Levitan Don R
Ecology Program, School of Life and Health Sciences, University of Delaware, 19716, Newark, DE, USA.
Oecologia. 1988 Sep;76(4):627-629. doi: 10.1007/BF00397880.
This study documents size- and density-dependent growth (positive and negative), in the sea urchin Diadema antillarum. In the summer of 1983, an inverse relationship was found between Diadema test diameter and population density at seven sites in Lameshur Bay, St. John, United States Virgin Islands. The regression of this relationship improved when test diameter was plotted against density per unit grazing area. A field experiment demonstrated that 1) Diadema has the ability to reduce skeletal body size, and 2) direction (growth or shrinkage) and rate of growth can be predicted accurately based on the urchin's body size and population density. The ability to adjust body size as density fluctuates may allow Diadema to persist when density increases, by shrinking and reducing metabolic costs, and to take advantage of decreases in density, by increasing in size and fecundity.
本研究记录了加勒比海胆（Diadema antillarum）的大小和密度依赖性生长（正向和负向）。1983年夏天，在美国维尔京群岛圣约翰岛拉梅舒尔湾的七个地点，发现海胆的测试直径与种群密度之间呈反比关系。当以测试直径对每单位摄食面积的密度作图时，这种关系的回归得到了改善。一项野外实验表明：1）海胆有能力减小骨骼体型；2）根据海胆的体型和种群密度，可以准确预测生长方向（生长或收缩）和生长速率。随着密度波动而调整体型的能力，可能使海胆在密度增加时通过收缩和降低代谢成本而存活下来，并在密度降低时通过增大体型和繁殖力而受益。
