军山湖耳河螺的种群动态及周年生产量

Population dynamics and annual production of Rivularia auriculata in the Junshan Lake

2005年4月～2006年3月期间,对军山湖耳河螺（Rivularia auriculata）进行了周年逐月采集,分析了耳河螺的种群动态,并采用瞬时生长率法测算了周年生产量.结果表明种群含三个年龄组,年均生物量13.37 g·m-2,年均密度8.12 ind·m-2.种群密度峰值出现在8月为24 ind·m-2,次年3月份有最低值为3.2 ind·m-2.生物量峰值则出现在9月为30.32 g·m-2、次年3月生物量有最小值为3.872 g·m-2.耳河螺周年生产量（带壳湿重）为3.5592（g·m-2·a-1）,周年P/B系数为0.27.与其他研究比较,结果较为合理.P/B系数较低,说明这一资源日趋贫乏,需要合理的保护利用.

We studied the population dynamics and annual production ofRivularia auriculata in the Junshan Lake from April 2005 to March 2006. The results showed that the population was composed of three years classes, with the annual average density being 8.12 ind＇m2, and the annual average biomass being 13.37 g＇m-2. The peaks of density and biomass were observed in August （24 ind-m2） and in September （30.32 g.m-2）, respectively. The lowest values of density （3.2 ind-m.2） and biomass （3.872 g.m2） were found in March. The annual production of R. auriculata calculated by instantaneous growth rate method was 3.5592 （g.m-2.a-1）, and the corresponding annual P/B ratio was 0.27. Compared with other research, the result was reasonable. The P/B ratio was low, showing this resource became rarer. So this resource should be protected and used reasonably.