The collapse of Mitra: molecular systematics and morphology of the Mitridae (Gastropoda: Neogastropoda)
Author
Fedosov, Alexander
Author
Puillandre, Nicolas
Author
Herrmann, Manfred
Author
Kantor, Yuri
Author
Oliverio, Marco
Author
Dgebuadze, Polina
Author
Modica, Maria Vittoria
Author
Bouchet, Philippe
text
Zoological Journal of the Linnean Society
2018
183
253
337
journal article
0024-4082
5A42EEF-F67A-44B6-8E02-5D18206EF104
GENUS
SWAINSONIA
H.
ADAMS
& A.
ADAMS
, 1853
(
FIGS
28B, C
,
29G–I
)
Type
species
:
Mitra fissurata
Lamarck, 1811
; by typification of replaced name (
Mitrella
Swainson, 1831
non-
Risso, 1826
).
Synonym
:
Mitrella
Swainson, 1831
(not
Risso, 1826
).
Type
species
:
Mitra fissurata
Lamarck, 1811
; SD,
Cossmann (1899: 152)
.
Figure 29.
Genera
Scabricola
and
Swainsonia
. A,
Scabricola variegata
, MNHN
IM-2013-40683, Philippines, off NocNocan Is., 10°15.1′N, 124°25.1′E, 4–12 m, 45.5 mm. B,
Scabricola desetangsii
, MNHN
IM-2013-50703, Papua New Guinea, KAVIENG 2014 Stn KR14, 02°42.3′S 150°39.1′E, 7–10 m, 24.6 mm. C,
Scabricola olivaeformis
, MNHN
IM-2013-18062, PAPUA
NIUGINI Stn PR
214, 05°10.2′S, 145°50.4′E, 1–8 m, 13 mm. D,
Scabricola coriacea
, syntype, NHMUK 1967728, Corrigidor I., Philippines, 11.1 mm. E,
Scabricola albina
, holotype, NHMUK 1966663, Batangas, Luzon I., Philippines, 26.7 mm. F,
Scabricola potensis
, lectotype, MNHN IM-2000-30283, New Caledonia, Belep Is., 24.5 mm. G,
Swainsonia fissurata
, Israel, off Eilat, 2–4 m, 63.1 mm. H,
Swainsonia fusca
, MNHN
IM-2013-40643, Mozambique, INHACA 2011 Stn MS08, 25°59.5′S, 32°52.9′E, 9–17 m, 18.2 mm. I,
Swainsonia casta
, MNHN
IM-2013-48000, Papua New Guinea, KAVIENG 2014 Stn KS17, 02°36.2′S, 150°46.3′E, 3 m, 30.5 mm.
Diagnosis
: Shell small to medium sized (
15–65 mm
), fusiform or elongate-biconical, weakly sculptured and often polished in appearance. Protoconch narrowly conical, of about three smooth, weakly convex, whorls. Spire ortho- or cyrtoconoid, spire whorls evenly convex to flattened; suture distinct, impressed. Sculpture of regular, shallow and widely spaced punctate spiral grooves, either covering the entire shell surface, or limited to the adapical whorl portion, or lacking entirely. Axial sculpture usually not developed or, when present, consisting of numerous, fine and low, rounded folds, developed on the spire but indistinct on the periphery of the last adult whorl. Shell base typically with convex outline, continuing into short and stout, deeply notched, siphonal canal. Siphonal fasciole indistinct or moderately developed. Aperture elongate, narrow to moderately wide. Outer aperture lip straight or gently evenly convex adapically; anterior edge of outer lip strongly convex, sometimes slightly drawn abapically. Inner lip with four to five fine or strong, subequal columellar folds. Shell light brown, orange or white, typically with intricate scalelike pattern of fine light or white lines.
Scabricola
-
type
radula with comb-like rachidian bearing six long, slen- der cusps, the four central ones notably exceeding the two marginal ones (
Fig. 28B, C
). Lateral teeth with very strong, robust cusp, giving tooth the appearance of a tin-opener, the serrate inner surface of tooth bearing three to four weaker cusps. Base of laterals with curved upper margin, forming a socket interlocking laterals of adjacent rows.
Distribution
: Indo-Pacific, upper subtidal depths, on sand.
Species included
:
Swainsonia biconica
Bozzetti
,
20113
,
S. casta
(Gmelin, 1791)
1
,
S. ekerae
Cernohorsky
,
19733
,
S. fissurata
(Lamarck, 1811)
2
,
S. fusca
(Swainson, 1824)
1
,
S. limata
(Reeve, 1845)
3
,
S. newcombii
(Pease, 1869)
3
,
S. ocellata
(
Swainson, 1831
)
3
.
Remarks
: Many contemporary authors have treated
Swainsonia
as a subgenus of
Scabricola
(
Cernohorsky, 1970
,
1991
;
Pechar, Prior & Parkinson, 1980
; but see
Poppe & Tagaro, 2008
), but our results indicate that it should be elevated to full genus. This treatment of
Scabricola
and
Swainsonia
, however, contradicts the phylogenetic hypothesis implied by radular morphology. The typical
Scabricola
radula (as described by
Cernohorsky, 1970
) is present in
Scabricola variegata
,
Swainsonia fusca
and
Swainsonia casta
, while the radulae of
Scabricola desetangsii
and
S. olivaeformis
show a divergent morphology.