Stephonyx rafaeli, Lowry & Kilgallen, 2014

Lowry, J. K. & Kilgallen, N. M., 2014, A generic review of the lysianassoid family Uristidae and descriptions of new taxa from Australian waters (Crustacea, Amphipoda, Uristidae), Zootaxa 3867 (1), pp. 1-92 : 74-75

Stephonyx rafaeli sp. nov.

( Figs 45–47 )

Types. Holotype, female, 34.0 mm, AM P.96585, off Wollongong , New South Wales, Australia (32°32.4’S 151°22.8’E), 1000 m, baited trap, 28 March 1994 – 29 March 1994, J.K. Lowry & K. Dempsey, MV Robin E [NSW-971] . Paratype, male, 26.4 mm, AM P.96586, same collection details as holotype .

Type locality. Off Wollongong , New South Wales, Australia (32°32.4’S 151°22.8’E), 1000 m depth .

Etymology. Named for the son of the first author on the occasion of his first birthday, 21 January 2014.

Additional material examined. New South Wales. 273 specimens, AM P.43443, off Wollongong (34°32.4'S 151°22.8'E), 1000 m, baited trap, 28–29 March 1994, J.K. Lowry & K. Dempsey, MV Robin E [NSW-971]; 89 specimens, AM P.43451, off Wollongong (34°32.4’S 151°22.8’E), 1000 m, baited trap, 28–29 March 1994, J.K. Lowry & K. Dempsey, MV Robin E [NSW-972]; 1 specimen, AM P.49816, north-east of Coffs Harbour (30°10.88’S 153°32.22’E), 1000 m, baited trap, 12–13 August 1993, P.B. Berents, R.T. Springthorpe & W. Vader, MV Cheryl Lee [NSW-876]; 26 specimens, AM P.44378, off Wollongong (34°33.42’S 151°21.35’E), 1000 m, baited trap, 6–7 May 1993, P. Freewater & party, MV Robin E [NSW-789]; 193 specimens, AM P.43434, off Wollongong (34°32.4’S 151°22.8’E), 1000 m, baited trap, 28–29 March 1994, J.K. Lowry & K. Dempsey, MV Robin E [NSW-973]; 2 specimens, AM P.88939, east of Shoalhaven Heads (34°53'S 151°15'E to 34°56'S 151°13'E), 1079 m, trawl, 26 October 1983, FRV Kapala, FRV Kapala [K83-14-06]; 1 specimen, AM P.48123, north-east of Coffs Harbour (30°10.93’ S 153°32.26’E), 963 m, baited trap, 11–12 August 1993, P.B. Berents, R.T. Springthorpe & W. Vader, MV Cheryl Lee [NSW-863]; 242 specimens, AM P.43426, off Wollongong (34°32.4’S 151°22.8’E), 1000 m, baited trap, 27–28 March 1994, J.K. Lowry & K. Dempsey, MV Robin E [NSW-953]; 173 specimens, AM P.43422, off Wollongong (34°32.4’S 151°22.8’E), 1000 m, baited trap, 27–28 March 1994, J.K. Lowry & K. Dempsey, MV Robin E [NSW-954]; 45 specimens, AM P.43431, off Wollongong (34°32.4’S 151°22.8’E), 1000 m, baited trap, 27–28 March 1994, J.K. Lowry & K. Dempsey, MV Robin E [NSW-955]; 233 specimens, AM P.44386, off Wollongong (34°33.22’S 151°21.4’E), 1000 m, baited trap, 7–8 May 1993, P. Freewater & party, MV Robin E [NSW-808]; 18 specimens, AM P.44369, off Wollongong (34°33.42’S 151°21.35’E), 1000 m, baited trap, 6–7 May 1993, P. Freewater & party, MV Robin E [NSW-788]; 3 specimens, AM P.43366, north-east of Coffs Harbour (30°10.93’ S 153°32.26’E), 1000 m, baited trap, 8–9 September 1994, J.K. Lowry & K. Dempsey, MV Carrie Ann [NSW-1000].

