• Once settled onto the substratum the worm forms a temporary delicate semi-transparent tube, which, when calcareous material is later added at the anterior end (Hayward & Ryland, 1995) dissolves over time (Dons, 1927). The tube is formed by a secretion of calcium carbonate (obtained from sea water) from the collar (Thomas, 1940).
• Growth rate is usually measured by the increase in length of the tube over a period of time. Dons (1927) found that the youngest sessile stages of the animals in Trondheim occurred when the tubes were 800-1200µm long and the animal was approximately 500µ in length.
• Hayward & Ryland (1995) and Dons (1927) stated that growth is rapid and sexual maturity is reached in approximately 4 months. Growth rate has been observed by Dons (1927) to be 1.5 mm per month, although this varied with external conditions. Males and females exhibit the same growth rate (Castric-Fey, 1983). Animals settling during spring show the best growth rate and the rate is greatest during the first year (Castric-Fey, 1983).
• Castric-Fey (1983) reported that the number of segments of the worm increases with age, with a linear relationship being present within the first 6 months.

Feeding takes place by spreading apart its branchial filaments to expose a central groove. Using cilia action, it induces a current and transports food particles towards it mouth. If particles are too large or too numerous, the tip of a filament bends over and removes it. No sorting of food particles takes place.