Living Scallops of Australia and Adjacent Waters (Mollusca: Bivalvia: Pectinoidea: Propeamussiidae, Cyclochlamydidae and Pectinidae)
Author
Dijkstra, Henk H.
Author
Beu, Alan G.
text
Records of the Australian Museum
2018
Rec. Aust. Mus.
2018-05-23
70
2
113
330
http://dx.doi.org/10.3853/j.2201-4349.70.2018.1670
journal article
10.3853/j.2201-4349.70.2018.1670
2201-4349
5299017
8084C
Parvamussium scitulum
(E. A.
Smith
, 1885
)
Figs 9, 10A–D,F
Amussium scitulum
Smith
, 1885: 312
, pl. 23, figs 4–4b.
Amusium (Propeamusium)
[sic]
scitulum
var.?
cmadoritinctum
Kuroda, 1931: 77
, figs 81–82.
Ctenamusium (Ctenamusium) cmadoritinctum
(Kuroda)
.–
Oyama, 1951: 80
, pl. 13, figs 3–4.
Ctenammssium
[sic]
cmadoritinctum
(Kuroda)
.–Habe, 1964b: 173, pl. 53, fig. 4.
Ctenamussium
[sic]
scitulum
(
Smith
)
.–
Koyama
et al
., 1981: 63
.
Propeamussium cmadoritinctum
(Kuroda)
.–Hayami, 1988a: 479, figs 2–1, 2.
Propeamussium (Parvamussium) scitulum
(
Smith
)
.–Dijkstra, 1990a: 3.
Parvamussium scitulum
(
Smith
)
.–Dijkstra, 1991: 16, figs 35–43; Dijkstra, 1995b: 31, figs 43–46, 153–154; Dijkstra, 1998a: 14, pl. 1, figs 3–6; Lamprell & Whitehead, 1992: [16], 179; Dijkstra & Kastoro, 1997: 261, figs 75–78; Hayami, 2000: 913, pl. 454, fig. 7; Dijkstra, 2001: 86; Dijkstra & Maestrati, 2008: 94; Xu & Zhang, 2008: 78, fig. 217; Dijkstra & Maestrati, 2010: 339; Huber, 2010: 224; Dijkstra, 2011: 42, pl. 1016, figs 5–8b; Dijkstra, 2013: 21, pl. 3, figs 2a–d, pl. 4, fig. 10; Dijkstra & Janssen, 2013: 192, figs 40–42; Dijkstra & Maestrati, 2013b: 474; Dijkstra & Maestrati, 2015: 605, figs 4A–C.
Comments on synonymy
.
Kuroda (1931: 77)
described a possible new variation of the present species from
Japan
,
Amusium scitulum
var.
cmadoritinctum
, which is more colourful and much larger in size than the
type
material of
Parvamussium scitulum
.
Smith (1885: 312)
suggested that the
type
specimens from New
Guinea
are possibly juveniles. The present specimens are indeed larger than the
type
material and the colour is highly variable, so we agree with
Kuroda (1931)
that the larger, coloured specimens are part of the variation of
P. scitulum
.
Type data
.
Amussium scitulum
Smith:
lectotype
(lv) designated by
Dijkstra
(1995b: 31)
NHMUK
1887.2.9.3319/ 1;
6 paralectotypes
(v)
NHMUK
1887.2.9.3319/2–7. Type locality:
S of New
Guinea
,
9°59'S
139°42'E
, dead,
51 m
(
Challenger
stn 188)
.
Amusium scitulum
var.
cmadoritinctum
Kuroda
:
holotype
(lv) and
paratype
(rv), figured in
Kuroda (1931: 72
, fig. 81 [
holotype
] and fig. 82 [
paratype
]),
Kikuchi Shell Museum
,
Kuroda
collection, now
Nishinomiya Shell Museum
(not seen). Type locality:
Japan
,
Kyushu
,
Kagoshima Prefecture
,
Yakushima Island
.
