Ylistrum balloti (Bernardi, 1861)

Dijkstra, Henk H. & Beu, Alan G., 2018, Living Scallops of Australia and Adjacent Waters (Mollusca: Bivalvia: Pectinoidea: Propeamussiidae, Cyclochlamydidae and Pectinidae), Records of the Australian Museum (Rec. Aust. Mus.) 70 (2), pp. 113-330 : 207-210

Ylistrum balloti (Bernardi, 1861)

Figs 47B, 48, 49A,C–D

Pecten balloti Bernardi, 1861: 46 , pl. 1, fig. 1; Lischke, 1869: 165.

Amussium [sic] balloti (Bernardi) .–Angas, 1877: 293; Slack- Smith & Bryce, 2004: 236.

Pecten lucens Tate, 1886: 115 (in part).

Pecten (Amussium) [sic] balloti Bernardi. –Küster & Kobelt, 1888: 179, pl. 50, fig. 1; Gregorio, 1898: 7, pl. 1, figs 3–4, 7; pl. 4, fig. 4.

Pecten (Amussium) [sic] tatei Gregorio, 1883: 133 ; Gregorio, 1898: 39 (unnecessary replacement name for Pecten lucens Tate, 1886 , not preoccupied by Pecten (Pleuronectia) lucidus Jeffreys, 1872 (nomen nudum) (Crosse & Fischer, 1872) = Pleuronectia lucida Jeffreys in Thomson, 1873).

Amusium lucens (Tate) .– Tate, 1899: 272 (in part).

Amusium japonicum (Gmelin) .–Hedley, 1918a: M9 (misidentification).

Amusium balloti (Bernardi) .– Iredale, 1939: 369;Allan, 1950: 282, pl. 31, fig. 15; Rippingale & McMichael, 1961: 173, pl. 24, fig. 8; Iredale & McMichael, 1962: 11; Coleman,

Figure 48. Distribution of Ylistrum balloti (Bernardi) .

1975: 261, fig. 712; Dijkstra, (1983–1994) 1988: 3, figs; Wells & Bryce, 1985: 158, pl. 60, fig. 579; Dijkstra et al., 1989: 24; Dijkstra, 1990a: 3, figs; Dijkstra, 1991: 25; Rombouts, 1991: 3, pl. 2, figs 5-5a; Lamprell & Whitehead, 1992: [18], pl. 7, fig. 38; Dijkstra & Marshall, 1997: 95; Beu & Darragh, 2001: 179, figs 63A, C, 64 B–C, 66A–H; Raines & Poppe, 2006: 136–137, upper figs; pl. 84, figs 1–3; Huber, 2010: 197.

Amusium ballotti [sic] (Bernardi).–Garrard, 1961: 5.

Amusium japonicum balloti (Bernardi) .–Habe, 1964a: 4, pl. 1, fig. 5; pl. 2, fig. 6; Abbott & Dance, 1982: 303, fig.; Wang, 1984b: 250, fig. 6; Waller, 1991: 18, 37, pl. 8, figs 5, 8.

Ylistrum balloti (Bernardi) .– Mynhardt et al., 2014: 407, figs 1G–L.

Type data. Pecten balloti Bernardi, 1861 : three syntypes (pr) MNHN Moll 21185. Type locality: New Caledonia.

Pecten lucens Tate, 1886 : lectotype (pr) SAM T969 B, designated by Beu & Darragh (2001: 181, figs 63A, C, 64B–C). Type locality: “oyster beds, Aldinga Bay” [i.e., Hallett Cove Sandstone, late Pliocene , coast SW of Adelaide, South Australia; Beu & Darragh (2001: 181)].

