IUBio Biosequences .. Software .. Molbio soft .. Network News .. FTP

Re, type localities and distributions of species

JAMES BLAKE jablake at ix.netcom.com
Tue Dec 5 00:08:23 EST 1995


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 
quite different?  

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?  



Jim Blake
ENSR
89 Water Street
Woods Hole, MA 02543
(jablake at ix.netcom.com)





More information about the Annelida mailing list

Send comments to us at biosci-help [At] net.bio.net