(Figs 12–16)
Megamaera serrata Bate, 1862: 226, pl. 39, fig. 5.
Moera spinosa Haswell, 1879a: 268, pl.10, fig. 5.— Haswell, 1882: 257.— Haswell, 1885: 105, figs 5–12 (part).
Ceradocus rubromaculatus.— Della Valle, 1893: 720 (in part).— Stebbing, 1906: 431 (in part).
Maera spinosa. Stebbing, 1910a: 642.
Ceradocus (Denticeradocus) serrata.— Sheard, 1939: 285, figs 4, 5a–m.
Ceradocus serratus.— J.L. Barnard, 1972a: 221, figs 130–131.— Ledoyer, 1979: 66, fig. 36.—Ledoyer, 1982: 440, fig. 165.— Barnard & Barnard, 1983: 616.— Lowry & Stoddart, 2003: 176 (catalogue).— Krapp-Schickel & Vader, 2009: 2061 –2065 (key).— Ren, 2012: 190, fig. 82.
Material examined. Christmas Island: 1 male specimen, 7.0 mm, dissected, 4 slides, AM P.92499, dive site ″ Million Dollar Bommie ″ (10°27′22″S 105°38′11″E), 12 m, coarse rubble, 18 October 2008, coll. J.K. Lowry (MI WA866); many specimens, AM P.81805, dive site ″ Million Dollar Bommie ″ (10°27′22″S 105°38′11″E), 12 m, coarse rubble, 18 October 2008, coll. J.K. Lowry (MI WA866); 1 specimen (damaged anterior half only), AM P.81806, dive site ″ Million Dollar Bommie ″ (10°27′22″S 105°38′11″E), 14 m, coral Acropora sp. with tufted algae, sand and red algae, 18 October 2008, coll. J.K. Lowry and K.B. Attwood (MI WA 867); 1 female specimen, AM P.81807, Winnifred Beach (10°29′48″S 105°32′44″E), 12.3 m, sand, 21 October 2008, hand collected on SCUBA, coll. K.B. Attwood (MI WA 909).
Cocos (Keeling) Islands: 1 male specimen, 6.1 mm, dissected, 4 slides, AM P.92247, dive site ″ Cabbage Patch ″, near Horsburgh Island (12°05′45″S 96°50′32″E), 10 m, rubble, 11 October 2008, coll. J.K. Lowry (MI WA 826); 13 specimens, AM P.81810, dive site ″ Cabbage Patch ″, near Horsburgh Island (12°05′45″S 96°50′32″E), 10 m, rubble, 11 October 2008, coll. J.K. Lowry, (MI WA 826); 1 specimen, AM P.81811, dive site ″ Manta Ray Corner ″, west of Direction Island (12°05′21″S 96°52′23″E), 13.6 m, coarse rubble, 8 October 2008, coll. L.E. Hughes and K.B. Attwood (MI WA 791); 1 specimen, AM P.81809, off West Island Jetty (12°05′15″S 96°50′14″E), 1.5 m, rubble, 14 October 2008, coll. L.E. Hughes (MI WA 843).
New South Wales: 3 specimens, AM P.83391, Jervis Bay (35°06′49″S 150°44′39″E), 19.4 m, 25 June 2008, coll. Geoscience Australia and M. McArthur (GA0312/JB_23); 3 specimens, AM P.77081, north east side of Little Broughton Island, north east of Port Stephens (32°37′43″S 152°18′56″E), 16.8 m, under stones, 11 March 2006, coll. P.B. Berents (NSW 2973); 2 specimens, AM P.77097, sewage pipeline, Nelson Bay, Port Stephens (32°43′11″S 152°08′28″E), 10 m, mass of intertwined dead algae, 15 March 2006, coll. C. Fraser (NSW 3042); 8 specimens, AM P.77095, sewage pipeline, Nelson Bay, Port Stephens (32°43′11″S 152°08′28″E), 10.9 m, bottom growth, 15 March 2006, coll. K.B. Attwood (NSW 3038); 1 specimen, AM P.62904, north west side of Toomeree Headland, Port Stephens (32°42′07″S 152°10′31″E), 11 m, macroalga Ecklonia sp. and mixed algae, 1 June 1998, coll. R.A. Evans (NSW 1500); 1 specimen, AM P.82943, north east of Port Stephens, south west side of Looking Glass Isle, Broughton Island (32°37′43″S 152°18′56″E), 16.3 m, hand collected on SCUBA, 13 March 2006, coll. R.T. Springthorpe (MI NSW 2983).
Tasmania: 3 specimens, AM P.88451, Hobart (42°52′S 147°19′E), unknown depth, 17 March 2009, coll. A. Davey; 1 specimen, AM P.88450, Burnie (41°04′S 145°54′E), unknown depth, 1 March 2005, coll. A. Davey; 2 specimens, AM P. 83568, 100 m north of Fleurieu Point, Freycinet Peninsula (42°10′S 148°15′E), 10 m, coarse shell and sand, 30 April 1991, coll. S.J. Keable and R.T. Springthorpe (TAS 314); 3 specimens, AM P. 83569, 100 m north of Fleurieu Point, Freycinet Peninsula (42°10′S 148°15′E), 10 m, green algae and some green alga Halophila sp., 30 April 1991, coll. S.J. Keable and R.T. Springthorpe (TAS 322).
