February, 2000 
SCAMIT Newsletter 
Vol. 18, No.10 
Metacaprella kennerlyi can be exceedingly 
abundant in some parts of Puget Sound, 
southeastern Alaska, and Prince William 
Sound. 
None of the sponge inhabiting barnacles are 
currently included on the SCAMIT listing, 
although at least one ( Membranobalanus 
orcutti ) is taken in the area. They are just not 
among the animals normally taken in a 
nearshore monitoring program. Still, it is nice 
to be aware of them and to have a little 
understanding of their biology and taxonomy. 
Van Syoc & Winther (1999) cover the group, 
naming a new species of Acasta, and providing 
a key to the known species from both the east 
and west coasts of the Americas. Since they list 
Spheciospongia confoederata among the hosts 
for our local species we should keep our eyes 
open for Membranobalanus orcutti in our 
sampling. 
Gnathiid isopods have complex life cycles and 
we see them in a number of different forms. 
Usually it is only the form of the adult male 
which is documented in the literature. Smit et 
al (1999) redescribe the adult male, but also 
describe the praniza larva of G. africana in 
some detail and discuss the development of 
species in the genus. They use a stage name 
unfamiliar to me (zuphea) to refer to juveniles 
which have passed the unsegmented praniza 
stage, but are still immature. Their thorough 
examination of these two stages of this species 
might prove a useful model for those of us 
evaluating local Gnathia and Caecognathia 
species to better speciate juveniles and females 
of species which co-occur. 
For years west coast chiton workers have dealt 
with a series of forms, usually ascribed as 
varieties within one variable species, Tonicella 
lineata. Clark (1999) has further examined the 
situation and concluded that there are actually a 
complex of sibling species, two of which are 
described as new in the paper. Four species are 
included in the T. lineata species complex, and 
all have overlapping distribution with one or 
more congener(s). Of the group, only T. lineata 
is not considered to occur within the southern 
California bight by Clark. Most of the records 
of ‘T. lineata’ from our area are probably his T. 
venusta, which can be easily separated from 
the other three siblings by presence of pleural 
flammulations (girdle barring) of lighter color 
within a dark girdle base color. The species 
also differ in scales, valve ornament, and 
radular characters. The author provides a useful 
summary character table, but does not 
construct a key to separate the species. 
Speciation in the huge gastropod genus Conus 
provides a much more complex problem, and 
one which requires very careful attention to 
detail in character definition. The structure of 
the radula is highly complex in these species; 
modified as a venom delivery system for 
hunting worms, mollusks, and fish. Kohn et al 
(1999) attempt to put the radular house in order 
with a careful analysis and development of 
character states from radular teeth. The 
complexity of the system has usually led past 
workers to ignore it as a source of characters, 
concentrating instead on the shell. Among the 
species included in their analysis is C. 
californicus , our only local representative of 
the genus. 
While the rapid radiation of the genus Conus 
since the Eocene has proven fascinating, older 
and higher level events are equally compelling. 
The origin of the specialized gastropod fauna 
now known to inhabit hydrothermal vent areas 
and mid-ocean spreading centers is one such 
example. The relative age of origin of these 
animals was investigated by McArthur & Koop 
(1999) using 28S rDNA sequence data As is 
often the case when technologies are new and 
first cuts must be made, the results were not 
definitive. Nevertheless they were quite 
interesting and this was far from a wasted 
effort. Monophyly of the Neritopsina, 
Vetigastropoda, Neomphalina, 
Caenogastropoda, and Heterobranchia was 
supported, although Kishino & Hasegawa 
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