Periclimenes aleator Bruce, 1991

Bruce, A. J., 2008, Palaemonoid shrimps from the Australian north west shelf, Zootaxa 1815, pp. 1-24 : 10-11

Periclimenes aleator Bruce, 1991

( Fig. 6)

Periclimenes aleator Bruce, 1991b: 315–322 , figs. 10–14. – Li & Bruce, 2006: 673–674 , fig. 14.

Material examined. 1 ♀, CL 6.9, Cruise SS 10/2005 172, Western Australia, off Barrow Island , 21°00’24”S 114°22’52”E to 21°00’02”S 114°22’30”E, 399–408m, beam trawl, 13 December 2005, coll. G.C. Poore, NMV J55452 .

Diagnosis. A member of the alcocki species group ( Li & Bruce, 2006), rostrum not overreaching scaphocerite, distinctly exceeding antennular peduncle, dentition 1–2+5–9/3–4, hepatic spine distinctly lower than antennal spine, cornea not markedly reduced, diameter more than 0.13 of carapace length; ambulatory dactyl with accessory tooth normal, not unusually long or twisted, telson with four pairs of well developed dorsolateral spines.

Remarks. The single specimen is complete with both second pereiopods detached. The rostrum ( Fig. 6A) has a dentition 9/4 with the distal ventral tooth minute and close to the tip ( Fig. 6B), the posterior tooth, postorbital, well separated from the epigastric spine. A well marked postrostral carina extends over the anterior half of the carapace. The cornea is about 0.11 of CL. The major second pereiopod has not been previously described. The second pereiopods are markedly unequal and dissimilar, with the dactylus carried ventrally. The major left chela ( Fig. 6C) about 1.6 times CL, palm subcylindrical, oval in section, about 4.6 times longer than depth, tuberculate, particularly ventrally with small acute tubercles, extending onto fixed finger, glabrous, dactyl ( Fig. 6D,E) about half palm length, 6.3 times longer than central depth, slightly swollen proximally, scaphoid with narrow medial lamina, tip with small stout hooked tooth, cutting edge distal half sharp, entire, proximal half with small distal tooth separated be deep notch from large acute tooth, fitting into deep fossa on proximal region of fixed finger, fixed finger ( Fig. 6D) inflated, distal cutting edge and tip similar to dactyl, proximal cutting edge with large acute tooth opposing dactylar notch, with similar tooth proximally; carpus short, stout, about 0.18 of palm length, 1.2 times longer than distal width, distally expanded, unarmed, feebly tuberculate ventrally; merus almost half palm length, 4.0 times longer than deep, unarmed, densely tuberculate ventrally; ischium subequal to merus length, 4.5 times longer than distal width, tapering slightly proximally. The minor right chela ( Fig. 6F) slightly longer than CL, about 0.66 of major chela length, palm about 4.0 times longer than central depth, subcylindrical, slightly swollen proximally, finely tuberculate, dactyl ( Fig. 6G) 0.55 of palm length, tip with small hooked tooth, distal two thirds of cutting edge entire, proximal third with two small acute teeth, fixed finger similar, with two larger acute teeth proximally, separated by deep U-shaped notch; proximal segments similar to major chela but smaller, less strongly tuberculate. Third pereiopod with dactyl ( Fig. 6I) about 3.5 times longer than basal width, 0.19 of propod length ( Fig. 6H), unguis fused to corpus, about 0.5 of corpus length, accessory spine acute, 0.5 of unguis length, corpus about 2.5 times longer than basal depth; propod 8.6 times longer than depth, with single non-pectinate distoventral spine, about 0.33 of dactyl length, four shorter ventral spines.

The specimen differs slightly from the holotype female in the smaller corneal diameter and the much more strongly developed minor second pereiopod. It also differs from the specimen New Caledonia, 514–522m, illustrated in Li & Bruce (2006, fig. 12) in the smaller corneal diameter, more robust second pereiopod and ambulatory dactyls, with the ambulatory propods lacking distodorsally pectinate spines .

Distribution. New to the Australian fauna. Type locality, Loyalty Islands. Also known from Indonesia,

New Caledonia, Vanuatu, Solomon Islands, and Fijian Islands.