The White-tuft Protula, Protula tubularia, is a marine worm belonging to the class of sedentary Polychaetes and the order of Serpulidae which lives in a white calcareous tube and is present throughout the Mediterranean Sea at depths that can vary from 10 meters to over 100 metres. It is a very common annelid.

Filograna implexa (Salmacina incrustans) is a marine species of tubular worm belonging to the class of sedentary Polychaeta of the Serpulidae family. This species is found in the waters of the Mediterranean Sea, the English Channel, the North Sea, the Gulf of Mexico and off the coast of Monzambique, and from South Africa to New Zealand.

The red-tuft Protula lives throughout the Mediterranean Sea in small tubes at depths that can vary from 10 meters to over 100 meters. It is a very common annelid throughout the Mediterranean and therefore we can easily find it among the Posidonia oceanica meadows, on the various detrital bottoms and in coral reefs. The red color characterizes this worm from the other species of the same family.