Additional material examined. — AUSTRALIA: QUEENSLAND: Gulf of Carpentaria, Mapoon, 11°58'S 141°53'E, dead (4 v, C.338790); GBR, off Cairns, 16°51'S 146°01'E – 146°04'E, dead, 33–35 m (many, C.138333); off Cairns, 16°52'– 16°53'S 146°06'E,dead, 37–38 m (3 v,C.138267);off Townsville,6–7 mls E of Keeper Reef, 18°45' S 147°23'E,dead, 43 m (10 v,C.131710);Townsville,Cape Bowling Green, 19°17'S 147°25' E, alive, 31–33 m (3 pr,C.072999); E of Broad Sound, 21°58'S 150°45'E, dead, 57 m (6 v, C.338795);W of Swain Reefs, 22°0'S 151°30'E,dead, 73 m (1 v,C.097585);off Broad Sound, 22°06'S 150°49'E, dead, 53 m (3 v,C.116495);inside Swain Reefs, 22°14'S 152°27'E,alive, 60 m (5 pr, QM MO.33653); SE of Swain Reefs, 22°31' S 152°32'E, dead, 100 m (8 v, C.151494);Port Clinton, 22°34.35'S 150°44.57'E, S arm channel, alive, 11 m (1 pr, C.300337); off Yeppoon, 22°40' S 151°16'E, dead, 58 m (1 v, C.338787); 30 mls NE of Yeppoon, 22°50' S 151°11'E, alive, 46–55 m, scallop beds (many,C.338793);Keppel Bay,North Keppel Island, 23°04'S 150°54' E,dead (1 pr, C.086829);Keppel Bay, off Yeppoon, 23°07'S 150°46'E,alive (3 pr,C.076938);Keppel Bay, off Yeppoon, 23°07'S 150°46'E,alive (many,C.093047);Keppel Bay,between Outer Rock & Man & Wife, NE of South Keppel Island, 23°08' S 150°56'E, dead, 24–26 m (3 pr,C.070780);Keppel Bay, 1.5ml NW of South Keppel Island, 23°09'S 150°57'E,dead, 13–20 m (3 pr, C.070779); Keppel Bay, Roslyn Bay, Double Point, 23°10'S 150°47'E, dead,(2 v,C.100490);GBR,Capricorn Group,off North West Island, 23°18'S 151°42'E, (4 pr, alive,C.303800; 1 v, dead,C.338794);Keppel Bay, 23°25' S 150°55'E,dead (1 pr, C.086828); Capricorn Group, Heron Island, 23°26'S 151°57' E, dead (1 v, C.072664; 1 pr, C.093020); Capricorn Group, One Tree Island, 23°30'S 152°05'E, dead, 55 m (3 v, C.338786); Gladstone Harbour, 23°51'S 151°16'E, alive (1 pr, C.093046); off Burnett Heads, 24°46' S 152°24'E, dead, 46–55 m (17 v,C.064355);Bargara, 24°49'S 152°28'E, alive (6 pr, C.080460; 1 pr, C.097660); off Bundaberg, 24°52'S 152°23'E, alive (1 pr, C.080071; 1 pr, C.081192); Hervey Bay, 25°06'S 152°49'E, dead (3 v, C.094770); off S end Frazer Island, 25°48' S 153°46'E, alive, 73 m (1 pr + 4 v, C.111356); off Wide Bay, 25°50'S 153°27' E, dead, 55 m (2 pr,C.097590); 25 mls SE of Double Island Point, 26°13'S 153°22'E, dead, 60 m (7 v, C.031277); Caloundra, 26°49'S 153°10'E, dead (1 v, C.012847;1 v,C.012849);Moreton Bay, 27°15'S 153°15' E, dead (1 pr, C.012171);S Moreton Bay, off Jacobs Well, 27°27'S 153°33'E,alive, 49 m (3 pr,C.103412);Moreton Bay, off Dunwich, Stradbroke Island, 27°30'S 153°24'E, dead, 5–7 m (7 v, C.093045); off S end of Stradbroke Island, 27°43'S 152°35' E, alive, 48–59 m (7 pr, C.070454); off Southport, 27°58'S 153°25' E,alive, 18–36 m (2 pr,C.338791). NEW SOUTH WALES: off Tweed Heads, 28°10'S 153°42'E, alive, 54 m (6 pr, C.097591); off Tweed Heads, 28°17'S 153°44'E, dead, 73 m (1 v, C.117648); off Ballina, 28°52'S 153°37'E, dead (1 pr,C.093030); N of North Solitary Island, 29°52'– 29°48'S 153°25'– 153°26'E, dead, 