Hart M W, Strathmann R R
Biol Bull. 1994 Jun;186(3):291-299. doi: 10.2307/1542275.
Phenotypic plasticity in feeding structures has been described for several larvae of marine invertebrates, including four species of echinoids. In these echinoids, larvae grown with scarce food grow a longer ciliated band than larvae grown with abundant food. Such phenotypic plasticity may be functionally significant if longer ciliated bands permit higher feeding rates when food is scarce. We replicate an earlier result showing that larvae of a sand dollar, Dendraster excentricus, grow longer ciliated bands in culture with scarce food. We show that these larvae can capture suspended food particles at the tips of longer arms, and that longer ciliated bands result in higher maximum clearance rates. The maximum clearance rate is enhanced by this phenotypic plasticity both early and late in larval life. However, longer ciliated bands did not completely compensate for reduced food supply: larvae grown with scarce food needed more time to complete larval development and metamorphosed into smaller juvenile sand dollars relative to larvae grown with abundant food.
海洋无脊椎动物的几种幼虫，包括四种海胆，已被描述在摄食结构上具有表型可塑性。在这些海胆中，在食物稀缺环境中生长的幼虫比在食物充足环境中生长的幼虫长出更长的纤毛带。如果更长的纤毛带在食物稀缺时能实现更高的摄食率，那么这种表型可塑性可能具有重要的功能意义。我们重复了之前的一项研究结果，即饼海胆（Dendraster excentricus）的幼虫在食物稀缺的培养环境中会长出更长的纤毛带。我们发现这些幼虫能够在较长触手的末端捕获悬浮的食物颗粒，并且更长的纤毛带会导致更高的最大清除率。这种表型可塑性在幼虫生命的早期和晚期都提高了最大清除率。然而，更长的纤毛带并不能完全弥补食物供应的减少：与在食物充足环境中生长的幼虫相比，在食物稀缺环境中生长的幼虫需要更多时间来完成幼虫发育，并且变态成为更小的幼年饼海胆。
