Trumpet Worm, Lagis koreni
The trumpet worm (Lagis koreni) is a species of polychaete worm that is classified within the Annelida phylum. It can be found in the waters around Europe including the North Sea, the Arctic Ocean, the Mediterranean Sea, the Atlantic Ocean, and the Adriatic Sea. This species is typically found submersed in sand in the neritic zone.
The trumpet worm can reach an average length of about one inch and is typically light pink in color, with visible red veins and two pairs of red gills. This species resides in a narrow, cone shaped tube that is comprised of shell fragments and sand. The head protrudes from this shell and holds four tentacles and two groupings of gold spines, which are used to dig into the sand. When the worm retreats completely into the shell, it is covered by an operculum. The protected body of this worm is comprised of about fifteen segments that hold chaetae. The chaetae, or bristles, grow laterally and have four sets of teeth and six to eight rows of sharp hooks.
The shell of the trumpet worm is open on both ends, with the smallest end resting at or slightly above the surface of the sand. The worm rests with its head down, sifting sub-surface particles from the sand and digging a feeding cavern in the process. The particles that it consumes are moved along a ciliated groove, but some of the particles fall out of this groove. These particles fall into the feeding cavern, however, and are saved for later consumption. The main diet of this worm is thought to consist of small copepods, foraminifera, and ciliates, but it has been found to prefer food like crustaceans, nematodes, and large foraminifera even though these species are too large for it to consume properly.
The spawning season for the trumpet worm occurs during the summer months. One study, conducted off the coast of Wales, showed that the worm released bundles of sperm into the water column in May, after which point the ova began to develop. After this, the larvae developed within the water column alongside zooplankton for several weeks. During the study, the worms did not settle on the seabed until June, after they had undergone a metamorphosis. The larvae began secreting the mucous that binds their shells while still in the pelagic area of the water, and matured quickly once they reached the seabed, reaching full maturity by the onset of winter.
The trumpet worm is often seen in large numbers along the seabed, sometimes reaching one thousand individuals in a 10.7 square foot area. It is often found with the white furrow shell, Ophiura ophiura, Phaxas pellucidus, and many types of polychaete worms. One study, conducted in Liverpool Bay, showed that in areas where dredging had disturbed the sand, the trumpet worm and Phaxas pellucidus often dominated the habitat. Common predators of the trumpet worm include the plaice and the common dab.
Image Caption: Pectinaria koreni, worm and tube. Credit: Cwmhiraeth/Wikipedia (CC BY-SA 3.0)