64 m (1 v, C.338792); off Red Head, 32°04'S 152°43' E, dead, 64 m (1 pr, C.093026); Port Stephens, 32°42' S 152°05'E, dead (2 pr, C.093029); off Newcastle, 32°56'S 151°57'E, dead, 73–82 m (10 v, C.093025); off Broken Bay, 33°32'S 151°26'E, alive, 49–64 m (2 pr, C.093028;1 pr, C.302854);Sydney Harbour, Mosman Bay, 33°50'S 151°13'E,alive (1 pr, C.012176); Sydney, Port Jackson, 33°51'S 151°14'E, dead (4 v, C.086831; 9 v, C.093027;4 v,C.151423);Sydney S, Cronulla, 34°03'S 151°09'E,dead(1 v,C.338796). WESTERN AUSTRALIA: Sandy Hook Island, Esperance, 34°02'S 122°0'E, alive, 31–35 m (10 pr, WAM);GreatAustralian Bight, E of Hood Point, 34°21'S 121°16'E,dead, 82 m (3 v,C.338784);Doubtful Island Bay, mouth of Gordon Inlet,nearAlbany, 34°12'S 119°38'E,alive, 22–37 m (2 pr, WAM);E of Cheyne Bay, 34°55'S 119°0'E,dead, 71–76 m (2 v,C.338785);King George Sound, 35°03'S 117°58'E,dead (1 pr,C.069360);Hamelin Bay, 34°12'S 115°01'E, dead (1 v, C.093018); W of Rottnest Island, 32°42'S 115°13'E, alive, 43–46 m (4 pr, WAM); off Fremantle, 32°12'S 115°44' E, alive (1 pr, C.093017); Perth, W of City Beach, 31°56.8'S 115°34'E, dead, 27.4 m (1 v, WAM); Geraldton, 28°46'S 114°37'E, dead (1 pr, C.140196); Albrolhos Islands , Goss Passage, 28°29'S 113°46'E, dead, 34 m (1 v, WAM); outside Wallabi Group, Abrolhos Island, 28°25' S 113°33' E, dead (1 pr, C.093019); N of Dirk Hartog Island, 25°29'S 112°57'E, dead, 73 m (11 v, WAM);Carnarvon, 24°53'S 113°40'E,alive, 24 m (1 pr, WAM);15 ml WSW of Carnarvon, 24°58'S 113°27'E,alive, 26 m (1 pr, WAM);off Carnarvon, 24°52' S 113°36'E, alive, 24 m (1 pr, C.106491); off Carnarvon, 24°52'S 113°36'E, alive (5 pr, C.133270); off Dampier, 20°40'S 116°43'E,alive, 13–15 m (3 pr, WAM);off Port Hedland, 20°18'S 118°35' E, alive, 22–26 m (2 pr, WAM); 26 mls NNE of Dampier, 20°14' S 116°50'E, alive, 40–41 m (1 pr,C.338825);North West Shelf,44 mls NW of Port Hedland, 19°56' S 117°53'– 117°53.4'E,alive, 40 m (4 pr,C.338827);45 mls NNE of Port Hedland, 19°55'S 117°56'– 117°55.6'E,alive, 40 m (1 pr,C.338828);North West Shelf,52 mls NNE of Port Hedland, 19°30'– 19°28'S 118°49' – 118°55.4'E, alive, 36–37 m (4 pr + 1 v, C.148701); 74 mls NNE of Port Hedland, 19°05'– 19°05.3'S 118°53'– 118°54'E, alive, 80 m (1 pr, C.338822);77 mls NNE of Port Hedland,19°05'– 19°04.9' S 118°58' – 118°58.2'E,dead, 82 m (4 v,C.149341); 78 mls NNE of Port Hedland,19°04'– 19°04.2'S 119°04' – 119°0.7'E, alive, 82 m (3 pr + 5 v, C.149961); 80 mls NNE of Port Hedland, 19°03'– 19°03.4'S 119°03' – 119°03.5'E,alive, 82 m (2 pr + 18 v, C.146782);72 mls NW of Bedout Island, 18°51'S 118°19'E, dead, 46 m (1 v, WAM); off Broome, 17°58'S 122°14'E, alive, 37 m (2 pr, WAM). CORAL SEA: Chesterfield Islands , 20°21.2'S 160°58.6'E, alive, 74–75 m (1 pr, ZMA Moll.145184); Chesterfield Islands , 20°28' S 160°56'E, alive, 78 m (1 pr, ZMA Moll.145179).— NEW CALEDONIA: 19°29' S 163°49'E,alive, 40 m (4 pr, ZMA Moll.145195); 22°17'S 166°20'E, alive, 20 m (1 pr, ZMA Moll.145181). NORFOLK ISLAND: 29°02'S 167°57' E, dead (1 v, C.059877).

