Taxonomical Study On A Sample Of Pulmonates From Santa Maria Da Vitória, Bahia, Brazil, With Description Of A New Genus And Four New Species (Mollusca: Orthalicidae And Megalobulimidae) L R L. S Abstract
Author
Simone, Ollusca Rthalicidae And Egalobulimidae Luiz Ricardo L.
text
Papéis Avulsos de Zoologia
2012
2012-12-20
52
36
431
439
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0031-10492012021600001&lng=en&tlng=en
journal article
10.1590/S0031-10492012021600001
1807-0205
EEA7C3F0-0F45-47E0-9C04-D14DA23BA6F4
Spixia coltrorum
new species
(
Figs. 9-14
)
Types:
Holotype
MZSP 103920
.
Paratypes
:
MZSP 103922
,
2
shells
;
MZSP 103921
,
1
shell
,
USNM
, 1 shell;
MNRJ
, 1 shell;
MZSP 103923
,
8
shells; all from type locality
.
Type locality:
BRAZIL
.
Bahia
;
Santa Maria da Vitória
, ~
13°24’S
,
44°12’W
, ~
460 m
of elevation (
Coltro
col.,
i/2012
)
.
Diagnosis:
Shell with superior half clearly narrower than inferior half, in a non-uniform growth. Sculpture of delicate, uniform axial riblets, opaque surface.
Peristome partially projected, with 4 teeth of somewhat same size and equidistant.
Description:
Shell up to
45 mm
; outline somewhat turriform, elongated; width ~36% of length (
Figs. 9-11
). Color white, with scanty axial pale brown spots randomly distributed in last whorls. Protoconch of 2 rounded whorls, sculptured by delicate reticulate of spiral and axial lyre; each cord very narrow and low, separated from each other by distance equivalent to 3-times its width; both spiral and axial cords predominating or a weak predominance of axial cords (
Fig. 13
); limit with teleoconch unclear; mostly eroded and absent amongst specimens (
Fig. 11
). Teleoconch of more than 8 whorls; whorls profile almost straight, weakly convex; suture weakly deep. Sculpture a series of delicate and uniform axial riblets, ~
110 in
penultimate whorl. Superior half of spire clearly narrower than inferior half, marked by a somewhat abrupt increase, whorls not uniformly growing (
Figs. 9-10
). Last whorl uniform with preceding whorls, marked by pair of grooves 1/6 whorl preceding peristome, corresponding to teeth of outer lip; anterior most groove weakly deeper than posterior groove (
Fig. 12
). Peristome oval, deflected, with ~32% of shell length and ~73% of shell width; weakly prosogyre (
Fig. 10
). Outer lip arched, with short straight middle region; inner lip strongly concave, superior half weakly convex, covered by thin callus with similar width than remaining peristome. Peristome with 4 teeth of somewhat similar size and equidistant from each other (
Figs. 9, 11
); parietal tooth located approximately at middle region of callus; palatal tooth located just anterior to middle inflexure of inner lip, this tooth largest; two teeth in outer lip, one located in its middle level, another located slightly at right from anterior corner, this tooth being smallest. Umbilicus opened, narrow, partially covered by inferior half of inner lip, flanked by blunt oblique fold running parallel to furrow of anterior peristome tooth (
Figs. 12, 14
).
Measurements (in mm):
Holotype
: 40.0 by 16.0;
Paratype
MZSP
103921: 40.6 by 16.2.
Distribution:
Known only for
type
locality.
Habitat:
Caatinga environment.
Material examined:
Types
.
Etymology:
The specific epithet is in honor of the Coltro brothers, José and Marcus, who contribute greatly with study material, including the present one.
FIGURES 1‑14:
Shell of types:
1-8)
Kora corallina
new species
;
1)
Holotype, apertural view (H 43.4 mm);
2)
Same, right view;
3)
Same, dorsal view;
4)
Same, detail of sculpture of penultimate whorl;
5)
Same, detail of apical region, frontal-slightly apical view;
6)
Same, detail of umbilicus, anterior-slightly left view;
7)
Paratype MZSP 103911, frontal view (H 42.9 mm);
8)
Paratype MZSP 103912, frontal view (H 48.9 mm);
9-14)
Spixia coltrorum
new species
;
9)
Holotype, apertural view (H 40.0 mm);
10)
Same, right view;
11)
Paratype MZSP 103921, frontal view (H 40.6 mm);
12)
Same, anterior view;
13)
Holotype, detail of apical region in profile;
14)
Paratype MZSP 103921, detail of umbilicus, anterior-slightly left view.
Discussion:
The genus
Spixia
so far comprised four species (
Simone, 2006:172
), all of relatively large size, and with entire, rounded peristome, possessing 4 well-developed teeth, which characterizes the genus. From the species, the most similar is
Spixia striata
(Spix, 1827)
, from which
S. coltrorum
differs by wider umbilicus, opaque surface, more acuminate spire, and by proportionally larger aperture. A single species was never figured,
S. hillairii
(Gray in
Pfeiffer, 1845
), but according to the description,
S. coltrorum
differs by the white peristome (
S. hillairii
has it pink), in having more teleoconch whorls (
S. hillairii
has 6.5 whorls), and in lacking so developed sculpture (
Pfeiffer, 1845:84
).
S. coltrorum
differs from
S. charpentieri
Pfeiffer,
1850 in
being larger, in having sharper pointed aspire, narrower protoconch, and in lacking fifth tooth in outer lip.
S. coltrorum
still differs from
S. paraguayana
(Ancey, 1892)
by less developed peristome, by paler color, and by less developed axial sculpture.
The interesting axial brown spots somewhat randomly disposed in the spire (
Figs. 9-11
) is a current feature amongst the odontostomines, and well developed in
S. coltrorum
.
One of the main features of the species, the different growth between superior and inferior halves of the spire, is very clear in
holotype
(
Figs. 9-10
), while it is not so clear in other species (
Fig. 11
). Other interesting finding is the loss of the protoconch in most specimens (
Fig. 11
). From the examined ones, only 3 of them possess preserved protoconch. The structure is fractured in the remaining specimens, with a calcified scar.