South Australia: 3 specimens, AM P.83469, American River Inlet, Muston Point, Kangaroo Island (35°47′S 137°46′E), 4–5 m, clumps of sponge in channel below wharf, 2 February 1979, coll. P.A. Hutchings (SA 56); 3 specimens, SAMA C6453, Corny Point (34°53′47″S 137°00′38″E), January 1926; 1 specimen, SAMA C6586, Edithburg Jetty, Yorke Peninsula (35°06′05″S 137°43′59″E), under rocks, 17 May 2006, coll. K.L. Gowlett- Holmes; 1 specimen, SAMA C6454, 20 km due west of Outer Harbour, Gulf of St Vincent (34°46′47″S 138°28′50″E), 23–25 m, 18 April 1975, coll. J McPhalain, (quadrant G2); 1 specimen, SAMA C6636, 20 km due west of Outer Harbour, Gulf of St Vincent (34°46′47″S 138°28′50″E), 23–25 m, 17 April 1975, coll. J. McPhalain, G6; 1 specimen, SAMA C6451, northwest point of Marum Island, Sir Joseph Banks Group (34°31′00″S 137°15′00″E), reef sand pockets and seagrass Posidonia sp., 23 January 1986, coll. W. Zeidler and K. Gowlett- Holmes; 10+ specimens, SAMA C7865, west of Aldinga, Gulf of St Vincent (33°16′00″S 138°26′59″E), 38–41 m, in prawn trawl, 8 May 1987, coll. K.L. Gowlett-Homes and S. Corigliano, FV Rivoli Queen; 1 specimen, NMV J46912, Tiparra Reef, Tiparra Bay (34°04′00″S 137°23′00″E), 5 m, 15 March 1985 (SA 16).
Western Australia: 1 specimen, AM P.79850, off end of South Mole, Arthur Head, Fremantle (32°03′S 115°44′E), 6 m, spirorbid tube worms, 25 December 1983, coll. J.K. Lowry (WA 283); many specimens, AM P.79849, off end of South Mole, Arthur Head, Fremantle (32°03′S 115°44′E), 6 m, sponge, detritus, epizoic, green alga Caulerpa sp., 25 December 1983, coll. J.K. Lowry (WA 287); 1 specimen, AM P. 79380, 500 m off Chinamans Rock, Kalbarri (27°42′S 114°09′E), 6 m, rocky bottom, curly brown plus coralline algae, 10 January 1984, coll. J.K. Lowry (WA 459); 1 specimen, AM P.79851, near Mistaken Island, Vancouver Peninsula, King George Sound (35°04′S 117°56′E), 6 m, seagrass, 13 December 1983, coll. R.T. Springthorpe (WA 121); 7 specimens, AM P.79312, rocks near Migo Island, Port Harding, Torbay Bay (35°04′S 117°39′E), 6–7 m, green alga Caulerpa sp. and detritus, 15 December 1983, coll. J.K. Lowry (WA 144); 5 specimens, NMV J57178, North Lumps, 2 km off Mullaloo (31°47′18″S 115°42′48″E), 7 m, 2 May 1986 (SWA 113); 1 specimen, NMV J57169, Seven Mile Beach, North of Dongara (29°12′00″S 114°53′00″E), 22 April 1986, 1 m (SWA 83); 1 specimen, NMV J57177, North Lumps, 2 km off Mullaloo (31°47′18″S 115°42′48″E), 8 m, 2 May 1987 (SWA 112); 1 specimen, NMV J57168, Cliff Head, 30 km south of Dongara (29°32′00″S 114°59′00″E), 3 m, 22 April 1986 (SWA 84); 1 specimen, NMV J57176 East of Wreck Rock (31°47′54″S 115°42′48″E), 3 m, 2 March 1986 (SWA 115).
Type locality. Flinders and Hummock Islands, Bass Strait.
Distribution. Indian Ocean, Cocos (Keeling) Islands; Christmas Island (current study). Australia. New South Wales: Split Solitary Island; Port Stephens; Port Jackson; Merimbula; Twofold Bay; Jervis Bay (J.L. Barnard 1972a; current study). Victoria: Shoreham; Port Phillip Bay (J.L. Barnard 1972a). Tasmania: Flinders and Hummock Islands, Bass Strait (Bate, 1862). South Australia: Kangaroo Island; Spencer Gulf; Yorke Peninsula; Outer Harbour; Sir Joseph Banks Group; Tiparra (current study). Western Australia: Kalbarri; Fremantle; King George Sound; Torbay Bay, Dongara, Mullaloo (current study). Madagascar. (Ledoyer 1979; 1982).