Monocorophium insidiosum

Monocorophium insidiosum is found in estuarine and coastal environments. It is frequently seen in the English Channel, Mediterranean Sea, North Sea, Baltic Sea, and Japanese coastal regions. Reports have also confirmed its presence along parts of the American coastline. Monocorophium insidiosum favors high-turbidity conditions and lives on muddy or sandy substrates. Although the population decrease as salinity falls below 1 PSU (practical salinity units), population growth occurs in brackish water with salinities as low as 1.2–5.7 PSU.

Monocorophium insidiosum is known for its tube-building behavior. It constructs protective tubes using a mixture of organic material (such as algae and detritus) and inorganic particles (like sand), and are capable of building tubes entirely from material secreted by the organism. These tubes allow the species to attach itself to hard substrates and prevents them from being washed away by currents and tides. Monocorophium insidiosum can molt up to 20 times over its lifetime.