. Although gradually changed salinity could insignificantly alter larval survival rates, metamorphosis rates, sizes of metamorphosis and length of larval planktonic stage, apparently widen salinity range of larval survival and metamorphosis. The experimental method of gradually changed salinity was better than that of abruptly changed salinity.