Ambicholestes (Austrolestes) minutus, Just, 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 : 50-52

Ambicholestes (Austrolestes) minutus n.sp.

Figs 20 -22

Material examined. HOLOTYPE: male of 2.2 mm, Northwest Shelf, Western Australia, 19°04.8'S 118°50.TE, 84 m, sand with ca. 10% gravel and some detritus, grab, 29 June 1983, CSIRO Fisheries , Stn 03/83/B5G, AM P446 l5. PARATYPE: Northwest Shelf , Western Australia, 19°05.3'S l 18°54.0'E, 83 m, sand with ca. 10% gravel and some detritus, grab, 15 February 1983, CSIRO Fisheries, Stn 01l83/B4G, AM P446 l6 (1 male) .

Diagnosis. Austrolestes with rostrum present in normal position. Cephalon along dorsal midline as long as pereonites 1 and 2 combined. Antenna 2 peduncle article 3 with proximal dorsomedial recurved robust seta.

Further description. Rostrum short, pointed, triangular. Antenna 1 longer than combined length of cephalon and pereon by about 1/2 pleon length, with up to 8 flagellar articles (left flagellum in holotype appears to be regenerating); peduncle article 1 with recurved robust seta ventrally in proximal half. Antenna 2 distinctly longer than cephalon and entire body combined; ventroapical projection of peduncle article 2 about 11/2 times longer than wide, distally tapering with rounded apex carrying a few long setae.

Coxal plates 5 and 6 with posterior lobe poorly produced ventrally, posterior margin with rounded triangular projection. Pleonal side plates 1 and 2 evenly rounded.

Mandibular palp overreaching mandibular incisor with about 113 palp length, dorsolaterally with scattered acute microscales.

Pereopod 1 article 5 without posterior robust setae; article 6 with posterodistal tooth, 2 midposterior robust setae and 1 robust seta more distally. Pereopod 2 article 2 lateral anterior margin faintly convex, fringed with moderately long plumose setae with inflated bases, proximally with transverse row of small acute teeth, similar teeth present proximally on medial anterior margin; article 6 with 3 posterior robust setae. Pereopods 5 and 6 article 2 anteriorly with 1 long and 1 or 2 short setae, article 5 with up to 6 short robust setae in crescent.

Uropod 1 peduncle about 2113 times longer than wide, with 2 or 3 distal robust setae; outer ramus about 31/2 times longer than wide, with single lateral row of up to 8 robust setae; inner ramus about 2/5 length of outer

Figures

Fig. 20. Ambicholestes (Austrolestes) minutus n.sp., holotype. Scale bar: 0.5 mm.