May, 1999 
SCAMIT Newsletter 
Vol. 18, No.l 
apparently what happened to the white abalone 
Haliotis sorenseni in California waters. 
Impacts of both recreational and commercial 
harvest combined with prolonged warm water 
intrusions have lead to virtually a total collapse 
of the white abalone population. Recent census 
has found the species at a perilously low ebb, 
perhaps without the minimal spawn size to 
guarantee any successful reproduction. Davis 
et al (1998) suggest that the situation, while 
dire, is not hopeless. They list a series of steps 
to be taken if the species is not to be driven to 
extinction. Though these all succeed as hoped, 
the return from devastation is a slow process. 
Captive breeding and field release of other 
abalone species, combined with large areal 
closures of both the sport and commercial 
fisheries have yet to yield even one significant 
recovery in a California abalone stock. 
Coan (1999) adds yet another chapter to his 
ongoing series of treatments of bivalve families 
on a regional basis. This time he addresses the 
Sportellidae. A small family, but one with it’s 
share of nomenclatural problems. This is 
probably a preview of one section of the on- 
the-verge-of-completion Bivalves of 
California, a project of Dr. Coan and Paul 
Valentich Scott on a base of work by the late 
Dr. Frank Bernard. The author provides a 
comparison table of distinguishing characters 
for all regional species in the family. While 
none of these small clams are among the 
species we usually take during near-shore 
monitoring efforts, we should be aware of 
them, and this paper is a definite help in a 
fairly obscure corner of the local biota. 
Human transport, the usual agent of 
detrimental NIS movement, is also used for 
establishing non-native food organisms, both 
now and in the past. Man has moved some 
species around so often, that it is very difficult 
to determine their origin, or even what they are 
(as geograhically isolated non-interbreeding 
populations are brought into contact by 
transport, some species boundaries may blur or 
dissolve). Gene pools have been stirred 
vigorously for groups like oysters, by human 
transport and farming worldwide. The advent 
of molecular analyses has now made it feasible 
for researchers to attempt to unravel such 
puzzles, determining what the morphological 
boundaries of the various species are, and 
tracing their history via their DNA. Three 
recent papers (Josefowicz & O’ Foighil 1998, 
O’ Foighil et al 1998, and O’ Foighil et al 
1999) are just such attempts. The first deals 
with the entire “flat oyster” group (subfamily 
Ostraeinae), and provides phylogenetic 
analysis of 41 taxa, including a group of 4 
outgroup species from the related subfamily 
Lophinae. Not surprisingly the results of the 
molecular analysis differ markedly from the 
existing morphology based classification of the 
subfamily, and the authors suggest some 
changes. The other two papers deal with 
specific taxa, and attempt to track down their 
origins and dispersal. 
Use of a negative character, shell loss, is 
examined by Mikkelsen (1998) in both 
‘traditional’ and phylogenetic analyses. Shell 
reduction and loss has occurred several times 
in the gastropod mollusks, and has been used 
as a key character in definition of some groups. 
Reductions in other hard parts such as radula 
and operculum are also considered. The nature 
of, and caveats necessary in use of such 
characters is the subject of the article. The 
author demonstrates, through different 
treatments of three existing data sets, the 
impact of coding choices on the analytic result. 
Once having lost the protective outer shell, or 
reduced and/or internalized it, mollusks must 
find some other protection from predators. 
Many of the shell-less or internally shelled 
gastropods have adopted chemical defenses 
instead, producing poisonous, noxious, or just 
plain distasteful substances from special 
glands. Others have become adept at producing 
copious mucus at a moment’s notice, a truly 
disgusting prospect for many potential 
predators, and quite an effective defense. Still 
others (including cephalopods) opt for stealth 
3 
