Aora aoriformis (Ledoyer) Myers, 1998

Myers, Alan A., 1998, The Amphipoda (Crustacea) of New Caledonia: Aoridae, Records of the Australian Museum 50 (2), pp. 187-210 : 188

Aora aoriformis (Ledoyer) n.comb.

Figs. 1 -2

Lembos aoriformis Ledoyer, 1984: 33 , fig. 15.

Material examined. NCL-28 (3 66, 3 繾⤬ NCL-31 (1 ~), NCL­ 95 (3 66, 6 繾⤬ NCL-97 (1 6), NCL-98 (1066, 17 繾⤬ NCL­ 111 (4 66, 5 繾⤬ NCL-112 (2 繾⤬ NCL-113 (2 66, 3 繾⤬ NCL-116 (1 6, 8 ~~, 2 immature), NCL-128 (1 6, 2 繾⤬ NCL­ 129 (25 66, 34 繾⤬ NCL-130 (2 66, 13 繾⤮

Description. Male and female to 3.5 mm. Male pereon segments lacking sternal processes. Head lateral lobes only moderately produced; eye relatively large, situated proximal to lobes; distoventral margin poorly recessed, shallow. Antenna 1 markedly longer than body; peduncular articles in the basi-distallength ratios 7: 12:3; accessory flagellum well developed with 4 articles, the terminal article rudimentary, flagellum poorly setiferous, over twice length of peduncle, with. about 33 articles, all except the most proximal with aesthetascs. Antenna 2 only moderately setiferous, less than half length of antenna 1; peduncular articles 4 and 5 subequal in length; flagellum subequal in length with peduncular article 5 with 7 articles, the terminal ones with strong 獥瑡敾 Mouthparts conforming to normal Aora structure; mandible palp article 3 subequal in length with article 2, slender, posterior margin convex with a few long marginal setae and an understory of short setae. Male gnathopod 1 weakly setiferous; coxa strongly produced forward, subacute;. basis elongate, anterior margin with strong acute or subacute medial spine; merus produced into acute ending tooth, shorter than and weakly deflected from the carpus; carpus subrectangular, parallel-sided; propodus sub~ectangular, subequal in width with carpus, palm obsolete; dactylus large, falcate, only a little shorter than propodus. Female gnathopod 1 coxa subrectangular deeper than broad; merus unproduced; carpus subtriangular, shorter than that of male; propodus and carpus subequal in length, palm very oblique defined by a stout seta; dactylus of moderate length, slightly overlapping palm. Male gnathopod 2 coxa subround; basis slender, anterior margin concave; carpus and propodus subequal in length, only moderately setiferous; propodus subrectangular, palm oblique, defined by a spine; dactylus fitting palm. Female gnathopod 2 coxa much larger than that of male; basis a little more slender than that of male, with anterior margin substraight; carpus a little shorter than propodus, subtriangular; propodus palm evenly convex, defined by a stout seta; dactylus short, fitting palm. Pereopods 5-7 in the length ratios 4:7:9; propodus.posterior margin with stout setae distally. Epimera 2-3 each with a small distoventral tooth. Uropod 1 peduncle a little longer than outer ramus and with strong distoventral spine about one third length of peduncle; outer ramus a little longer than inner; both rami with marginal stout setae. Uropod 2 peduncle shorter than inner ramus and with short triangular distoventral spine; inner ramus distinctly longer than outer; both rami with marginal stout setae. Uropod 3 rami longer than peduncle; rami subequal in length; outer ramus with slender distal setae, one marginal seta and with small second article; inner ramus with marginal stout seta and a slender distal seta. Telson dorsolateral crests each with three slender setae.

Remarks. This species is small and fragile. The large, pale eye allows separation of freshly preserved (in alcohol) specimens of this species from A. spinimerus , which is sometimes found in the same samples.

This species was originally assigned to the genus Lembos by Ledoyer (1984) based on the male gnathopod merus being shorter than the carpus, male coxa 1 being of the " Lembos " type, presumably referring to the forward produced, anterodistal margin and the mandibular palp being weakly falcate with a row of small setae. The shortened male gnathopod 1 merus is unusual in Aora , but occurs also in A. spinicornis , the acrte coxa occurs in several Aora species e.g., A. typica , A. hebes and A. spinicornis and the mandible palp is similar to that of A. hircosa . In all respects this and the following species conform to the genus Aora Kr 0yer.

Habitat. Amongst Padina , Sargassum , seagrasses and coral rubble, 0- 10 m.

Distribution. New Caledonian endemic.

Figures

Figure 1. Aora aoriformis (Ledoyer). Off Ilot Maitre, Noumea Lagoon, New Caledonia, NCL-98.