World Congress of Malacology Antwerp ... - Unitas Malacologica

A recent review of the biogeography of the Sacoglossa yielded 36 species that had been described
before 1900 plus 13 species described between 1901 and 1950 and never collected since the original
description. If names were only used by taxonomists, the easy thing would be to ignore these species
names until something turned up that would once and for all establish their identity with the selection
of neotypes. However, species names are also used for conservation and environmental monitoring. If
taxonomists decide to leave out these uncertain species names, are we then manipulating the data?
Are we also trying to manipulate the conservationists and decision makers? If the names are included
in species lists, may a certain place then become a species diversity hotspot? A center of endemism?
When it may just be the victim of a long deceased, incompetent taxonomist. These questions will be
discussed using sacoglossan examples.
Examining changes in morphological disparity along a latitudinal gradient in the
Neogastropoda
Johnson, Nicholas A.
Committee on Evolutionary Biology, University of Chicago, Chicago, IL 60637, USA,
Email: naj@uchicago.edu
The morphological disparity (examination of the distribution of morphology) of Neogastropod
radulae was investigated across regional assemblages in the western North Atlantic. This is a
preliminary analysis with radulae scored for over 60 species. Regional species assemblages were
compiled from published collection lists for the Bay of Fundy (16/24 species), Long Island (14/19
species), Delaware (13/18 species), North Carolina (30/110 species), and northern Florida (43/139
species). (Numbers in parentheses are the number of species occurring in that locality included in the
analysis out of the total number of species recorded at that locality). The radula of each included
species was scored for 47 characters. These include a mix of binary, meristic, multi-state, and
quantitative characters. The entire resulting dataset was ordinated using principle coordinate analysis,
and then grouped by locality. The differences in volume, centroid, and nearest-neighbor distance
between localities were quantified, and the analysis was performed using morphological rarefaction
to control for differences introduced purely because of differences in species number. Average
nearest-neighbor distance between species in the morphospace is uncorrelated with latitude, while
volume decreases significantly with increasing latitude. There is also a marked shift in the
morphospace centroid caused primarily by the loss of the Marginellidae from northern species lists.
Instances of apparent “displacement” of one family by another in the morphospace will also be
discussed.
Development of an initial conservation assessment for North American freshwater gastropods
Johnson, Paul D. 1 ; Bogan, Arthur E. 2 ; Strong Ellen E. 3 ; Brown, Kenneth M. 4 ; Corderio, Jay E. 5
1. Alabama Aquatic Biodiversity Center, Rout 3, Box 86, Marion, AL 36756 USA,
Email: paul.johnson@dcnr.alabama.gov
2. North Carolina Museum of Natural Sciences, 11 West Jones Street, Raleigh, NC 27601 USA,
Email: Arthur.Bogan@ncmail.net
3. Smithsonian Institution, National Museum of Natural History, Department of Invertebrate
Zoology, P.O. Box 37012, MRC 163, Washington DC 20013-7012 USA,
Email: StrongE@si.edu
4. Louisiana State University, Department of Biological Sciences, Baton Rouge, LA 70803 USA,
5. NatureServe, 11 Avenue de Lafayette, 5th Floor, Boston, MA 02111 USA,
Email: kmbrown@lsu.edu; jay_cordeiro@natureserve.org
In 1993 the American Fisheries Society (AFS) published a general conservation assessment of
freshwater mussels of North America authored by J.D. Williams et al. This mussel assessment was
followed by similar assessments for crayfishes and southeastern fishes. The AFS has granted
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