Iphimedia caledoniana, Lowry & Myers, 2003

Lowry, J. K. & Myers, A. A., 2003, New Amphipod Crustaceans From The Indo-West Pacific (Amathillopsidae: Eusiridae: Iphimediidae), Raffles Bulletin of Zoology 51 (2), pp. 219-256 : 229-235

Iphimedia caledoniana , new species

( Figs. 1 , 12-14 )

Material examined. – Holotype – sex unknown, 6.1 mm, AM P46979, off Ilôt Maitre , New Caledonia, 22 20.57’S 166 25.43’E, purple sponge, 20 m, coll. ORSTOM divers, 7 Nov.1995, stn NCL- 39.

Paratypes – 1 specimen, AM P47000, off Ilôt Maitre , New Caledonia, 22 20.57’S 166 25.43’E, living with Halimeda incrassata , 20 m, coll. ORSTOM divers, 7 Nov.1995 , stn NCL- 39; 4 specimens AM P46980 off Recif To , Passe de Boulari, New Caledonia, 22 30.15’S 166 26.43’E, stones encrusted with Lithothamnion , 30 m, coll. ORSTOM divers, 8 Nov.1995 ; 1 specimen AM P46983 off Ilôt Maitre , New Caledonia, 22 20.57’S 166 25.43’E, dead coral, 20 m, coll. ORSTOM divers, 7 Nov.1995 ; 1 specimen, AM P46985, off Recif To , Passe de Boulari, New Caledonia, 22 30.15’S 166 26.43’E, stones encrusted with Lithothamnion , 30 m, coll. ORSTOM divers, 8 Nov.1995 ; 1 specimen, AM P46989, Between Ile Ngé and Sèche Croissant, New Caledonia, 22 19.41’S 166 20.89’E, Iodyctium buchneri (purple bryozoan) 20 m, coll. ORSTOM divers, 9 Nov.1995 ; 1 specimen, AM P46990, between Ile Ngé and Sèche Croissant, New Caledonia, 22 19.41’S 166 20.89’E, Caulerpa sp., 20 m, coll. ORSTOM divers, 9 Nov.1995 ; 1 specimen, AM P47000, off Ilôt Maitre , New Caledonia, 22 20.57’S 166 25.43’E, purple sponge, 20 m, coll. ORSTOM divers, 7 Nov.1995 , stn NCL-39.

Type locality. – Ilôt Maitre, South-east Lagoon, New Caledonia.

Description. – Head laterocephalic margin with rounded spine, ventrolateral corner an acute spine; eyes reniform. Antenna 1 peduncular article 1 with posterodorsal spines, without posteroventral spine; peduncular article 2 with posterodorsal spine, with a posteroventral spine; accessory flagellum absent. Maxilla 1 palp well developed, about as long as or longer than outer plate, 2-articulate.

Pereon. Pereonite 1 enlarged, slightly produced over head. Gnathopod 1-2 coxa small, ventrally truncated, ventral margins smooth. Pereopod 3 coxa ventrally truncated, posteroventrally subacute, ventral margins smooth. Pereopod 4 coxa ventral margins smooth. Pereopod 5 coxa posteroventral corner broadly rounded; basis posterodorsal corner subquadrate, posterior margin without spines, smooth, posteroventral corner rounded; merus posteroventral lobe produced about halfway along carpus. Pereopod 6 coxa posteroventral corner subquadrate; basis posterodorsal corner subquadrate, posterior margin without spines, smooth, posteroventral corner with small spine; merus posteroventral lobe produced about halfway along carpus. Pereopod 7 coxa with posteroventral spine; basis posterodorsal corner rounded, posterior margin without spines, weakly serrate, posteroventral corner rounded; merus posteroventral lobe produced about halfway along carpus. Pereonite 7 without mid-dorsal carina, dorsodistal margin with 2 large spines, without posteroventral spine.

Pleon. Pleonite 1 without mid-dorsal carina, dorsodistal margin slightly to strongly produced, with 2 large spines. Pleonite 2 without mid-dorsal carina, dorsodistal margin slightly to strongly produced, with 2 large spines. Pleonite 3 without mid-dorsal carina, dorsodistal margin slightly to strongly produced, with 2 straight spines. Epimeron 1 posterior margin without mid-lateral spines; posteroventral corner produced into a spine. Epimeron 2 posterior margin without mid-lateral spines, posteroventral corner produced into a spine. Epimeron 3 posterior margin with 1 ventrolateral, recurved, smooth spine, posteroventral corner produced into a smooth spine. Telson emarginate, slightly longer than broad, parallel sided, with 2 distolateral spines and a pair of distal fine setae.

Remarks. – This species can be distinguished from all other described world species of Iphimedia by the following combination of characters: eyes reniform, pereonite 1 enlarged and slightly produced over head, pereopod 7 basis posteroventral corner rounded and pereonite 7 with two dorsal spines.

Distribution. – New Caledonia.

Etymology. – Named for New Caledonia, the area where this species lives.

Figures

Fig. 1. Oradarea dawa, new species, AM P64452: A, Pereopod 7 basis, showing scale patterns, scale bar = 30; B, Pereopod 7 basis, showing groups of scales with proximal insertion line and sockets where scales are missing, scale bar = 10. Iphimedia caledoniana, new species, AM P64453: C, Pereopod 7 basis, showing scale patterns, scale bar = 30; D, Pereopod 7 basis, close up showing groups of scales with proximal insertion line and sockets where scales are missing, scale bar = 10.

Fig. 12. Iphimedia caledoniana, new species, unknown sex, 6.1 mm, AM P46979, off Ilôt Maitre, New Caledonia.

Fig. 13. Iphimedia caledoniana, new species, unknown sex, 6.1 mm, AM P46979, off Ilôt Maitre, New Caledonia. Scale bar = 0.2mm.

Fig. 14. Iphimedia caledoniana, new species, unknown sex, 6.1 mm, AM P46979, off Ilôt Maitre, New Caledonia. Scale bar = 0.2mm.