Alitta virens (common names include sandworm and king ragworm; older scientific names, including Nereis virens, are still frequently used) is an annelid worm that burrows in wet sand and mud. They constuct burrows of different shapes (I,U,J and Y)  They range from being very complex to very simple. Long term burrows are held together by mucus.
Alitta virens, commonly known as the sandworm or king ragworm, is a type of annelid worm that lives in wet sand and mud. It creates burrows with various shapes (I, U, J, and Y) ranging from simple to complex. These burrows are held together by mucus over time.