Relationships

It was believed that the host serves as a reliable refuge for the scaleworms by protecting them from predation. G. clavigera does not inhabit any defenses thus when it is dislodged from the host, it is easily eaten by fish. Since the sea cucumber does not benefit from the worm, thus the relationship was described as commensalism (Britayev and Zamyshliak, 1996). However, another research showed that sea cucumber tissue was found in the gut content of the scaleworm (Britaev & Lyskin, 2002). This shows the scaleworm feeds on sea cucumber tissues. This provides some evidence that the relationship might be parasitism instead of commensalism. However, the scaleworm also feed on copepods which are parasites on sea cucumbers. Holothurians provide shelter to the scaleworm while the worm removes parasites for the holothurians in return, this relationship could be described as mutualism. This makes the reaction between g. clavigera and it host is even more complex. Thus, there is still no definite description about this relationship.

Also, since holothurian tissues are highly toxic, g. clavigera which feed on the tissue have to develop resistance to the toxic (Bakus, 1968). This is a result of long coevolution to this feeding habit. There are still a lot of unknown about the living strategies of the scaleworm.