Additional material examined
. —AUSTRALIA:
QUEENSLAND
: N Gulf of Carpentaria,
10°05.2'S
139°28.5'E
, dead,
37 m
(8 v, C.165156); off Bowen,
19°48'S
148°53'E
, dead,
62 m
(many v, C.165485); GBR, Swain Reefs,
3 km
NE of W side of Gillett Cay, 21°70'S
152°43.3' E
, dead,
64–73 m
(many v, C.165488; many v, C.165489; many v, C.165519, in part); SE of Swain Reefs, 22°20'09"–
22°26'16"S
153°17'05"E
, dead,
187 m
(many v, C.462540); SE of Swain Reefs,
22°31.4' S
152°32.6' E
, dead,
100 m
(1 v, C.157661, in part; 13 v, C.157662); SE of Swain Reefs,
22°32.4'S
152°33.9'E
, dead,
92 m
(2 v, C.338461); 4 ml E of North Reef,
23°09'S
151°58'E
, dead,
64 m
(1 v, C.165157); Capricorn Group, One tree Island,
23°30'S
152°05'E
, dead,
55 m
(14 v, C.165486; 2 v, C.165158); E of Lady Musgrave Island,
23°50.1'S
152°32.1'E
, dead,
132 m
(6 v, C.157665); E of Lady Musgrave Island,
23°51.2'S
152°34.5'E
, dead,
175–200 m
(12 v, C.338460); off S end of Frazer Island,
25°48'S
153°46'E
, dead,
73 m
(21 v, C.165490).
WESTERN AUSTRALIA
: W of Broome, approx.
17°58'S
122°14'E
, dead,
90 m
(many v,
WAM
474.91; many v,
WAM
420.91); N of Broome, approx.
17°58'S
122°14'E
, dead,
56 m
(13 v,
WAM
421.91);
94 n.
ml NNE of Port Hedland,
18°48'S
119°0'E
, dead,
92–94 m
(many v, C.157691); NNW of Dampier, c.
19°34'S
116°08'E
, dead, c.
101 m
(13 v,
WAM
489.91).
NORTHERN TERRITORY
: Arafura Sea, c. 245 ml NE of Croker Island,
8°36'S
135°08'E
, dead,
82 m
(1 v, C.157726; 2 v, C.157725); Arafura Sea, c.
330 km
NW of Wessel
Islands
,
8°26'S
135°22' E
, dead,
75 m
(11 v, C.157727; 12 v, C.157728);Arafura Sea, 180 ml NW of Wessel
Islands
,
8°56'S
135°25'E
, dead,
73 m
Figure 10
. A–D, F,
Parvamussium scitulum
(Smith)
, separate valves,
AM
C.165490, HMAS
Kimbla
stn Q11, off S end of Frazer Island, QLD,
25°48'S
153°46'E
,
73 m
; rv anterior auricle exterior (A), rv interior (B), lv auricles exterior (C), rv exterior (D), lv exterior (F).E, J–M,
Parvamussium squalidulum
Dijkstra
, separate valves,
AM
C.462546, Lord Howe Island shelf,
31°36'S
159°09'E
,
35 m
; rv anterior auricle exterior (E), rv exterior (J), rv interior (K), lv exterior (L), lv anterior auricle exterior (M).
G–I,
Parvamussium slacksmithae
sp. nov.
,
paratype
(G, H)
AM
C.209769 and
holotype
(I),
AM
C.157685, FRV
Soela
stn 26-18, 72 nautical miles NNW of Dampier,WA, 19°28.9'–
19°29.0'S
116°29.4'–
116°29.0'E
,
110 m
; rv exterior (G), rv anterior auricle exterior (H), lv exterior (I). Scale bars represent
1 mm
(A, C),
4 mm
(B, D, F, I, K),
0.5 mm
(E, H, M),
5 mm
(G, J, L).
(8 v,C.157724);
NW
Gulf
of
Carpentaria
,
8°48'S
137°01'E
,dead (1 v, C.338462);
125 km
N of Goulburn Island
,
10°23'S
133°36'E
, dead,
62 m
(20 v, C.165483)
;
41 km
NE of
Goulburn Island
,
11°10.5'S
133°43'E
, dead,
47 m
(many v,C.165482)
;
84 km
NE of
Goulburn Island
,
10°48.5'S
133°48'E
, dead,
60 m
(17 v, C.165484)
.
