Systematics of a widely distributed western North American springsnail, Pyrgulopsis micrococcus (Caenogastropoda, Hydrobiidae), with descriptions of three new congeners
Author
Hershler, Robert
Author
Liu, Hsiu-Ping
Author
Bradford, Corbin
text
ZooKeys
2013
330
27
52
http://dx.doi.org/10.3897/zookeys.330.5852
journal article
http://dx.doi.org/10.3897/zookeys.330.5852
1313-2970-330-27
Pyrgulopsis turbatrix Hershler, 1998
Figs 4
I-L
, 9
Pyrgulopsis turbatrix
Hershler, 1998: 50, figs. 6K, 18
G-J
, 30
D-F
(Horseshutem Springs, Pahrump Valley, Nye County, Nevada).
Pyrgulopsis micrococcus
. -
Hershler 1989
(in part).
Pyrgulopsis micrococcus
. -
Hershler and Pratt 1990
(in part).
Pyrgulopsis micrococcus
clade D. -
Liu et al. (2003)
.
Types.
Holotype, USNM 883978; paratypes, USNM 860699 (from same lot).
Other material examined.
CALIFORNIA.
Inyo
County: USNM 853508, USNM 883373, Hanaupah Spring, Hanaupah Canyon, Death Valley (
36.18684°N
,
117.02537°W
), USNM 853512, spring above Darwin Falls, Panamint Valley (
36.31783°N
,
115.52700°W
), USNM 857969, stream below Darwin Falls, Panamint Valley (
36.32033°N
,
117.51917°W
), USNM 857968, Saline Marsh, Saline Valley (
36.69350°N
,
117.83033°W
). San Bernardino County: SBMNH uncat., roadside spring between north shore highway and Big Bear Lake at point 1.2 km east of road which crosses lake, Southern California coastal drainage (
34.26424°N
,
116.87497°W
), USNM 860450, spring southwest of Big Bear Ranger Station, southern California coastal drainage (
34.26281°N
,
116.90185°W
). NEVADA. Clark County: USNM 883551, Willow Spring, Indian Springs Valley (
36.41700°N
,
115.76419°W
), USNM 883981, La Madre Spring, Las Vegas Valley (
36.18381°N
,
115.50638°W
), USNM 1002785, Harris Spring, Las Vegas Valley (
36.24071°N
,
115.54351°W
). Nye County: USNM 854967, Wood Canyon Spring, Pahrump Valley (
36.39924°N
,
115.93258°W
).
Revised diagnosis.
A medium-sized congener (maximum shell height, 3.7 mm) having an ovate to narrow-conic shell. Differentiated from similar regional species by the combination of its relatively large, narrow shell; elongate penial filament; and small size of the terminal gland on penis.
Description.
Shell (Fig. 9
A-D
) ovate to narrow conic, rarely broadly conic, whorls 4.25-5.25. Teleoconch whorls strongly convex, shouldered. Aperture ovate, parietal lip complete, usually slightly disjunct, last 0.25 whorl sometimes loosened behind body whorl, umbilicus narrow. Outer lip thin, prosocline.
Figure 9. Shells, opercula and radula,
Pyrgulopsis turbatrix
. A Paratype, USNM 860699.
B-D
Shells, SBMNH uncat., USNM 853508, USNM 853510 E, F Opercula (outer, inner sides), USNM 860699 G Portion of radular ribbon, USNM 860699 H Central teeth, USNM 860699 I Lateral and outer marginal teeth, USNM 860699. Scale bars
A-D
1.0 mm; E, F 250
µm
; G 20
µm
; H, I 10
µm
.
Operculum (Fig. 9
E-F
) as for genus; edges of last 0.5 whorl frilled on outer side; muscle attachment margins slightly thickened on inner side. Radula (Fig. 9
G-I
) as for genus; dorsal edge of central teeth moderately to highly concave, lateral cusps
three-seven
, basal cusps
one-two
. Lateral teeth having
two-six
cusps on inner sides and
three-six
cusps on outer sides. Inner marginal teeth with 14-31 cusps, outer marginal teeth with 15-33 cusps. Radula data are from USNM 857968, USNM 860450, USNM 860699, USNM 883373.
Penis (Fig. 4
I-L
) medium-sized; filament long, narrow, tapering, oblique; lobe medium-sized, tapering, slightly oblique; ventral surface of lobe having a small (terminal) gland (199/200 specimens) and rarely one or two additional glandular dots (3 specimens), dorsal surface sometimes having a small (penial) gland at base of filament (24/200 specimens) and rarely having an additional glandular dot (one specimen). Penial data are from USNM 854967, USNM 857969, USNM 860450, USNM 860699, USNM 883373, USNM 883981, USNM 1002785.
Distribution.
Spring Mountains region (Frenchman Flat; Indian Springs, Las Vegas, Pahrump Valleys [
Pyrgulopsis turbatrix
]), San Bernardino Mountains (Mojave, Southern California Coastal drainages [M19, M20, M21]), central Death Valley region (Amargosa River drainage, Panamint and Saline Valleys [M9-M22, M24, M27, M28]). The populations from the latter two areas were previously assigned to
Pyrgulopsis micrococcus
.
Remarks.
The penial gland was not observed in>25% of the males in any of the seven samples that we studied and consequently has been removed from the diagnosis. The three geographically separated subunits of
Pyrgulopsis turbatrix
are somewhat diverged genetically-e.g., mean sequence divergence is 0.9+/-0.2% (ranging from 1.1-1.5%) for COI and 0.9+/-0.2% (ranging from 1.1-1.3%) for NDI, but we have not found any consistent morphological differences among them.