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

本文在潮间带上游地区进行了黄颡鱼种内竞争和与其他底栖动物种间竞争的数值评价实验研究。实验中使用了三种尺寸的瓷器容器。每个容器内的种群密度分别为0、1 / 4、1 / 2、1 / 2和1968 - 1970年期间最高密度3800只/ m^2的两倍。选择波形巴菲亚、菲律宾Ruditapes philippinarum和Musculista senhousia作为底栖动物。对沉积物中有机氮含量进行了分析，并将其作为判别白腹露斑蝽食用量的指标之一。实验研究结果表明，斑胸虫种内竞争对食用量、死亡率和生长率的影响如下：在实验的所有种群密度中都没有发现食物竞争。竞争对死亡率有一定影响，但不取决于人口密度。竞争对增长率的影响取决于密度。本文对斑蝶与波纹帕菲亚的种间竞争作了如下结论：没有看到争夺食物的竞争。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小于前一种情况。

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.