Several subjects staffs – A Brazilian opinion

     I have read with interest several topics discussed in the Conch-L and
perhaps I can contribute with some thoughts.

    Subspecies:
     The point of view of Mayr was already resumed in the Conch-L, and it is
followed or at least respected by most malacologists. The subspecies in
biological terms are geographically separated morpho-types. However in
practical Malacology, subspecies means “different, but not enough”. It is
common to see citations of subspecies occurring in same place, which is not
very consistent.
     Who decides?
     All taxonomical levels are obviously defined by the researchers,
however the animals should decide . The animals don’t care about our concept
about them, they live, reproduce, eat and die without our permission. A true
taxon should encompass an actual biological unity, a real phenomenon, this
is the concern of the biologists. However the animals don’t tell us with
words, we must  extract information from several ways, such as morphology,
ecology, biology, etc.
     In my current work in malacology I don’t use subspecies, because, with
rare exceptions (e.g., Liguus), there is lack of biological base. I usually
consider as full species (e.g., the Cypraea spurca group – C. spurca, C.
acicularis), or synonyms (e.g., Strombus pugilis forms). All of these
decisions were based on studies of the internal morphology.

     Forms and varieties:
     Human beings name everything, buildings, mountains, and even
hurricanes, obviously we would not resist naming the several forms of a
species, as, e.g., the several colors of the Chlamys nobilis. Forms and
varieties have no taxonomical value, but do have value in being at least
pointed out, not only for dealers, which surely will find clients wanting
all different variety of a given species, as well as for biologists. A
practical example is the Terebra brasiliensis, Bratcher in her revisionary
work indicated 2 conchological “varieties” for this species: smooth and
furrowed. I studied the 2 forms and detected that there are several
anatomical differences between both, such as lack of radula, proboscis and
venom apparatus in one, fully present in other. I recently described the
furrowed form as Terebra spirosulcata (Simone, 1999).

    Campanile symbolicum:
     This species present several distinctive features, in morphology, sperm
ultrastructure, and DNA, surely it does, which have been used for separated
it from any other group. I have recently performed a phylogeny of 19 species
of 12 families of Cerithioidea, with Campanile as one of the outgroups.  To
my surprise, the single obtained tree presents Campanile inside of the
ingroup, i.e., as a true cerithioidean, closely related to the Turritellidae
and Vermetidae. The quantity of exclusive characters (autapomorpies) of
Campanile doesn’t approach it to other non-cerithioidean groups, on the
other hand it shares several Cerithioidean characters (synapomorphies). The
large quantity of differences of an organism doesn’t necessarily indicate
that they must be an isolated taxon, especially if there are basic
characters in common with other group.

    Synonymies:
     I have realized that there is a concept that when a species is
synonymyzed is an error by the author who described that species. This is
not entirely true. Sometimes we are studding a sample of a population that
in the present knowledge it is impossible to identify securely, generally
due to taxonomical confusion of the group or due to own characters of the
population that differs it from the others. In these cases it is better to
describe as a separated species than to name it arbitrarily as a known
species, without being certain about its identity . In Science it is better
(or not so bad) to call something equal as different than something
different as equal. The taxonomical resolution is also simpler in former
case.

     Morphological versus Molecular data:
     The organisms are a whole, and not parts. The most complete our
analysis the closer we arrive in the “truth”. However it is impossible to
analyze “the whole” of a given organism,  not even in human beings. So, we
must study parts. There is a truism that molecular data (e.g., DNA) is
better and more reliable than morphological ones. I think this is not true,
except if the morphological analysis was a restrict one (such as simply the
shell) structure. Holistic morphological analysis is as reliable than
molecular one.
     Molecular and morphological analyzers are not enemies, on the contrary,
they should be complementary. The danger is to drop the morphological
studies in present low level of knowledge. Morphology is the first step in
the biological study, and in molluscs is very far from an acceptable level.
     It is possible to analyze the whole morphology of an organism, however
this is difficult in molecular terms. Only samples of DNA, for example, are
analyzed, and sometimes there is no way to be sure about the value of the
analyzed portion, it could be only genetic garbage, resulted of a process
without selective pressure.
     The given example: dog disparity forms, is not good. If we
phylogenetically analyze the Carnivora, or even the Canidae, in
morphological terms, surely the Canis familiaris samples will result in a
single branch (perhaps mixed with Canis lupus). It is not intuitive to
imagine the domestic dog races sprayed all over the tree, among the
different branches of the carnivora.

    Cymatium pileare-aquatile-martinianum:
     I will study the Tonnoideans very soon. The complex C. pileare was not
analyzed in detailed morpholology and interesting differences in color and
habitat were pointed out in Conch-L messages. I am at your disposal to
analyze the problem if preserved material could send to me. I collected
supposed C. pileare from Brazilian coast, and additional material would be
useful.

     Thank you all
     Luiz
____________________________________
Luiz Ricardo L. Simone, M. Sc.
Graduate Student
Museu de Zoologia da Universidade de São Paulo
Cx. Postal 42694
04299-970 São Paulo, SP, Brazil