THE NAUTILUS 119(1): 1-10, 2005
Page 1
Hainiota, a new genus of freshwater mussel
(BivaKia: Unionidae) from the Gulf of Mexico drainages
of the southeastern United States
Ke^^n J. Roe
Delaware Museum of Natural Histon'
4S40 Kenuett Pike
Wilmington. DE 19807 USA
[email protected]
Paul D. Ilarlfiold
U.S. Fi.sli and Wildlile Senice
657S Dogwood X'iew Park\\'ay, Suite A
Jackson, \1S 39213 USA
PauLHartfiekl@fws.(Jov
ABSTRACT
Hdiniotn. a new genus ol freshwater mussel containing lour
species fonnerh' assigned to the genus Lampsilis Rafinesque,
1820, is described. In addition to the genus Lampsilis. mem-
bers of Hamiota had previously been placed in tlie genera Vil-
losa Frierson, 1927, and Lipimia Swainson, 1840. Several char-
acters incluchng the packaging of their lanae in a superconglu-
tinate lure to attract host fishes, placement and shape of the
marsupia. and release ot glochidia through the excinnent si-
phon, support the recognition of these species as a distinct
genus.
INTRODUCTION
Following the discoven-in 198S bv' Robert Butler of the
first superconglutinate lure en.snared on a snag in a trib-
utarv of the Choetavvhatchee River, a number of publi-
cations (e.g., Haag et al., 1995; Hartfield and Butler,
1997; O'Brien and Biim Box, 1999; Blalock-Herod et al.,
2002) have confirmed through direct observation the
supposition that these imifjue lures are produced bv fcjur
species of freshwater mussels endemic to the Gulf of
Mexico drainages of the soutlieastem United States.
Herein, we confirm earlier published suggestions that
diese four species represent a distinct genus of fresh-
w"ater mussels (Fuller and Bereza, 1973; O'Brien and
Brim Bo.x, 1999). The recognition of this genus is based
on sev'eral characters including the production of the su-
perconglutinate lure, and the unique shape and place-
ment of tlie marsupia (the region of the demibranchs
where female unionoid mussels brood developing lar-
vae), and is supported bv molecular evidence (Roe et al.,
2001). Use of marsupial features is consistent with pre-
vious designations of unionid "divisions" initiated by
Simpson (1900a) and continued by Heard and Guckert
(1970). The designation oi Hamiota increases the num-
ber of North .A,merican imionids genera to 50 (Turgeon
et al., 1998).
MATERIALS AND METHODS
A list of specimens examined is included in Appentlix 1.
Acronyms usetl in the text are: Academy of Natural Sci-
ences of Philadelphia (ANSP), Delaware Museum of
Natural Histon-(DMNH), Florida Museum of Natural
History (UF), United States National Museum (USNM),
University of Alabama Unionid Collection (UAUC), and
Mississippi Museum of Natural Science (MMNS). Ab-
breviated svnionvmies are pi'esented for each taxon and
include novel combinations and publications with illus-
tration. Measiu'ements were taken to the nearest 0.05
mm using dial calipers.
SYSTEMATICS
Familv Unionidae Rafinesque, 1820
Tribe Lampsiliiii \(in Ihering, 1901
Hamiota new genus. Type species: Hamiota suhaii'^ulatd (Lea,
1840) bv original designation
Diagnosis: A monophv'letic group of ireshvvatei' bi-
valves (Roe et al., 2001) in which all of tlie glochidia are
released simultaneously encased in mucous packages
that are referred to as superconglutinates (Haag et al.,
1995, fig. 1). The superconglutinate lure exits the mantle
cavity via the excurrent opening and is encased within a
transparent mucous tube (Llartfield and Butler, 1997;
O'Brien and Brim Box, 1999). When acted upon by wa-
ter currents the superconglutinate mimics the move-
ments of a sv\imming fish, and has been shown to elicit
attacks from fislies (Haag and Warren, 1999). The mar-
supium is restricted to the ventral portion of the outer
demibranchs of female mussels (Figiu'e 1). The precise
shape and pigmentation of the marsupia, as well as the
degree of posterior mantle margin development, varies
across species.
Description: Members ol tliis genus are small-to me-
dium-sized freshwater bivalves, and adult valves gener-
ally are between 45-100 mm in length. Shells range
from ovate to elliptical in outline, and are somewhat
Specimen codes extracted from OCR text.
BioStor
