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Biology/Natural History: This species is a filter feeder. It traps microscopic particles in mucus, which it then swallows. Since its food comes from suspended particles it has no need to move around much. It mounts a stone or other object out of the mud and remains there for a long time. Deep-water individuals frequently have the tiny white parasitic snail Odostomia columbiana next to the aperture. Odostomia uses its eversible proboscis to suck body juices from Trichotropis. Trichotropis also often has ascidians, hydroids, diatoms, sponges, barnacles, or other sessile animals growing on it. This species is a protandric hermaphrodite. For its first year it is a male, then becomes female but retains the penis (behind its right eye). Females lay disk-shaped egg capsules at night, then die.
Cancellate means checkered. The spiral and longitudinal ridges form a checkered pattern on the shell, but the pattern is often hard to see because of the thick hairy periostracum.