低盐度对泥东风螺(Babylonia lutosa)稚螺生长与存活的影响

Effects of low salinity on the growth and survival of Babylonia lutosa juveniles

采用盐度渐变和突变2种方法试验低盐度对平均体重3.7 mg、平均壳高(2.24±0.24)mm的泥东风螺稚螺生长与存活的影响。结果表明:盐度28时,稚螺的生长速度最快,盐度降到24时,对稚螺的影响并不明显,摄食基本正常,但活力略有降低;变态7 d的泥东风螺稚螺能够适应高于21的低盐环境,存活基本正常,有比较高的成活率,但对其摄食和生长有一定的影响;当盐度突变至18时,泥东风螺稚螺仍能存活,突变至15时,则不能存活;而盐度渐变至15时,稚螺仍可存活;盐度逐渐降低只可扩大泥东风螺稚螺的存活盐度范围,但其对最适生长盐度范围影响有限。

We applied two methods of acute and gradual salinity changes in our experiment to explore effects on the growth and survival of Babylonia lutosa juveniles. The average weight was 3. 7mg and the average shell-height was（ 2. 24 ± 0. 24） mm. The results showed that the juveniles grew fastest in salinity 28. Abnormal juveniles of Babylonia lutosa could adapt to the low salinity environment which with higher survival rates than those in salinity 21. The feeding,growth and survival of Babylonia lutosa juveniles were normal under salinity21 condition. When acute salinity became 18,Babylonia lutosa juveniles could still survive but suffer severe influence on feeding and growth. Those juveniles could not survive when acute salinity change under 15 but gradual salinity change could do with severe influence on feeding and growth. In conclusion,the survival range of Babylonia lutosa juveniles would be wider with gradual salinity change,but the adaptable growth range was limited.