Description. Shell up to c. 140 mm high, circular, acline, almost equivalve, equilateral, valves weakly convex, equally inflated, auricles equal in size, umbonal angle c. 140°; left valve brownish or red-brownish with commarginal darker colour bands, right valve white with scattered brown spots; interior white.

Both valves almost smooth, glossy, with very weak, irregular commarginal corrugations only; a few delicate radial striae on some specimens. Posterior auricles and left anterior auricle smooth, symmetrical. Right anterior auricle with 6–7 closely spaced radial costae. Interior with 42–54 prominent radial carinae, arranged in vaguely recognisable pairs. Hinge weak, with delicate dorsal teeth. Byssal notch shallow; ctenolium functional only in juvenile stage, lacking in adult.

Dimensions. Illustrated specimen: QLD, GBR, Capricorn Group, trawled off North West Island (AM C.303800): rv: H 128.8, L 137.6 mm; lv: H 128.4, L 134.3 mm; D 29.2 mm.

Habitat. Littoral to sublittoral depths, living free on clean sand, partially buried with only the outline of the shell showing.

Distribution. Southwestern Australia from the Great Australian Bight to southern Western Australia, more rarely northwards to northern Australia; southeastern and eastern Australia from Jervis Bay (southern New South Wales) up to north Queensland. Populations are scarce in the Northern Territory and are absent from South Australia and Victoria. Also known from Indonesia, 145–155 m, dead (Dijkstra, 1991: 25), the Chesterfield Islands (Coral Sea), New Caledonia and Norfolk Island, 64–90 m, dead (Dijkstra &

Figure 49. A, C, D, Ylistrum balloti (Bernardi) , pair, specimen in Fig. 47B; lv exterior (A), rv exterior (C), lv interior (D). B, E, Annachlamys flabellata (Lamarck) , pair, specimen in Fig. 47D, E; lv exterior (B), rv exterior (E). Scale bars represent 50 mm (A, C, D), 30 mm (B, E).

Marshall , 1997: 95). Maximum depth range of live-taken specimens from Australia is 11–82 m.

Remarks. Specimens of Ylistrum balloti from western Australia are generally red-purplish, from eastern Australia brownish, from the Chesterfield Islands and Norfolk Island creamy, and from New Caledonia creamy to brownish. Other morphological characters are identical. The interior rib carinae are variable in number and spacing, but are arranged vaguely in pairs in many specimens.

Joll (1989) described swimming in Ylistrum balloti , which swims further and faster than Amusium pleuronectes ; Y. balloti swims at 0.8–1.0 m s-1, with a maximum of 1.6 m s-1 (3.1 knots) and swims for up to 23.1 m in one swimming event, achieving a maximum distance of 30.8 m in four swimming events. This species is trawled commercially in Queensland and Western Australia, and swimming has been studied in these areas because many specimens are able to swim away from the trawl (Dredge, 2006, and references therein).