Dear annelid enthusiasts,
The recent exchange of information about Sabella spallanzanii opens an
interesting area of discussion, namely that of the importance of type
localities for species that have become widely distributed due to man's
activities. The question might be raised as to what importance is the
type locality, other than than the source of the original material, for
a species that has been widely dispersed in ballast water, mud
adhereing to seed oysters, or attached to a growth on a ship's hull? I
suppose I could ask the question--Who cares about the type locality?
Of what importance is such information?
There are several examples where knowledge of the type locality has
actually become misleading in understanding the origins of species or
species groups. In San Francisco Bay, there are essentially no
endemics; virtually all of the fauna has been introduced in some
manner. There are quite a few examples of invertebrates that have
species epithets of "californiensis" or "franciscanus" that were
introduced into San Francisco Bay from some exotic locality. In some
instances, the origin of such species is still not known. Jim Carlton
has pointed out that the homeland of the isopod, Synidotea laticauda,
originally described from SF Bay, is still unknown. In Tomales Bay,
both of the spionids, Pseudopolydora kempi (Southern) and P.
paucibranchiata (Okuda) were introduced sometime in the late 1960's or
early 1970's via seed spat of the Pacific Oyster imported from Japan.
Seed oysters contain considerable mud packed between shells and when
laid out on tidal flats there is nothing to prevent small worms and
other invertebrates from staking out their own territories. I suspect
that quite few of the nereids, syllids, and other polychaetes common in
Tomales Bay and other estuarine environments of California have
probably been introduced (and are still being introduced) into these
waters. Any species (adults or larvae of same) that is euryhaline
should have some chance of surviving in ballast water shipments as Jim
Carlton has so convincingly demonstrated in his experiements.
So, I ask the question as to what importance is the type locality in
understanding a species, if it has been moved around from place to
place and the actual area of the world where it originated is somewhere
I recall a conversation I once had with a colleague who refused to
accept an identification I had made because the type locality was
somewhere far distant from where the specimens being identified were
collected. When I asked the question as to what the type locality had
to do with the distribution of a species, I was met with a very puzzled
look. The answer was something like, "Why, that is where it is from."
I think you see the point, namely that type localities are only the
places where the animals were first collected, not necessarily where
they are most common or where they originated.
Does anyone out there have any comment on this issue or examples of
species that have obviously been moved around by ships or other means?
89 Water Street
Woods Hole, MA 02543
(jablake at ix.netcom.com)