Queensland. 1 specimen, AM P.57599, east of Flynn Reef (16°37.82’S 146°23.08’E), 1000 m, baited trap, 6–7 June 1993, J.K. Lowry, P. Freewater & W. Vader, RV Sunbird [QLD-930/SEAS].

Description. Based on holotype, female, 34.0 mm, AM P. 96585. Head, lateral cephalic lobe rounded; eyes lageniform. Antenna 1 peduncular article 1 without anterodistal lobe; accessory flagellum with an elongate article 1 (at least twice as long as article 2) partially covering callynophore; 10-articulate, terminal article not offset; primary flagellum with strong 2-field callynophore; calceoli absent. Antenna 2 peduncular article 3 short; articles 3 to 5 not enlarged, brush setae absent; flagellum short; calceoli absent. Labrum, epistome and upper lip separate; epistome less produced than upper lip, broadly rounded; upper lip slightly produced, rounded apically. Mandible molar with asymmetrically reduced column, proximally setose, distally triturating; palp attached about midway, article 2 not broadened distally, article 3 blade-like. Maxilla 1 outer plate setal-tooth 7 present, cuspidate along most of inner margin; palp distal margin with apical robust setae. Maxilliped outer plate with 5 long, slender apical robust setae.

Gnathopod 1 chelate; coxa reduced, significantly shorter than coxa 2, subquadrate; basis moderately setose along anterior margin; ischium very long (length 4 × to 6 × breadth); carpus very long (length more than 4 × breadth), slightly longer than propodus, without posterior lobe; propodus margins subparallel, palm obtuse, entire, slightly concave; dactylus simple. Gnathopod 2 propodus palm transverse, straight. Pereopod 4 coxa with a welldeveloped posteroventral lobe. Pereopod 5 coxa without distinct lateral ridge; basis broader than long, posterior margin not serrate. Pereopod 7 basis posterodistally produced less than halfway along merus.

Pleonite 3 without mid-dorsal carina, not produced dorsodistally, posterodorsal margin not produced. Epimeron 3 posterior margin smooth, posteroventral corner appearing subquadrate, forming a minute spine. Urosomite 1 not projecting over urosomite 2, with anterodorsal notch and slightly rounded boss. Uropod 2 inner ramus without constriction. Uropod 3 peduncle without dorsolateral flange; outer ramus article 2 short, with strong plumose setae on both rami. Telson deeply cleft , with dorsal robust setae, with 2 apical robust setae on each lobe.

Sexually dimorphic characters. Based on paratype, male, 26.4 mm, AM P.96586. Antenna 1 flagellum with very strong 1-field callynophore, calceoli present. Antenna 2 peduncle articles 3–4 with brush setae; calceoli present.

Depth range. 963 – 1079 m.

Remarks. Based on the keys in Diffenthal and Horton (2007) and Narahara et al. (2012) Stephonyx rafaeli is similar to S. biscayensis . In S. rafaeli the lateral cephalic lobe is apically rounded (apically acute in S. biscayensis ), the carpus of the first gnathopod is longer than the propodus (subequal in S. biscayensis ), the palm of gnathopod 2 is transverse (slightly acute in S. biscayensis ) and the carpus of gnathopod 2 is much shorter in S. rafaeli .

Distribution. Australia. Off the east coast from Flynn Reef, Queensland, to Shoalhaven Heads, New South Wales.

Figures

FIGURE 45. Stephonyx rafaeli sp. nov., holotype, female, 34.0 mm, AM P. 96585, from off Wollongong, New South Wales, Australia.

FIGURE 46. Stephonyx rafaeli sp. nov., holotype, female, 34.0 mm, AM P. 96585; paratype, male 26.4 mm, AM P. 96586, from off Wollongong, New South Wales, Australia. Scale bars: 0.5 mm.

FIGURE 47. Stephonyx rafaeli sp. nov., holotype, female, 34.0 mm, AM P. 96585, from off Wollongong, New South Wales, Australia. Scale bars: 0.5 mm.