Hyalinoecia artifex is an abundant species on the US Atlantic margin, although little is known about its behavior, ecology, or reproduction. We provide field notes and high-resolution in situ imagery of this species observed and collected in 2013 and 2015. Hyalinoecia artifex occurred primarily on soft sediment at a density of 10.9±0.95 individuals m^–2 (mean±standard error). Although they were found adjacent to mussel beds associated with methane seeps, worms were negatively associated with authigenic carbonate and other epibenthic megafauna in the study area. Quill worms moved across the sediment by extending their heads from the tubes and dragging the tubes forward. Stable isotope analysis indicated that H. artifex is a secondary consumer. Most individuals collected in 2015 were ripe, with mature oocytes up to 400 µm. Oocytes were yolky, yellow in color and positively buoyant; no brooding was observed.