This positioning ensures that more food floats past the star, therefore increasing nutrient uptake. "O. bennetti" is gonochoric,meaning it has both female and male individuals. Reproduction occurs when some of the pinnules burst, releasing gametes into the water column. Sperm will fertilize eggs, which will hatch to produce free-swimming larvae. These larvae settle after a few days, where they begin to produce their stalk and start to grow. "O. bennetti" has been observed having a symbiotic relationship with various species of polychaete worms. This relationship has been described as commensalistic, meaning that the polychaete worms benefit greatly from the feather star, as it provides shelter, protection, and food, and there is little to no negative effect on O. bennetti. Individuals of the species "Hololepidella laingensis" and "Paradyte crinoidicola" have been found on "O. bennetti" in Papua New Guinea, with an average of 2–4 worms per individual star, as competition between these worms is fierce. In Vietnam, these stars were found with a total of 11 symbiont species on only 18 individuals, meaning that these feather stars serve as excellent shelters for smaller animals looking for protection and food.