H. norvegicus, Gunnerus, 1768 [2] Hydroides norvegica is a species of tube-forming annelid worm in the family Serpulidae.

[3] A study was made of the rate of growth of H. norvegica and other sedentary organisms in Madras Harbour, India.

The worms attached themselves in very large numbers to suitable surfaces and secreted translucent tubes which later becomes calcareous.

In the laboratory, tanks containing artificially fertilized eggs were kept and the worms underwent all the normal stages of development and attained a very large size (ten centimetres long).

The dominant species involved were found to be the little striped barnacle, Balanus amphitrite, the crested oyster, Ostrea equestris and Hydroides norvegica and a stable community was produced after two to four months at fifty feet and slightly longer at one hundred feet.

In four months, H. norvegica reached a length of three centimetres, and with the other fouling organisms covered the panels that were used.