Undercover speciation of wentletraps (Caenogastropoda: Epitoniidae) in the Southwestern Atlantic
Author
Zelaya, Diego G.
Author
Güller, Marina
text
Zootaxa
2017
4286
1
41
69
journal article
32762
10.11646/zootaxa.4286.1.2
dddc215c-61ae-484e-bc8e-1314354620b2
1175-5326
828294
3B62E1C2-79C6-4A14-9F6D-80D8872118FA
Epitonium striatellum
(
Nyst, 1871
)
(
Figure 5
)
Scalaria tenuistriata
d’Orbigny, 1839: 390
, pl. 54, figs. 4–6
Scala striatella
Nyst, 1871
: 134
–135 (
nomen novum
pro
Scalaria tenuistriata
d’Orbigny, 1839
non
Bronn, 1831)
Epitonium (Asperiscala) tenuistriatum
:
Clench & Turner, 1952
: 299
–300, pl. 138;
Rios, 1994
: 98
, pl. 32, fig. 397
Epitonium tenuistriatum
:
Castellanos, 1970
: 63
, pl. 4, fig. 8;
Scarabino, 1977
: 183
, pl. 2, fig. 9
Type
locality.
Bahía Blanca [
38°42’S
62°10’W
,
Buenos
Aires Province
,
Argentina
].
Type material.
Lectotype (NHMUK 1854.12.4.359/1) and one paralectotype (NHMUK 1854.12.4.359/2) [not examined].
Material
examined.
Uruguay
:
Rocha
: [
33°54’00’’S
53°31’00’’W
],
La Coronilla
(MACN-In 19214: 2 sh.); [
34°23’S
53°47’W
],
Cabo Polonio
(
USNM
359204
: 1 sh); [
34°39’0’’S
54°10’0’’W
],
La Paloma
(MACN-In 29687: 13 sh.; MACN-In 28767: 3 sh.); [
34°39’36’’S
54°09’21’’W
],
Cabo Santa María
,
Rocha
(MACN-In 15305: 1 sh.)
.
Argentina
:
Buenos
Aires Province
:
38°25’18.50’’S
56°30’37.07’’W
, off Mar del Plata (MACN-In 10740: 1 sh.; MACN-In 11995: 1 sh.); [
38°53’13’’S
62°05’52’’W
], Base Naval Puerto Belgrano, Punta Alta (MACN-In 6620- 23: 1 sh.; MACN-In 11211: 2 sh.); [
39°42’S
62°07’W
], mouth of Río
Colorado
(MLP-Ma 1375: 9 sh.)
;
40°18’29.79’’S
62°14’15.66’’W
,
Bahía
San Blas (MACN-In 20266: 2 sh.)
.
Río
Negro
Province
: [
41°00’S
64°07’W
], Aguada de los Loros, San Antonio Este (MACN-In 13339-1: 3 sh.; MACN-In 13340: + 100 sh.); [
40°49’S
64°54’W
],
Punta Villarino
,
San Antonio Este
(MACN-In 13365: 3 sh.)
; 40°29’35.2’’S 65°31’44.7’’W, Las Grutas,
6 m
(MACN-In 40376: 1 sh.); 40°45’18.7’’S 64°56’31.8’’W, La Mar Grande, intertidal (MACN-In 40377: 8 sh.); 40°54’00.0’’S 65°06’43.1’’W,
6 m
(MACN-In 40378: 1 sh.); 40°54’08.3’’S 65°06’28.0’’W,
9 m
(MACN-In 40379: 1 sh.).
Known
distribution.
Rio de Janeiro
(
22°54’S
),
Brazil
(
Rios 1994
) to Golfo San Matías (
40°54’S
)
,
Río
Negro
Province
,
Argentina
.
Bathymetric
range of living specimens unknown; shells found from the intertidal to
9 m
.
Description.
Shell large (maximum L observed =
23.9 mm
, apex missing; to
28.5 mm
according to
Clench & Turner (1952))
, elongate, thin, white, translucent (
Fig. 5
A–C, E, F). Protoconch and first whorls of teleoconch very eroded in all available specimens (
Fig. 5
D). Teleoconch with up to 8 whorls, slightly convex in outline; suture deep, partially covered by axial sculpture (
Fig. 5
A–C, E, F, H); last whorl evenly curved at the base. Aperture ovate; peristome with a small basal expansion. Outer margin slightly thickened. Fasciole small. Umbilicus absent (
Fig. 5
A–C, E, F).
Teleoconch densely sculptured with axial and spiral elements, which form a cancellate pattern (
Fig. 5
A–C, E, F, H, I). Axial ribs prosocline, extremely low, recurved, giving the appearance of thin, rounded cords, formed by fusion of several layers, obliquely aligned between adjoining whorls (
Fig. 5
G–I). Number of ribs increasing in successive whorls: from
36–40 in
the first whorl to
52–58 in
the last whorl of larger studied specimens. Ribs evenly curved along the whorl, well-entering into the suture, fused at their bases with the ribs of adjacent whorl (
Fig. 5
H); ribs on the last whorl extending to the umbilical area. Interspaces between ribs with numerous, thick spiral threads, as wide as axial elements in the first whorl, slightly narrower than axial sculpture in subsequent whorls (
Fig. 5
H, I). Among spiral elements it is possible to recognize primary and secondary threads, which produce rectangular interspaces in their intersection with axial sculpture (
Fig. 5
H, I). Spiral sculpture not crossing over axial sculpture.
Operculum, jaw and radula: Unknown.
Remarks.
Although
Nyst (1871)
noted the homonymy of
Scalaria tenuistriata
d’Orbigny, 1839
and
Scalaria tenuistriata
Bronn, 1831
, and proposed
Epitonium striatellum
(formerly under
Scala
) as a replacement name for the first, subsequent literature (e.g.,
Clench & Turner 1952
;
Castellanos 1970
;
Scarabino 1977
;
Rios 1994
) retained the usage of d’Orbigny’s name.
Lima
et al.
(2012)
provided a list of the
Epitonium
species present in the Atlantic coast of South America. In their list, the authors omitted both
E. tenuistriatum
and
E. striatellum
, but listed
Epitonium striatissimum
(Monterosato, 1878)
as being present in Argentine waters. That species is distributed in the Mediterranean, Madeira, and SE United States, from North Carolina to Florida (
Bouchet & Warén 1986
), with no documented records in Patagonia thus far known.