Pogonophorans Deep Sea Tube Worms

In 1900, a strange tube-dwelling worm was dredged from deep waters around Indonesia. While somewhat resembling tube-dwelling it lacked obvious segmentation; even more strangely, it also lacked a mouth, gut, or anus.

The name Pogonophora is Greek for "beard-bearers,“ comes from the fact that many species have from one to many tentacles at the anterior end.

The not well known anatomy of pogonophorans was interpreted to show that pogonophorans were chordate relatives

Lower half of the body is segmented not the top half They have no digestive system in the deep sea versions

1)Bilaterally symmetrical and vermiform 1)Bilaterally symmetrical and vermiform. 2)Body has more than two cell layers, tissues and organs. 3)Body cavity is a true coelom. 4)Body possesses no gut, mouth or anus. 5)Body possesses 3 separte sections, a prosoma, a trunk and a opisthosoma.

6)Has a simple nervous system with an anterior nerve ring and a ventral nerve chord. 7)Has a true closed circulatory system. 8)Has simple respiratory organs. 9)Reproduction normally sexual and gonochoristic. 10)Feed on detritus, or dissolved nutrients, or through symbiosis with bacteria. 11)All live in marine environments.

This was the first discovery of the Pogonophora, an animal phylum restricted to the deep sea and remarkably common in certain habitats there. About 80 pogonophoran species are known today, with new species still being discovered.

One of the most spectacular zoological discoveries of recent years was the finding in 1977 of giant pogonophoran worms, 1.5 meters long, growing in heated, sulfur-rich water around warm-water vents in the Pacific Ocean, 2600 meters below the surface (pictured at right).

These worms are sometimes placed in their own phylum, the Vestimentifera, but they are similar to pogonophorans in most respects, and the current tendency is to group these rift-dwelling worms together with the rest of the Pogonophora into one phylum.