Protula tubularia

Protula tubularia is a species of the phylum of annelids, belonging to the class Polychaeta, order Sabellida and family Serpulidae. This benthic species inhabits the rocky bottoms of waters up to 90 meters deep in the Mediterranean Sea and the eastern Atlantic Ocean, from the coasts of the United Kingdom to South Africa.

Specimens of Protula tubularia live inside a calcareous tube of circular section and about 1 cm in diameter, which can reach a length of about 7-10 cm. The tube is externally more or less smooth, except for some smooth growth rings. Inside the calcareous tube we find the body of the animal, formed by about 100 different segments along its entire body. The external part of the animal's body that we can observe, thta is to say the duster, corresponds to the animal's gills, and they are formed by two lobes of equal size, slightly spiralized, and whose tufts are whitish or pinkish in color with different spots regularly arranged along them. Protula tubularia does not have a calcareous operculum with which to close the tube if it feels threatened, but in such a circumstance the animal will completely retract its body into the tube, leaving the entrance uncovered.

The feeding of Protula tubularia is obtained by filtering the water column surrounding the specimen by the gill plume. Therefore, specimens of this species are found in regions where there are gentle but frequent currents that carry organic particles towards them in order to capture them.

The reproduction of Protula tubularia occurs mainly during the summer months, when the female and male specimens release eggs and sperm respectively, forming a planktonic egg that will give rise to a larva that after a few days will be deposited on the seabed to give rise to a juvenile.

It is difficult to differentiate certain species similar in appearance to Protula tubularia, especially those belonging to the same genus Protula. The geographical location of the specimens is one of the factors that will allow us to identify the species, since colors and shapes can be very similar among them.