Experimental transmission of the nematode Echinomermella matsi to the sea urchin Strongylocentrotus droebachiensis in the laboratory.

Three experiments were conducted to investigate the possibility of maintaining the Echinomermella matsi-Strongylocentrotus droebachiensis system in the laboratory. The experiments were performed by injecting E. matsi larvae taken directly from gravid female nematodes into the mouths of sea urchins. In all experiments, this treatment resulted in a higher infection in treated animals than in unmanipulated controls. The successful establishment of larvae indicates that E. matsi has a monoxenous life cycle. The growth of larvae in experimentally infected hosts was slow, indicating that the generation time of the parasite is of the same magnitude as the life expectancy of the host, 1-2 yr. This slow growth rate suggests that considerable resources will be needed to maintain the system in the laboratory.