A NZ invader of Calif Shelf & Slope

Marine Biology Laboratory mblcsdla at netcom.com
Thu Dec 14 23:32:20 EST 1995



Geoffrey Read wrote:

> However, other NZ marine > fauna have apparently reached West Coast USA
across the Pacific (a nudibranch > was it recently?), and, as Jim
indicates, the shallow water is the area where > intrusions are most
likely. For what it's worth A. verrilli in NZ is a > near-shore species. 
> 

With apologies to the group, I will mention a non-annelid here.  A recent
New Zealand arrival to the California coast (although not the one to which
Geoff referred perhaps) is the cephalaspid gastropod Philine auriformis. 
This guy was first reported in Calif by Gosliner (1995) from San Francisco
Bay where it became established within the past decade. SF Bay is, of
course, the typical setting for such invasions, as Jim Blake suggested. 
However it seems not to have been satisfied with confinement to the Bay
and has appeared on the open coast in southern California within the past
year.  It is now being taken routinely in quarterly sampling (both trawls
and benthic grabs) from the Los Angeles region to as far south as San
Diego in depths from 20 to 305 meters.  On the Palos Verdes Shelf near Los
Angeles several hundred have been taken in a ten minute trawl with a small
otter trawl.  Jim Blake contrasted shelf and slope depth communities to
those of estuaries, citing the former's relative immunity to invasion by
non-native species.  Philine auriformis appears to be an exception to the
general case, although its foothold in a hospitable estuary may have
facilitated its subsequent invasion of the shelf and slope.  Another
possibility is an introduction directly to the southern Californian shelf and
slope.

Dave Montagne
Marine Biology Lab
County Sanitation Districts of LA County
mblcsdla at netcom.com




More information about the Annelida mailing list