Xu Min, Sakamoto Shingo, Komatsu Teruhisa
Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa City, Chiba 277-0882 Japan.
J Appl Phycol. 2016;28(6):3679-3687. doi: 10.1007/s10811-016-0869-5. Epub 2016 May 12.
is one of the most important contributors to the rafts of floating seaweed in the waters off the coasts of northeastern Asia. These rafts serve as spawning and nursery grounds for many marine organisms, including Japanese saury and yellowtail. Thus, the details of the attachment/detachment mechanisms of are of commercial significance for the aquaculture industry. Here, we describe variations in the attachment strength of as it relates to its developmental stage and depth along a bottom gradient. We measured the attachment strength/dislodgement force of samples with holdfast detachment in Shidagaura Cove, Shimoda, Japan, from December 2014 to May 2015. After we had determined the dislodgement forces required to detach thalli from the substratum (using a spring scale device) in the field, we transferred released individuals to the laboratory and measured selected morphological traits. Attachment strength was linearly related to the holdfast basal area when thalli were immature (prior to mid-March), but not when they were mature (mid-March to May). Thus, attachment strength was maintained through the reproductive phase and declined thereafter, allowing released thalli to join the drifting raft community. Rafting may be a mechanism by which the species expands its distribution range, as floating thalli continuing to shed germlings that are able to recruit when suitable habitat is encountered. Attachment strengths were greater in the shallows than in deeper water, reflecting the differences in wave forces experienced at different depths.
是东北亚沿海海域漂浮海藻筏最重要的促成因素之一。这些海藻筏是许多海洋生物的产卵和育幼场所，包括日本秋刀鱼和黄尾鱼。因此，其附着/脱离机制的细节对水产养殖业具有商业意义。在此，我们描述了其附着强度随发育阶段和沿底部梯度的深度的变化。我们于2014年12月至2015年5月在日本下田市志田浦湾测量了具有固着器脱离的样本的附着强度/脱离力。在野外确定了将藻体从基质上分离所需的脱离力（使用弹簧秤装置）后，我们将释放的个体转移到实验室并测量了选定的形态特征。当藻体未成熟时（3月中旬之前），附着强度与固着器基部面积呈线性关系，但当它们成熟时（3月中旬至5月）则不然。因此，附着强度在生殖阶段得以维持，此后下降，使释放的藻体能够加入漂流的海藻筏群落。漂流可能是该物种扩大其分布范围的一种机制，因为漂浮的藻体不断脱落幼芽，当遇到合适的栖息地时这些幼芽能够定居。浅水区的附着强度大于深水区，这反映了不同深度所受波浪力的差异。
