39
The transportation of live animals therefore
requires great care and suitable precautions to
maintain sustainable aquaculture and biological
diversity. Monitoring studies are indeed necessary
to avoid the further dispersal of species already
known to be harmful in existing cultured and
natural environments. It is needless to say that not
only these polydorid polychaetes but other as yet
unrecognized and potentially invasive animals
and plants may have been unintentionally transported as a result of the international trade in
economically important mollusk species.
Fig. 3 A neighbor-joining tree inferred from the nuclear
18S rRNA gene sequences of spionid polychaetes. The
18S rRNA gene sequences of the four harmful Polydora
species are highlighted in boldface type . Bootstrap values
of >50 % as a percentage of 1,000 bootstrap replicates are
given at the respective nodes. The scale bar represents the
number of substitutions per site
Harmful Shell Borers, Polydora Species (Polychaeta: Spionidae), from Commercially…