摘要
本文报道了舟山蚂蚁岛长沙塘双齿围沙蚕的生境、分布数量、食性和繁殖习性。研究结果表明,长沙塘滩涂平坦,潮水涨退缓慢,年平均水温为15.6℃,盐度为20—30％,中潮区上部底质为细软泥沙,有机质含量平均4.14％,硅藻繁生,平均一平方米沙蚕密度为112条,生物量261克。该生境最适于沙蚕生活,高潮区数量较少,中潮区下部基本无分布。沙蚕的食物为有机质和泥沙,硅藻,极少量浮游甲壳类。繁殖期为4—9月,产卵高峰期为5—6月。产卵时水温为20.2℃,产卵后10—20多小时死亡。最后,还提出人工增养殖和资源保护的若干建议。
This paper reports the study from 1982 to 1983 on the environmental conditions, distribution and amount and feeding and breeding habits of the Perinereis aibuhitensis in Ma Yi island of Zhoushan Archipelago. The results are summarized as follows:1. It is widely distributed in Zhoushan Archipelago of East China Sea, such as Taohua, Zhujianjian, Liu Heng, Ma Yi and among them it is found most abundant in Ma Yi island.2. The long beach of Ma Yi island is very plain, where the rise and fall of tide is slow and the substrate is mainly composed of fine sand rich in organic materials. A great amount of diaton is found on the beach. Annual mean water temperature is 15.6℃. The salinity ranges from 20 to 30‰; pH 7.02-8.1. These habitat factors provide proper conditions for Perinereis aibuhitensis.3. The substrat of the upper part of the middle tide zone is soft fine sandy mud, which contains 4.14% organic material. The density of the worm reaches 112 per square meter. In the high tide zone and the lower part of the middle tide zone, the gravel and slime mud substrate is poor in organic material and no diaton is found. Consequently less and even no worm exit.4. The depth range of the worm is from zero to 30 centimeters. The change is of seasonal nature and is related to the temperautre and its reproduction.5. According to an analysis of the digestive tracts of 320 samples. Its food composition is sandy mud mixed with organic materials, diaton and occasionally planktonic crustacean.6. The breeding season is from April to September and the peak appears in the period from May to June. During the breeding season, the water temperature is 20.2℃. It will die 10-20 hours after the spawning.In the last part of the paper some suggestions for artificial propagation and the protection of the stock are put forward.
