Evaluation of intra-specific or inter-specific competition for T. lubrica by a bio-economical method.

在潮间带上部进行了数值评价润滑毛虫种内竞争及其与其他底栖动物种间竞争的实验研究。实验使用了中国制作的三种尺寸的容器。每个集装箱的种群密度分别为0、1/4、1/2、与1968-1970年最高密度3800只/m^2持平和两倍。波纹巴非鱼、菲律宾蛤仔和青蛙被选为底栖动物，而不是润滑性巴非鱼。通过对底泥中有机氮含量的分析，认为底泥中有机氮的含量是衡量罗非鱼摄食量的指标之一。结论罗非鱼种内竞争的实验研究结果表现为对摄食量、死亡率和生长率的影响。在实验的所有人口密度中，并没有看到对食物的竞争。对死亡率的竞争效应有一定程度，但不依赖于种群密度。对生长率的竞争效应依赖于密度。通过对油松毛虫和波纹巴非鱼种间竞争的研究，得出了以下结论。没有看到对食物的竞争。竞争对死亡率的影响与上述情况相同。竞争对增长率的影响略低于前一种情况。

Experimental studies on evaluating numerically the intra-specific competition within T. lubrica and the inter-specific competition between T. lubrica and other benthic animals were done in upper regions of intertidal zone. Three kinds of sizes of containers made from china were used for the experiment. The population densities in each container were 0, one-fourth, a half, the same and double of the highest density of 3800 per m^2 during the period from 1968 to 1970. Paphia undulata, Ruditapes philippinarum and Musculista senhousia were selected as benthic animals other than T. lubrica. The organic nitrogen content in the sediment was analyzed as One of indice for the quantity of food of T. lubrica.Conclusions of experimental studies for the intra-specific competition within T. lubrica were expressed as the effect to quantity of food, to death rates, and growth rates, as follows. Competition for food was not seen in all population densities of experiment. Competitional effect to death rate was seen to some extent, but did not depend on population density. Competitional effect to growth rate depended on the density. The following conclusions were given for the inter-specific competition between T. lubrica and Paphia undulata. Competitional for food was not seen. Competitional effect to death rate was the same as above case. Competitional effect to growth rate was slightly less than that in previous case.