Ambicholestes (Ambicholestes) magellani ( Just, 1984a ) Just, Jean, 1998

Just, Jean, 1998, Siphonoecetinae (Crustacea: Amphipoda: Ischyroceridae) 7: Australian Concholestids, Ambicholestes n. gen., with a Description of Six New Species, and a New, Restricted Diagnosis for Caribboecetes Just, 1983, Records of the Australian Museum 50 (1), pp. 27-54 : 32-35

Ambicholestes (Ambicholestes) magellani ( Just, 1984a) , n.comb.

Caribboecetes magellani Just, 1984a: 57 , figs 1C, 16, 17.

Material examined (237 specimens). Heron Island , south Queensland, reef crest, boulder zone, 30 September 1979, N.L. Bruce, QM Wl 1667 (1 specimen). Heron Island, south Queensland, centre of Wistari-Heron channel, 33 m, 2 October 1980, Boer & Hensby, AM P30981 (1) . Lizard Island , north Queensland, BK-119, AM P34958 (4) . Lizard Island , north Queensland, BK-122, AM P34959 (4) . Lizard Island , north Queensland, BK-130, AM P34960 (5) . Lizard Island , north Queensland, BK-131, AM P34961 (1) . Lizard Island , north Queensland, reef edge 200 m NW of Palfrey Island, 14°40'S 145°28'E, 3 m, coral sand and rubble between bommies, 16 October 1978, J.K. Lowry, AM P34962 (1) . Lizard Island , north Queensland, reef edge 200 m NW of Palfrey Island, 14°40'S 145°28'E, 3 m, sand beneath coral boulders, 16 October 1978, P.C. Ferrill, AM P34963 (19) . No. 5 Sandbank Reef , north Queensland, 13°45'S 144°16'E, 8-10 m, rubble washing from SW end of Reef, December 1982, 1. Loch, AM P34964 (88) . Escape Reef , south end, north Queensland, 15°53'S 145°49'E, 18 m, rubble washing, outer slope of shelf, 20 December 1981, I. Loch, AM P34965 (85) . Elizabeth Reef, SW end, Tasman Sea , 29°57.2'S 159°01.2'E, outer reef slope near "Yoshi Maru Ikawa" wreck, 12 m, algal turf on rocky substrate, airlift, 10 December 1987, R. T . Springthorpe & LK. Lowry, Site 30, AM P37917 (2) . Lizard Island , north Queensland, 14°40'S 145°28'E, outermost reef outside Research Point, seaward face, patches of coarse sand and rubble between bommies, 8 m, hand dredge, 16 July 1984, J. Just Stn AU-37, ZMUC (7) . Lizard Island , north Queensland, 14°40'S 145°28'E, outermost reef outside Research Point , seaward face, patches of coarse sand and rubble between bommies, 7-8 m, 17 July 1984, J. Just Stn AU-38, ZMUC (13), AM P44600 (8, in houses) .

Diagnosis. Rostrum absent. Anterior margin of cephalon evenly rounded. Antenna 2 peduncle article 3 with dorsal and medial microsetules. Article 2 of pereopod 2 with anterior margin bilobed; presumed stridulation organ present.

Further description. See Just (1984a).

Remarks. The original material of A. magellani from The Philippines consisted of two females. Mouthparts were not dissected out for study. The present material shows that the species has complexly lobate inner lobes of the lower lip. Male cephalon and antennae are moderately longer and more setose than in females.

Australian specimens generally carry more robust setae on pereopods 3-6 article 5 than the material from the Philippines, and uropod 3 carries up to 9 lateral robust setae (2 and 3 in the holotype). These differences may represent geographical variations. In all other respects, including colour, the present material agrees with the description and illustrations in Just (1984a).

Size. Largest male: 3.3 mm (north Queensland); largest female: 2.8 (north Queensland), 3.9 mm (Heron Island).

Biology. Of the 31 specimens from StnAU-37,AU-38 (both Lizard Island ), Wl 1667 (Heron Island) and P37917 (ElizabethReef) 30 were found in small prosobranch shells, each with a short, coarse-grained entrance tube. One specimen occupied a piece of calcareous polychaete tube. All other specimens listed are without their abode .

Specimens were found in sheltered places in and around coral reefs and bomrnies on sediments with a high content of medium to coarse coral rubble.

Distribution. Central Philippines; north-eastern Australia; 3-33 m depth.