Dubilier Nicole
Biol Bull. 1988 Feb;174(1):30-38. doi: 10.2307/1541756.
In small-scale laboratory experiments, organic-rich sediment lacking sulphide elicited settlement and metamorphosis in freshly hatched Capitella sp. I larvae, so that 90% settled within 30 min after hatching. Settlement times of somewhat older larvae were even shorter; 90% settled into the mud in less than 5 min. The addition of sulphide to these treatments (0.5 mM, 1.0 mM, and 2.0 mM) delayed settlement, so that it took several hours for 90% of the larvae to settle. Many of these larvae showed abnormal behavior and settled distant from the sediment. Sulphide alone (without sediment) enhanced settlement in a concentration-dependent manner (0.5-2.0 mM), as previously reported by Cuomo (1985). However, this response occurred over 12-24 h and abnormal larval settling behavior was observed. Hypoxia produced a similar response. Considerations of behavior and swimming capabilities of Capitella larvae, near-bottom hydrodynamic conditions in the field, and the time course of these responses to organic-rich sediment, sulphide, and hypoxia, lead to the conclusion that sulphide is not a settlement cue promoting habitat selection in Capitella sp. I larvae. The apparent enhancement of settlement by sulphide is hypothesized to be a sub-lethal toxic effect.
在小规模实验室实验中，缺乏硫化物的富含有机物的沉积物能促使刚孵化出的多毛类小头虫属I型幼虫沉降和变态，以至于90%的幼虫在孵化后30分钟内沉降。稍大一些幼虫的沉降时间甚至更短；90%的幼虫在不到5分钟内就沉入泥中。向这些处理组中添加硫化物（0.5 mM、1.0 mM和2.0 mM）会延迟沉降，以至于90%的幼虫需要数小时才能沉降。许多这些幼虫表现出异常行为，并且在远离沉积物的地方沉降。如库莫（1985年）之前所报道的，单独的硫化物（无沉积物）以浓度依赖的方式（0.5 - 2.0 mM）增强沉降。然而，这种反应在12 - 24小时内发生，并且观察到幼虫有异常的沉降行为。缺氧产生了类似的反应。考虑到小头虫幼虫的行为和游泳能力、现场近底水动力条件以及这些对富含有机物的沉积物、硫化物和缺氧的反应的时间进程，得出的结论是，硫化物不是促进多毛类小头虫属I型幼虫栖息地选择的沉降线索。据推测，硫化物对沉降的明显增强是一种亚致死毒性效应。
