Iphimedia mizegwadan, 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 : 241-244

Iphimedia mizegwadan , new species

( Figs. 21-23 )

Material examined. – Holotype – sex not known, 4.2 mm, AM P64444, Mizegwadan reef, 5 09.57’S 145 39.46’E, Madang Lagoon, Papua New Guinea, rubble, 3–4 m, coll. J. D. Thomas, 16 Feb.1990 stn JDT/PNG 48f.

Paratypes – 1 specimen, AM P64445, Mizegwadan Reef, 5 08.31’S 145 49.36’E, rubble, 12-15 m, coll. J. D. Thomas, 28 Jan.1990, stn JDT/ PNG 25c; 1 specimen, AM P64446, Mizegwadan reef, 5 09.57’S 145 39.46’E, Madang Lagoon , Papua New Guinea , rubble, 3–4 m, coll. J. D. Thomas, 16 Feb.1990 stn JDT/ PNG 48f; 1 specimen, AM P64447, gully in south entrance of Dam Awan, 5 09.27’S 145 49.86’E, rubble and sediment, J. D. Thomas, 22 Feb.1990, stn JDT/ PNG 57l; 1 specimen, AM P64448, western margin of Guzem reef, 5 09.35’E 145 48.43’E, rubble, mainly encrusted Acropora rubble, 2 m, coll. J. D. Thomas, 16 Apr.1991, stn JDT/ PNG 71f.

Type locality. – Mizegwadan reef, 5 09.57’S 145 39.46’E, Madang Lagoon , Papua New Guinea .

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

Pereon. Pereonite 1 enlarged. Gnathopod 1 coxa small, ventrally truncated, ventral margins smooth. Gnathopod 2 coxa small, ventrally acute, ventral margins smooth. Pereopod 3 coxa 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 as long as or longer than carpus. Pereopod 6 coxa posteroventral corner subquadrate; basis posterodorsal corner with spine, posterior margin without spines, smooth, posteroventral corner without spines, rounded; merus posteroventral lobe longer than carpus. Pereopod 7 coxa with posteroventral spine; basis posterodorsal corner rounded, posterior margin with 4 spines, weakly serrate, posteroventral corner with small spine; merus posteroventral lobe longer than carpus. Pereonite 7 without mid-dorsal carina, dorsodistal margin with two small spines. Pleon. Pleonite 1 without mid-dorsal carina, dorsodistal margin not produced, with 2 small spines. Pleonite 2 without mid-dorsal carina, dorsodistal margin not produced, with 2 small spines. Pleonite 3 without mid-dorsal carina, dorsodistal margin not produced, with 2 straight spines. Epimeron 1 posterior margin with 1 mid-lateral spine; posteroventral corner rounded. Epimeron 2 posterior margin with 1 mid-lateral spine, posteroventral corner rounded. Epimeron 3 posterior margin with 1 ventrolateral, straight, smooth spine, posteroventral corner produced into a small, smooth spine. Telson notched, slightly longer than broad, parallel sided, with pair of dorsodistal fine setae.

Remarks. – The ornamentation of the pereopod 7 basis is unique among the described species of Iphimedia . The unproduced dorsodistal margin of pereonite 7 is also found in few other species.

Distribution. – Papua New Guinea.

Etymology. – Named for Mizegwadan reef, the type locality.

Figures

Fig. 21. Iphimedia mizegwadan, new species, unknown sex, 4.2 mm, AM P64444, Mizegwadan reef, Madang Lagoon, Papua New Guinea.

Fig. 22. Iphimedia mizegwadan, new species, unknown sex, 4.2 mm, AM P64444, Mizegwadan reef, Madang Lagoon, Papua New Guinea. Scale bar = 0.1mm.

Fig. 23. Iphimedia mizegwadan, new species, unknown sex, 4.2 mm, AM P64444, Mizegwadan reef, Madang Lagoon, Papua New Guinea. Scale bar = 0.2mm, uropods; telson 0.1mm.