The lugworm, Arenicola cristata, is a large cigar-shaped polychaete with 17 setae-bearing segments (Voss 1980). The surface of the body is roughly textured and green to brownish-green in color. Three body regions are apparent when examining the appearance and behavior of the lugworm (Ruppert & Fox 1988). The front region is a muscular portion primarily used for digging. Eleven pairs of bushy red gills cover the middle of the body, which controls respiration (Kaplan 1988; Ruppert & Fox 1988). Excretion occurs at the back, which is usually the only portion visible above the sediment when the worm is buried.