TASMAN
SEA:
Middleton Reef
,
29°24'S
159°04'E
, dead,
273.5 m
(many v, C.461378)
;
Middleton Reef
,
29°29'S
159°05'E
, dead,
117.5 m
(many v,C.461379)
;
Middleton Reef
,
29°24'S
159°06'E
, dead,
121 m
(13 v, C.461388)
;
Middleton Reef
,
29°25'S
159°02.E, dead,
298 m
(many v, C.461382)
;
Middleton Reef
,
29°25'S
159°05'E
, dead,
167 m
(12 v, C.461389;25 v, C.461395)
;
Middleton Reef
,
29°30' S
159°03'E
, dead,
254 m
(many v, C.461384)
;
Middleton Reef
,
29°30'S
159°07'E
,dead,
295 m
(29 v, C.461381 [in part])
;
Lord Howe Shelf
,
31°25'S
159°02'E
,dead,
58.5 m
(2 v, C.461411)
;
Lord Howe Shelf
,
31°25'S
159°03' E
, dead,
64 m
(4 v, C.461405)
;
Lord Howe Shelf
,
31°26'S
159°07' E
, dead,
96 m
(many v, C.461380;1 v, C.461398)
;
Lord Howe Shelf
,
31°27'S
159°08'E
, dead,
57.5 m
(5 v, C.461406)
;
Lord Howe Shelf
,
31°30'S
159°05'E
, dead,
48 m
(1 v, C.461403)
;
Lord Howe Shelf
,
31°31'S
159°07'E
, dead,
51.5 m
(1 v, C.461397)
;
Lord Howe Shelf
,
31°36'S
159°09'E
, dead,
35 m
(27 v, C.462546)
;
Lord Howe Shelf
,
31°43' S
159°04'E
, dead,
98 m
(11 v, C.461391)
;
Lord Howe Shelf
,
31°44'S
159°04'E
, dead,
117.5 m
(9 v, C.462547)
;
Lord Howe Island
,
Balls Pyramid
,
31°44'S
159°11'E
, dead,
53.5 m
(3 v, C.461408)
;
Lord Howe Island
,
Balls Pyramid
,
31°44' S
159°18'E
, dead,
78 m
(1 v, C.461404)
;
Lord Howe Island
,
Balls Pyramyd
,
31°46'S
159°09'E
, dead,
157.5 m
(8 v, C.461386 [in part])
;
off
Lord Howe Island
,
31°34.95'S
159°0.3'E
, dead,
73 m
(many v, C.165487).
Description
. Shell fragile, small, up to c.
12 mm
high, subcircular, compressed, inequivalve, inequilateral, right valve more convex than left, auricles rather small and unequal, umbonal angle c. 120°, prodissoconch c. 210 µm in height. Left valve stained, opaque, right valve semitranslucent white.
Left valve very weakly inflated, weakly sculptured with delicate, variable radial striations, somewhat stronger near posterior margin than elsewhere. Microscopic close-set commarginal striae developed on disc of some specimens, somewhat more widely spaced near umbonal area. Anterior auricle with prominent commarginal lamellae close to flank of disc, decreasing in prominence or absent near antero-dorsal margin; posterior auricle with fine radial and commarginal striations, almost absent from some specimens.
Right valve either smooth or weakly sculptured with a few growth lines. Internal riblets extending to submarginal area, 9 or
10 in
most specimens, some specimens with 1 or 2 rudimentary interstitial riblets. Resilifer triangular. Dorsal margin straight. Byssal notch narrow.
Habitat
. Living in the sublittoral and bathyal zones, free on soft sediment (sand, muddy sand or mud with coral rubble or gravel).
Distribution
.
Japan
to tropical western Pacific,
40–500 m
(?alive) (Hayami, 2000);
Indonesia
,
50–385 m
(dead) (Dijkstra, 1990a, 1991; Dijkstra & Kastoro, 1997);
Papua New Guinea
,
60–125 m
; Chesterfield
Islands
, Coral Sea,
300 m
;
New Caledonia
,
250–350 m
;
Loyalty
Islands
,
70–200 m
;
Wallis and Futuna
Islands
,
200–240 m
(dead) (Dijkstra, 1995b, 1998a, 2001; Dijkstra & Maestrati, 2008);
Fiji
,
80–120 m
;
Tonga
,
327–360 m
(dead) (Dijkstra & Maestrati, 2008); Austral
Islands
,
200–620 m
(dead) (Dijkstra & Maestrati, 2010). Now also extended westwards into the Indian Ocean from the
Mozambique
Channel, northwestern and southern
Madagascar
and northeastern
South Africa
, in
53–112 m
(Dijkstra & Maestrati, 2015). Maximum depth range of live-taken specimens is
60–
350 m
. Lamprell & Whitehead (1992: [16], 179) recorded this species from deep water off
Australia
, but without any locality data. The present material from
Australia
taken only dead at
37–
200 m
.
Remarks
. The present material from
Australia
is somewhat more variable in sculpture (smooth or almost smooth to typically striate) than the
type
specimens from eastern
Indonesia
.
Figure 11
. Distribution of
Parvamussium slacksmithae
sp. nov.
(circles),
P. squalidulum
Dijkstra
(stars),
P. torresi
(
Smith
)
(triangles) and
P. whissoni
sp. nov.
(square).