MERISTIC AND MORPHOMETRIC VARIATION OF SOME POPULATONS
OF NOTROPIS VOLUCELLUS AND NOTROPIS WICKLIFFI IN THE UPPER
MISSISSIPPI RIVER BASIN

Robert A. Hrabik
Missouri Department of Conservation, Long Term Resource Monitoring Program,
3815 East Jackson Boulevard, Jackson, MO 63755

The taxonomy and systematics of the Notropis volucellus species-group is largely
unresolved and the species-group is probably polyphyletic.  Notropis wickliffi has
only recently been elevated to the species level, but done so subjectively.  The
species occur sympatrically in the Upper Mississippi River and are difficult to
identify and separate because they are phenotypically similar.  When the United
States Congress approved the Water Resources and Development Act of 1986, the
Long Term Resource Monitoring Program (LTRMP) for the Upper Mississippi
River was initiated.  This program established six remote state-operated field
stations on the Upper Mississippi and Illinois Rivers.  The field stations collect
physical and biological data on these rivers, including an ambitious fisheries data
collection program.  LTRMP biologists were having difficulty separating N.
volucellus and N.wickliffi in samples.  The purpose of this study was to provide
LTRMP biologists with taxonomic characters that will aide in a cursory separation
of N. volucellus and N. wickliffi from the Upper Mississippi River.  Specimens
examined in this study included Mississippi River populations, and populations
from tributaries within and outside the Upper Mississippi River basin for
comparison.  The results confirm that N. volucellus is a complex of several forms
and concur with the assessment of other ichthyologists that N. wickliffi is a valid
taxon.  Tributary forms of N. volucellus differed from big river forms meristically
and morphometrically.  Notropis volucellus from the Mississippi River and N.
wickliffi were meristically and morphometrically similar, but can be separated by
pigmentation patterns.  It was suggested that several N. volucellus forms in the
Upper Mississippi River basin be elevated to either subspecies or species levels
and vernacular names for the populations were proposed.  However, because the
forms are closely related and the systematics of the N.volucellus species-group is
unresolved, none of the populations were elevated to a taxonomic rank pending a
genetic evaluation.

Keywords:  taxonomy, Mississippi River, mimic shiner, channel shiner,
distribution, systematics, ecology.


Robert A. Hrabik
phone: 573-243-2659; FAX: 573-243-2897
e-mail: Robert_Hrabik@nbs.gov.
all info may be included on website; prefer platform presentation