中国对虾Penaeus orientalis Kishinouye存活和生长的初步研究

PRELIMINARY STUDIES ON THE GROWTH AND SURVIVAL OF THE CHINESE PRAWN PEN A EU S ORIENTALIS KISHINOUYE

本文提出几种不同的实验条件对中国对虾存活、生长和蜕皮的影响;连续测量了中国对虾各期溞状幼虫和糠虾幼虫蜕皮间期的体长变化。实验数据经数理统计,主要结果如下:1、不同的饲养密度、投饵量和换水率对中国对虾的存活有显著的影响(α=0.05)。较高的密度、投饵过量和换水不足的综合效应导致水体中溶解氧含量下降,氨氮和pH超出允许的范围。2、水体溶解氧含量降至临界水平是对虾大量死亡的主要原因,溶解氧含量是影响对虾存活的限制因子。3、当摄食不足时,中国对虾会表现出蜕皮后零生长、负生长。4、第一、二、三期溞状幼虫在蜕皮间期内身体分别能延长12％,11％和7％。本文还提出了一些关于加强对虾养成期管理的建议;讨论了对虾蜕皮后体长不增加或体长缩短这一现象、机理以及该现象在对虾养成管理中的意义。

The effects of varying experimental conditions were studied on the survival and molting of the Chinese prawn Penaeus orientalis Kishinouye The body length and carapace length of the prawn zoea and mysis were measured continually during the larval intermolt periods. The main results are given as follows:1. Stocking densities (5, 15, and 30% juvenile prawns per meter) , feeding rates( 50,100 and 200% of the normal feeding rate) and water exchange rates ( 0, 20, and50% of the aquarium water volume daily) had significant effects on the prawn survival(α = 0.05) DO dropping quickly, NH4-N and pH going beyond the allowed rangesresulted from the synthetical effects of higer densities, over feeding and less waterexchange during the experiment.2. The mass prawn mortality in the course of the experiment was due to the dropping of DO to a critical level, therefore, the DO content in the water is the limitting factor affecting the survival of the prawn.3. Juvenile prawns show zero growth even negative growth when food is not sufficient.4. The body length of the 1st, 2nd and 3rd zoea was proved to increase by 12, 11 and 7% respectively during its intermolt period.Suggestion for improving culture management of the prawn in China are proposed and the significance of the discovery of the zero growth, negative growth and intermolt growth of the prawn are discussed.