Icilius caledoniana, Watson & Lowry & Steinberg, 2004

Watson, M. J., Lowry, J. K. & Steinberg, P. D., 2004, Revision Of The Iciliidae (Crustacea: Amphipoda), Raffles Bulletin of Zoology 52 (2), pp. 467-495 : 476-479

Icilius caledoniana , new species

( Figs. 7-8 )

Material examined. – Holotype - female, AM P54156 .

Paratypes – 2 females, P54157, 1 male, P54158 (all from type locality).

Others – 12 ex. , P47351; 1 ex., AM P54158 ; 1 male and 1 juvenile, P54159; off Ilot Maitre , New Caledonia, 22 19.61' S 166 24.7’E, living on the calcareous green alga Halimeda sp. , 10.5 m depth, coll. I. Takeuchi, 14 Nov.1995 .

Type locality. – Off Ilot Maitre , New Caledonia, 22 19.61' S 166 24.7’E, living on the calcareous green alga Halimeda sp. , 10.5 m depth

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Description. – (based on female holotype, P54156 and female paratypes P54157). Head rostrum rounded. Antenna 1 peduncular article 1 longer than (1.19 x) article 2; accessory flagellum present, accessory flagellum 1-articulate; flagellum 29+ articles. Antenna 2 flagellum 28+ articles. Mandible left incisor with 5 serrations, right incisor with 6 serrations; accessory setal rows: left with 8 setae, right with 9 setae; molar, triturating surface well developed basally; palp article 2 slender, length 4 x breadth, 1.14 x article 3; article 3 slender, straight, slightly falcate distally. Upper lip apically notched, setose. Lower lip inner lobes present; outer lobes entire; mandibular lobes rounded apically. Maxilla 1 inner plate with 4 apical pappose setae; outer plate with 11 setal-teeth; palp with 8 apical robust setae and many subapical slender setae.

Pereon. Pereonite 7 posterodorsal margin with large mid-dorsal bulge, without setae along posterior margin. Gnathopods 1 and 2 not sexually dimorphic; simple with long, slender setae along posterior margin. Gnathopod 1 basis 0.86 x carpus length; carpus 0.96 x propodus length. Gnathopod 2 basis 0.78 x carpus length; carpus 1.18 x propodus length. Pereopods 3–4 sexually dimorphic; pereopods 3–4 similar in size to pereopods 5–6; simple; basis without midmedial row of vertical pappose setae, without submarginal row of robust setae, without marginal row of pappose setae. Pereopod 3 carpus length 2.38 x breadth; propodus length 4.29 x breadth, 1.58 x carpus length, with 2 rows of posterodistal robust setae. Pereopod 4 carpus length 3.21 x breadth; propodus length 5.33 x breadth, propodus 1.42 x carpus length, with 2 rows of posterodistal robust setae. Pereopod 5 coxa with rounded posteroventral corner; basis length 2.75 x breadth, basis with weakly setose posterior margin; pereopod 5 carpus with well developed anterodistal bump, with weakly setose posterior margin; propodus length 7.3 x breadth, propodus with weakly setose posterior margin. Pereopod 6 coxa with subacute posterodistal corner; basis length 1.88 x breadth, basis with weakly setose posterior margin; carpus with well developed anterodistal bump, with weakly setose posterior margin; propodus length 3.5 x breadth, propodus with weakly setose posterior margin. Pereopod 7 coxa with rounded posteroventral corner; basis length 1.68 x breadth, basis with rounded posterodorsal corner, with weakly setose posterior margin, posteroventral corner bicuspidate, outer cusp much longer than inner; carpus with well developed anterodistal bump, with weakly setose posterior margin; propodus length 9.38 x breadth, propodus with weakly setose posterior margin.

Pleon. Pleonite 1 posterodorsal margin with mid-dorsal spine, pleonite 1 without setae along posterior margin, posterolateral margins without spines. Pleonite 2 with mid-dorsal spine, without setae along posterior margin, posterolateral margin without spines. Pleonite 3 smooth, without spines or bulges, without setae along posterior margin, posterolateral margin without spines. Urosomite 1 short, less than 2 x length of urosomite 2. Uropod 1 outer ramus 0.85 x inner ramus. Uropod 2 outer ramus 0.56 x inner ramus. Uropod 3 peduncle with well developed distomedial flange; outer ramus 0.37 x inner ramus; inner ramus without proximal setal fan. Telson longer than broad, tapering distally, with tiny apical setae.

Figures

Fig. 7. Icilius caledoniana, new species: female holotype AM P54156; female paratype AM P54157, UR, PL; off Ilot Maitre, New Caledonia. Scales for A1-2, LL, PL1-3, UL, UR represent 0.2 mm, remainder represent 0.1 mm.

Fig. 8. Icilius caledoniana, new species: female paratype AM P54157; mature male AM P54158; off Ilot Maitre, New Caledonia. Scales represent 0.2 mm.